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Background: Prehospital blood transfusion has been widely practiced in the military and is drawing renewed scrutiny after many years of civilian use., Objective: The objective of this article is to quantify the benefit derived from prehospital transfusion of blood products., Methods: Deidentified data were extracted retrospectively from the flight records of a critical care transportation program between April 2018 and January 2020. Patients who were transported before a prehospital blood transfusion protocol were compared with patients after initiation of the blood transfusion protocol. Demographic data, vital signs, laboratory analytics, and other outcome measures were analyzed., Results: Nine scene transport patients who met the transfusion criteria before a blood transfusion protocol were compared with 11 patients transported after initiation of the protocol. Identical outcome measures were analyzed. Patients who received prehospital blood transfusions had a statistically significantly longer hospital length of stay (16.5 vs 3.7 days, P = .03) and were more often taken directly to the operating room (80% vs 28%, P = .04). No statistically significant difference was identified when comparing mean arterial pressure, heart rate, respiratory rate, hemoglobin, hematocrit, or survival to hospital discharge., Conclusions: Trauma patients who received prehospital blood transfusion had a longer hospital length of stay and were more often taken directly to the operating room, but without improvement in survival., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Summary: We report the case of a 76-year-old male with a remote history of papillary thyroid cancer who developed severe paroxysmal headaches in the setting of episodic hypertension. Brain imaging revealed multiple lesions, initially of inconclusive etiology, but suspicious for metastatic foci. A search for the primary malignancy revealed an adrenal tumor, and biochemical testing confirmed the diagnosis of a norepinephrine-secreting pheochromocytoma. Serial imaging demonstrated multiple cerebral infarctions of varying ages, evidence of vessel narrowing and irregularities in the anterior and posterior circulations, and hypoperfusion in watershed areas. An exhaustive work-up for other etiologies of stroke including thromboembolic causes or vasculitis was unremarkable. There was resolution of symptoms, absence of new infarctions, and improvement in vessel caliber after adequate alpha-adrenergic receptor blockade for the management of pheochromocytoma. This clinicoradiologic constellation of findings suggested that the etiology of the multiple infarctions was reversible cerebral vasoconstriction syndrome (RCVS). Pheochromocytoma remains a poorly recognized cause of RCVS. Unexplained multifocal cerebral infarctions in the setting of severe hypertension should prompt the consideration of a vasoactive tumor as the driver of cerebrovascular dysfunction. A missed or delayed diagnosis has the potential for serious neurologic morbidity for an otherwise treatable condition., Learning Points: The constellation of multifocal watershed cerebral infarctions of uncertain etiology in a patient with malignant hypertension should trigger the consideration of undiagnosed catecholamine secreting tumors, such as pheochromocytomas and paragangliomas. Reversible cerebral vasoconstriction syndrome is a serious but reversible cerebrovascular manifestation of pheochromocytomas that may lead to strokes (ischemic and hemorrhagic), seizures, and cerebral edema. Alpha-adrenergic receptor blockade can reverse cerebral vasoconstriction and prevent further cerebral ischemia and infarctions. Early diagnosis of catecholamine secreting tumors has the potential for reducing neurologic morbidity and mortality in patients presenting with cerebrovascular complications.

A patient presented with multiple unrelated tumors and was found to have a small but functional adrenal pheochromocytoma. After pheochromocytoma resection, shock developed unresponsive to vasopressin in recommended doses (0.04 U/min infusion plus repeated 1-U boluses) but responded dramatically to an angiotensin II infusion (20 ng/kg/min) with a mean arterial pressure >100 mm Hg. The patient's blood pressure was maintained for 42 hours postoperatively with an infusion rate that ranged from 2 to 38 ng/kg/min. Because vasopressin may not always be effective for postresection shock in people with pheochromocytomas, angiotensin II may prove to be an effective alternative.

Somatic mutations in cancer are more frequent in heterochromatic and late-replicating regions of the genome. We report that regional disparities in mutation density are virtually abolished within transcriptionally silent genomic regions of cutaneous squamous cell carcinomas (cSCCs) arising in an XPC(-/-) background. XPC(-/-) cells lack global genome nucleotide excision repair (GG-NER), thus establishing differential access of DNA repair machinery within chromatin-rich regions of the genome as the primary cause for the regional disparity. Strikingly, we find that increasing levels of transcription reduce mutation prevalence on both strands of gene bodies embedded within H3K9me3-dense regions, and only to those levels observed in H3K9me3-sparse regions, also in an XPC-dependent manner. Therefore, transcription appears to reduce mutation prevalence specifically by relieving the constraints imposed by chromatin structure on DNA repair. We model this relationship among transcription, chromatin state, and DNA repair, revealing a new, personalized determinant of cancer risk., (Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.)

We report a case of propofol infusion syndrome (PRIS) in a young female treated for status epilepticus. In this case, PRIS rapidly evolved to full cardiovascular collapse despite aggressive supportive care in the intensive care unit, as well as prompt discontinuation of the offending agent. She progressed to refractory cardiac arrest requiring emergent initiation of venoarterial extracorporeal membrane oxygenation (ECMO) during cardiopulmonary resuscitation (CPR). She regained a perfusing rhythm after prolonged (>8 hours) asystole, was weaned off ECMO and eventually all life support, and was discharged to home. We also present a review of the available literature on the use of ECMO for PRIS.

Catecholamine-secreting paragangliomas (CSPs) present challenges for the managing team of surgeons and anesthesiologists. Without proper preoperative management and planning, the patient is at high risk for complications and significant morbidity. A review of the literature looking at all aspects of the care of patients with CSP was performed to provide a consensus on the comprehensive care of these difficult patients. A case study is also provided to illustrate the management algorithm. Specific recommendations are made with regards to preoperative workup, including serum and urine testing, tumor localization, angiography, and embolization. Preoperative and intraoperative management techniques by the surgical and anesthesiology teams are discussed, including pharmaceutical interventions and fluid management. Aspects of postoperative care are also discussed. Management of patients with CSP requires significant attention to detail by a multidisciplinary team of surgeons and anesthesiologists. By following the recommendations included within this article, the morbidity associated with removal of these tumors can be significantly reduced or eliminated.

We report the quantification of a hemodynamic profile sufficient to support consciousness during cardiopulmonary resuscitation. A 62-yr-old man experienced cardiac arrest while being evaluated for heart failure after heart transplantation. During the emergency, hemodynamic data were obtained from bedside monitors and reviewed at regular intervals. His mean arterial blood pressure and heart rate were correlated with consciousness during cardiopulmonary resuscitation. A mean arterial blood pressure of 50 mm Hg with a heart rate of 100 bpm supported consciousness during cardiac arrest. This case helps to validate the recent emphasis on hard, fast, basic life support.

Cardiac output can be measured accurately by transpulmonary arterial thermodilution using the PiCCO (Pulsion Medical Systems, Munich, Germany) system with a femoral artery catheter. We have investigated the accuracy of a new 50 cm 4 French gauge radial artery catheter and the ability to use the system with a shorter radial catheter. We studied 18 patients who had undergone coronary artery surgery and made three simultaneous measurements of cardiac output by arterial thermodilution and with a pulmonary artery catheter. The radial catheter was withdrawn in 5 cm increments and the measurements were repeated. We found close agreement between arterial thermodilution and pulmonary artery thermodilution with a mean (SD) bias of 0.38 (0.77) l x min(-1). Arterial thermodilution became unreliable once the catheter had been withdrawn by more than 5 cm. We conclude that cardiac output measurement with arterial thermodilution with a radial catheter is interchangeable with that derived from a pulmonary artery catheter, and that a centrally sited arterial catheter is required for accurate determination of cardiac output by transpulmonary arterial thermodilution.

Objective: To validate a new system of continuous cardiac output monitoring., Design: Multicenter, prospective, nonrandomized clinical study., Setting: Four university hospitals., Patients: Forty-seven adult intensive care unit patients., Interventions: Pulmonary artery catheterization., Measurements and Main Results: Continuous and bolus cardiac output measurements were obtained over 72 hrs. The 327 continuous cardiac output measurements compared favorably with bolus cardiac output measurements (bias = 0.12 L/min, precision = +/-0.84). The continuous cardiac measurement was not adversely affected by temperatures of <37 degrees C or >38 degrees C, high (>7.5 L/min) or low (<4.5 L/min) cardiac output values, or duration (72 hrs) of the study., Conclusions: This continuous cardiac output system provides a reliable estimate of cardiac output for clinical use if applied in conditions similar to this study. The combination of a continuous measure of cardiac output with other continuous physiologic monitoring (arterial and mixed venous oxygen saturation, oxygen consumption, etc.) may provide important information that no single parameter could achieve.

Implantable biomedical sensors built on a silicon substrate capped with glass are currently being developed for intravascular applications. Electrical techniques for inhibiting thrombus formation on the surface of a proposed optical sensor in direct contact with blood have been investigated. Glass-on-silicon specimens (4 X 1.2 X 0.4 mm3) were coated with indium-tin oxide, a transparent conductor, and implanted in the vena cava and iliac veins of three dogs for 10, 20, or 33 days. The equilibrium surface-blood interface potentials of the specimens were modified by implanted current sources which supplied either direct current (8-15 microA) or 100 KHz alternating current (5 microA, root mean square). Light-microscopic and scanning electron-microscopic analyses showed each of the DC-polarized specimens to be free of thrombus, in contrast to nonpolarized (control) specimens on which varying amounts of adsorbed protein and thrombus deposits were found. Like the control specimens, the AC-polarized specimens formed thrombus, but the appearance of the deposits differed. These findings support the view that the polarity, magnitude and time dependence of the potential across conducting surface-blood interface significantly influence thrombogenicity. Further work is necessary to determine the roles of electrochemical and electrostatic factors in preventing thrombus formation on foreign materials.

In vitro and in vivo studies have suggested that human complement component C5a plays a key role in neutrophil injury in the adult respiratory distress syndrome (ARDS). First, using leukocyte aggregometry, we demonstrated that the addition of a recently developed rabbit anti-human polyclonal antibody to C5a des arg to endotoxin-activated plasma prevented leukocyte aggregation in vitro. We then administered the anti-C5a des arg antibody to septic primates (Macaca fascicularis). Three groups of primates, control, septic, and anti-C5a antibody treated septic, were studied (n = 4 in each group). A 30-min infusion of Escherichia coli (1 X 10(10)/kg) resulted in severe sepsis and ARDS. Primates were killed 4 h after completion of the E. coli infusion. Septic animals not treated with anti-C5a antibody had 75% mortality (3/4), decreased oxygenation, severe pulmonary edema, and profound hypotension. Septic primates treated with anti-C5a antibodies did not die and did not develop decreased oxygenation (P less than 0.05) or increased extravascular lung water (P less than 0.05). They also had a marked recovery in their mean arterial blood pressure (P less than 0.05). This study demonstrates that treatment with rabbit anti-human C5a des arg antibodies attenuates ARDS and some of the systemic manifestations of sepsis in nonhuman primates.

The end-tidal carbon dioxide tension (PetCO2) measured after a single, large tidal-volume breath (15 ml/kg body weight) was compared to simultaneous measurements of PaCO2 in 6 dogs with normal lungs who were receiving high-frequency jet ventilation (HFJV). There was an excellent linear correlation between PetCO2 and the PaCO2 over the entire range of CO2 tensions commonly encountered in clinical practice (PetCO2 = 0.9 PaCO2 + 2.2 torr; n = 51, r = .98, p less than .001, range of PaCO2 = 12-72 torr). We conclude that when lung function is normal, a simple system of measuring PetCO2 after a large breath is an accurate method of monitoring the effectiveness of CO2 elimination during HFJV.

The measurement of extravascular lung water by a double-indicator dilution technique using cold indocyanine green dye was evaluated in dogs. Pulmonary edema was induced in 11 animals by volume overload; 12 animals served as controls. For each measurement, the two indicators (cold dye) were injected into the superior vena cava and detected in the femoral artery. The extravascular thermal volume was calculated using the mean transit times of the two indicator curves. Pretermination measurements of extravascular thermal volume correlated closely with standard gravimetric analysis of pulmonary extravascular tissue weight (EVTV - 1.15 PEW + 2.1 ml/kg, n = 21, r = 0.97, P less than 0.001; where EVTV = extravascular thermal volume and PEW = pulmonary extravascular tissue weight). Throughout the experiment, the arterial oxygen tension and alveolar-arterial oxygen tension gradient, correlated poorly with EVTV (linear correlation: r = 0.47, 0.45, respectively). The intrapulmonary shunt correlated better with EVTV (r = 0.72). Nonlinear correlation of EVTV with intravascular pressures (left ventricular filling pressures, colloid oncotic pressures, and the pulmonary artery occlusion pressure-colloid oncotic pressure gradient) were more significant than linear relationships. The critical pressures at which lung water rapidly increased in this model occurred at left ventricular filling pressures of 22-27 mmHg and at pulmonary artery occlusion pressure-colloid oncotic pressure gradients of 25-30 mmHg. The thermal dye technique appears to provide an accurate measurement of lung water changes in this pressure edema model.

Colloid oncotic pressure (COP), pulmonary artery wedge pressure (WP), and the COP-WP gradient were measured in seven critically ill adult patients and compared with extravascular lung water determined using the thermal-dye double-indicator dilution technique and a bedside lung water computer. Correlation coefficients for changes in extravascular lung water vs. COP, WP, and COP-WP were not significant, and in this patient population the COP-WP gradient did not predict changes in extravascular lung water.

New techniques for determining the hematocrit (Hct) and oxygen saturation (SO2) of whole blood from backscattered light measurements are described. First, theoretical and experimental results are presented which show that the empirical linear relationship between SO2 and the infrared-red backscattered light intensity ratio on which previous instruments have been based is an inadequate description primarily because it does not account for the strong effects of Hct and transducer geometry. Then it is shown that the ratio of backscattered intensities from two appropriately positioned infrared sources can be plotted against the infrared-red intensity ratio to produce a family of calibration curves from which SO2 and Hct can be independently determined. Finally, a practical implementation of an oximetry system which employs a microelectronic catheter-tip optical sensor and a microprocessor-based signal processor is proposed.

The effect of preserving the heart and lungs with hypothermia and Collins solution was studied in 13 mongrel dogs undergoing combined heart-lung transplantation. The five control animals who underwent an immediate transplant following Collins solution perfusion had small increases in extravascular lung water when measured 2.5 hours posttransplant as seen in a previous study. The eight animals who had hypothermic preservation following Collins solution perfusion had significantly higher extravascular lung water than controls (16.3 +/- 1.8 ml/kg in preserved animals; 11.2 +/- 1.7 ml/kg in controls p less than 0.05). The level of lung water reached at 2.5 hours postoperatively was similar to that reached with a previously reported, unacceptable preservation technique. Survival beyond this point was poor due to severe pulmonary edema. We conclude that the use of this solution, given under the experimental conditions which we describe, is not acceptable for hypothermic preservation of the heart and lungs for combined transplantation.

The diagnosis of pulmonary edema is frequently made from characteristic findings on the chest roentgenogram that suggest an increase in lung water. Optimal radiographic technique depends on a cooperative upright patient, which is not possible with most critically ill patients. These patients may also have multiple radiographic abnormalities that make interpretation of the chest roentgenogram difficult. The ability of portable chest roentgenograms to accurately identify the presence of excess lung water and monitor changes in lung water has not previously been evaluated in critically ill adults who are intubated and ventilated and in the supine position when the films are exposed. In 12 patients the pulmonary edema seen on portable chest roentgenograms was given a score (0 to 390 points), which was then compared with a determination of extravascular lung water using the thermal-dye indicator dilution technique. A linear correlation was observed (r = 0.51; p less than 0.05; n = 73). Evaluation of a change in radiographic score vs a change in lung water showed no linear correlation (r = 0.1; p greater than 0.05). While portable chest roentgenograms exposed under the conditions described were a useful technique for demonstrating pulmonary edema, they were not accurate in monitoring modest changes in lung water in critically ill patients.

A case of poisoning with a new organophosphate (fenthion) is reported in which the initial cholinergic crisis was delayed 5 days and recurred 24 days after ingestion. Psychosis was a persistent and sometimes singular manifestation. Because of the high lipid solubility of this pesticide, toxin analysis of repeated fat biopsies was an essential component of the management of this patient.

The measurement of lung water by the thermal-dye double indicator dilution technique was evaluated in dogs with normal and edematous lungs during a state of reduced cardiac output. The technique used cold indocyanine green dye to measure extravascular thermal volume (EVTV) as an estimate of extravascular lung water (EVLW). Anesthesia was maintained with pentobarbital. In 15 of 21 animals, pulmonary edema was first induced with oleic acid (0.75 to 0.18 ml/kg). Cardiac output (CO) was then decreased by a combination of propranolol and slow exsanguination (mean CO reduction to 36% of baseline). Extravascular lung water produced in this model ranged from 1.4 to 30.2 ml/kg. Predetermination measurements of EVTV correlated closely with EVLW as determined by gravimetric analysis (EVTV = 1.1 EVLW + 4.7 ml/kg, n = 21, r = 0.93, P less than 0.001). Thermodilution cardiac output measured in the abdominal aorta (used in the calculation of the EVTV) correlated well with simultaneous measurements of cardiac output by both indocyanine green dye dilution and pulmonary artery thermodilution (r = 0.86 and r = 0.88, respectively, pretermination). The thermal-dye technique appears to provide an accurate reflection of lung water in normal and edematous lungs, even in the presence of a low cardiac output.

The effects of prostaglandin E1 (PGE1) on the adult respiratory distress syndrome were studied in the septic primate (Macaca fascicularis). A 30-min infusion of Escherichia coli (1 X 10(10)/kg) resulted in severe septic shock and adult respiratory distress syndrome. Primates, if living, were killed 4 h after completion of the E. coli infusion. Three groups of primates were studied (n = 4 in each group). The control group (Group 1) received PGE1 at 100 ng/kg/min throughout the experiment. The septic group (Group 2) received a 30-min infusion of E. coli. The treatment group (Group 3) received a continuous PGE1 infusion (100 ng/kg/min) along with the E. coli infusion which was begun 30 min after the PGE1 infusion was started. Control primates had hemodynamic changes consistent with the vasodilatory effect of PGE1 (heart rate and cardiac output increased; blood pressure and systemic vascular resistance (SVR) decreased). All control animals survived the experiment and had no evidence of pulmonary damage. Primates given E. coli developed severe hypotension, decreased SVR, and lung injury evidenced by pulmonary edema, decreased oxygenation, and increased extravascular lung water. Primates treated with both PGE1 and E. coli developed similar cardiovascular and pulmonary changes as the septic group. There was no statistically significant difference between Group 2 and Group 3 animals with regard to mean arterial blood pressure, SVR, extravascular lung water, alveolar-arterial oxygen difference, or survival.(ABSTRACT TRUNCATED AT 250 WORDS)

A 14-year-old boy with a retrohepatic para-aortic pheochromocytoma demonstrates the potential difficulties of localization in an unusual extra-adrenal site of pheochromocytoma. Ultrasonography, computed tomography, metaiodobenzylguanidine scanning, and angiography with venous sampling failed to define the true anatomic location of this tumor. Collateral venous drainage produced confusing venous sampling data and represents a potential pitfall in the interpretation of these studies.

Nasal continuous positive airway pressure (CPAP) has been widely and safely used in the treatment of sleep disorders but has not been previously utilized for therapy of pulmonary atelectasis in adults. We observed three patients with significant atelectasis which was refractory to conventional chest physiotherapy. Bronchoscopy was not a viable therapeutic option in any patient. Therapy with continuous nasal CPAP was initiated at 10 to 15 cm H2O. The patients tolerated the therapy well and had prompt resolution of atelectasis. Nasal CPAP may be an effective modality for therapy of pulmonary atelectasis in spontaneously breathing patients, particularly when conventional therapies are not tolerated or are ineffectual.

The effect of hypothermic preservation of the heart and lungs with a crystalloid solution was evaluated in 12 mongrel dogs receiving heart-lung allografts. Six animals served as controls and received an immediate heart-lung transplant. Six animals were in the experimental group and received a heart-lung transplant after 5 hours of preservation at 4 degrees C following perfusion of both organs with a crystalloid solution. Physiological function of the heart and lungs was studied for 20 hours after transplantation. While cardiac function was minimally depressed following preservation, pulmonary function testing demonstrated significantly greater increases in extravascular lung water in experimental animals, suggesting that an ischemic lung injury occurred with this preservation technique. The model allows for future evaluation of other methods of combined preservation of both the heart and lungs for transplantation.

The effects of resuscitation with crystalloid and colloid solutions in the presence of increased pulmonary capillary permeability were studied. Twenty-four hours after oleic acid administration, dogs were anesthetized and bled to produce hemorrhagic shock. One hour later, resuscitation was performed with saline, 5% albumin, or 6% hydroxyethyl starch solution to restore and then maintain cardiac output at pre-oleic acid values for 6 h. Dogs were recovered and, 24 h later, were reanesthetized for final measurements. Oleic acid administration resulted in increases in pulmonary artery pressure, pulmonary vascular resistance, and extravascular lung water (EVLW). Resuscitation from hemorrhagic shock restored pulmonary hemodynamics to pre-hemorrhage levels and did not affect EVLW, PaO2, shunt fraction, dead-space-to-tidal-volume ratio, or pulmonary compliance. There were no differences in these parameters related to the choice of resuscitation fluid. Saline resuscitation markedly reduced plasma oncotic pressure and the plasma oncotic-pulmonary artery occlusion pressure gradient. Values for these two variables were markedly lower with saline than with colloid resuscitation. The authors conclude that the pulmonary effects of crystalloid and colloid solutions are similar in the presence of moderate increases in pulmonary capillary permeability.

The thermal dye double indicator dilution technique for estimating lung water was compared with gravimetric analyses in nine human subjects who were organ donors. As observed in animal studies, the thermal dye measurement of extravascular thermal volume (EVTV) consistently overestimated gravimetric extravascular lung water (EVLW), the mean (SEM) difference being 3.43 (0.59) ml/kg. In eight of the nine subjects the EVTV -3.43 ml/kg would yield an estimate of EVLW that would be from 3.23 ml/kg under to 3.37 ml/kg over the actual value EVLW at the 95% confidence limits. Reproducibility, assessed with the standard error of the mean percentage, suggested that a 15% change in EVTV can be reliably detected with repeated measurements. One subject was excluded from analysis because the EVTV measurement grossly underestimated its actual EVLW. This error was associated with regional injury observed on gross examination of the lung. Experimental and clinical evidence suggest that the thermal dye measurement provides a reliable estimate of lung water in diffuse pulmonary oedema states.

After heart-lung transplantation in primates, cardiopulmonary reflexes were tested and shown to be present. The Hering-Breuer and cough reflexes were tested, as well as responses to an inhaled respiratory stimulant, vasodilator, and an intravenous anticholinesterase and antimuscarinic agent. Recovery of these responses, except to the anticholinesterase agent, suggests that reinervation occurs in autotransplanted organs in primates. The Hering-Breuer reflex was present at 1.9 and 2.2 months after the operation in two animals subjected to autotransplantation. These cardiopulmonary reflex responses were also demonstrated in two allograft recipients studied at 15 and 16.9 months after the operation. Return of protective reflexes such as coughing may be an important mechanism to prevent aspiration pneumonitis and other complications in humans.

Monitoring of the effectiveness of ventilation is a significant problem during high-frequency ventilation (HFV). The time necessary to achieve equilibrium of the arterial tension of carbon dioxide (Paco2) following step changes in ventilation is appreciable, because of large body stores of CO2. Waiting for Paco2 to reach equilibrium is not only time-consuming but a potentially dangerous means of monitoring ventilator adjustments during HFV. Five kittens of mean +/- SD 1,082 +/- 383 gm weight were studied during HFV, both with normal lungs and lungs injured by saline lavage-induced surfactant depletion. The transcutaneous tension of carbon dioxide (Ptcco2) was monitored continuously to determine the time required to achieve equilibrium of Paco2 following a step change in ventilation. The rate of pulmonary CO2 elimination (VECO2) was measured immediately before and immediately after (less than 12 sec) step changes in ventilation and was used to predict the change in Paco2 achieved once equilibrium was reestablished. With normal lungs, equilibration time following step changes in ventilation was found to be approximately 20 minutes. After step decreases in ventilation of the injured lung, achieving equilibrium state took significantly longer, approximately 30 minutes. The Paco2 predicted was significantly related to the change in Paco2 achieved at equilibrium for both normal and injured lung studies. We concluded that direct monitoring of VECO2 during HFV may be a useful clinical monitoring technique, allowing rapid and accurate assessment of the efficiency of ventilation following step changes in ventilation and potentially assisting in optimizing ventilator settings.

Interhospital transport of the critically ill patient involves maintaining the same quality of care that was present before transport. This requires planning for equipment, space, and personnel needs during transport, and instituting adequate pathophysiologically based treatment and stabilization prior to transport. Under such conditions, transport can be safely accomplished and have a positive impact on patient care.

The peptide leukotrienes have been detected in animals that have received endotoxin injections and also have been associated with patients suffering from the adult respiratory distress syndrome (ARDS). The ability of leukotriene D4 (LTD4) to cause pulmonary capillary permeability changes was investigated in ten anesthetized mongrel dogs. Four dogs were used as controls and six dogs received intravenous LTD4 (0.25 microgram/kg). There was a variable response in that two treated animals showed no apparent effect of LTD4. Analysis of the results from the remaining four treated animals demonstrated a significant increase in extravascular lung water (EVLW) that peaked 3 hr after LTD4 from 5.4 +/- 0.6 to 10.3 +/- 0.5 ml/kg (P less than .01). In these four dogs, EVLW increased before slight, but statistically significant, rises in pulmonary artery wedge pressure (4 +/- 1 to 9 +/- 1 mm Hg, P less than .01) and mean pulmonary artery pressure (13 +/- 1 to 17 +/- 1 mm Hg, P less than .01) occurred. During the same period, cardiac output decreased 56 +/- 7% (P less than .01), but no change in airway resistance was observed. This study is the first in vivo demonstration that LTD4 directly alters pulmonary fluid balance in the dog. We conclude LTD4 can cause increases in EVLW and may be an important mediator of the permeability changes observed in various clinical events that lead to the adult respiratory distress syndrome.

The effect of graded application of positive end-expiratory pressure (PEEP) was studied in 10 mongrel dogs with pulmonary edema induced by oleic acid infusion. Six animals received progressive increases in PEEP (5 cm H2O) 120 min after the injection of oleic acid. These animals were compared to 4 control animals who did not receive PEEP. We found no difference between the 2 groups in lung water measured by a double indicator dilution technique during PEEP application. Lung water determined by gravimetric analysis was also not different between groups at the end of the experiment. PEEP did result in significant reductions in shunt fraction and alveolar-arterial oxygen tension difference suggesting that PEEP improves gas exchange in pulmonary edema by increasing lung volume, but not by altering lung water accumulation.

Thermodilution cardiac output measurements are commonly employed in the management of critically ill patients. Serial measurements often show significant variation, and poor reproducibility limits their clinical utility. There are no clinical studies revealing when to perform thermodilution cardiac output measurements in relation to the respiratory cycle. We prospectively studied 32 patients in a randomized scheme comparing three thermodilution cardiac output measurements at peak-inspiration, at end-exhalation, or randomly in spontaneously breathing and mechanically ventilated patients. Saline injections initiated at peak-inspiration or end-exhalation resulted in cardiac output measurements with much smaller standard deviations than those seen with random injections. Thermodilution cardiac output measurements performed at random times in the respiratory cycle should be avoided, and we recommend initiating these measurements at end-exhalation.

The anaesthetic records of 261 heart transplant recipients were reviewed. Data collected included demographic characteristics, physical status, results of preoperative cardiac catheterization studies, anaesthetics agents and incidences of complications which may have been related to anaesthetic management. Forty-five patients received a volatile agent (methoxyflurane 31, enflurane 10, halothane 4) and 216 patients were anaesthetized with a high-dose narcotic technique (morphine 122, fentanyl 71, hydromorphone 14, meperidine 9). Hypotension and arrhythmias were correlated with use of volatile and narcotic anaesthetics, respectively. No mortality was associated with anaesthetic management.

A clinical study was performed in two phases to determine whether pulmonary artery oximeter catheters that were impregnated or bonded with heparin would affect the accuracy of measurements of in vivo mixed venous oxygen saturation (Sv-O2). In phase 1, 40 patients were catheterized with either a heparin-impregnated or a plain pulmonary artery catheter. Blood was sampled at random times to correlate in vivo with in vitro Sv-O2 measurements. In phase 2, 16 patients who were not receiving systemic heparin therapy or aspirin and who had no coagulopathies were catheterized with either a heparin-bonded or a plain pulmonary artery catheter in a blinded order. In phase 1, a total of 364 blood samples were obtained from 40 patients. Linear regression analysis of the pooled data demonstrated y = 0.98x - 0.01, r = 0.93, P less than 0.001, and n = 141 with heparin-impregnated catheters; and y = 0.87x + 8.0, r = 0.81, P less than 0.001, and n = 223 with plain catheters. The mean difference (in vivo minus in vitro) revealed a similar error (-1.3 +/- 0.4 versus -1.4 +/- 0.4, respectively, mean +/- SE). The 95% confidence limits of an individual value (+/- 8.1 versus +/- 12.3) suggested slightly greater accuracy with heparin-impregnated catheters. In phase 2, a total of 134 blood samples were obtained from 16 patients. Linear regression analysis showed nearly equal performance with heparin-bonded and plain catheters (r = 0.97 versus r = 0.98, respectively) with similar slopes (1.0 versus 1.1, respectively) but different intercepts (-0.6 versus -8.4, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)