Injuries of the inferior vena cava.

Injuries of the IVC, whether caused by blunt or penetrating mechanisms, are usually fatal. Patients who arrive in shock and fail to respond to initial resuscitative measures, those who are still actively bleeding at the time of laparotomy, and those with wounds of the retrohepatic vena cava have a low probability of survival. Death most commonly is caused by intraoperative exsanguination. Knowledge of the anatomy and exposure techniques for the five different segments of the intra-abdominal vena cava is very important to trauma surgeons. Although some wounds of the vena cava, especially those of the retrohepatic vena cava, are best left unexplored, most injuries inferior to this level can be exposed and repaired by lateral suture technique. Preservation of a lumen of at least 25% of normal is probably important in the suprarenal vena cava but is of no provable value inferior to the renal veins. No evidence supports the need to expose and repair vena caval wounds that have spontaneously stopped bleeding. Such wounds, especially in the retrohepatic area, may be managed expectantly provided that there is no strong suspicion of an associated injury to a major artery or hollow viscus.

Portal vein injuries.

Wounds of the portal vein are caused most commonly by penetrating trauma and carry a very high mortality rate. Most deaths are caused by exsanguination, occurring intraoperatively as surgeons struggle to control the hemorrhage from the portal vein and associated vascular injuries. A thorough knowledge of the anatomy of the area and of the likely patterns of wounding is important. At surgery, surgeons must be prepared to deal with multiple vessel wounding. Although most investigators have advocated lateral repair of the portal vein when it can be accomplished, portal ligation seems to be a safe alternative. Complex repairs are justified only when a contraindication to ligation exists. Postoperative care must recognize the need for extraordinary fluid replacement and the small risk for postoperative bowel infarction after repair or ligation of the portal vein.

Blunt duodenal rupture: a 6-year statewide experience.

OBJECTIVES: To characterize the incidence, presentation, diagnostic features, injury pattern, and mortality of blunt duodenal rupture. METHODS: The records of 103,864 patients entered into a state-wide trauma registry during a 6-year period were screened for the diagnosis of blunt duodenal injury. The hospital records of all patients meeting diagnostic criteria of blunt duodenal rupture from 28 trauma centers were reviewed. RESULTS: Blunt duodenal injury was identified in 206 (0.2%) patients. Thirty (14.5%) of these had full-thickness rupture of the duodenum. Of these 30 patients, 21 had been involved in motor vehicle crashes. Twenty-five presented with either abdominal pain, tenderness, or guarding on physical examination. Diagnostic peritoneal lavage was performed on 12 patients. Three patients were found to have isolated rupture of the duodenum. Computerized tomography was the primary diagnostic investigation in eighteen cases. Extravasation of contrast was noted in only two cases. Four studies were interpreted as normal. The second portion of the duodenum was most commonly injured, and there was a high incidence of associated intra-abdominal injuries. Seven patients underwent operation >12 hours after admission. Twenty-six patients survived to hospital discharge. Two deaths were caused by duodenal injury-related sepsis. CONCLUSION: Blunt rupture of the duodenum is rare. Most blunt duodenal injuries do not result in full-thickness injury. The majority of patients with duodenal rupture presented with either a history or a physical examination suggestive of intra-abdominal injury. Computerized tomography results were often negative or nonspecific. Delay in diagnosis of duodenal rupture remains common but does not appear to affect mortality. Overall mortality was lower than previously reported.

Open-chest cardiac massage without major thoracotomy: metabolic indicators of coronary and cerebral perfusion.

OBJECTIVE: To compare the coronary and cerebral perfusion achieved using a novel method of minimally-invasive, direct cardiac massage to that obtained using bimanual, open-chest cardiac massage. DESIGN: Prospective, controlled animal study with repeated measures. SETTING: University research laboratory. SUBJECTS: Large domestic swine. INTERVENTIONS: Aortic, coronary sinus, jugular venous and pulmonary artery catheters were placed. Following an equilibration period, ventricular fibrillation was induced. After 4 min of untreated ventricular fibrillation, animals underwent bimanual, open-chest cardiac massage (N = 6) or minimally-invasive, direct cardiac massage using a novel device for direct cardiac compression (N = 6). Adrenaline was administered at a dose of 1 mg intravenously every 5 min. MEASUREMENTS: Systemic metabolic parameters, (arterial PO2, PCO2 and lactate concentration) and coronary sinus and jugular venous metabolic parameters (pH, PVO2, SVO2, PVCO2 and lactate concentration) were measured and calculated (coronary sinus/jugular-arterial SVO2, coronary sinus/jugular-arterial PCO2 and lactate differences) at baseline and at 10, 20 and 30 min following induction of ventricular fibrillation. Animals were euthanised after 30 min with no attempt at defibrillation. MAIN RESULTS: Oxygen tension and oxygen saturation of coronary sinus blood declined significantly during the experimental period, but no differences were noted between treatment groups. The coronary sinus-arterial oxygen saturation difference increased during the study with no significant differences between groups. Coronary sinus PCO2 and the coronary sinus-arterial PCO2 difference increased significantly in both experimental groups during cardiac massage. No inter-group differences were noted. A similar relationship was noted in coronary sinus lactate values. The coronary sinus-arterial lactate difference displayed a positive balance at all intervals with no differences noted between group values. The oxygen tension and oxygen saturation of jugular venous blood, were reduced from baseline levels with both treatments. The jugular-arterial oxygen saturation difference increased in both groups compared to baseline values. Between group values were significantly different only at the 20 min interval. Both the jugular venous PCO2 and the jugular-arterial PCO2 gradient were elevated at all intervals, but no inter-group differences were noted. Jugular venous lactate concentration rose steadily with time in both groups. No significant increase in the jugular-arterial lactate gradient was noted at any time point. CONCLUSIONS: Minimally-invasive, direct cardiac massage provides coronary and cerebral perfusion similar to that achieved using standard open-chest cardiac massage. This method may provide a more effective substitute for standard, closed-chest cardiac massage in cases of refractory cardiac arrest.

Extended intravascular shunting in an experimental model of vascular injury.

PURPOSE: To examine the extended patency (> 24 hrs) of heparin-bonded intravascular shunts in a porcine model of vascular injury. PROCEDURES: Adult swine underwent bilateral, common iliac artery resection (n = 5) or bilateral common iliac vein resection (n = 5) and vessel replacement with interposition, heparin-bonded shunts. Three control swine had vessel dissection only. Hematologic and coagulation profiles were measured at baseline and 24 hrs. Limb perfusion was assessed at 24 hrs by clinical exam and angiography. RESULTS: At 24 hrs, all limbs in both shunt groups were well perfused. All arterial shunts were angiographically patent. No distal emboli were detected. Nine of 10 venous shunts were patent, seven were lined with non-occluding thrombus. No alterations in hematologic or coagulation profiles were noted. CONCLUSIONS: Heparin-bonded shunts remained patent in arteries for 24 hours. Shunts placed in the venous system were prone to thrombus formation but most remained patent.

Detection of pulmonary aspiration of gastric contents in an animal model by assay of peptic activity in bronchoalveolar fluid.

OBJECTIVE: To determine whether peptic activity in bronchoalveolar fluid, due to the presence of the gastric proteolytic enzyme pepsin, could serve as a biochemical marker for pulmonary aspiration of gastric contents. DESIGN: Prospective, experimental trial. SETTING: A university animal research laboratory. SUBJECTS: Thirty-six New Zealand rabbits, weighing 2 to 4 kg. INTERVENTIONS: New Zealand rabbits were anesthetized, intubated via tracheostomy, and mechanically ventilated. Pulmonary aspiration was induced by the intratracheal instillation of 2 mL/kg human gastric juice (pH 1.2 +/- 0.2; pepsin activity 0.02 +/- 0.006 microgram/mL; human gastric juice group, n = 24) or normal saline solution (pH 5.2 +/- 0.2; normal saline solution group; n = 12). Mechanical ventilation was continued. Bronchoalveolar lavage was performed at 15 mins (human gastric juice group, n = 8; normal saline solution group, n = 4), 30 mins (human gastric juice group, n = 8; normal saline solution group, n = 4), or 60 mins (human gastric juice group, n = 8; normal saline solution group, n = 4) postaspiration. MEASUREMENTS AND MAIN RESULTS: Peak airway pressure and PaO2 values were measured at baseline and 15 and 30 mins after aspiration. The pH of retrieved bronchoalveolar lavage fluid was measured and pepsin activity in sample fluid was determined. Changes from baseline in peak airway pressure and PaO2 were significant in human gastric juice animals at 15 and 30 mins when compared with normal saline solution animals (PaO2 -4% vs. -44%, peak airway pressure 20% vs. 36% at 15 mins; PaO2 -16% vs. -79%, peak airway pressure 28% vs. 69% at 30 mins; normal saline solution group vs. human gastric juice group, p < .02). Bronchoalveolar lavage fluid pH was not significantly different between groups at any time postaspiration (6.6 +/- 0.7 vs. 6.0 +/- 0.4 at 15 mins; 7.4 +/- 0.9 vs. 6.5 +/- 0.4 at 30 mins; 7.2 +/- 0.5 vs. 6.4 +/- 0.4 at 60 mins, normal saline solution group vs. human gastric juice group, p = NS). No peptic activity was present in bronchoalveolar lavage fluid from normal saline solution animals at any time. In the human gastric juice group, peptic activity was detected in postaspiration bronchoalveolar lavage fluid in eight of eight animals at 15 mins, six of eight animals at 30 mins, and five of eight animals at 60 mins (normal saline solution group vs. human gastric juice group; p < .001 at 15 mins, p < .01 at 30 mins, p = NS at 60 mins). Peptic activity of bronchoalveolar lavage fluid varied; mean values were greater at 15 mins than at 30 or 60 mins (pepsin activity: 0.004 +/- 0.002 microgram/mL vs. 0.002 +/- 0.001 microgram/mL vs. 0.0006 +/- 0.0001 microgram/mL, respectively, p < .05). CONCLUSIONS: The results of this study suggest that peptic activity in bronchoalveolar lavage fluid can be detected up to 60 mins after induced, experimental gastric juice aspiration and may prove a clinically useful biochemical marker for episodes of occult pulmonary aspiration of gastric contents.

Glucose dynamics during continuous hemodiafiltration and total parenteral nutrition.

OBJECTIVE: To determine glucose balance during dextrose-free continuous hemodiafiltration with or without dextrose-containing ultrafiltrate replacement fluid and full nutritional support. DESIGN: Prospective, nonrandomized, observational study. SETTING: A 24-bed multiple trauma critical care unit in a level-I trauma center. PATIENTS: Seventeen multiple trauma patients with multiple organ dysfunction syndrome requiring hemodialysis for acute renal failure. INTERVENTIONS: Continuous hemodiafiltration effluent volume and glucose concentration were measured. Study days were classified according to whether dextrose was used in the ultrafiltrate replacement therapy. Use of dextrose in replacement therapy was determined clinically. Parenteral nutrition was not altered for potential glucose absorption from continuous hemodiafiltration. Ultrafiltrate replacement consisted of 5% dextrose in saline on 21 study days (D5YES) and dextrose-free solutions on 54 study days (D5NO). RESULTS: The D5YES group received 316 +/- 145 g glucose/day from the ultrafiltrate replacement fluid, in addition to glucose in total parenteral nutrition (total glucose intake = 942 +/- 229 g/day in D5YES, 682 +/- 154 g/day in D5NO) (p < 0.05). Glucose loss in continuous hemodiafiltration effluent was 82 +/- 61 g/day in D5YES and 57 +/- 22 g/day in D5NO (P < 0.05), for a net glucose uptake of 8.1 +/- 2.1 mg/kg per min in D5YES and 5.4 +/- 1.5 mg/kg per min in D5NO (p < 0.05). Glucose loss was predictable when dialysate and ultrafiltrate replacement fluids were dextrose-free (R2 = 0.77), but less so when dextrose was used as ultrafiltrate replacement (R2 = 0.47). CONCLUSION: Dextrose-free dialysate promotes glucose loss during continuous hemodiafiltration, but the loss is small and predictable. Use of a dextrose-containing ultrafiltrate replacement fluid results in a significant increase in glucose intake without a commensurate increase in glucose loss, and makes glucose loss in effluent less predictable.

Clamp control of the right ventricular angle to facilitate exposure and repair of cardiac wounds.

Penetrating cardiac wounds, especially those of the posterior surface, present a major challenge to the trauma surgeon. Previously described methods to assist in cardiac exposure include manual control and apex stitch. The authors describe a simple technique to facilitate exposure during acute control and repair of traumatic cardiac wounds. Using an atraumatic vascular clamp in the fashion described allows for improved exposure and easier repair of heart surface wounds.

Direct cardiac massage without major thoracotomy: feasibility and systemic blood flow.

BACKGROUND: Open-chest cardiac massage (OC-CM) provides higher blood pressure and flow than closed-chest compression and may improve the probability of successful resuscitation from cardiac arrest. Its clinical use has been limited by its requirement for a major thoracotomy. The present pilot study tested the technical feasibility of performing effective direct cardiac massage without a major thoracic incision, by using a simple, manually-powered plunger-like device, inserted through a small thoracic incision, to cyclically compress the cardiac ventricles. The method was termed minimally-invasive direct cardiac massage (MID-CM). Systemic blood flow using MID-CM was compared to that with OC-CM, by both direct systemic hemodynamic measurements, cumulative metabolic indicators of the ratio of whole body oxygen delivery and oxygen consumption, and a metabolic index of pulmonary blood flow. METHODS: In 12 large swine, baseline systemic and pulmonary hemodynamic measurements were performed. Arterial and mixed venous blood gases and metabolic indicators of systemic blood flow were measured. Ventricular fibrillation was induced and after 4 min, animals underwent either bimanual OC-CM (N = 6) or MID-CM (N = 6). At 10, 20 and 30 min, hemodynamic and metabolic measurements were repeated. RESULTS: Systemic Blood Pressure: Aortic systolic and diastolic blood pressures were reduced from baseline levels with both OC-CM and MID-CM. No difference in pressure was noted between OC-CM and MID-CM groups. Pulmonary Artery Pressure: Pulmonary artery systolic pressure was elevated from baseline during OC-CM and MID-CM. Pulmonary artery diastolic pressures remained constant throughout the resuscitation period in both groups. No differences in pulmonary systolic or diastolic pressure were noted between OC-CM and MID-CM groups. A trend towards higher pulmonary systolic pressures appeared with MID-CM. Thermodilution Blood Flow: Cardiac index fell from baseline levels with OC-CM and MID-CM. No difference in cardiac index was noted between OC-CM and MID-CM groups. Metabolic Indices: Mixed venous O2 saturation decreased from baseline levels during resuscitation in both experimental groups, with a further decrease at 30 min compared to 10- and 20-min levels. No difference was noted between OC-CM and MID-CM groups at any point. Arterial pH was reduced from baseline levels at 30 min in both groups compared to baseline but no difference was noted between groups.(ABSTRACT TRUNCATED AT 400 WORDS)

Correlation between measured energy expenditure and clinically obtained variables in trauma and sepsis patients.

BACKGROUND: Indirect calorimetry is the preferred method for determining caloric requirements of patients, but availability of the device is limited by high cost. A study was therefore conducted to determine whether clinically obtainable variables could be used to predict metabolic rate. METHODS: Patients with severe trauma or sepsis who required mechanical ventilation were measured by an open-circuit indirect calorimeter. Several clinical variables were obtained simultaneously. Measurements were repeated every 12 hours for up to 10 days. RESULTS: Twenty-six trauma and 30 sepsis patients were measured 423 times. Mean resting energy expenditure was 36 +/- 7 kcal/kg (trauma) vs 45 +/- 8 kcal/kg (sepsis) (p < .0001). The single strongest correlate with resting energy expenditure was minute ventilation (R2 = 0.61, p < .0001). Doses of dopamine, dobutamine, morphine, fentanyl, and neuromuscular blocking agents each correlated positively with resting energy expenditure. In the case of the inotropics and neuromuscular blockers, there was a probable covariance with severity of illness. A multiple regression equation was developed using minute ventilation, predicted basal energy expenditure, and the presence or absence of sepsis: resting energy expenditure = -11000 + minute ventilation (100) + basal energy expenditure (1.5) + dobutamine dose (40) + body temperature (250) + diagnosis of sepsis (300) (R2 = 0.77, p < .0001). CONCLUSION: Severe trauma and sepsis patients are hypermetabolic, but energy expenditure is predictable from clinical data. The regression equations probably apply only to severe trauma and sepsis. Other studies should be conducted to predict energy expenditure in other patient types.

Urea removal during continuous hemodiafiltration.

OBJECTIVE: To compare urea nitrogen removal by continuous hemodiafiltration vs. functional native kidneys in critically ill, septic patients receiving > 2 g of amino acids/kg body weight per day. DESIGN: Prospective, comparative, unblinded study. SETTING: Trauma critical care units of a Level I adult trauma hospital. PATIENTS: Fifteen septic patients with multiple organ failure including renal failure who were receiving continuous hemodiafiltration; 11 septic patients with multiple organ failure without renal failure (control group). Ages of patients ranged from 18 to 60 yrs. INTERVENTIONS: Collection of effluent (dialysate + ultrafiltrate) from hemodiafilters. Collection of urine from control patients. MEASUREMENTS: Urea nitrogen and creatinine concentrations in blood, urine, and the hemodiafiltration effluent, measured every 24 hrs for 6 days. Effluent and urine volumes were measured. MAIN RESULTS: Hemodiafilters were operational for 21.8 +/- 3.0 hrs/day. Mean urea nitrogen removal in the renal failure group was 28 +/- 10 g/day. Blood urea nitrogen was stable over the 6-day study period. In control subjects, urea nitrogen removal was 27 +/- 9 g/day, which was not significantly different from the continuous hemodiafiltration group. Blood urea nitrogen concentrations in control patients increased over the 6-day study period (p < .05). Urea nitrogen removal correlated moderately well with amino acid intake in the control group (r2 = .30), but not in the continuous hemodiafiltration group (r2 = .0004). In patients receiving continuous hemodiafiltration, effluent volume was most significantly correlated with urea nitrogen removal (r2 = .69). CONCLUSIONS: The technique of continuous hemodiafiltration can remove substantial amounts of urea nitrogen, similar to that of normal native kidneys. In addition, at amino acid intake rates of > 2 g/kg body weight/day, urea nitrogen removal during continuous hemodiafiltration remains a function of effluent volume, so there is no need to restrict amino acid intake in acute renal failure patients supported with continuous hemodiafiltration.

Causes and costs of injuries in multiple trauma patients requiring extrication from motor vehicle crashes.

Prospective and contemporaneous medical and economic cost studies of 144 victims of motor vehicle crashes admitted to a regional level I trauma center with multiple injuries (ISS > or = 16) revealed 122 non-ejected patients, of whom 102 required extrication (EXTRIC) from the vehicle for physical or medical reasons and 20 who did not (N group). There were no differences in age (EXTRIC, 34 +/- 17 years; N, 41 +/- 24 years), type of crash (Frontal: 57% EXTRIC, 60% N; Lateral: 32% EXTRIC, 35% N) restraint use (35% EXTRIC, 35% N), or mortality (29% EXTRIC, 30% N). However, the estimated maximum speed before the crash was higher in EXTRIC patients (50 +/- 16 mph vs. 46 +/- 18 mph N, p < 0.04), as was the change in velocity (delta V) on impact (EXTRIC 30 +/- 15 mph; N, 24 +/- 8 mph, p < 0.01). Brain injuries (51% EXTRIC vs. 35% N) and lower extremity injuries were more numerous in EXTRIC patients (59% vs. 20% N, p < 0.003) and the number of splenic, lower extremity, and pelvic injuries associated with shock was greater in EXTRIC patients, p < 0.02; as were postinjury complications. As a result, operating room costs from orthopedic and plastic surgery increased professional charges in the EXTRIC group versus the N group ($20,000, EXTRIC; $17,000, N) and critical care costs ($13,000, EXTRIC; $4,000, N) with total costs of $72,000 and $77,000, respectively. The lower extremity injuries in EXTRIC patients were primarily a result of body part contacts with intrusions (CIs) of the car occupant compartment structures [73% with vs. 24% without (p < 0.0001)]. In lateral MVCs, brain injuries were also more commonly associated with CIs of the side window frame or A pillar (72% CI vs. 25% no CI; p < 0.035); but as a whole in MVCs in which extrication was necessary, lower extremity injuries from instrument panel or toepan CIs appeared more frequent than those resulting from contacts only (p < 0.0001). In EXTRIC patients, 69% of those in shock had CI injuries, and 80% of the deaths in the EXTRIC group were associated with CI injury. These data suggest that measures designed to prevent CIs by strengthening car passenger compartment structures may reduce the incidence of severe brain and lower extremity injuries and may reduce the need for extrication after MVCs.

Amino acid loss and plasma concentration during continuous hemodiafiltration.

Amino acid loss, plasma concentration, and the relationship between amino acid intake and balance during continuous hemodiafiltration (CHD) were investigated in a prospective, nonrandomized study of trauma patients exhibiting the systemic inflammatory response with acute renal failure. Data were compared with those from a group of similar patients who had maintained renal function (control). Both groups received similar amounts of nonprotein calories (3015 +/- 753 nonprotein calories per day in the control group vs 3077 +/- 1018 nonprotein calories per day in the CHD group) and amino acids (2.24 +/- 0.36 g/kg per day in the control group vs 2.19 +/- 0.48 g/kg per day in the CHD group) via the parenteral route. Amino acid solutions were either 19% or 45% branched-chain amino acid enriched. Studies were performed every 12 hours for a maximum of 6 days. Amino acid loss was 2.5 +/- 2.3 g/12 h in the control group vs 6.6 +/- 2.4 g/12 h in the CHD group (p < .0001). Increasing the dialysate rate from 15 to 30 mL/min increased amino acid loss from 5.7 +/- 1.7 to 7.9 +/- 2.6 g/12 h (p < .0001). Amino acid loss was unrelated to amino acid intake but was directly related to plasma amino acid concentration, CHD effluent volume, and the efficiency of filtration as measured by the ratio of filtered urea nitrogen to blood urea nitrogen (R2 = .69). A linear relationship was found between amino acid intake and balance (R2 = .991). The patterns of plasma amino acid concentrations were consistent with metabolic changes wrought by a combination of sepsis and multiple organ dysfunction and type of amino acid intake but seemed unaffected by increased amino acid loss in CHD effluent. Amino acid losses were 2 to 3 times greater from CHD than from normal kidney. However, CHD amino acid losses may not be clinically significant unless amino acid intake is restricted to levels used typically in traditional hemodialysis.

Penetrating cardiac wounds: prospective study of factors influencing initial resuscitation.

A prospective study of 66 consecutive patients with cardiac wounds seen over a 27-month period is reported. No patient was excluded. Patients were stratified by injury mechanism and by physiologic scoring at admission using the cardiovascular-respiratory elements of the Trauma Score (CVRS). Admission cardiac rhythm was obtained in patients with a CVRS of 0 and a Glasgow Coma Scale (GCS) score of 3. Information concerning the anatomic extent of the cardiac wound, the presence or absence of tamponade, and the degree of injury to other structures was also collected prospectively. Seventy percent of the cardiac wounds were caused by gunshots. The probability of successful resuscitation was significantly related to mechanism of injury and physiologic condition on arrival. Among patients arriving with a CVRS of 0 and a GCS score of 3, survival correlated with cardiac rhythm. Pericardial tamponade did not prove to be an independent predictor of early survival. The presence of tamponade was statistically linked to the mechanism of injury. Transport by non-official conveyance was associated with a higher CVRS on arrival. Intoxication with alcohol or cocaine had no evident effect on resuscitation probability.

Sonography in blunt abdominal trauma: a preliminary progress report.

Evaluation of blunt abdominal trauma is clinically challenging. Diagnostic peritoneal lavage (DPL) and computed tomographic (CT) scanning have become primary diagnostic modalities. We examined the efficacy and role of ultrasonographic (US) studies in the initial abdominal evaluation of blunt trauma patients. Over an 8-month period, patients whose abdominal work-up indicated the need for DPL or CT were evaluated sonographically within the first hour after admission by trauma fellows (PGY-6) with at least 1 hour of theoretical training and 1 hour of practical training. Sonograms considered positive were those showing free peritoneal fluid or organ disruption. Hard copies of the sonograms were evaluated by a staff radiologist without knowledge of the fellows' interpretations or of DPL or CT results. Based on the fellows' interpretation of the real-time sonograms, among the first 163 patients studied were 11 true-positive, 146 true-negative, one false-positive, and five false-negative results. Sixteen patients had intra-abdominal injury documented by DPL, CT, or laparotomy. Ultrasonography was 91% sensitive in detecting the presence of hemoperitoneum. Overall, ultrasonography was 69% sensitive, 99% specific, and 96% accurate in diagnosing abdominal injury. We conclude that emergency sonography on admission can serve as a valuable adjunct to the physical diagnosis of clinically significant hemoperitoneum. It is noninvasive, portable, and accurate in determining the need for further diagnostic/surgical intervention.

Ventriculoarterial coupling influences regional contractility.

The purpose of this study was to adjudicate whether concomitant manipulation of inotropic state and arterial elastance influences linear indices of regional contractility. Fifteen autonomically denervated open-chest porcine hearts were instrumented with midmyocardial ultrasonic crystals and aortic and left ventricular chamber microamanometers. Linear left anterior descending coronary artery regional stroke work vs preload relationships (RSW) were generated by 10-sec vena caval occlusion at control and altered contractile states (either dopamine, 5 micrograms/kg/min, or propranolol, 0.2 mg/kg) and following arterial elastance variation (phenylephrine or nitroprusside), effecting an average 30% change in mean arterial pressure (MAP). Global contractility (dP/dt) was doubled (227% of control) by dopamine and halved (35% of control) by propranolol at constant preload (end-diastolic volume, end-diastolic pressure) and afterload (MAP). Regional contractility (RSW slope) was increased from 135 +/- 11 to 211 +/- 28, P less than 0.01, by dopamine, but unchanged with propranolol (106 +/- 10 vs 118 +/- 14, NS). Bidirectional changes in aortic elastance depressed the dopamine-augmented RSW slope (115 +/- 17, nitroprusside; 132 +/- 14, phenylephrine; P less than 0.01 vs dopamine). These differences were attenuated by propranolol infusion (98 +/- 7, nitroprusside; 132 +/- 9, phenylephrine; NS vs propranolol). Thus, optimizing ventriculoarterial coupling should supersede simple afterload manipulation in perioperative cardiac support.

Heart/heart-lung transplantation. The domino procedure.

Orthotopic heart transplantation has become an accepted therapeutic modality limited only by availability of donor organs. Heart-lung transplantation is also being performed with increasing frequency due to improvements in distant procurement techniques. Although the majority of patients requiring heart-lung transplantation have cardiac dysfunction, there is a subset with no cardiac compromise that can serve as donors of cardiac allografts before heart-lung transplantation. We report a technique for sequential heart/heart-lung transplantation in such a subset of patients.

Hypothermia or continuous ventilation decreases ischemia-reperfusion injury in an ex vivo rat lung model.

The susceptibility of lung tissue to ischemia-reperfusion injury has made distant procurement of heart-lung allografts difficult. The effects of hypothermia, ventilation without perfusion, and various reperfusion solutions (PSS/Ficoll or whole blood) on the development of ischemia-reperfusion lung injury were investigated. Use of an ex vivo rat lung model in which the above variables were individually varied permitted a direct approach for these studies. Normothermic ischemia for 1 hour caused significant damage, documented by increased iodine 125 bovine serum albumin (125I-BSA) in alveolar lavage fluid and lung parenchyma compared with nonischemic controls. Hypothermic (4 degrees C) ischemia for 4 hours in lungs reperfused with salt solution and for as many as 12 hours in lungs reperfused with whole blood caused no significant increase in 125I-BSA in alveolar lavage fluid and lung parenchyma compared with nonischemic controls. Lungs ventilated without perfusion showed no increase in 125I-BSA leakage compared with controls. The ex vivo rat lung model is excellent for studying ischemia-reperfusion injury. It is reproducible, allows for variance of reperfusion solutions, and permits change in temperature and ventilation easily.