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Summary: Viscoelastic haemostatic assays provide rapid testing at the bed‐side that identify all phases of haemostasis, from initial fibrin formation to clot lysis. In obstetric patients, altered haemostasis is common as pregnancy is associated with coagulation changes that may contribute to bleeding events such as postpartum haemorrhage, as well as thrombosis events. In this narrative review, we examine the potential clinical utility of viscoelastic haemostatic assays in postpartum haemorrhage and consider the current recommendations for their use in obstetric patients. We discuss the clinical benefits associated with the use of viscoelastic haemostatic assays due to the provision of (near) real‐time readouts with a short turnaround, coupled with the identification of coagulation defects such as hypofibrinogenaemia. The use of viscoelastic haemostatic assay‐guided algorithms may be beneficial to diagnose coagulopathy, predict postpartum haemorrhage, reduce transfusion requirements and monitor fibrinolysis in women with obstetric haemorrhage. Further studies are required to assess whether viscoelastic haemostatic assay‐guided treatment improves clinical outcomes, and to confirm the utility of prepartum viscoelastic haemostatic assay measurements for identifying patients at risk of postpartum haemorrhage. [ABSTRACT FROM AUTHOR]

Objectives:The maximum surgical blood ordering schedule (MSBOS) provides guidelines for pre-operative pre-transfusion testing for elective surgical procedures. This study compared blood ordering and utilization during the period when the MSBOS was created by achieving consensus between the blood bank and the various surgical specialties, and after the introduction of an MSBOS created by using department-specific red blood cell (RBC) transfusion data (data driven MSBOS, dMSBOS). Methods:The dMSBOS was created by analyzing 12 months of RBC transfusion data for each procedure across a regional health system. Pre-transfusion testing and the RBC crossmatch:transfusion (C:T) ratios at 8 of the hospitals were compared between the 12 month period before the dMSBOS was introduced, and the 15 months after its introduction. Results:There were significant reductions in the median monthly number of type and screens not associated with RBC crossmatches (10 714–10 061;p < 0.0001) and the median number of type and screens associated with RBC crossmatches (10 127–9 349;p = 0.0014) on surgical patients after dMSBOS implementation. There were significant decreases in the median number of monthly RBC units crossmatched (2 981–2 444;p < 0.0001) and transfused (890–791;p < 0.0001) to surgical patients after implementing the dMSBOS. The overall system-wide C:T ratio trended down after dMSBOS implementation (from 3.34 to 3.17,p = 0.067). Discussion:Crossmatching fewer RBC units facilitates more efficient management of the blood bank’s inventory. Conclusion:The dMSBOS was effective in reducing the extent of unnecessary pre-transfusion testing before surgery and reduced the number of RBCs that were crossmatched for specific patients. [ABSTRACT FROM AUTHOR]

Background and objectives Extracorporeal membrane oxygenation ( ECMO) is a method of life support for either isolated cardiac failure or respiratory failure, with or without cardiac failure. When used for hemodynamic support, the ECMO circuit presents a non-endothelialized, artificial surface to blood inciting an inflammatory response which activates haemostatic pathways. Anticoagulation may complicate a pre-existing coagulopathy and/or inadequate surgical hemostasis of varying severity. There is no standardized method to achieve and monitor anticoagulation or guide transfusion therapy during ECMO. We tested the hypothesis that institutions across the world conduct similar management of anticoagulation and transfusion during adult ECMO support. Methods This is a descriptive, self-reporting cross-sectional survey of anticoagulation and transfusion practice for patients age 18 or older on ECMO. This 38 multiple-choice question survey was sent to 166 institutions, internationally, utilizing adult ECMO. About 32·4% (54) of institutions responded. Responses were anonymously collected. Descriptive analyses were calculated. Results Our findings indicate there appears to be a significant practice variation among institutions regarding anticoagulation and transfusion during adult ECMO support. Discussion The lack of standard practices among institutions may reflect a paucity of data regarding optimal anticoagulation and transfusion for patients requiring ECMO. Standardized protocols for anticoagulation and transfusion may help increase quality of care for and reduce morbidity, mortality and cost to patients and healthcare centres. Further study is required for standardized, high quality care. [ABSTRACT FROM AUTHOR]

The authors focus on patient blood management (PBM) associated with transfusion medicine. The authors state that PBM is about applying the latest and highest-quality evidence to the practice of transfusion medicine, and mention significance of development of the transfusion practitioner (TP) in PBM. The authors cite example of promulgation of tranexamic acid (TXA) by the hospital transfusion committee, transfusion medicine physicians, and PBM committee.

SUMMARY Objectives To determine what percentage of red blood cell ( RBC) units that were issued to the operating room ( OR) were returned unused, and to determine how often all of the RBCs that were issued for a patient were returned unused using the institution's maximum surgical blood ordering schedule ( MSBOS) as a guide. Background The MSBOS provides guidelines for blood ordering, but is merely a suggestion for the ordering clinicians. This study examined how closely ordering practices followed the MSBOS, and how often ordered RBCs were actually transfused. Methods For a 4-week period, RBC issue and utilization data were collected on elective surgery patients who were eligible for electronic cross-match at a tertiary care hospital. These data were compared to the MSBOS. Results There were 1350 surgical procedures performed. Of these cases, 439 patients had a type and screen (T&S) performed, and 215/439 (49%) patients had at least 1 RBC issued during their case. To these 215 patients, 742 RBC units were issued and 537/742 (72%) of these units were returned to the blood bank unused. In 152/215 (71%) cases with issued RBCs, all of the RBCs were returned to the blood bank unused. Amongst the surgical categories in this study, the percentage of cases where none of the issued RBCs were transfused ranged from 38 to 93%. Conclusions Significant numbers of RBC units are issued but not transfused during surgery. Involving the surgical team in the blood issuing process and using a data-driven MSBOS may reduce the number of unused units. [ABSTRACT FROM AUTHOR]

The article discusses the implementation aspect of a blood management programme in the hospital for immediate blood requirements such as postoperative period. Topics include regulation of amount of erythrocyte transfusion, taking care before transfusion, and implementation of patient blood management in transfusion.

There is mixed evidence concerning cognitive function and heroin dependence. In this study, abstinent heroin-dependent individuals (n = 86) and age- and sex-matched non-drug-using controls (n = 88) were compared on self-report measures of impulsivity and computerized assessments of cognitive function. Abstinent heroin-dependent individuals reported greater motor impulsivity and experience seeking and showed functional weaknesses in cognitive ability, including impulsivity and distractibility (d = 0.28 to 0.49), but not decision making or working memory. Self-reported impulsivity was uncorrelated with cognitive function. These results suggest underlying brain-related factors in heroin dependence and have implications for therapeutic intervention. [ABSTRACT FROM AUTHOR]

Objectives: To determine the extent of RBC sublethal injury in male donor units as measured by both the mechanical fragility index (MFI) and percentage haemolysis after RBCs underwent leucoreduction (LR), irradiation (IRRAD), and washing. Background: RBCs frequently undergo post-collection processing to meet certain recipient's special needs. The extent of haemolysis and sublethal injury following these interventions has not been fully characterised. Methods: Eight to ten day old male, AS-5 RBCs underwent either LR, IRRAD or washing. A control group of male, AS-5 RBCs were unmanipulated. The MFI, percent haemolysis, and plasma free haemoglobin (PFHb) were measured immediately after manipulation and, for a series of irradiated RBCs, 28 days after irradiation (IRRAD28). Results: The MFI of the washed units was significantly higher than unmanipulated, LR, IRRAD, IRRAD28 units ( P < 0·0001). The percent haemolysis was highest in the IRRAD28 units (1·4%) followed by the washed units (0·74%); the other three units demonstrated significantly less haemolysis ( P < 0·0001). The largest mean total amount of PFHb per unit was found in the IRRAD28 units (500·5 mg/unit) followed by the washed units (149·8 mg/unit); the mean total amount of PFHb in the three other types of units was significantly less than that found in both the IRRAD28 and washed units ( P at least < 0·001). Conclusion: There is a significant quantity of PFHb in IRRAD28 RBC units, and potentially in washed allogeneic RBC units. Clinical correlation is required to determine if this quantity of PFHb and the transfusion of potentially fragile RBCs causes adverse events. [ABSTRACT FROM AUTHOR]

The mechanical fragility index (MFI) is an in vitro measure of sublethal injury to RBCs. In our previous experiments, we demonstrated that an increase in sublethal injury (increasing MFI) was a component of the RBC storage lesion, and that the MFI was significantly higher amongst the RBC units from male donors compared to pre-menopausal female donors during storage. It was hypothesized that hormonal or menstrual factors contributed to this difference. In this study, we found that RBC units donated by post-menopausal women demonstrated an MFI that was significantly higher than those donated by pre-menopausal women throughout storage. [ABSTRACT FROM AUTHOR]

Background The mechanical fragility index (MFI) is an in vitro measurement of the extent of RBC sublethal injury. Sublethal injury might constitute a component of the RBC storage lesion, thus the MFI was determined serially during routine RBC storage. Methods Leucoreduced AS-5- and SAGM-preserved RBCs were stored under routine blood bank conditions. The mechanical fragility (MF) of each unit was serially measured during storage. Results For both AS-5 and SAGM units, male and female RBCs demonstrated statistically significant increases in the MFI during storage. The MFI was significantly lower in AS-5 units compared to SAGM units throughout storage. Female RBCs had significantly lower MFI vs. male RBCs in both AS-5 and SAGM units at all times. No significant differences in MFI were observed between ABO groups for both genders for AS-5 RBCs. Conclusions The MF of RBCs increases during storage. Both gender and preservation solution influenced the MFI; however, the male:female MFI ratios were similar at all time-points and remained stable, suggesting that gender-based biological differences exist independent of storage solution. The MF could be a useful test for evaluating the effect of novel interventions intended to mitigate the susceptibility of RBCs to sublethal injury during storage. [ABSTRACT FROM AUTHOR]

Background and objective: A prospective crossover randomized trial was conducted to compare the performance of three commonly used anaesthetic facemasks: a clear plastic ‘Anaesthetic Facemask’ with pre-inflated air cushion, no inflation valve, and for single use (Intersurgical Limited, Wokingham, UK), a clear plastic ‘Air Cushion Mask’ with inflatable air cushion and inflation valve, and for single use (Proact Medical Limited, Kettering, UK), and a black antistatic reusable rubber facemask with pre-inilated air cushion, and no inflation valve (Datex Ohmeda Limited, Hatfield, UK). Methods: After local Ethics Committee approval, written consent was taken from 60 ASA 1 or 2 patients undergoing elective ENT procedures. Following routine intravenous anaesthetic induction and muscle relaxation, a Guedel's oropharyngeal airway was inserted and each of the facemasks tried in a crossover fashion. The degree of chest expansion, the feel on the reservoir bag, the degree of leak around the mask and the overall satisfaction of the anaesthetist were graded and recorded for each facemask. Results: Both the plastic facemasks performed similarly in all the four criteria. The antistatic rubber facemask performed significantly better than the plastic facemasks in these criteria (P < 0.05). Conclusions: This study has shown that the antistatic rubber facemask outperformed the two plastic facemasks during routine induction of general anaesthesia. We hope this will encourage manufacturers to improve disposable facemask design to simulate the antistatic rubber facemask. [ABSTRACT FROM AUTHOR]

Background Study Design and Methods Results Conclusions Liberal or overtransfusion (OT) may be regarded as “inappropriate,” but it is not reported as a transfusion‐related adverse event. A definition of OT is lacking. OT may include overdosing of components, giving the incorrect component, or unnecessary administration without evidence of need for transfusion. OT can be associated with hypercoagulability, thrombosis, alloimmunization, increased mortality, longer hospital stay, increased infection rates, and adverse cardiocirculatory events.In 2023, an expert panel formed a hemovigilance international taskforce embedded in the German Interdisciplinary Taskforce for Clinical Hemotherapy (IAKH). The group was charged with proposing simple criteria to be used by hemovigilance systems to document instances of OT.This international initiative combined a narrative review of the literature for the rate and outcomes of OT with transfusion error reports to propose a definition for OT, including a definition for transfusion‐induced hypercoagulopathy (TIH), three new codes for OT/TIH and subcodes A to G, three severity categories (serious adverse event, adverse event, near miss), and four incident codes (definite, probable, possible, not determinable). These codes can be used by hemovigilance systems to appropriately document instances of OT.Global adoption of these codes within hemovigilance systems would assist with the recognition and reporting of instances of OT, promote effective policies for adequate clinical administration techniques, and support technical guidelines for avoidance of OT. Thereby, incorporation of OT into hemovigilance strategies could support adequate use of blood products, increase patient safety, and facilitate blood supply and availability. [ABSTRACT FROM AUTHOR]

The concept of rapid delivery of multiple blood products to the bedside of a massively haemorrhaging patient seems to be a logical approach to the management of the massively bleeding patient. However, controversy exists in the use of fixed blood component ratios. Assessing the extent of the coagulopathy through point-of-care testing might provide patients with product administration as needed, and avoid excessive transfusion and its associated complications. [ABSTRACT FROM AUTHOR]

Background: I.V. infusion of drag-reducing polymers (DRPs) has been shown to improve survival time in animals subjected to haemorrhagic shock. We hypothesized that DRPs might prolong survival time in rats following acute myocardial ischaemia (AMI).Methods: Sixteen adult male rats were anaesthetized and mechanically ventilated. An i.v. infusion of either Dextran-40 2.5% (Control, n=8) or Dextran-40 2.5% containing 50 microg ml(-1) of an aloe vera-based DRP (DRP, n=8) was initiated at 3.5 ml h(-1). The left anterior descending coronary artery was ligated. Blood pressure, skin-tissue perfusion, and heart rate were monitored and arterial blood samples were analysed.Results: The mortality at 60 min following coronary ligation was 0% in the DRP group vs 50% in the control group (P=0.025). DRP-treated animals maintained higher mean arterial pressure [60.9 (5.1) vs 47.5 (5.1) mm Hg, P=0.004] and tissue perfusion [4.2 (3.4) vs 1.2 (0.5) TPU, P=0.029]. The DRP group trended towards better acid-base status with base excess [-5.0 (1.7) vs -8.1 (5.1) mmol litre(-1), P=0.083] and pH [7.42 (0.07) vs 7.35 (0.02), P=0.03].Conclusions: Administration of nanomolar concentrations of aloe vera-based DRP prolonged survival time in animals with AMI. DRPs may offer a novel method to treat organ/tissue hypoperfusion. [ABSTRACT FROM AUTHOR]

The incidence of maternal hemorrhage and blood transfusion has increased over time. Causes of massive hemorrhage, defined as a transfusion > 10 units of erythrocytes, include abnormal placental insertion, preeclampsia, and placental abruption. Although ratio-based transfusion has been described for managing massive hemorrhage, a goal-directed approach using laboratory or point-of-care data may lead to better outcomes. Autotransfusion, which involves the collection, washing, and filtration of maternal shed blood, avoids many of the complications associated with allogeneic blood transfusion. In this review, we provide an overview of transfusion practices related to the management of obstetric hemorrhage., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

We describe the peripartum management of a 26-year-old primigravida with a platelet storage pool disorder who underwent spontaneous vaginal delivery of twins with epidural analgesia. Postpartum hemorrhage from uterine atony, and cervical and vaginal lacerations were treated successfully with 1-desamino-8D-arginine vasopressin and blood products. The use of thromboelastography in the assessment and management of bleeding risk in the setting of platelet storage pool disorder is described., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Background: I.V. infusion of drag-reducing polymers (DRPs) has been shown to improve survival time in animals subjected to haemorrhagic shock. We hypothesized that DRPs might prolong survival time in rats following acute myocardial ischaemia (AMI)., Methods: Sixteen adult male rats were anaesthetized and mechanically ventilated. An i.v. infusion of either Dextran-40 2.5% (Control, n=8) or Dextran-40 2.5% containing 50 microg ml(-1) of an aloe vera-based DRP (DRP, n=8) was initiated at 3.5 ml h(-1). The left anterior descending coronary artery was ligated. Blood pressure, skin-tissue perfusion, and heart rate were monitored and arterial blood samples were analysed., Results: The mortality at 60 min following coronary ligation was 0% in the DRP group vs 50% in the control group (P=0.025). DRP-treated animals maintained higher mean arterial pressure [60.9 (5.1) vs 47.5 (5.1) mm Hg, P=0.004] and tissue perfusion [4.2 (3.4) vs 1.2 (0.5) TPU, P=0.029]. The DRP group trended towards better acid-base status with base excess [-5.0 (1.7) vs -8.1 (5.1) mmol litre(-1), P=0.083] and pH [7.42 (0.07) vs 7.35 (0.02), P=0.03]., Conclusions: Administration of nanomolar concentrations of aloe vera-based DRP prolonged survival time in animals with AMI. DRPs may offer a novel method to treat organ/tissue hypoperfusion.

Wider selection of young patients for prosthetic valve replacement for valvular heart disease has resulted in an increase in number of women with heart disease reaching childbearing age. Such patients presenting in labor for emergency cesarean section require special consideration. We present a report of a parturient who presented at 36 weeks of gestation with severe aortic and mitral stenosis, pulmonary edema and severe preeclampsia. The goals of our anesthetic management included (1) careful airway management (2) maintaining stable hemodynamics (3) optimizing fluid status, and (4) preventing seizures. Issues related to management of patients with severe valvular disease, prosthetic valves and complications due to anticoagulant therapy during pregnancy are discussed.

Implications: Two case reports illustrate errors that can occur during intraoperative red blood cell salvage and emphasize the need for standardized procedures and quality improvement processes for this intervention.

Implications: We describe a patient who experienced intraoperative bleeding after being treated with platelet receptor glycoprotein IIb/IIIa antagonist eptifibatide. We used Sonoclot and Thrombelastograph to monitor antiplatelet effects of eptifibatide.

Unlabelled: Metabolic acidosis and changes in serum osmolarity are consequences of 0.9% normal saline (NS) solution administration. We sought to determine if these physiologic changes influence patient outcome. Patients undergoing aortic reconstructive surgery were enrolled and were randomly assigned to receive lactated Ringer's (LR) solution (n = 33) or NS (n = 33) in a double-blinded fashion. Anesthetic and fluid management were standardized. Multiple measures of outcome were monitored. The NS patients developed a hyperchloremic acidosis and received more bicarbonate therapy (30 +/- 62 mL in the NS group versus 4 +/- 16 mL in the LR group; mean +/- SD), which was given if the base deficit was greater than -5 mEq/L. The NS patients also received a larger volume of platelet transfusion (478 +/- 302 mL in the NS group versus 223 +/- 24 mL in the LR group; mean +/- SD). When all blood products were summed, the NS group received significantly more blood products (P = 0.02). There were no differences in duration of mechanical ventilation, intensive care unit stay, hospital stay, and incidence of complications. When NS was used as the primary intraoperative solution, significantly more acidosis was seen on completion of surgery. This acidosis resulted in no apparent change in outcome but required larger amounts of bicarbonate to achieve predetermined measurements of base deficit and was associated with the use of larger amounts of blood products. These changes should be considered when choosing fluids for surgical procedures involving extensive blood loss and requiring extensive fluid administration., Implications: Predominant use of 0.9% saline solution in major surgery has little impact on outcome as assessed by duration of mechanical ventilation, intensive care unit stay, hospital stay, and postoperative complications, but it does appear to be associated with increased perioperative blood loss.

Background: The results of in-hospital resuscitations may depend on a variety of factors related to the patient, the environment, and the extent of resuscitation efforts. We studied these factors in a large tertiary referral hospital with a dedicated certified resuscitation team responding to all cardiac arrests., Methods: Statistical analysis of 445 prospectively recorded resuscitation records of patients who experienced cardiac arrest and received advanced cardiac life support resuscitation. We also report the outcomes of an additional 37 patients who received limited resuscitation efforts because of advance directives prohibiting tracheal intubation, chest compressions, or both., Main Outcome Measures: Survival immediately after resuscitation, at 24 hours, at 48 hours, and until hospital discharge., Results: Overall, 104 (23%) of 445 patients who received full advanced cardiac life support survived to hospital discharge. Survival was highest for patients with primary cardiac disease (30%), followed by those with infectious diseases (15%), with only 8% of patients with end-stage diseases surviving to hospital discharge. Neither sex nor age affected survival. Longer resuscitations, increased epinephrine and atropine administration, multiple defibrillations, and multiple arrhythmias were all associated with poor survival. Patients who experienced arrests on a nursing unit or intensive care unit had better survival rates than those in other hospital locations. Survival for witnessed arrests (25%) was significantly better than for nonwitnessed arrests (7%) (P =.005). There was a disproportionately high incidence of nonwitnessed arrests during the night (12 AM to 6 AM) in unmonitored beds, resulting in uniformly poor survival to hospital discharge (0%). None of the patients whose advance directives limited resuscitation survived., Conclusions: Very ill patients in unmonitored beds are at increased risk for a nonwitnessed cardiac arrest and poor resuscitation outcome during the night. Closer vigilance of these patients at night is warranted. The outcome of limited resuscitation efforts is very poor.

Two cases of inadvertent dural puncture in patients at high risk for dural puncture headache are presented. These patients were managed with an immediate epidural blood patch through a catheter placed at another level with placement of this catheter occurring immediately following the dural puncture. Following the blood patch, the patients were anesthetized with the epidural catheter being used for supplementation of the general anesthetic and for postoperative pain management. Neither patient required further management of a dural puncture headache nor did it appear that the blood interfered with the patients receiving adequate postoperative analgesia through the use of this epidural catheter.

Background: Cell salvage has been used in obstetrics to a limited degree because of a fear of amniotic fluid embolism. In this study, cell salvage was combined with blood filtration using a leukocyte depletion filter. A comparison of this washed, filtered product was then made with maternal central venous blood., Methods: The squamous cell concentration, lamellar body count, quantitative bacterial colonization, potassium level, and fetal hemoglobin concentration were measured in four sequential blood samples collected from 15 women undergoing elective cesarean section. The blood samples collected included (1) unwashed blood from the surgical field (prewash), (2) washed blood (postwash), (3) washed and filtered blood (postfiltration), and (4) maternal central venous blood drawn from a femoral catheter at the time of placental separation., Results: Significant reductions in the following parameters were seen when the postfiltration samples were compared to the prewash samples (median [25th-75th percentile]): squamous cell concentration (0.0 [0.0-0.1 counts/high-powered field (HPF)] vs. 8.3 counts/HPF [4. 0-10.5 counts/HPF], P < 0.05); bacterial contamination (0.1 [0.0-0. 2] vs. 3.0 [0.6-7.7] colony-forming units (CFU)/ml, P < 0.01); and lamellar body concentration (0.0 [0.0-1.0] vs. 22.0 [18.5-29.5] thousands/microl, P < 0.01). No significant differences existed between the postfiltration and maternal samples for each of these parameters. Fetal hemoglobin was in higher concentrations in the postfiltration sample when compared with maternal blood (1.9 [1.1-2. 5] vs. 0.5% [0.3-0.7] ). Potassium levels were significantly less in the postfiltration sample when compared with maternal (1.4 [1.0-1.5] vs. 3.8 mEq/l [3.7-4.0])., Conclusions: Leukocyte depletion filtering of cell-salvaged blood obtained from cesarean section significantly reduces particulate contaminants to a concentration equivalent to maternal venous blood.

Objective: The intraoperative development of metabolic acidosis is frequently attributed to hypovolemia, tissue hypoperfusion, and lactic acidosis. In this study, dilutional acidosis was evaluated as a possible mechanism for the routine development of intraoperative acidosis in noncardiac, nonvascular surgery patients., Design: Prospective, observational study., Setting: University-affiliated Veteran's Affairs Medical Center and a staff model, health maintenance organization hospital., Patients: Twelve patients undergoing prolonged surgical procedures expected to last > or = 4 hrs were enrolled in the study., Interventions: Perioperative management was based on the judgment of the attending anesthesiologist and surgeon without knowledge of the study's intent., Measurements and Main Results: Arterial blood gas parameters, serum electrolytes, and urine electrolytes were measured pre- and postoperatively. Pulmonary artery catheters were placed for hemodynamic measurement and oxygen delivery calculations. Plasma volume was measured both pre- and postoperatively, using the Evans blue dye dilution technique. Although significant changes in lactate level (1.1 +/- 0.6-1.8 +/- 1.0) occurred, the change was not large enough to explain the degree of change in base excess (0.8 +/- 2.3 to -2.7 +/- 2.9). Chloride levels significantly increased (106 +/- 3-110 +/- 5) with a correlation (r2 = .92; p < .0001) between the degree of change in chloride and the degree of change in base excess. Plasma volume did not change. Furthermore, a correlation between the volume of normal saline administered and the change in base excess was found (r2 = .86; p < .0001), although no correlation was found with Ringer's lactate solution. An even stronger correlation was noted when the total chloride amount administered was compared with the change in base excess (r2 = .93; p < .0001)., Conclusions: In this patient population, a common source of increasing base deficit is related to chloride administration. The largest source of chloride is usually normal saline. Classically, dilutional acidosis would explain the predominance of this acidotic change; however, no increase in plasma volume occurred. The absence of plasma volume change would suggest that the mechanism postulated to result in dilutional acidosis is incomplete. The common treatment of administering more fluid for intraoperative acidosis may be inappropriate, may have caused the acidosis, and may further exacerbate the acidosis. Chloride levels should be assessed whenever a metabolic acidosis is seen perioperatively.

This case report describes a patient who had paroxysmal ventricular bigeminy of an unrecognized etiology. After 24 hours of observation, it was noted that the patient's head position correlated with the bigeminy. A single-lumen infusion catheter, which had been placed through an internal jugular cannula, was transduced and demonstrated a ventricular pressure waveform. This catheter was removed and the ectopy resolved. The factors associated with this arrhythmia are discussed.

In a practice that may be unique to military health care, extremity nerve blocks are established by anesthesiologists before transporting the patient to a remote clinic for surgery without further monitoring by anesthesia personnel. The safety and acceptance of this practice was assessed through a prospective survey of the surgeons and their patients. Six hundred seventy-seven blocks were performed in a 1-yr period with no adverse events related to this practice. Completed surveys were received from 406 (60%) of the surgeons and 232 (34%) of the patients. Of the blocks performed, 638 (94%) were brachial plexus blocks, with axillary blocks accounting for 87% of the brachial plexus blocks. Of the responding patients, 78% stated that they would be willing to undergo a repeat block. The surgeons were satisfied with the operating conditions in 96% of the cases. This study supports the safety and efficacy of this practice.

Multiple reports of cauda equina syndrome and transient radicular nerve root irritation have suggested that lidocaine spinal anesthesia may be responsible. In this case report, a patient with a preexisting diabetic neuropathy received a partial block following a tetracaine spinal, which was followed by a lidocaine spinal. Following block resolution, a new conus medullaris syndrome was diagnosed. Because of the close proximity of the cauda equina and the conus medullaris, differentiation between these syndromes can be difficult. The preexisting diabetic neuropathy may have predisposed this patient to neurologic injury. The choice of a different local anesthetic drug with less neurotoxic potential such as bupivacaine may have prevented this injury.

The purpose of this study was to evaluate the plasma potassium (K+) response after administration of tromethamine (THAM) or sodium bicarbonate (NaHCO3) in an acidotic rabbit model. Eighteen healthy, adult female New Zealand White rabbits were subjected to severe hypoxia until a base deficit of -10 mEq/L resulted. Rabbits were then randomized to receive THAM solution, NaHCO3, or no drug (control). The drug was administered over 2 min in quantities calculated to correct a base deficit of 10 or greater. Plasma K+ and sodium (Na+) were measured for 45 min after drug administration. No difference in K+ response was noted after THAM, NaHCO3, or no drug. In contrast, THAM resulted in significantly lower Na+ concentrations when compared to the NaHCO3 or the control group (P < 0.05). In this rabbit model, alkalinization after THAM administration results in K+ changes similar to those after NaHCO3. THAM should be considered when treating acidosis in patients where hypernatremia is a concern.

Study Objective: To evaluate the effects of oral, intramuscular (i.m.) and intravenous (i.v. glycopyrrolate on oral and gastric secretions, and to assess how these routes of administration change intubating conditions., Design: Randomized, double-blinded study., Setting: University hospital operating room., Patients: 37 ASA status I and II general anesthesia patients., Interventions: Patients were randomized to receive glycopyrrolate or placebo just before surgery by three routes: oral, i.m., and i.v.. Glycopyrrolate was received once by one route and placebo by the other two routes. A placebo group received three placebos and no glycopyrrolate., Measurements and Main Results: Mouth conditions and intubating conditions were qualitatively assessed by the patient and the intubating anesthesiologist. No difference between groups was noted. Oral and gastric volumes were measured and showed significantly less gastric volume for the i.v. group as compared with the other groups. Oral secretions were reduced in both the i.v. and i.m. groups when compared with placebo or glycopyrrolate administered orally., Conclusions: Preoperative glycopyrrolate is significantly more effective at reducing oral and gastric secretions if administered intravenously immediately before induction.

Current clinical practice regarding acid-base balance is derived from the traditional Henderson-Hasselbalch equation. An alternate theory, developed by Stewart, relates hydrogen ion concentration ([H+]) changes to three independent variables: the strong ion difference, weak acids, and PCO2. The insight into acid-base balance gained by this approach has potentially important clinical applications. To test the theory in vivo, electrolyte and blood gas values were measured in rabbits subjected to a period of hypoxia sufficient to produce a severe metabolic acidosis, followed by a period of reoxygenation. These variables were used to calculate [H+] by Stewart's original formula, which was then compared to the measured value. A high correlation was found between measured and calculated values for a pH range of 7.3-7.6; however, progressive deterioration in correlation was observed outside this range. Perhaps the presence of an unidentified anion, thought to be phosphate, causes a breakdown in the accuracy of Stewart's formula at pH extremes. The addition of phosphate values to the calculation, along with calcium and magnesium, restored the agreement throughout the physiologic range. To make the formula clinically applicable, modification to incorporate phosphate levels is required to achieve the necessary accuracy in biologic solutions at more acidemic pH ranges.

Study Objective: Sodium thiopental has been used to determine whether fluid aspirated from an epidural catheter is previously injected local anesthetic or cerebrospinal fluid (CSF). The purpose of this study was to test the efficacy of this test in distinguishing opioids from CSF., Design: in vitro study., Setting: Laboratory of a university hospital., Measurements and Main Results: Three in vitro studies were performed. The first study tested for precipitation when thiopental was mixed with several commonly used epidural medications. Then, thiopental was mixed in combinations of opioids with local anesthetics to see if the opioid might prevent the precipitation of the local anesthetics. Finally, lidocaine was serially diluted and precipitation with thiopental was assessed. It was found that certain concentrations of opioids as well as normal saline do not precipitate with thiopental. In addition, the ratio of opioids to local anesthetic of 10:1 prevented precipitation when thiopental was added. Local anesthetics combined with cerebrospinal fluid in a 1:10 ratio produced a precipitate on mixing with thiopental., Conclusions: Use of thiopental to differentiate opioids from cerebrospinal fluid is unreliable. In addition, in some simulated situations, opioids may mask the presence of local anesthetic.

Frequently fluid may be aspirated from epidural catheters during epidural anesthesia/analgesia. This fluid may be either cerebrospinal fluid or local anesthetic. Several methods for differentiation of the two fluids have been recommended. In this study, the reliability of the "glucose test" was analyzed. Epidural catheters were inserted into 43 healthy, nondiabetic parturients and then gently aspirated. Aspirate was tested for glucose using glucose oxidase paper. Positive aspirates were assessed for the presence of prealbumin, which is a protein marker for cerebrospinal fluid. Of the patients undergoing cesarean section, 17 of 27 patients yielded a glucose-positive aspirate, and of the patients undergoing labor analgesia, 6 of 16 patients were found to be positive for glucose. None of these patients developed total spinal anesthesia or postdural puncture headache. Visually, none of the aspirates were significantly blood-tinged, blood being a possible source of glucose. When the glucose-positive aspirates were subjected to immunoelectrophoresis, 6 of 7 aspirates revealed a prealbumin band. In conclusion, the glucose test for cerebrospinal fluid may be misleading. The source of this glucose may be normal cerebrospinal fluid drainage into the epidural space.

In December 1983, Harefield Hospital started a programme for combined heart and lung transplantation. Fifty-two transplants have been successfully performed, with 36 survivors (April 1986). Patient selection and anaesthetic management of both donor and recipient are discussed. Two case histories are presented which illustrate the principles of anaesthetic management and postoperative care.

A common problem of medical audit programs is effectively correcting problems identified in an audit. A physician may ignore a letter from the audit committee, and because many of the problems deserve attention but are not life threatening, the medical staff hesitates to use disciplinary actions. This audit program offers a physician educational corrective actions without notation on his record. Disciplinary measures are invoked by the medical staff bylaws only if the physician refuses or fails the educational route.