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Transfusion associated-graft versus host disease (TA-GVHD) is a rare complication of blood transfusion. It carries a very high mortality rate. Although the phenomenon has been well described in immunocompromised patients, this review focuses on the immunocompetent host. Cases of TA-GVHD continue to be reported following a variety of surgical procedures, especially cardiac procedures requiring cardiopulmonary bypass. Additional risk factors for TA-GVHD include blood component transfusion in populations with limited genetic diversity, the use of directed donations from family members, and the transfusion of fresh blood. As there is no effective treatment, the focus is on prevention.

There is strong, recent, convincing evidence that delirium, immobility, sedation, and ventilator management are closely interrelated. The purpose of this study was to evaluate the efficacy and safety of the ABCDE bundle in critically-ill patients receiving mechanical ventilation. We hypothesized that implementation of the ABCDE bundle would result in improved patient outcomes. This prospective, cohort, before-after study was conducted at a large, tertiary medical center located in the Midwestern United States. Subjects were recruited from 5 adult intensive care units (ICUs), 1 progressive care unit, and another unit that cared for critically-ill immunocompromised patients. A total of 186 (93 pre- and 94 post-ABCDE bundle implementation) mechanically ventilated patients were included in this analysis. The primary endpoint, defined a priori, was ventilator free days. Baseline characteristics including age, APACHE II score, Charlson Comorbidity Score, and sedative drug use prior to enrollment were similar between the two groups. After ABCDE bundle implementation, patients were more likely to receive a spontaneous awakening trial [Pre N=35 (53%) vs. Post N=42 (71.2%); p=0.0372], a spontaneous breathing trial [Pre N=65 (70.7%) vs. Post N=79 (84%); p=0.0290], and get out of bed at least once during their ICU stay [N=44 (47.3%) vs. Post N=57 (60.6%); p-0.0675]. Patients in the post ABCDE bundle group spent more days breathing without ventilator assistance than those in the pre group [24 days vs. 21 days; p=0.0371]. Patients treated with the ABCDE bundle were less likely to experience delirium [Pre N=70 (75.3%) vs. Post N=62 (66.0%); p=0.1623] and spent significantly fewer days delirious [Pre N=2 (1, 5) vs. Post N=1 (0, 3); p=0.00437]. No significant differences in the time to ICU or hospital discharge, incidence or duration of coma, or change in residence were noted between groups. ICU mortality was higher in the pre (N=24, 25.8%) vs. post (N= 14 14.9%) group (p=0.0913). Six subjects (6.5%) in the pre- and 5 (5.3%) in the post ABCDE bundle period self-extubated (p=0.7421). The number of subjects who self-extubated who later required reintubation did not differ between groups [Pre N=1 (1.1%) vs. Post N=1 (1.1%); p=0.9999]. Our results suggest patients treated with the ABCDE bundle experience more days breathing without assistance and a shorter duration of ICU delirium. Adoption of this interprofessional, multicomponent bundle into everyday clinical care is warranted.

Background Trauma centers are closing at an alarming rate, but the need for trauma care persists. This article shows the sustainability and feasibility of a joint trauma system whereby 2 university-affiliated hospitals function as a single trauma center system in a moderate-sized city. Methods Since 1994, 3 days per week, trauma patients are transported by emergency medical services (EMS) to hospital A. The other 4 days they are transported to hospital B. Trauma registry data from 1994 to 2008 were analyzed. Cost data were also examined. Results The joint system admitted 28,338 trauma patients. On each center's nontrauma days, trauma team activation was required infrequently. The 2 centers share costs; they perform joint outreach, educational training, and quality control. The joint trauma system has been sustained since 1994. Conclusions Two hospitals functioning as a single trauma center system is a viable model of care for injured patients in a moderate-sized city with mostly blunt trauma.

Background The literature reports a wide variation in the incidence of venous thromboembolic (VTE) disease in trauma patients. The performance of routine surveillance venous duplex ultrasound of bilateral lower extremities is controversial. Furthermore, recent examinations of the national trauma databank registry have suggested that routine duplex surveillance is associated with higher deep venous thrombosis (DVT) detection rates. Materials and Methods We examined the incidence and risk factors for VTE disease in 2827 trauma patients admitted over a 2-y period to a state-verified level I trauma center. Detailed chart review was carried out for patients with VTE disease. We then evaluated the effects of a routine bilateral lower extremity duplex surveillance guideline on VTE detection in the subset of injury patients admitted to the trauma service. Results We found an approximately 2% incidence of venous thromboembolic disease in a mostly blunt trauma population. Amongst patients with VTE disease, the most common risk factors were obesity and significant head injury. We then evaluated the 998 patients with injury who were admitted to the trauma service 1 y before and after surveillance guideline implementation. Despite a nearly 5-fold increase in the number of duplex scans, with a substantial increase in cost, we found no significant difference in the incidence of DVT. Conclusions Our preliminary data argue against the use of routine duplex surveillance of lower extremities for DVT in trauma patients. A larger, prospective analysis is necessary to confirm these findings.

The purpose of the study was to determine whether applying highly recommended changes in the 2005 American Heart Association (AHA) Guidelines would improve outcomes after out-of-hospital cardiac arrest.In 2005, AHA recommended multiple ways to improve circulation during cardiopulmonary resuscitation (CPR).Conglomerate quality assurance data were analyzed during prospective implementation of the 2005 AHA Guidelines in five emergency medical services (EMS) systems. All EMS personnel were trained in the key new aspects of the 2005 AHA Guidelines, including use of an impedance threshold device. The primary outcome was survival to hospital discharge. Secondary outcomes were return of spontaneous circulation (ROSC), survival by initial cardiac arrest rhythm, and the cerebral performance category (CPC) score at hospital discharge.There were 1,605 patients in the intervention group and 1,641 patients in the control group. Demographics, the rate of bystander CPR, and time from the 911 call for help to arrival of EMS personnel were similar between groups. Survival to hospital discharge was 10.1% in the control group versus 13.1% in the intervention group (P = .007). For patients with a presenting rhythm of ventricular fibrillation/ventricular tachycardia, survival to discharge was 20% in controls versus 32.3% in the intervention group (P.001). Survival to discharge with a CPC classification of 1 or 2 was 33.3% (10/30) in the control versus 59.6% (31/52) in the intervention group (P = .038).Compared with controls, patients with out-of-hospital cardiac arrest treated with a renewed emphasis on improved circulation during CPR had significantly higher neurologically intact hospital discharge rates.

Objective: The purpose of this study is to: 1) describe a newly discovered mechanism of blood flow to the brain during cardiopulmonary resuscitation using the impedance threshold device in a piglet model of cardiac arrest, and 2) describe the survival benefits in humans of applying all of the highly recommended changes in the 2005 guidelines related to increasing circulation during cardiopulmonary resuscitation, including use of the impedance threshold device, from six emergency medical services systems in the United States. Design: Animal studies prospective trial with each piglet serving as its own control. Historical controls were used for the human studies. Subjects: Piglets and patients with out-of-hospital cardiac arrest. Interventions: Piglets (10-12 kg) were treated with an active (n = 9) or sham (n = 9) impedance threshold device after 6 mins of ventricular fibrillation. Humans were treated with cardiopulmonary resuscitation per the American Heart Association 2005 guidelines and the impedance threshold device. Measurements and Main Results: Animals: The primary endpoint in the piglet study was carotid blood flow which increased from 59 mL/min without an impedance threshold device to 91 mL/min (p = 0.017) with impedance threshold device use. Airway pressures during the chest recoil phase decreased from -0.46 mm Hg to -2.59 mm Hg (p = 0.0006) with the active impedance threshold device. Intracranial pressure decreased more rapidly and to a greater degree during the decompression phase of cardiopulmonary resuscitation with the active impedance threshold device. Humans: Conglomerate quality assurance data were analyzed from six emergency medical services systems in the United States serving a population of 3 million people. There were 920 patients treated for cardiac arrest after implementation of the 2005 American Heart Association guidelines, including impedance threshold device use, and 1750 patients in the control group during the year before implementation. Demographics were similar between the two groups. Survival to hospital discharge was 9.3% in the control group versus 13.6% in the intervention group. The odds ratio, 95% confidence interval, and p value were 1.54 (1.19-1.99) and p = 0.0008, respectively. This survival advantage was conferred to patients with a presenting cardiac arrest rhythm of ventricular fibrillation (28.5% vs. 18.0%, p = 0.0008). Conclusions: Use of the impedance threshold device in piglets increased carotid blood flow and coronary and cerebral perfusion pressures and reduced intracranial pressure during the decompression phase of cardiopulmonary resuscitation at a faster rate than controls, resulting in a longer duration of time when intracranial pressures are at their nadir. Patients in six emergency medical services systems treated with the impedance threshold device together with the renewed emphasis on more compressions, fewer ventilations, and complete chest wall recoil had a nearly 50% increase in survival rates after out-of-hospital cardiac arrest compared with historical controls.

The debilitating and persistent effects of ICU-acquired delirium and weakness warrant testing of prevention strategies. The purpose of this study was to evaluate the effectiveness and safety of implementing the Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle into everyday practice.Eighteen-month, prospective, cohort, before-after study conducted between November 2010 and May 2012.Five adult ICUs, one step-down unit, and one oncology/hematology special care unit located in a 624-bed tertiary medical center.Two hundred ninety-six patients (146 prebundle and 150 postbundle implementation), who are 19 years old or older, managed by the institutions' medical or surgical critical care service.Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle.For mechanically ventilated patients (n = 187), we examined the association between bundle implementation and ventilator-free days. For all patients, we used regression models to quantify the relationship between Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle implementation and the prevalence/duration of delirium and coma, early mobilization, mortality, time to discharge, and change in residence. Safety outcomes and bundle adherence were monitored. Patients in the postimplementation period spent three more days breathing without mechanical assistance than did those in the preimplementation period (median [interquartile range], 24 [7-26] vs 21 [0-25]; p = 0.04). After adjusting for age, sex, severity of illness, comorbidity, and mechanical ventilation status, patients managed with the Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle experienced a near halving of the odds of delirium (odds ratio, 0.55; 95% CI, 0.33-0.93; p = 0.03) and increased odds of mobilizing out of bed at least once during an ICU stay (odds ratio, 2.11; 95% CI, 1.29-3.45; p = 0.003). No significant differences were noted in self-extubation or reintubation rates.Critically ill patients managed with the Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle spent three more days breathing without assistance, experienced less delirium, and were more likely to be mobilized during their ICU stay than patients treated with usual care.

Background As alcohol use is highly prevalent in trauma patients, we hypothesized that a significant proportion of hospitalized trauma patients would demonstrate alcohol withdrawal (AW). Methods The trauma registries at a joint trauma center system from 1999 to 2008 were evaluated for patients aged at least 16 years. Results Of 19,369 trauma admissions, 159 patients had AW. Blood alcohol concentration (BAC) testing was performed in 31.5% of the patients. BAC was significantly higher in AW patients versus other traumas (205.7 ± 130.1 vs 102.9 ± 121.7 mg/dL). BAC was 0 in 14.4% of AW patients. As compared with other trauma patients, patients with AW had a significantly greater age (50.2 vs 42.1 years), hospital length of stay (10 vs 3 days), intensive care unit length of stay (2 vs 0 days), need for mechanical ventilation (34% vs 12.7%), and pneumonia (12% vs 2.3%). AW patients were less frequently discharged to home (59.8% vs 69.9%). Mortality was not different. Conclusions AW was diagnosed in few patients. Of note, it occurred in patients with an initial BAC of 0. AW is associated with adverse outcomes.

Farm machinery is a major source of injury. The objective of this study is to characterize the incidence, injury characteristics, and outcomes of patients admitted with farm machinery injuries (FMIs) to an urban joint trauma system in a rural state. A retrospective 15-year review of the trauma registries of the two trauma centers that function as a single state-designated Level I joint trauma center system was conducted. There were 65 admissions for FMIs at hospital A and 41 at hospital B; this represents under 0.4% of total trauma admissions. The patients ranged in age from 2 to 87 years. At hospital A, 89% of admitted patients sustained extremity injuries, 16% sustained torso trauma, 92% required surgical intervention, and the mortality rate was 0%. At hospital B, 60% of admitted patients sustained extremity injuries, 36.6% of patients sustained torso trauma, 63% required surgical intervention, and the mortality rate was 14.6%. Tractor-related injuries were responsible for 17% of admissions at hospital A and 69% at hospital B. Of the six fatalities, five were tractor related. The data demonstrate that FMIs affect people in nearly all decades of life. FMIs at the two hospitals had differing injury characteristics and outcomes, in large part secondary to the differing frequency of tractor-related injuries. FMIs frequently required surgical intervention.

Single lung inhalation injury causes tissue damage to the contralateral lung. We therefore examined airway blood flow after smoke inhalation in chronic instrumented sheep to get further information about the underlying pathophysiology. The right lung and lower trachea of 5 animals were smoke-exposed, while their left lung was air-insufflated using a split ventilation technique. Three animals, where both lungs were only air-insufflated, served as controls. Blood flow to the airway was measured using a labeled microsphere technique. All animals were studied for 24 h following smoke inhalation. Then they were sacrificed and their tissues harvested. The airway blood flow to the smoke-exposed lung was elevated 11-fold immediately after inhalation injury. The bronchial blood flow to the air insufflated lung became significantly elevated 24 h post-smoke, although to a lesser extent. The control animals did not show any changes of bronchial blood flow during the observation time. Damage to one lung can lead to pathophysiologic changes in the contralateral lung. This response appears to be mediated by hematogenous factors.

We evaluated regional blood flows in a hyperdynamic sepsis model and the reversal of increased flows by blockade of nitric oxide (NO) synthase. Seven awake sheep were continuously infused with Escherichia coli endotoxin [lipopolysaccharide (LPS), 10 ng.kg-1.min-1] for 48 h. The NO synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME, 25 mg/kg) was injected after 24 h. Blood flows to systemic organs were determined with the radioactive microsphere technique. LPS induced elevation of cardiac index by 36% (P < 0.05) and a fall in systemic vascular resistance index by 37% (P < 0.05) at 0 h [time of L-NAME administration, 24 h after infusion of LPS had begun] L-NAME administration normalized cardiac index [6.1 +/- 0.5 at 4 h posttreatment, 6.1 +/- 0.5 l.min-1.m-2 at -24 h (baseline)] and systemic vascular resistance index (1,333 +/- 105 at 4 h posttreatment, 1,280 +/- 163 dyn.s.cm-5.m2 at -24 h) and reduced all regional blood flows to near-baseline levels for the remainder of the study period (24 h). O2 consumption was unaffected by treatment.

Nutritive (systemic arterial) airway blood flow (mL/min/100 grams tissue) was studied in various size airways at four randomized levels of positive end expiratory pressure (PEEP) in smoke injured and normal lungs. Seven sheep were studied 24 hours after an isolated injury to the left lung using cotton smoke. Radioactive 15-microns microspheres were utilized to measure this airway blood flow. These data demonstrated a marked increase in systemic arterial blood flow to the airways in the injured left lung. Increasing levels of PEEP significantly reduced this hyperemic response. PEEP did not significantly affect the uninjured right lung. Systemic airway blood flow was never reduced to below normal control levels (uninjured) in either lung despite PEEP of up to 20 cm H2O. Severe reduction in airway nutritive flow, and the possibility of airway necrosis, does not appear to occur at PEEP levels of up to 20 cm H2O.

Splanchnic ischemia has been associated with bacterial translocation and increased endotoxin absorption from the gut. To study the effects of major burn on splanchnic circulation, minipigs were randomized to receive 40% flame burn and Parkland resuscitation or sham burn and maintenance fluids. Total and fractionated blood flow, O2 delivery and consumption, mucosal pH of the intestine, and endotoxin levels in the superior mesenteric vein were measured for 48 h, and then abdominal organs were harvested for bacteriological culture and histopathological analysis. Total mesenteric blood flow and fractionated blood flow to the mucosa-submucosa of the jejunum, cecum, and colon decreased 2 and 4 h postburn. Although mesenteric O2 consumption was unchanged, mesenteric O2 delivery and intestinal mucosal pH were decreased during the early postburn period. Concomitantly, endotoxin levels in the superior mesenteric vein were significantly elevated during the first 8 h postburn. The bacteriological cultures of the systemic tissue samples showed increased bacterial translocation in the burn group. After major burns, there is a transient selective splanchnic vasoconstriction, which is associated with intestinal mucosal acidosis and increased incidence of bacterial translocation and endotoxin absorption from the gut.

We have previously utilized the technique of transcranial Doppler (TCD) ultrasound to determine cerebral perfusion in patients undergoing cardiopulmonary resuscitation (CPR). In order to assess if TCD can reliably measure alterations in cerebral perfusion under conditions of normal and low cardiac outputs, we compared TCD measured blood flow velocities in the middle cerebral artery (MCA) of six piglets with radioactive microsphere determinations of total cerebral perfusion at baseline normal sinus rhythm (NSR), during CPR, and following return of spontaneous circulation (ROSC). Peak systolic and mean blood flow velocities were compared to the microsphere perfusion results on 15 different occasions; six during NSR, five during CPR, and four following ROSC. Although qualitative alterations in TCD measurements reflected changes in microsphere perfusion, we could not find a statistically significant correlation between either peak systolic or mean MCA blood flow velocities and microsphere perfusion measurements either overall or in any subgroup. The possible reasons which may explain the findings are discussed.

This study examined the difference between clinical impressions and autopsy findings in a group of patients dying on a university surgical service after blunt injury, penetrating injury, or thermal burns. Of 215 patients dying between the years 1984 and 1988, 212 were included in this study (autopsy rate, 98.6%). Major discrepancies in clinical diagnosis versus the anatomic diagnosis at autopsy were found to occur in approximately 30% of patients. The incidence of errors in diagnosis which may have impacted on survival in these groups of injured patients was quite low (5.1%). These data support the continued practice of obtaining autopsy in all patients dying from trauma. This information is clinically relevant, and, in today's atmosphere of quality assurance, absolutely necessary for a modern trauma center.

The rectilinear biphasic (RLB) waveform has been shown to effectively defibrillate short-duration ventricular fibrillation (VF) at significantly lower energies than a monophasic damped sine (MDS) waveform. This article reports RLB waveform defibrillation effectiveness for patients presenting in VF during out-of-hospital cardiac arrest when compared with historical MDS effectiveness.External RLB defibrillators were deployed in the Omaha Fire Department's emergency medical services (EMS) system. The RLB defibrillators delivered an escalating three-shock sequence of 120, 150, and 200 J. The results observed during the first year of full deployment were compared with the results observed during the previous year when only MDS defibrillators were deployed in the system. The MDS defibrillators delivered an escalating three-shock sequence of 200, 300, and 360 J. Defibrillation was defined as termination of VF for at least 5 seconds after a defibrillation shock.There were 141 adult patients presenting in VF without trauma during the first year using RLB defibrillators. By comparison, there were 153 adult patients during the comparable year using MDS defibrillators. The 120-J RLB shocks had a significantly higher first-shock rate of successful VF termination (67%, 95% CI: 59%-75%) compared with the initial 200-J MDS shocks (48%, 95% CI: 40%-57%, p0.0025; odds ratio 2.14 [1.33-3.42]). The number of patients who were defibrillated to a return of spontaneous circulation with a sinus rhythm was significantly greater (25%, 95% CI: 18%-33%) when using the RLB defibrillator compared with using the MDS defibrillator (15%, 95% CI: 10%-22%, p = 0.05; odds ratio 1.85 [1.04-3.31]).The RLB defibrillator terminated the VF of patients in out-of-hospital cardiac arrest with superior rates using significantly less energy compared with historical rates for a higher-energy MDS defibrillator.

This study evaluates the use of transcranial Doppler (TCD) ultrasound in assessing the changes experienced by the cerebral circulation during cardiopulmonary resuscitation (CPR) and compares it with measurements of internal carotid artery (ICA) flow rates (ultrasonic flow-meter measurements) and cerebral blood flow (CBF) (radioactive-microsphere measurements) in a porcine cardiac arrest model undergoing closed chest CPR.Sixteen piglets were anesthetized and subjected to TCD monitoring, ICA flow-rate measurements, and CBF measurements during CPR following induction of ventricular fibrillation. A total of 14 comparisons between TCD and CBF measurements, and 36 comparisons between TCD and ICA flow measurements were performed. Correlations were determined using Pearson's method, and the validity of the correlation was determined using Bonferoni's adjusted probabilities.The correlation between mean cerebral blood flow velocity and mean total ICA flow rate was 0.67 (P.01). The correlation between peak systolic blood flow velocity and CBF was 0.76 (P = .02).TCD can provide on-line information about cerebral perfusion during CPR.

OBJECTIVE: To investigate the effects of N omega-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthesis, on hemodynamics, gas exchange and oxygen transport in an ovine model of hyperdynamic sepsis. DESIGN: Prospective, nonrandomized, controlled study, with repeated measurements. SETTING: University research laboratory. SUBJECTS: Twenty healthy adult sheep (weighing 20 to 45 kg) were divided into two groups of 12 treated sheep and eight control sheep and studied. INTERVENTIONS: Twenty awake, chronically instrumented sheep received a continuous infusion of endotoxin (10 ng/kg/min) over 48 hrs. Twenty-four hours after the start of the endotoxin infusion, 12 sheep (treatment group) received a bolus of the nitric oxide synthesis inhibitor N omega-nitro-L-arginine methyl ester (25 mg/kg), while the other eight animals (control group) received the carrier (0.9% NaCl). MEASUREMENTS AND MAIN RESULTS: Twenty-four hours after the start of the endotoxin infusion, both groups exhibited a hyperdynamic state with increased cardiac indices, decreased systemic vascular resistance indices, impaired oxygenation, and increased pulmonary shunt fractions. In both groups, oxygen delivery was significantly increased, while oxygen consumption remained virtually unchanged, resulting in a decreased oxygen extraction ratio. In the control group, the significant alterations in systemic hemodynamics, lung function and oxygen transport persisted for the remainder of the study. Administration of N omega-nitro-L-arginine methyl ester normalized cardiac index and systemic vascular resistance index, increased mean arterial blood pressure, and decreased heart rate. Although oxygen delivery significantly decreased after administration of N omega-nitro-L-arginine methyl ester, oxygen consumption did not change, resulting in a normalization of oxygen extraction ratio. Despite a significant reduction of pulmonary shunt fraction, oxygenation did not improve. Pulmonary arterial pressure and pulmonary vascular resistance index showed a peak 2 hrs after administration of the nitric oxide synthesis inhibitor and then tended to decrease. In contrast, the effects of N omega-nitro-L-arginine methyl ester on the systemic circulation persisted for the remainder of the study. CONCLUSIONS: The data support the assumption that augmented nitric oxide production is a major cause of the hemodynamic alterations seen in hyperdynamic endotoxemia. Administration of the nitric oxide synthesis inhibitor N omega-nitro-L-arginine methyl ester normalized the endotoxin-induced hyperdynamic state, but did not impair oxygen consumption, indicating adequate tissue perfusion of metabolically active organs. Inhibition of nitric oxide synthesis may be a therapeutic option in the treatment of hyperdynamic septic patients when conventional therapy fails to maintain a minimum of cardiovascular performance.

Discrepancies exist between experimental measurements of the systemic blood flow to sheep lung by use of microsphere techniques and flow probes on the bronchial artery. In these studies, we simultaneously measured the blood flow through the bronchial artery, using a transit time flow probe, and the systemic blood flow to left lung, using radioactive microspheres. All measurements were made on conscious sheep previously prepared with chronic catheterizations of the left atrium, aorta, and vena cava and a flow probe around the bronchial artery. Inflatable occluder cuffs were placed around the pulmonary and bronchoesophageal arteries. Bronchial artery blood flow in six sheep was 25.3 +/- 5.2 ml/min or 0.4% of the cardiac output. Systemic blood flow to left lung, measured with microspheres, was 54.1 +/- 14.2 ml/min. Calculated systemic blood flow to that portion of sheep lung perfused by the bronchial artery was 127.6 +/- 35.3 ml/min or 1.9% of cardiac output. Occlusion of the bronchoesophageal artery reduced bronchial artery flow to near zero, whereas total systemic blood to the lung was reduced by only 55%. Blood flow to the intraparenchymal cartilaginous airways was reduced 60–90% after occlusion of the bronchoesophageal artery. Sheep, like most mammals, have multiple and complex systemic arterial inputs to the lungs. We conclude that multiple branches of the bronchoesophageal artery provide most but not all of the systemic blood flow to the intraparenchymal cartilaginous airways but that over one-half of the total systemic blood flow to sheep lung comes from sources other than the common bronchial artery.

Study objective: A number of studies have demonstrated a correlation between end-tidal carbon dioxide (ETco 2 ), cardiac output, and return of spontaneous circulation in experimental animals and in patients undergoing closed-chest CPR. Our study attempted to correlate ETco 2 to cerebral blood flow during cardiac arrest. Design: Sixteen piglets were anesthetized, intubated, and instrumented for cerebral blood flow studies. An ultrasonic flow probe was placed on both internal carotid arteries for continuous flow measurements. The animal was fibrillated, and closed-chest CPR was begun. Continuous ETc0 2 measurements were obtained and compared with simultaneous internal carotid, cardiac output, and cerebral blood flow measurements. Measurements and main results: Correlations between ETco 2 and carotid and cerebral blood flow were determined using Pearson's method. The correlation between ETco 2 and total internal carotid flow was .58 ( P = .01, Bonferroni's adjusted P = .30). Correlation between ETco 2 and cerebral blood flow was .64 ( P = .01, Bonferroni's adjusted P = .09). A partial correlation coefficient for ETco 2 versus cardiac output was .70, whereas it was only .30 for ETco 2 versus cerebral blood flow. Conclusion: Partial correlation coefficients suggest that ETco 2 correlates with cerebral blood flow when changes in cerebral blood flow parallel changes in cardiac output.

This study evaluates the impact of the autopsy on a general surgical training program from 1984 through 1988. We have retrospectively examined the charts of all patients who died during this period. Included in this analysis are the records of patients from the general, cardiac, pediatric, and transplant surgery departments during this 5-year period. In all, 628 patients were evaluated. The overall autopsy rate was 73%. The clinical impressions prior to death are correlated with the anatomic diagnoses found during autopsy. Significant diagnostic discrepancies (errors unrecognized and directly related to or associated with the cause of death) were determined. On a yearly basis, diagnostic discrepancies range between 23% to 39%. Gross and histologic examination of surgical patients reveals significant information concerning the cause of death. These data confirm the educational benefit of autopsy despite escalating utilization of sophisticated, noninvasive diagnostic modalities. It is our opinion that the mortality conference, with formal autopsy presentation, is a vital forum for the discussion of patient care and quality assurance issues. Autopsy remains the most specific indicator of errors in diagnosis, management, judgment, and technique in surgical practice today.

We investigated the contribution of the bronchial blood flow to the lung lymph flow (QL) and lung edema formation after inhalation injury in sheep (n = 18). The animals were equally divided into three groups and chronically prepared by implantation of cardiopulmonary catheters and a flow probe on the common bronchial artery. Groups 1 and 2 sheep were insufflated with 48 breaths of cotton smoke while group 3 received only room air. Just before injury, the bronchial artery of group 2 animals was occluded. The occlusion was maintained for the duration of the 24-h study period. At the end of the investigation, samples of lung were taken for determination of blood-free wet weight-to-dry weight ratio (W/D). Inhalation injury induced a sevenfold increase in QL in group 1 (7 +/- 1 to 50 +/- 9 ml/h; P less than 0.05) but only a threefold increase in group 2 (10 +/- 2 to 28 +/- 7 ml/h; P less than 0.05). The mean W/D value of group 1 animals was 23% higher than that of group 2 (5.1 +/- 0.4 vs. 3.9 +/- 0.2; P less than 0.05). Our data suggest that the bronchial circulation contributes to edema formation in the lung that is often seen after the acute lung injury with smoke inhalation.

The systemic blood flow to the airways of the left lung was determined by the radioactive microsphere technique before and 17 h after smoke inhalation in six conscious sheep (smoke group) and six sheep insufflated with air alone (sham group). Smoke inhalation caused a sixfold increase in systemic blood flow to the lower trachea (baseline 10.6 +/- 1.7 vs. injury 60.9 +/- 16.1 ml.min-1.100 g-1) and an 11- to 14-fold increase to the intrapulmonary central airways (baseline range 9.5 +/- 1.9 to 13.5 +/- 3.7 ml.min-1.100 g-1 vs. injury 104.6 +/- 32.2 to 187.3 +/- 83.6 ml.min-1.100 g-1). There was a trend for this hyperemic response to be greater as airway diameter decreased from the trachea to 2-mm-diam central airways. In airways smaller than 2 mm, the hyperemic response appeared to diminish. The total systemic blood flow to whole lung is predominantly to small peripheral airways and showed no significant increase from its baseline level of 17.5 +/- 3.7 ml.min-1.100 g-1 in the lung homogenate. Occlusion of the bronchoesophageal artery decreased central airway blood flow 60-80% and peripheral airway blood flow 40-60% in both the sham and the smoke groups.

It is still a common practice to continue unsuccessful field resuscitations in the emergency department (ED) even after prolonged estimated down times. The authors studied patients who arrested in the field and did not regain a pulse before their arrival in the ED to determine if any ever leave the hospital neurologically intact. All cardiac arrests in the urban St Louis area that were brought to our facility over a 2 1 2 - year period by advanced life support units (excluding all patients with hypothermia, drug overdose, near drowning, and traumatic cardiac arrest) were reviewed. Of 243 such patients 32 (13%) arrived with a pulse. Twenty-three of these patients were admitted and 10 discharged alive, 7 were neurologically intact. Out of 211 patients who arrived without a pulse, 24 (11%) developed a pulse with further resuscitative efforts in the ED. Eighteen of these patients were admitted but only one was discharged neurologically intact. The only survivor in the group without a pulse arrested while en route to the ED. It is concluded that cardiac arrest victims who arrive in the ED without a pulse on arrival or en route have almost no chance of functional recovery.

Percutaneous transtracheal ventilation using a large gauge intravenous-type catheter can be used successfully in the setting of complete upper airway obstruction in animals. In this study, using a large animal model, satisfactory oxygenation and ventilation was achieved by inversely varying the catheter size and the inspiration to expiration ratio (I:E). Specifically, 30 to 63 kg ruminants with an obstructed upper airway were resuscitated for 30 minutes from a hypoxic, hypercarbic, and acidotic state using 12- and 14-gauge catheters connected to a 50 psi oxygen source via a two-way valve with an I:E of 1:4 and 1:9 seconds, respectively. Shorter expiratory time or increased inspiratory time with these intravenous catheters resulted in significant hemodynamic compromise, barotrauma, inadequate carbon dioxide elimination, acidemia, and frequent death.

The effects of aspiration of saline and acid on lymph albumin and pulmonary albumin contents were studied. Two radiolabeled species of albumin were used, I 125 -albumin was allowed to equilibrate while 131 I-albumin was injected at Time 0 of the experiment. One percent of total injected albumin was found in the lung in the saline and control groups for both the equilibrated and non-equilibrated varieties of albumin. Seven percent of injected dose of 125 I-albumin (equilibrated) was found in the lung after acid aspiration, while 16% of the nonequilibrated 131 I-albumin was found. The rate of “wash in” of 131 I-albumin was significantly increased in the lymph of acid aspirated animals as compared to controls. These data suggest that the previously demonstrated increase in microvascular permeability after acid aspiration results in an increase in extravascular pulmonary albumin. This effect should greatly alter the local osmotic gradient and result in altered fluid balance.

An ovine anti-neutrophil antibody has been produced by immunizing rabbits with purified sheep neutrophils. Serial intraarterial infusions of anti-neutrophil antibody in awake instrumented sheep produced selective and profound neutropenia. Intravascular infusion of endotoxin ( Escherichia coli , 1.5 μg/kg/30 min) resulted in significant and equivalent increases in pulmonary artery pressure, peripheral vascular resistance, and protein-rich pulmonary lymph flow in an endotoxin group ( n = 9) and a depletion + endotoxin group ( n = 4). Changes in cardiopulmonary parameters were most pronounced 2 to 8 hr after endotoxin administration in both groups. Cardiac index (CI) showed a precipitous and transient fall in both experimental groups at 0.5 to 1 hr after endotoxin infusion; however, by 8 hr CI rose significantly in the endotoxin group, while it remained unchanged in the depletion + endotoxin group. A significant rise in the peripheral neutrophil count was associated with the increase in CI in the endotoxin group. Plasma and pulmonary lymph levels of thromboxane -B 2 were unchanged during the depletion period with a significant increase 1 hr after endotoxin infusion. In this study questions arise regarding the exclusive role of circulating neutrophils in the microvascular permeability changes seen in sepsis-mediated adult respiratory distress syndrome.

Previous reports have suggested that the ischemic kidney develops a compression syndrome due to intracapsular edema and that decapsulation may improve function. This report evaluates renal function in ischemic kidneys with and without decapsulation. Thirteen dogs underwent creation of a split urinary bladder and the formation of bilateral cystocutaneous fistulas for measurement of split renal function. After systemic heparinization the suprarenal aorta was crossclamped for 112 hr. One kidney underwent removal of the anterior aspect of the capsule and the other intact kidney served as the control. The animals received 1000 ml/24 hr, 0.15 N NaCl solution IV postoperatively. Urine volume, osmolarity, creatinine, and sodium were quantitated during three consecutive 24-hr periods. Seventy-two hours following the ischemic injury, the dogs were reexplored. Renal interstitial pressures were measured and renal biopsies and an intravenous pyelogram performed prior to sacrifice. Significantly greater urine volume was produced by the decapsulated kidney (302 ± 35 ml/24 hr) than by the nondecapsulated kidney (173 ± 39 ml/24 hr). Urine sodium excretion/24 hr was consistently greater from the decapsulated kidney than from the intact kidney while urine osmolarity at 72 hr from the decapsulated kidney was 584 ± 76 and from the intact kidney was 325 ± 76 mosmole/liter (P < 0.05). Renal interstitial pressures were significantly greater in the intact kidney than in the decapsulated kidney. These data suggest that release of intercapsular compression can improve renal function in the ischemic canine kidney.

Six hundred sixty-four patients who have had metabolic intestinal surgery for the treatment of morbid obesity are reviewed. Particular attention is directed to difference in weight loss, morbidity and mortality in end-to-side and end-to-end shunts, the former performed in 300 patients and the latter in 262 patients. Unsatisfactory weight loss was observed in 20% of patients with end-to-side shunts, while only 8% of patients with end-to-end shunts failed to lose a sufficient amount of weight. Morbidity and mortality were significantly increased in this latter group. This led to adoption of a modification of the end-to-side operation by developing a plication ?REVENT REFLUX. Our preliminary observation indicates that in 102 patients who have had this operation, similar weight loss is attained to that of end-to-end shunts with no greater morbidity or mortality than the end-to-side type.

We have attempted to determine the membrane parameters, permeability-surface area product (PS) and reflection coefficient (sigma), necessary to describe solute exchange in the pulmonary circulation. Experimental lymph-to-plasma ratios were obtained for total protein (Rtot) and albumin (Ralb) using lung lymph collected from goats with chronic lung lymph fistulae. Lymph flow (QL) and solute flow (QS) were varied by increasing microvascular pressure in a stepwise manner by inflating a balloon in the left atrium. The increased QL and decreased Ralb from multiple experiments in four goats were used to plot PS vs. sigma using the equation of Patlak et al. (J. Theor. Biol. 5: 426–442, 1963). The region of intersection of two or more such curves should identify the two membrane constants. However, these curves rarely intersected suggesting that perhaps the lung barrier was not adequately represented by a single homoporous membrane. To evaluate heteroporosity, the three-pore model of Blake and Staub (Microvasc. Res. 12: 197–220, 1976) was investigated. By use of their pore sizes and relative pore distributions, values for the fluid filtration coefficient, PS, and sigma of each pore type were calculated, and finally QL and R were predicted at various microvascular pressures. When these calculated values of QL and R were plotted using the equation of Patlak et al., an equivalent homoporous PS and sigma could still be found. Therefore, a heteroporous membrane does not appear to explain the failure of our data plots to intersect. Possible alternative models are suggested.

One hundred twenty-nine infants with esophageal atresia and tracheoesophageal fistula were reviewed from 1955 to 1978. The overall mortality was 38%. Factors associated with the increased mortality include prematurity, pneumonia, and congenital defects other than this anomaly. A classification based on these factors is introduced, which provides the clinician with a prognostic survival rate greater than 90% with only physical examination, chest and abdominal roentgenography, and intravenous pyelography. Postoperative mortality was reduced to 11% in the last five years of the study; this is attributed to the exclusive use of the retropleural approach to the esophagus, more intensive postoperative ventilatory support, and routine use of parenteral nutrition.

This study has demonstrated in an awake goat the differential effects of infusing low dose epinephrine and norepinephrine. Epinephrine increases pulmonary fluid exchange, possibly as a result of β stimulation to the heart; whereas norepinephrine results in little change in pulmonary fluid balance, primarily affecting vascular vasoreactivity. This study underscores the importance of testing drug responses in awake animal models.

A 20-year-old man injured in a motor vehicular accident sustained a nonpenetrating double blowout injury of the upper thoracic esophagus. A simultaneous membraneous rupture of the trachea occurred. Treatment was by operative primary closure. A collective review of blunt upper thoracic esophageal perforations reveals a nearly uniform occurrence of associated tracheal injury. Language: en

One hundred forty-four critically ill patients admitted to an intensive care setting were randomly assigned to cimetidine or antacid treatament groups. Gastric pH was monitored hourly. One hundred twenty-three (85%) patients demonstrated a fall in pH to less than 4 and were considered to require prophylaxis. Prophylaxis was considered adequate if the measured pH could then be maintained at greater than or equal to 4. Fifty-eight patients received antacids alone, the average requirement being 41 cc/hour. Sixty-five patients received cimetidine. Seventeen (26%) of the cimetidine prophylaxis patients failed to raise their pH and were than placed on hourly administration of antacid with successful elevations of pH to greater than or equal to 4 in all cases on an average supplementary dose of 53 cc/hour. Risk factors, including sepsis, hypotension, head injury, respiratory failure, degree of trauma, and age, were not statistically different in the two treated groups. Using these same criteria, responders to cimetidine could not be differentiated from nonresponders. All patients were protected from significant stress bleeding while on this study. Significant complications of either treatment were minimal. Antacids offered consistent protection against gastric acidity and were 100% effective. A routine schedule of 300 mg every six hours of cimetidine was effective in only 47% of patients, and the maximum dose of cimetidine was effective in only 74% of patients. Hourly measurement of intragastric pH is required for monitoring the response to prophylaxis of stress bleeding in severely ill patients.

The success of prophylactic digitalization in reducing the incidence of supraventricular tachyarrhythmias (SVT) was studied in 140 randomly grouped, consecutive patients undergoing myocardial revascularization operations. The test group received either 1 or 1.5 mg. of digoxin the day before operation and were maintained postoperatively on 0.25 mg. of digoxin daily. There was a significant increase (p

The sections in this article are: 1 Historical Background 2 Pressure-Volume Relationships 2.1 Excised Lungs 2.2 Liquid Filling 2.3 Temperature 2.4 Quantification 3 Rheological Properties 3.1 Hysteresis, Stress Adaptation, and Creep 3.2 Structural Basis 3.3 Rheological Models 4 Force-Bearing Structures 4.1 Airways and Vasculature 4.2 Pleura and Interlobular Septa 4.3 Alveolar Septa 5 Connective Tissue 5.1 Components 5.2 Collagen-Elastin Interactions 6 Interfacial Tension 6.1 Air-Liquid Interface 6.2 Estimation of Interfacial Tension From Pressure-Volume Curves 6.3 Direct Estimation of Interfacial Tension in Situ 6.4 Cell Medium Interfacial Tension 7 Contractile Elements 7.1 Airways 7.2 Alveolar Duct 7.3 Septa 7.4 Functional Implications 8 Postmortem Changes 8.1 Lung Tissue 8.2 Lung Surface 8.3 Airways 9 Nonuniformities of Ventilation 9.1 Synchrony of Ventilation 9.2 Gas Dilution

Previous studies have documented the efficacy of prophylaxis in the prevention of stress ulceration and bleeding in critically ill patients. In an effort to determine whether all critically ill patients require prophylaxis, 144 patients admitted to an intensive care unit were monitored by continuous indwelling nasogastric or gastrostomy tubes. Any patient with a measured gastric pH of less than 4 was treated with prophylactic cimetidine or antacids to maintain a pH of 4 or greater. One hundred twenty-three (85 percent) met this criterion. The gastric pH of 21 patients (15 percent) never fell below 4 during continuous monitoring for 26+/- 4.2 hours. There was a significantly lower incidence of hypotension and respiratory failure in this group ( pl < 0.05). Mortality was higher in the patients who required prophylaxis (15 percent) than in those who did not (0 percent). No bleeding was encountered in any patient in either group. These data suggest that patients who do not require prophylaxis may be determined by continuous monitoring of intragastric pH. If, within 24 hours, intragastric pH does not fall below 4, minimal indications for prophylaxis exist. Intragastric pH monitoring is a simple, effective tool in the care and management of critically ill or traumatized patients.

Background. Frozen section analysis of cyst wall has been advocated as standard of care prior to surgical drainage of pancreatic pseudocysts. Recent studies have indicated that frozen section may be unreliable. Our aim was to investigate the role and accuracy of frozen section analysis of the cyst wall in the operative management of pancreatic cystic lesions. Methods. A retrospective review was performed of 44 patients who underwent operation for a cystic lesion of the pancreas. Results. Of the 25 patients with a diagnosis of pseudocyst, 9 patients had frozen section intra-operatively. Eight frozen sections demonstrated pseudocyst, and correlated with final pathology. One frozen section demonstrated a true cyst. Twenty-three patients had a final diagnosis of pseudocyst. Nineteen patients had a diagnosis of cystic neoplasm, and six patients had frozen sections. Three frozen sections were consistent with cystic neoplasm and correlated with final pathology. Three frozen sections demonstrated characteristics of pseudocyst, two correlated with final pathology, and one showed cystic neoplasm on final pathology. Conclusion. Routine use of frozen section may not be necessary; however, frozen section is useful when the intra-operative appearance does not correlate with pre-operative diagnosis.

Hemostasis remains a major technical problem in surgery of the liver and spleen. A high power neodymium-doped yttrium aluminum garnet (Nd:YAG) laser has been coupled with a fiberoptic delivery system and quartz blade designed to yield maximal hemostasis and minimal tissue injury. In a series of experiments we were unable to demonstrate a significant advantage of its use in partial hepatic lobectomy.

Pure lung lymph has previously been obtained in awake sheep and goats via a cannula placed in an efferent duct of the caudal mediastinal lymph node (CMN). We describe a modification in goats wherein a segment of the thoracic duct collecting pulmonary efferents is isolated and cannulated. Lymph purity and responses to elevation of pulmonary microvascular pressure are illustrated and are found to be comparable to data obtained from a series of animals prepared by standard CMN cannulation. We have adopted the alternative procedure whenever, at cannulation may be complicated. When used in combination with the CMN approach, the overall rate of successful cannulation has increased from 50% to about 80%.