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Many studies portend the use of Butorphanol and Fentanyl as pre-medication agents, but as there is no firm conclusion derived as yet, especially on dose sparing of induction dose of propofol by butorphanol and fentanyl and its effect on entropy. This study would help to throw some light in this regard. Written informed consent was obtained. All patients were kept nil per oral for 8 hours prior to surgery. All patients on arrival to the operation theatre, intra venous line was secured with 18G cannula and intra venous fluid was on flow. Average requirement of propofol was found to be 1.272 ± 0.133(mg/kg) in Group F and 1.238± 0.122(mg/kg) in Group B with P value of 0.117.The results of our study shows that the reduction in the induction dose of propofol with 20 μg/kg of butorphanol was comparable to fentanyl 2 μg/kg.

BACKGROUND The dialysis bath holds up to 90 mmHg carbon dioxide (CO2 ) in order to keep pH low and salts in their soluble forms. CO2 crosses the dialyzer membrane and diffuses to patients. In post-dilution on-line hemodiafiltration (HDF) many liters of CO2 -containing dialysis bath - in the form of infusate - are delivered directly to patients bypassing the filtering membrane, but the precise amount of CO2 delivered is unknown. METHODS To gain insights on this issue 18 outpatients undergoing their regular on-line HDF were investigated by means of blood gas analysis. RESULTS Arterial pre-dialysis samples show slight hypocapnia (35.40 ± 3.22 mmHg) consistent with the secondary compensatory response to metabolic acidosis. In blood coming back to patients (venous line of extracorporeal circuit) pCO2 doubled, amounting to 69 ± 5.5 mmHg (P

Successes of extracorporeal life support increased the use of centrifugal pumps. However, reports of hemolysis call for caution in using these pumps, especially in neonatology and in pediatric intensive care. Cavitation can be a cause of blood damage. The aim of our study was to obtain information about the cavitation conditions and to provide the safest operating range of centrifugal pumps. A series of tests were undertaken to determine the points at which pump performance decreases 3% and gas bubbles start to appear downstream of the pump. Two pumps were tested; pump R with a closed impeller and pump S with a semiopen impeller. The performance tests demonstrated that pump S has an optimal region narrower than pump R and it is shifted to the higher flows. When the pump performance started to decrease, the inlet pressure varies but close to −150 mmHg in the test with low gas content and higher than −100 mmHg in the tests with increased gas content. The same trend was observed at the points of development of massive gas emboli. Importantly, small packages of bubbles downstream of the pump were registered at relatively high inlet pressures. The gaseous cavitation in centrifugal pumps is a phenomenon that appears with decreasing inlet pump pressures. There are a few ways to increase inlet pump pressures: (1) positioning the pump as low as possible in relation to the patient; (2) selecting appropriate sized venous cannulas and their careful positioning; and (3) controlling patient’s volume status.

Objective The use of minimally invasive or transcatheter interventions rather than standard full sternotomy operations to treat tricuspid valve (TV) disease is increasing. The debate however is still open regarding venous drainage management during cardiopulmonary bypass (CPB) and wheatear or not superior and inferior vena cava should be occluded during the opening of the right atrium to avoid air entrance in the venous line. The aim of the present study is to report operative outcomes and midterm follow-up results of minimally invasive TV surgery performed without caval occlusion. Methods A retrospective outcome evaluation from institutional records was performed with prospective data entry. Considered were consecutive patients who underwent right mini-thoracotomy TV surgery isolated or combined with mitral valve surgery during the period from June 2013 to February 2020. A telephone and echocardiographic follow-up was performed. Results During the study period, 68 consecutive patients underwent minimally invasive TV surgery without occlusion of cava veins. The mean age was 69 ± 14 years and 48 (70%) were female. All operations were performed safely without air-lock during CPB. A perioperative cerebral stroke occurred in one patient. The survival at a 5- and 8-year follow-up was 100% and 79%, respectively. No severe tricuspid regurgitation was evident at echocardiographic follow-up. Conclusion Our results show that performing tricuspid surgery without caval occlusion is safe. The air was captured by the active vacuum drainage system without causing damage. Midterm follow-up data confirm that a minimally invasive approach does not alter the quality of surgery.

The objective of this study was to compare the hemodynamic performances and gaseous microemboli (GME) handling ability of two pediatric oxygenators in a simulated pediatric cardiopulmonary bypass (CPB) model and the importance of adding an arterial filter in the circuit. The circuit consisted of a Braile Infant oxygenator or a Maquet Quadrox-I Pediatric oxygenator without integrated arterial filter (parallel arrangement), 1/4 in. ID tubing A-V loop, and a 12-Fr arterial cannula, primed with lactated Ringer's solution and packed red blood cells. Trials were conducted at flow rates ranging from 500 to 2000 mL/min (500 mL/min increment) at 35°C and 28°C. Real-time pressure and flow data were recorded using a custom-based data acquisition system. For GME testing, 5 cc of air was manually injected into the venous line. GME were recorded using the Emboli Detection and Classification Quantifier (EDAC) System. An additional experiment using a separate arterial filter was conducted. There was no difference in the mean circuit pressure, pressure drop, total hemodynamic energy level, and energy loss between the two oxygenators. The venous line pressures were higher in the Braile than in the Quadrox group during all trials (P

Study Objective: The objective of the study is to compare the anti-factor Xa (AXa) level in the blood, after arterial and venous line administration of equivalent doses of enoxaparin for prevention of thrombosis in the extracorporeal blood circuit.Design: The design of the study is a dual centre, prospective, open-labelled randomized crossover, 7 weeks trial.Setting: The setting of the study is on a patient on long-term haemodialysis (HD) or haemodiafiltration (HDF) using high-flux membrane.Participant: There were eight patients on HD and eight on HDF.Intervention: Participants were randomly assigned to receive enoxaparin either through the arterial line or venous line of extracorporeal blood circuit for an initial study interval of 2 weeks, followed by 2 weeks of alternate route administration. During the run-in period of 1 week and the follow-up period of 2 weeks, enoxaparin was administered through the arterial line.Outcomes: The primary outcome measure was to compare AXa blood level 4 h after enoxaparin administration. The secondary outcome measures were manual compression time to stop bleeding from arteriovenous fistula, extracorporeal circuit clotting and systemic bleeding episodes.Results: The mean AXa blood level, 4 h after venous circuit administration (0.58 +/- 0.21 (HD), 0.82 +/- 0.29 (HDF)) of enoxaparin, was significantly greater than that after arterial administration of enoxaparin (0.39 +/- 0.25 (HD), 0.39 +/- 0.14 (HDF) U/mL), (P

Peripheral intravenous (PIV) catheters are the most commonly used catheters in hospitals, with up to 70% of patients requiring a peripheral venous line during their hospital stay. This represents 200 million PIV catheters used per year in acute-care hospitals in the United States alone. These medical devices are also used in other health care settings, such as long-term care facilities and nursing homes, and common indications include the administration of medications, nutrients, and fluids. These catheters require proper maintenance and care to avoid complications such as phlebitis, infiltration, occlusion, local infection, and bloodstream infection. Recently it has been suggested that PIV catheter use may lead to a higher rate of complications than previously thought. This is important because some studies have claimed that the rate of bloodstream infections due to PIV catheters is actually comparable to the rates observed with central venous catheters, rather than much lower as previously thought. Moreover, catheter-related infections are now seen as largely preventable. Our goal was to review the current literature and provide an overview of the various approaches used to manage PIV catheter sites as well as review current recommendations.

Introduction It is important to have a venous line for infusion as an emergency treatment for patients suffering from crush syndrome or bleeding under confined space (CS) conditions in disaster medicine. However, it is not easy to for Emergency Life-Saving Technicians (ELSTs) to establish a venous line in such settings. Although previous studies have described the use of mechanical intraosseous (IO) devices and IO access while wearing chemical protection gears, problems for the use of IO devices under CS conditions have not been considered. This study aimed to investigate usefulness and problems of using a Bone Injection Gun™ (BIG) for IO infusion by ELSTs and rescue workers in CS conditions. Methods The time required and success rate for IO infusion using a BIG in a manikin leg were measured, and for administering intravenous infusion in a manikin arm using either rescue gloves or plastic gloves by ELSTs or rescue workers under CS conditions. Results Wearing rescue gloves, ELSTs were significantly faster in placing intraosseous infusion (IOI) compared with rescue workers. The success rate of the placement was not significantly different between ELSTs and rescue workers whether or not they wore rescue or plastic gloves. Conclusions Although the finite usefulness of IOI with BIG under CS conditions is indicated, some problems such as the timing of removal of the IOI and difficulty in finding the location of the trocar needle after activating BIG are pointed out. Therefore, there are rooms to consider using IOI with BIG under CS condition. (Hong Kong j.emerg. med. 2014;21:23-30)

Background We developed and tested a clinical simulation program in the principles and conduct of postcardiotomy extracorporeal membrane oxygenation (ECMO) with the aim of improving confidence, proficiency, and crisis management. Methods Twenty-three thoracic surgery residents from unique residency programs participated in an ECMO course involving didactic lectures and hands-on simulation. A current postcardiotomy ECMO circuit was used in a simulation center to give residents training with basic operations and crisis management. Pretraining and posttraining assessments concerning confidence and knowledge were administered. Before and after the training, residents were asked to identify components of the ECMO circuit and manage crisis scenarios, including venous line collapse, arterial hypertension, and arterial desaturation. Results In the hands-on portion, residents had difficulty identifying the gas source and flow rate, centrifugal pump head inlet, and oxygenator outflow line. Timely and accurate ECMO component identification improved significantly after training. The arterial desaturation crisis scenario gave the residents difficulty, with only 22% providing the appropriate treatment recommendations in a timely and accurate fashion. At the end of the simulation training, most residents were able to manage the crises correctly in a timely manner. Posttraining confidence-related scores increased significantly. Most of the residents strongly recommended the course to their peers and reported simulation-based training was helpful in their postcardiotomy ECMO education. Conclusions We developed a simulation-based postcardiotomy ECMO training program that resulted in improved ECMO confidence in thoracic surgery residents. Crisis management in a simulated environment enabled residents to acquire technical and behavioral skills that are important in managing critical ECMO-related problems.

Objective: Usually only FDA-approved oxygenators are subject of studies by the international scientific community. The objective of this study is to evaluate two types of neonatal membrane oxygenators in terms of transmembrane pressure gradient, hemodynamic energy transmission and gaseous microemboli capture in simulated cardiopulmonary bypass systems. Methods: We investigated the Braile Infant 1500 (Braile Biomédica, São José do Rio Preto, Brazil), an oxygenator commonly used in Brazilian operating rooms, and compared it to the Dideco Kids D100 (Sorin Group, Arvada, CO, USA), that is an FDA-approved and widely used model in the USA. Cardiopulmonary bypass circuits were primed with lactated Ringer's solution and packed red blood cells (Hematocrit 40%). Trials were conducted at flow rates of 500 ml/min and 700 ml/min at 35ºC and 25ºC. Real-time pressure and flow data were recorded using a custom-based data acquisition system. For gaseous microemboli testing, 5cc of air were manually injected into the venous line. Gaseous microemboli were recorded using the Emboli Detection and Classification Quantifier. Results: Braile Infant 1500 had a lower pressure drop (P

We devised a miniaturized circuit incorporating a TinyPump in the venous line to amplify the venous return. We compared this system to the conventional blood-primed circuit and investigated whether this circuit could maintain hematocrit levels without blood transfusion and reduce coagulation and inflammatory cascades.Thirteen 1-week-old piglets (3.7 ± 0.2 kg) were divided into group M (miniaturized circuits with TinyPump-assisted venous drainage without blood, n = 7) and group C (conventional circuits with blood priming, n = 6). Cardiopulmonary bypass (CPB) was performed at 150 to 180 mL·kg(-1)·min(-1) for 2 hours, including 60 minutes of cardioplegic cardiac arrest. Modified ultrafiltration (MUF) was subsequently performed. Data were acquired before CPB and after the end of MUF.The priming volume including the hemofilter circuit of the main circuit required 152 mL in group M and 300 mL in group C. The mean hematocrit values in group M and group C were not significantly different during CPB (21.5% ± 2.0% versus 23.2% ± 1.3%) or after MUF (30.7% ± 2.1% versus 32.9% ± 4.0%). After MUF, group M had lower thrombin-antithrombin complex levels (16.7 ± 5.0 ng/mL versus 28.4 ± 8.4 ng/mL, p0.01) and interleukin-8 levels (2,867 ± 758 pg/mL versus 13,730 ± 5,220 pg/mL, p0.01) than group C. The pulmonary vascular resistance index was lower in group M after MUF (4,105 ± 862 dynes·cm(-5)·kg(-1) versus 6,304 ± 1,477 dynes·cm(-5)·kg(-1), p0.01). The lung water content was also better in group M (83.7% ± 0.5% versus 84.9% ± 0.5%, p0.01).The minicircuit with TinyPump-assisted venous drainage successfully maintained acceptable hematocrit levels and the cardiopulmonary function in neonatal piglets. Employing this technique may attenuate blood requirements and inflammatory responses, thereby improving the clinical outcomes of neonatal open-heart surgery.

We present an unexpected finding when preparing for a right internal jugular venous line placement. A 77 year old female admitted for sepsis was transferred to intensive care unit for circulatory shock. Soon she had a PEA arrest requiring 11 minutes of CPR. 2D echocardiogram showed large

Venous air embolism was suspected in 3 hospitalised horses on the basis of an inadvertently open jugular venous line. Subsequently the 3 horses developed clinical signs including cardiovascular collapse, cardiac dysrhythmia, pulmonary oedema, behavioural abnormalities and neurological signs consistent with central nervous system injury. Treatment included intranasal oxygen therapy, i.v. fluid administration and anti-inflammatory therapy. Specific therapy aimed at treating air embolism in man is reviewed, with pertinent therapy potentially applicable to horses emphasised.

Peripheral venous catheters (PVC) are the most frequently used invasive devices in hospitals. Up to 70% of patients require a peripheral venous line during their hospital stay, and conservative estimates suggest that PVC days account for 15-20% of total patient days in acute care hospitals. Most published studies focus on thrombophlebitis and address the issue of scheduled catheter change, but there is still no consensus on the optimal time point for PVC change, or whether catheter replacement is required at all. Although PVC-associated catheter-related bloodstream infections (PVC-BSI) are far more serious than thrombophlebitis, few studies address this issue, and a large multicentre trial is lacking. Some studies on thrombophlebitis mention that no, or only a few, PVC-BSIs were identified, but such results must be interpreted with caution. Current data available on PVC-BSI suggest incidence density rates of 0.2-0.7 episodes per 1000 device days, which appear low when compared with other catheters. However, some studies report absolute PVC-BSI numbers in the range of central line-associated infections. It remains unclear whether PVC-BSI should be considered a serious healthcare problem or simply a very rare event. More research is needed both to capture the dimension of the problem and to provide efficient control measures.

UNDAR*‡§ This study investigated delivery of gaseous microemboli (GME) with vacuum-assisted venous drainage (VAVD) at various flow rates and perfusion modes in a simulated neonatal cardiopulmonary bypass (CPB) model. Four transducers (postpump, postoxygenator, postfilter, and venous line) of the emboli detection and classification (EDAC) quantifier were inserted into the CPB circuit to detect and classify GME. Four negative pressures (0, 15, 30, and 45 mm Hg), 3 flow rates (750, 1,000, and 1,250 ml/min), and 2 perfusion modes (pulsatile and nonpulsatile) were tested. After injecting 10 ml air into the venous line via an 18G needle, 2-minute segments of data were recorded simultaneously through 4 transducers. This entire process was repeated 6 times for each unique combination of pressure, flow rate, and perfusion mode, yielding a total of 144 experiments. Independent of perfusion mode and flow rate, the use of VAVD with higher negative pressures delivered significantly more GME at the postpump site. There was no difference in delivery at the postfilter site. The majority of GME were trapped by the Capiox Baby-RX hollow-fiber membrane oxygenator. Compared with nonpulsatile flow, pulsatile flow transferred more GME at the postpump site at all 3 flow rates. Our results suggest that VAVD with higher negative pressures, increased flow rates, and pulsatile flow could deliver more GME at the postpump site when a fixed volume air is introduced into the venous line. The Emboli Detection and Classification Quantifier is a sensitive tool for the detection and classification of GME as small as 10 microns in this simulated neonatal model. ASAIO Journal 2008; 54:416‐422.

We compared the effects of perfusion modes (pulsatile vs. nonpulsatile) on gaseous microemboli delivery using the Emboli Detection and Classification (EDAC) Quantifier at postpump, postoxygenator, and postarterial filter sites in a simulated pediatric cardiopulmonary bypass (CPB) model. The mock loop was subjected to five different pump flow rates of equal 100 ml/min intervals, ranging from 400 to 800 ml/min. When the target pump flow rate was achieved, 5 cc air was introduced into the venous line. The EDAC system recorded gaseous microemboli counts simultaneously at three locations in 5-minute intervals. Regardless of the type of perfusion mode, when the pump flow rate was increased, more gaseous microemboli were generated at postpump site. Compared with nonpulsatile flow, pulsatile flow did deliver significantly more gaseous microemboli at postpump site, but there was no difference between two groups at postoxygenator and postarterial filter sites. Capiox Baby-RX hollow-fiber membrane oxygenator significantly reduced the gaseous microemboli counts in both groups at all five pump flow rates with either pulsatile flow or nonpulsatile flow in this model. Our results suggest that using this novel EDAC system, we could detect the size of gaseous microemboli, as small as 10 microm, and the percentage of detected gaseous microemboli

Objective. To determine the efficacy of decreasing cardiopulmonary bypass (CPB) prime volume for neonates and small infants by using low prime oxygenators, small diameter polyvinyl chloride (PVC) tubing and removing the arterial line filter (ALF) in an effort to reduce intraoperative exposure to multiple units of packed red blood cells (PRBC). Methods. Two retrospective database studies comparing neonatal CPB prime volume were undertaken: Study 1 — A CPB circuit consisting of a 1/8 inch arterial line, a 3/16 inch venous line and a low prime oxygenator with 172 ml total circuit prime ( n = 74) was compared to a circuit with a 3/16 inch arterial line, a 1/4 inch venous line and a higher prime oxygenator with a 350 ml total circuit prime ( n = 74). Study 2 — The 172 ml circuit ( n = 389) was compared to a circuit that included an ALF and had a total circuit prime volume of 218 ml ( n = 389). Results. Study 1— of the 74 neonates and small infants whose CPB prime volume was 350 ml, 19 were exposed to two or more intraoperative exogenous PRBC units while only 3 neonates and small infants in the 172 ml prime group ( n = 74) received two or more units ( p = 0.0002). Study 2 — of the 389 neonates and small infants where an ALF was used (prime volume 218 ml), 54 were exposed to two or more exogenous PRBC units while only 36 of the 389 patients where an ALF was not used (prime volume 172 ml) received two or more units of intraoperative PRBCs ( p = 0.0436). Conclusion. Decreasing the neonatal and small infant extracorporeal circuit prime volume by as little as 46 ml resulted in significantly fewer multiple exposures to exogenous PRBC units. Perfusion (2007) 22, 327—331.

Minimized perfusion circuits (MPCs) have been criticized for insufficient air elimination. The deairing capabilities of a new MPC, including an ultrasound controlled deairing unit, were compared to a standard extracorporeal circuit (ECC) in a laboratory setup. During blood flow of 4.0l/min, we injected 30-cc air over a period of 30 s into the venous line of both systems (n = 10 measurements/15-min intervals). Air was detected during the first 2 min post injection using a dual-channel ultrasound bubble counter. Venous air bubble measurements were made after the MPC bubble trap and the ECC hard-shell reservoir, respectively. Arterial air bubble data were obtained after the arterial filters (40 microm). Venous bubble count was significantly (P0.01) reduced in the MPC group (5-250 microm, 681 +/- 177;40 microm, 288 +/- 92) compared with the ECC group (5-250 microm, 19 272 +/- 682;40 microm, 7642 +/- 520). After the arterial filter, minimal numbers of air bubbles (5-250 microm, 172 +/- 59;40 microm, 0) could be detected in the MPC group, but large amounts of air (5-250 microm, 16 194 +/- 1072;40 microm, 3732 +/- 997) were measured in the ECC group. The air elimination of the modern MPC is superior to conventional ECC, which may result in a reduction of neurological complications.

Vascular access procedures play an important role in pediatric surgical practice. Different clinical situations require different vascular access types including central venous, peripheral venous, and peripheral arterial access. In this chapter, we outline the core technical principles of ultrasound-guided vascular access, with particular focus on equipment selection, patient setup, anatomic landmarks, and key techniques. We describe the use of transverse and in-line transducer orientations and suggest clinical scenarios for the use of each. Finally, we describe a lateral approach technique of tunneled internal jugular venous line placement as well as keys to successfully addressing common difficult access scenarios.

A growing body of evidence indicates the superiority of minimized cardiopulmonary bypass (CPB) systems compared to conventional systems in terms of inflammatory reactions and transfusion requirements. Evident benefits of minimized CPB systems, however, do not come without consequences. Kinetic-assisted drainage, as used in these circuits, can result in severe fluctuations of venous line pressures and, consequently, fluctuation of the blood flow delivered to the patient. Furthermore, subatmospheric venous line pressures can cause gaseous microemboli. Another limitation is the absence of cardiotomy suction, which can lead to excessive blood loss via a cell saver. The most serious limitation of minimized circuits is that these circuits are very constrained in the case of complications or changing of the surgery plan. We developed a versatile minimized system (VMS) with a priming volume of about 600 ml. A compliance chamber in the venous line decreases peaks of pressure fluctuations. This chamber also acts as a bubble trap. Additionally, the open venous reservoir is connected parallel to the venous line and excluded from the circulation during an uncomplicated CPB. This reservoir can be included in the circulation via a roller pump and be used as a cardiotomy reservoir. The amount and rate of returned blood in the circulation is regulated by a movable level detector. Further, the circuit can easily be converted to an open system with vacuum-assisted venous drainage in the case of unexpected complications. The VMS combines the benefits of minimized circuits with the versatility and safety of a conventional CPB system. Perfusionists familiar with this system can secure an adequate and timely response at expected and unexpected intraoperative complications.

Extracorporeal life support (ECLS) with a roller pump system uses a closed cardiopulmonary bypass (CPB) circuit not equipped with a venous reservoir. Hence, gas emboli cannot escape the ECLS circuit, predisposing to clot formation, membrane failure and potential gas embolism. Rarely, some patients may develop a continuous release of gas into the venous circulation from multiple sources. Two pediatric ECLS cases are presented with continuous venous gas embolism. A ‘gas trap’ was devised by creating a column of fluid erected vertically on the venous line. This allowed gas to rise within the column, separating it from the ECLS circuit, thus, preventing gas from lodging in the membrane.

Background: LMWH ensures circuit permeability in hemodialysis but can lead to systemic bleeding for patients with hemorrhagic risk. Other anticoagulation alternatives are laborious and cumbersome with BHD. Regional citrate anticoagulation can be simplified with DCB, a new hemodialysis method using a dialysate containing only sodium chloride and bicarbonate. The optimal amount of ionic complement (Ca++, Mg++, K+) is automatically perfused into venous line according to the value of ionic dialysance measured every 15 minutes by the Integra dialysis monitor (Hospal, Italy). Methods: Thirty DCB-citrate sessions were performed in 10 patients at increased risk of bleeding. After resolution of bleeding risk, the same number of BHD sessions was performed in patients. The aim of this study is to compare pressure time of the arterio-venous access (PT), index thrombosis circuit (ITC 0:clean to 5:total thrombosis), Kt/V and biochemical data at the end of sessions (mean ± SD). DCB-citrate (n = 21) BHD-LMWH (n = 21) p PT (min) 4 ± 1.1 9 ± 4.6

Our recent article opened a valuable discussion on the safety of miniaturized perfusion systems (MPSs) with respect to the risk of gaseous microemboli (GME) [1, 2]. We would like to comment on this. Although the clinical advantages of MPSs are well known, it is still important to focus on avoiding possible side effects in order to increase patient safety [3]. In our study, we observed excessive negative pressures (ENPs) in the venous line during the use of MPSs, possibly due to volume depletion [2]. ENPs correlate with an increase in the volume of GME. Similar results were published by Simons et al. [1] in their in vitro studies. GME may have clinical consequences, e.g. postoperative stroke or transitory psychotic syndrome [2]. In an effort to minimize this risk, many safety devices were added to MPSs. We distinguish between two groups. The first one includes de-airing devices such as venous bubble traps and the new generation of oxygenators with or without integral arterial filters. The second group focuses on venous line ENPs, either using volume buffer capacity systems such as the better bladder (BB) or an automatic pump flow regulator. Venous bubble traps connected to the venous line separate air from blood via a 175-μm mesh screen. This leads to a significant reduction in GME [4]. Such traps make use of the bubbles’ buoyancy. The traps prevent larger bubbles from entering the pump where they could be further broken down to smaller emboli, which would then become suspended in blood [5]. This technique, however, does not resolve the problem of ENPs and cavitation phenomena leading to more arterial GME. Current automatic pump flow regulators do not respond instantaneously and are not fast enough to fully compensate for negative pressure peaks. This may occasionally lead to reduced flows. Even the most careful volume management by an experienced team of perfusionists and anaesthesiologists cannot guarantee 100% safety. Another device introduced to reduce subatmospheric pressure peaks in the venous line is the BB [6]. The system comprises a flexible thin-walled tube inside a rigid transparent box and is capable of absorbing venous line pressure fluctuations. The adjustable volume of air between the tube and the casing allows buffering. The study by Simons et al. [6] showed a 40% reduction in venous line pressure fluctuations with the BB. Despite these elegant results, the BB cannot eliminate ENPs completely. In Figure 2 of the study by Simons et al., ENP peaks of up to −200 mmHg are still observed. The durations of ENPs seem to be longer, as can be inferred from the oblique curve in the graph. However, the main reason for ENPs is volume depletion, which remains untreated in this case. This system would certainly provide more time for perfusionists to replenish the intravascular volume. We would like to mention that, in our experimental model, the utilization of a one-way-valve connected to the venous side of MPSs for automatic pressure and volume compensation has been evaluated. The results will be published soon. In summary, to lower complications, optimization and a refined perfusion management of the routinely used MPSs are required.

O objetivo deste estudo foi aferir a porcentagem de recirculação sangüínea (%R), nas diferentes formas de punções nas fístulas artério-venosa de pacientes em hemodiálise. Verificou-se o nível de uréia sangüínea em oito pacientes utilizando o modelo clássico de punção e de outros três grupos de oito pacientes com diferentes tipos de punção, simultânea e imediatamente após transcorridos 10 minutos de sessão, na linha arterial (A), linha venosa (V) e membro contra-lateral ao acesso vascular (S), aplicando-se a fórmula %R = (S-A) I (S-V) . 100. Constatamos que na forma clássica de punção houve uma a porcentagem de recirculação significativamente menor. The aim of this study was to verify the percentage of recirculation (%R) in patients on hemodialysis in different models of insertion of needles in arteriovenous fistula. Urea concentration was measured in samples of the arterial (A), venous line (V) and blood from the apposite arm (S) 10 minutes later in 8 patients using the classical model (apposite-oriented, ³ 5 cm apart needles) as well as in patients with three other different models (8 patients in each group). The percentage of recirculation was calculated according to the formula %R= (S-A) / (S-V).100 . A significant lower percentage of recirculation occurred in the use of the classical model.

Vacuum-assisted venous return (VAVR) has been reported to offer benefits for adults undergoing cardiopulmonary bypass (CPB), such as improved venous return, lowering priming volume (by eliminating the need to prime the venous line), and the use of smaller venous cannulae. All these benefits would be of particular value in pediatric perfusion because of the unique challenges of these smaller patients and the relatively large components of the CPB circuit. We have been using VAVR in children since the early summer of 1998 after we became comfortable with the technique and convinced of its efficacy in adults. Ours is a medium-sized pediatric caseload of slightly more than 100 CPB cases per year. With that caseload, it is most effective for us to minimize the inventory of different sizes of disposables used. We have opted for an oxygenator/reservoir that has a maximum flow of 4 liters with a priming volume of about 1 liter. We have been unhappy with the large prime volume in infants and earlier, in 1997-1998, were using a smaller prime oxygenator/reservoir until it was recalled. Faced again with a larger priming volume in the infants, we decided to try vacuum to decrease hemodilution and to evaluate other possible benefits. Through the use of VAVR, we have been able to decrease our priming volume, use smaller venous cannulae, and have more consistent return while experiencing no adverse effects of VAVR in our pediatric cardiac surgery patients.

Preterm infants have limited nutrient stores at birth, take time to establish enteral feeding, are at risk of accumulating significant nutrient deficits, and frequently suffer poor growth - all risks which are associated with poorer neurodevelopmental outcome. Parenteral nutrition (PN) provides a relatively safe means of meeting nutrient intakes, and is widely used in preterm infants in the initial period after birth. PN is also important for infants who may not tolerate enteral feeds such as those with congenital or acquired gut disorders such as necrotizing enterocolitis (NEC). PN is associated with several short-term benefits, but clear evidence of long-term benefit from controlled trials in neonates is lacking. There are many compositional, practical and risk aspects involved in neonatal PN. In most preterm infants, authorities recommend amino acid intakes approximating to 3.5-4 g/kg/day of protein, lipid intakes of 3-4 g/kg/day and sufficient carbohydrate to meet a total energy intake of 90-110 kcal/kg/day. Where PN is the sole source of nutrition, careful attention to micronutrient requirements is necessary. PN may be administered via peripheral venous access if the osmolality allows, but in many cases requires central venous access. Standardized PN bags may meet the nutrient needs of many preterm infants over the first few days, although restricted fluid intakes mean that many receive inadequate amounts especially of amino acids. PN can be associated with increased rates of bacterial and fungal sepsis, mechanical complications related to venous line placement and miscalculations and errors in manufacture, supply and administration. PN is also associated with metabolic derangements, hepatic dysfunction, and risks contamination with toxins such as aluminum, which enter the solutions during manufacturing. PN must only be administered in units with good quality control, strict asepsis in manufacture and administration and multidisciplinary teams focused on nutrient needs and intakes.

Aim: Without volume-buffering capacity in extracorporeal life support (ELS) systems, hypovolemia can acutely reduce support flow. This study aims at evaluating efficacy and safety of strategies for preserving stable ELS during hypovolemia. Material & Methods: Flow and/or pressure-guided servo pump control, a reserve-driven control strategy and a volume buffer capacity (VBC) device were evaluated with respect to pump flow, venous line pressure and arterial gaseous microemboli (GME) during simulated normovolemia and hypovolemia. Results: Normovolemia resulted in a GME-free pump flow of 3.1±0.0 L/min and a venous line pressure of −10±1 mmHg. Hypovolemia without servo pump control resulted in a GME-loaded flow of 2.3±0.4 L/min with a venous line pressure of −114±52 mmHg. Servo control resulted in an unstable and GME-loaded flow of 1.5±1.2 L/min. With and without servo pump control, the VBC device stabilised flow (SD = 0.2 and 0.0 L/min, respectively) and venous line pressure (SD=51 and 4 mmHg, respectively) with near-absent GME activity. Reserve-driven pump control combined with a VBC device restored a near GME-free flow of 2.7±0.0 L/min with a venous line pressure of −9±0 mmHg. Conclusion: In contrast to a reserve-driven pump control strategy combined with a VBC device, flow and pressure servo control for ELS show evident deficits in preserving stable and safe ELS flow during hypovolemia.

Use of ultrasound (US) when introducing central venous catheters (CVC) may improve success rates, reduce the number of needle punctures, and decrease complication rates, but has been hampered by supposed difficulty in learning how to perform the technique. This study describes the learning curve for US-guided jugular CVC placement after a training program. After an initial slide presentation and a video, intensivists who had not previously used US for CVC placement were evaluated qualitatively for US set up (score S1) and technical skills (score S2). Quantitative measures included durations of different components of the procedure (T 1, time from entry of the US into the patient’s room to sterile dressing of the intensivist; T 2, time needed for sterile drapes, venous line preparation, and sterile sheath placement; T 3, time from skin puncture to venous flashback; T 4, time from guide insertion to dressing; T tot, total duration of the procedure); number of skin punctures; and a difficulty score allocated by the intensivist. We performed 150 evaluations of 30 intensivists: 50 % had no prior experience of CVC placement and 50 % no prior US experience. Maximal S1 and S2 scores were obtained with the fourth and eighth placement procedures, respectively. T 1 and T 2 did not change with ongoing training (5 and 8 min, respectively), but T 3 and T 4 decreased, from 5 min (first procedure) to less than 1 min (seventh procedure), and from 10 min (first procedure) to 7 min (sixth procedure), respectively. T tot decreased from 34 to 21 min at the eighth procedure. The number of skin punctures and the difficulty score decreased rapidly with the number of evaluations. Our study demonstrates that skills in US-guided CVC placement can easily be acquired with training.

Microemboli may be a cause of postoperative neurological morbidity. Improved detection of microemboli may lead to better strategies to minimize embolization and improve neurological outcomes. Transcranial Doppler may have limited sensitivity for very small microemboli. The Emboli Detection and Classification (EDAC) Quantifier offers increased sensitivity (10 μm) and potentially improved capability for microemboli monitoring. EDAC was used to measure microemboli in the cardiopulmonary bypass circuit during 33 pediatric heart operations. More microemboli were detected in the venous than the arterial line (median, 11,830 vs 1298). Venous microemboli tended to be larger in size than arterial microemboli (>40 μm; 59% vs 7%). Increased venous and arterial microemboli were seen at the onset of bypass; increased venous microemboli were also seen with clamp removal. Thousands of microemboli

The use of total nutrient admixtures (TNA) has increased dramatically in both the clinical and home care setting since 1983. The popularity of these dosage forms rests in supplying all the nutrients in one container that meets the nutritional goals of the patient. In addition, TNA formulations obviate the need for either separate peripheral venous catheters or co-infusions into the primary venous line, thus simplifying this complex therapy. Moreover, the clinical benefits derived from this practice are related to a reduction in glucose-associated complications that assume particular importance in the acutely ill patient. Although much experience has been gained over the last 12 years, practice standards vary with the institution. Despite this, TNA therapy has been successful in the U.S. This paper attempts to delineate the important physicochemical variables that influence emulsion stability as they relate to clinical practice.

Although a growing body of evidence indicates superiority of minimized cardiopulmonary bypass (mCPB) systems over conventional CPB systems, limited venous return can result in severe fluctuations of venous line pressure which can result in gaseous emboli. In this study, we investigated the influence of sub-atmospheric pressures and volume buffer capacity added to the venous line on the generation of gaseous emboli in the mCPB circuit. Two different mCPB systems (MEC - Maquet, n=7 and ECC.O - Sorin, n=8) and a conventional closed cardiopulmonary bypass (cCPB) system (n=12) were clinically evaluated. In the search for a way to increase volume buffer capacity of mCPB systems, we additionally evaluated the ‘Better Bladder’ (BB) in a mock circulation by simulating, repeatedly, decreased venous return while measuring pressure and gaseous embolic activity. Arterial gaseous emboli activity during clinical perfusion with a cCPB system was the lowest in comparison to the mCPB systems (312±465 versus 311±421 with MEC and 1,966±1,782 with ECC.O, counts per 10 minute time interval, respectively; p=0.03). The average volume per bubble in the arterial line was the highest in cases with cCPB (12.5±8.3 nL versus 8.0±4.2 nL with MEC and 4.6±4.8 nL with ECC.O; p=0.04 for both). Significant cross-correlation was obtained at various time offsets from 0 to +35 s between sub-atmospheric pressure in the venous line and gaseous emboli activity in both the venous and arterial lines. The in vitro data showed that incorporation of the BB dampens fluctuations of venous line pressure by approximately 30% and decreases gaseous emboli by up to 85%. In conclusion, fluctuations of sub-atmospheric venous line pressure during kinetic-assisted drainage are related to gaseous emboli. Volume buffer capacity added to the venous line can effectively dampen pressure fluctuations resulting from abrupt changes in venous return and, therefore, can help to increase the safety of minimized cardiopulmonary bypass by reducing gaseous microemboli formation resulting from degassing.

Introduction It is important to have a venous line in cardiopulmonary arrest (CPA) patients as an emergency treatment measure in prehospital settings, but establishment of a peripheral venous line is difficult in such patients. This study aimed to investigate the current status of intravenous infusion (IVI) in CPA patients by Emergency Life-Saving Technicians (ELSTs) in Japan. We also considered alternative measures in case IVI was difficult or impossible. Methods We investigated a nationwide database between 1 January 2005 and 31 December 2008. From a total of 431,968 CPA cases, we calculated the IVI success rate and related parameters. The Bone Injection Gun (BIG) and simulator legs (adult, pediatric, and infant) were used by 100 ELSTs selected for the study to measure the time required and the success rate for intraosseous infusion (IOI). Results The number of CPA patients, IVI, adrenaline administration, and the IVI success rate in adult CPA patients increased every year. However, the IVI success rate in pediatric CPA patients did not increase. Although adrenaline administration elevated the ROSC rate, there was no improvement in the 1-month survival rate. The time required for IOI with BIG was not different among the leg models. The success rates of IOI with BIG were 93%, 94%, and 84% (p < 0.05 vs. adult and pediatric) in adult, pediatric, and infant models, respectively. Conclusions The rate of success of IVI in adult CPA patients has been increased yearly in Japan. However, as establishing a peripheral venous line in pediatric patients (1-7 years old) by ELSTs is extremely difficult in prehospital settings, there was no increase in the IVI success rate in such patients. As the study findings indicated IOI with BIG was easy and rapid, it may be necessary to consider IOI with BIG as an alternative option in case IVI is difficult or impossible in adult and pediatric patients.

Thermodilution (TD) is a gold standard for cardiac output (CO) measurement in critically ill patients [1]. Although transpulmonary thermodiluation is less invasive than the Swan-Ganz catheter, it still requires an arterial and deep venous line. This study will compare intermittent bolus transpulmonary TDCO with continuous CO (CCO) obtained by pulse contour analysis (PiCCO2; Pulsion Medical Systems) and non-invasive CO (NexCO) measurement via finger cuff using Finapres technology (Nexfin BMEYE).

During extracorporeal life support (ECLS), blood is exposed to a myriad of unphysiological factors that can affect outcome. One aspect of this is the sub-atmospheric pressure generated by the ECLS pump and imparted to blood elements along the pump inlet line. This pressure can be measured on the inlet line close to the pump head by adding a connector, or at the venous cannula connection site. We compared the two measurement sites located at both points; between the venous cannula-inlet tubing and inlet tubing-pump, with a range of cannulae and flows. We also investigated the effects on inlet pressure from pump afterload and increasing inlet tubing length.

The neonate cardiopulmonary bypass (CPB) circuit, including a KIDS D100 oxygenator (The Sorin Group, Mirandola, Italy) and a D130 arterial filter (The Sorin Group), was evaluated in vitro with respect to the removal of free micro gas bubbles. No gas bubbles > 40µm were measured after the arterial filter D130 upon manual introduction of 10 ml of air into the venous line or during the use of vacuum-assisted venous drainage (VAVD). The D130 arterial filter removed 88 % of gas bubbles < 40 µm during manual introduction of air into the venous line; however, only 50 % of gas bubbles < 40 µm were removed during the use of VAVD. The same CPB circuit was evaluated in vivo to compare with another CPB circuit, including a D901 oxygenator (The Sorin Group) and arterial filter D736 (The Sorin Group), in 155 neonates weighing ≤5 kg. The D100 circuit required significantly less priming volume than the D901 circuit. Postoperative haemoglobin was significantly higher, artificial ventilation time was significantly shorter and postoperative bleeding was significantly less in the D100 group. This neonate CPB circuit effectively removed the gas bubbles and required up to 37% less priming volume and, thus, decreased the need for blood transfusion.

We describe the occurrence and distribution of gaseous microemboli with real-time monitoring in a pediatric cardiopulmonary bypass (CPB) circuit and in the cerebral circulation of patients using the Emboli Detection and Classification (EDAC) system and transcranial Doppler (TCD). Four patients (weights 3.2-13.8 kg) were studied. EDAC monitors were located on the venous line and on the postfilter arterial line to measure gaseous microemboli in the CPB circuit. TCD was used to measure high-intensity transient signals (HITS) in the middle cerebral artery. Before the initiation of CPB, EDAC detected gaseous microemboli in two cases when giving volume through the arterial line. At the initiation of CPB, gross air appeared in the venous line and gaseous microemboli were detected in the arterial line in all patients. EDAC detected a total of 3192-14 699 gaseous microemboli in the arterial line during the whole CPB period, more than 99% of which were smaller than 40 microns. After cessation of CPB, EDAC detected gaseous microemboli in the arterial line in all cases. The TCD detected HITS in two cases (25 and 315), and detected no HITS in two cases. We observed that the venous line acted as a principal source of gaseous microemboli, particularly when using vacuum-assisted venous drainage, and that a significant number of these gaseous microemboli smaller than 40 microns were subsequently transferred to the patient. Using EDAC and TCD together could strengthen the monitoring of gaseous microemboli in the extracorporeal circuit and cerebral circulation.

Most patients in the hospital need vascular access: a peripheral venous line, a short-term non-cuffed central venous catheter (CVC), a long-term cuffed CVC, an implantable port or an arterial line. Such devices, although often indispensable and of benefit, may have the disadvantage of mechanical complications, local exit-site infections or catheter-associated bloodstream infections (CRBSI). Apart from peripheral venous lines, non-cuffed CVCs are the most frequent catheter type in hospitals. The risk for CRBSI of such catheters is high with an incidence density of 2 to 7 episodes per 1000 catheter-days depending on ward-type, institution and geographical region. This review describes the epidemiology, the frequency and the risk of CRBSI among non-cuffed CVCs, provides accepted definitions as well as descriptions of diagnostic techniques and highlights various prevention measures.

Venous cannulae undergo continuous improvements to achieve better and safer venous drainage. Several cannula tests have been reported, though cannula performance during inlet obstruction has never been a test criterion. In this study, five different cannulae for proximal venous drainage were tested in a mock circulation that enabled measurement of hydraulic conductance after inlet obstruction by vessel collapse. Values for hydraulic conductance ranged from 1.11 x 10(-2) L/min/mm Hg for a Thin-Flex Single Stage Venous Cannula with an open-end lighthouse tip to 1.55 x 10(-2) L/min/mm Hg for a DLP VAD Venous Cannula featuring a swirled tip profile, showing a difference that amounts to nearly 40% of the lowest conductance value. Excessive venous drainage results in potentially dangerous high-negative venous line pressures independent of cannula design. Cannulatip design featuring swirled and grooved tip structures increases drainage capacity and enhances cannula performance during inlet obstruction.

This study was undertaken to determine the impact of miniaturization of a cardiopulmonary bypass (CPB) circuit on blood transfusion and hemodynamics in neonatal open-heart surgery. Neonates (n = 102) undergoing open-heart surgery between 2002 and 2006 were included and divided into three groups: group 1 (n = 28), Dideco 902 oxygenator + 5/16" line; group 2 (n = 29), Dideco 901 oxygenator + 1/4" line; group3 (n = 45), Dideco 901 oxygenator + 3/16" arterial + 1/4" venous line. Amount of priming volume, blood and bicarbonate sodium use during CPB, and hemodynamics were compared. Priming volume in the groups 2 and 3 was significantly less compared with the group 1 (group 1, 575 +/- 37 ml; group 2, 328 +/- 12 ml, group 3, 326 +/- 5 ml, p < 0.05). Blood transfusion and bicarbonate sodium use during CPB in groups 2 and 3 were significantly less compared with group 1. Hemodynamics during CPB was comparable. There were no differences between groups 2 and 3 in any parameter. Miniaturization of the CPB circuit resulted in decrease in priming volume and subsequent reduction in blood and bicarbonate sodium use. Downsizing the lines had minimal impact on any of the parameters studied, and further efforts should be made to achieve neonatal open-heart surgery without blood transfusion.

(hematocrit 50-55%) and 2,700 mL of fresh frozen plasma. Two hours after starting infusion of blood products, an anesthesiologist noticed that the peripheral venous line was blocked. At this time, purpura in combination with a number of transparent tense bullae more than 2 cm in diameter was observed in the patient’s left forearm (Figure). The lesions were treated with ointment containing steroid for two days; unfortunately, we do not know the further outcome of the bullae because the patient died

Objective: To determine the optimal venous tubing diameter for adult cardiopulmonary bypass (CPB) to improve gravity drainage and to reduce priming volume. Methods: (A) Maximum bovine blood flow rates by gravity drainage were assessed in vitro for four different tubing diameters (1/2, 3/8, 5/16,1/4 inch) with three different lengths and various pre- and afterloads. Based on the results of (A) and multiple regression analyses, we developed equations to predict tubing sizes as a function of target flows. (C) The equations obtained in (B) were validated by ex vivo bovine experiments. (D) The clinically required maximal flows were determined retrospectively by reviewing 119 perfusion records at Zurich University. (E) Based on our model (B), the clinical patient and hardware requirements, the optimal venous tubing diameter was calculated. (F) The optimized venous tubing was evaluated in a prospective clinical trial involving 312 patients in Hangzhou. Results: For a mean body surface area of 1.83 ^ 0.2 m 2 , the maximal perfusion flow rate (D) achieved with 1/2-inchOa 1:27 cm 2 ) venous tubing was 4.62 ^ 0.57 l/min (range: 2.50‐6.24 l/min). Our validated model (B,C) predicted 1.0 cm 2 as optimal cross-sectional area for the venous line. New tubing packs developed accordingly were used routinely thereafter. The maximal flow rate was 4.93 ^ 0.58 l/ min (range: 3.9‐7.0) in patients with a mean body surface area of 1.62 ^ 0.21 m 2 . Conclusion: The new venous tubing with 1.0-cm 2 crosssectional area improves the drainage in the vast majority of adult patients undergoing CPB and reduces the priming volume (227 ml/m). Reduced hemodilution can prevent homologous transfusions if a predefined transfusion trigger level is not reached. q 2001 Elsevier Science B.V. All rights reserved.

To check whether in vivo EDTA prevents complement activation resulting from blood contact with the dialyzer membrane, sham hemodialysis (HD) was performed in seven healthy volunteers using Cuprophan hollow-fiber dialyzers. Blood samples were drawn from the arterial and venous blood lines of the dialyzer before and after EDTA was infused into the arterial line. Venous line plasma C3a concentrations before EDTA infusion were significantly higher than after EDTA. Also, venous line plasma C3a concentrations before and after EDTA infusion were significantly higher than in the arterial line. These results indicate that complement activation can be attenuated by EDTA during sham HD. Technical improvements in the procedure may permit complete inhibition of complement activation.

Venous line disconnection or needle dislodgement during hemodialysis with resultant hemorrhage is a potentially lethal event. The risk is compounded by the frequent failure of standard dialysis machines to detect the event, as blood flow through the venous needle typically creates enough back pressure to prevent venous pressure alarms even if the needle is completely out of the patient's AV access. Manufacturers are well aware of the risk and device literature contains specific warnings about it. The FDA publishes reports on its website about these events; so far this year there have been seven reported events with five deaths. Informal sources indicate that the actual (unreported) occurrence is much more frequent; we are aware of four additional events within our region alone. Efforts to reduce the risk include protocols requiring the access needles to always be visible, and use of enuresis detection devices. Anecdotal experience with these efforts suggests they are not highly effective. Protocols requiring documentation of more frequent needle site checks or alternate methods of securing the needles have not been formally evaluated. However, such efforts do not address the primary problem: there is a need for an engineered solution to this problem. Requirements for such a solution include: reliable detection of needle position and blood flow discrepancies, a useful alarm, and feedback to stop the blood pump. Persistence of this problem raises issues of regulatory oversight.