Evaluation of ventilatory therapy for acid aspiration.

Aspiration of hydrochloric acid in experimental animals results in severe, progressive hypoxia which is due to intrapulmonary shunting and depressed cardiac output. This preparation is useful therefore in studying the therapy of hypoxia. Mongrel dogs were subjected to acid aspiration and the effects of several ventilatory patterns on intrapulmonary shunt fractions and lung water accumulation observed. The combination of large tidal volumes (30 c.c. per kilogram) with positive end-expiratory pressure was effective in preventing intrapulmonary shunting and other ventilatory patterns were ineffective. Pulmonary edema uniformly followed acid aspiration and was not affected by ventilatory therapy. When ventilatory therapy was delayed for 4 hours, the progression of shunting apparently was limited, but the existing shunt was not reduced.

Withdrawal from positive end-expiratory pressure.

A retrospective review was carried out involving 82 patients who required positive end-expiratory pressure (PEEP) therapy for acute respiratory insufficiency. One third of the attempts at reducing the level of PEEP were unsuccessful and led to reinstitution of the original or an increased level of PEEP. Premature lowering of PEEP resulted in significant deterioration in oxygenation which persisted for more than 24 hours after reinstitution of PEEP in a significant number of patients. In addition, one half of these patients required increased levels of PEEP (above prelowering levels) to achieve adequate oxygenation. PEEP lowering attempts were categorized as either successes or failures. A comparison was made between the prelowering respiratory measurements of these two groups. The discriminant criteria produced were (1) an improving oxygenation index (rising (PaO2/FIO2) and (2) a stable or improving effective compliance. Using these prelowering criteria, it was possible to distinguish between the successes and failures in 95% of cases. Based on the data collected, proposed guidelines for PEEP lowering are presented.

Ventilation and perfusion alterations after smoke inhalation injury.

Previous studies of human victims of smoke inhalation injury have demonstrated retention of intravenously infused 133xenon2, 6 suggesting either: (1) true intrapulmonary shunting (Qs) secondary to alveolar collapse, flooding, or obliteration, or (2) perfusion of low ventilation/perfusion compartments (low VA/Q) secondary to bronchospasm, bronchial constriction, or partial bronchial occlusion by cellular debris. To differentiate between and quantitate the relative contribution of intrapulmonary shunt versus low VA/Q compartments, multiple inert gas analysis, as described by Wagner et al.,12 was applied to human victims of smoke inhalation. Studies of an animal model of injury were subsequently performed to confirm these observations. These experiments suggest that early alterations of ventilation and perfusion resulted from increased high VA/Q and dead-space ventilation. Late alterations included significantly increased perfusion of low VA/Q compartments and return of high VA/Q ventilation to baseline levels. True intrapulmonary shunting was notably absent. This physiologic sequence may represent early regional pulmonary vasospasm followed by regional bronchial obstruction and gradual alveolar secondary to bronchospasm, bronchial edema, or partial occlusion by cellular debris.

Care for victims of urban violence and the education of trauma and critical care surgeons. A troubled partnership?

This article reviews the current status of trauma care education and its relationship to critical care education. The critical linkage of both of these endeavors with urban hospitals oriented to indigent care is stressed. Within the specialty of surgery, the recent progress toward resolution of conflicts that have threatened trauma and critical care education programs is reviewed. The partnership between the trauma programs of urban hospitals will be strengthened by this resolution.

Laparotomy for intra-abdominal sepsis in patients in an intensive care unit.

Patients in an intensive care unit who have intra-abdominal (IA) infections producing clinical deterioration in their conditions require urgent intervention. However, detection is often difficult. To define preoperative criteria for, and improve the specificity of, laparotomy, we reviewed 100 explorations in 71 patients with suspected IA sepsis. Eighty-one explorations demonstrated an infected or ischemic process; 19 were negative. Preoperative features associated with a positive laparotomy were as follows: (1) objective evidence by physical examination, ultrasonography, or computed tomography suggesting an IA focus (89%); (2) septic shock (80%); and (3) positive blood cultures (95%). Absence of these features significantly lowered the accuracy of exploration. Septic shock or bacteremia had a 90% mortality regardless of findings at exploration. The best accuracy (89%) and survival (51%) rates were achieved with "directed" exploration before septic shock or bacteremia. Early use of sensitive detection techniques that permit directed laparotomy before septic deterioration should improve survival.

Diagnosis and treatment of splenic fungal abscesses in the immune-suppressed patient.

In an 18-month period candidal splenic abscesses were diagnosed and treated in eight patients. Predisposing factors consisted of recent exposure to cytotoxic chemotherapy, long-term use of prednisone, neutropenia, antibiotic therapy for greater than three weeks, and gastrointestinal tract colonization with Candida. The patients had a clinical profile of nontoxic appearance with a temperature of more than 38.5 degrees C that was unresponsive to antibiotics, pain and tenderness over the upper abdominal quadrants, focal defects visualized on ultrasound and/or computed tomographic scans, and an elevated alkaline phosphatase level. Candida infection was confirmed by histologic examination of the liver and/or spleen in all patients. Diagnosis was made by percutaneous biopsy in one patient and exploratory laparotomy in seven. Five patients had splenectomy and antifungal drugs. In three patients the fungal abscesses resolved with amphotericin B therapy alone. Seven of eight patients were cured of their splenic abscesses, and five of eight were long-term survivors.

Why surgeons prefer not to care for trauma patients.

A survey of the Washington State Chapter of the American College of Surgeons was undertaken to document the opinions of surgeons on trauma care issues. Thirty-nine percent of the total sample of surgeons who responded would prefer not to treat any trauma patients. These surgeons were more likely to be older, to practice in an urban setting, to feel that trauma call has a negative impact on elective practice, and to believe more strongly that reimbursement from trauma patients is not equal to that of nontrauma patients. They also agreed more strongly with the statements that these patients require a greater time commitment and pose an increased medicolegal risk. The most significant influence on preference not to treat trauma patients was exerted by the perception of a negative impact on practice, older age, and perception of increased medicolegal risk. Reimbursement issues and location of practice were less influential factors. This information can be used to target concerns and barriers to active, willing participation in a trauma care system and to tailor strategies to deal with them effectively.

Utilization of blood recycling in nonelective surgery.

Intraoperative infusion of autologous shed blood is efficacious in elective vascular, cardiac, and orthopedic surgery. Blood recycling has also been advocated for emergency and trauma surgery. We examined 33 candidates for autotransfusion during emergency surgery. Autologous blood accounted for only 11% of the total blood replaced. Only 25 of the patients survived long enough to permit reinfusion. Because of rapid hemostasis, nine of the remaining patients (36%) received less than the 2 units necessary to be cost-effective. No evidence was found for septicemia or coagulopathy caused by autotransfusion. We concluded that, as currently applied, recycling of shed blood during emergency surgery is of value in a limited group of patients. The collection and storage of heparinized shed blood during the preoperative and early intraoperative periods, with later processing and reinfusion in selected patients, may expand its applicability.

Determinants of organ malfunction or death in patients with intra-abdominal sepsis. A discriminant analysis.

One hundred and six patients found at operation to have intra-abdominal sepsis were prospectively followed up to determine the incidence of organ malfunction and death. These outcomes were correlated with age, preexisting disease, underlying cause of sepsis, shock, nutritional status, and alcoholism. Organ malfunction occurred in 31 patients (29%), 19 (61%) of whom died. Two (3%) of 75 patients without organ malfunction died. Discriminant analysis revealed a significantly increased risk of death in patients with shock at any time, age greater than 65 years, alcoholism, bowel infarction, or malnutrition. A discriminant equation based only on preoperative variables correctly assigned the outcome of death or survival in 97 (92%) of the patients based on probabilities derived from this analysis. At present, this information is primarily of interest for researchers comparing outcomes in groups of patients, but with additional refinements it may become clinically useful for individual patients.

Duration of preventive antibiotic administration for penetrating abdominal trauma.

Eighty-two patients with penetrating abdominal trauma and visceral injuries requiring laparotomy were prospectively randomized to receive either 12 hours or five days of penicillin G potassium and doxycycline hyclate beginning before operation. Distribution between groups was equivalent for all risk factors except shock, which was more prevalent in the 12-hour group. Antibiotics were first administered an average of 64 minutes following injury, and 90% of all patients had received antibiotics and were being operated on within 3 hours 15 minutes. Overall infection rates were 17% in patients with colon penetration, 14% in patients without colon penetration but with other intestinal penetration, and 0% in patients without intestinal penetration. Twelve-hour and five-day antibiotic regimens were comparable in the prevention of postoperative infectious complications following penetrating abdominal injuries. Intestinal penetration was the most important risk factor for developmental of infectious complications in this patient population.

Pancreaticoduodenectomy for trauma: a viable option?

Over a 6 year period, 10 patients underwent pancreaticoduodenectomy for trauma. This was reserved for proximal pancreatic duct or ampulla injuries at locations that precluded reconstruction and combined devascularization injuries of the pancreas and duodenum. This was thought to be the most conservative indication for the procedure. All patients are alive an average of 3.5 years after injury, and only two continue to require some form of long-term medical therapy. Ninety percent of the patients have returned to functional activity. When confined to strict criteria for resection, pancreaticoduodenectomy is a viable option. The long-term complications of this procedure are minimal and can be well controlled.

Enhanced survival in patients with variceal bleeding after elective portal decompression.

In a retrospective study of 49 patients who had bled from esophageal varices but who survived and did not require emergency portal decompression, 24 patients were discharged without surgical consultation and 25 underwent portal decompression using a small-stoma portacaval shunt. Shunted and nonshunted patients were similar both demographically and in clinical and chemical criteria for preoperative hepatocellular function. Among nonshunted patients, survival was 33 percent during a follow-up period of up to 39 months, whereas shunted patients had an 83 percent survival during a follow-up period of up to 43 months. This difference in survival was statistically significant (p = 0.03). Shunted patients showed a 10.5 percent incidence of hepatic encephalopathy. We conclude that survival after variceal hemorrhage may be significantly increased by a portacaval shunt procedure, especially if it is carried out semielectively in stable patients.

Pyogenic osteomyelitis of axial bones following civilian gunshot wounds.

A series of forty-five patients with low velocity gunshot wounds to the spine and pelvis were followed up for at least eight weeks to determine the incidence of pyogenic osteomyelitis and the role of debridement and fragment removal in its prevention. Four cases of osteomyelitis were found, and although debridement was not frequently done, the incidence of osteomyelitis was higher following debridement than it was without debridement. The most important cause appeared to be spread of contiguous intraabdominal abscesses into the injured paravertebral muscles and spine. If an intraabdominal abscess did not develop, the presence of gastrointestinal injury did not predispose the patient to osteomyelitis. Based on this study, we can conclude that debridement and fragment removal of the spine and pelvic bones are unnecessary for low velocity missile wounds.

Esophageal transection fails to salvage high-risk cirrhotic patients with variceal bleeding.

A small proportion of portal hypertensive patients with acute variceal bleeding do not respond to medical management and require emergency control of hemorrhage, yet are not candidates for shunt surgery. Transgastric esophageal transection and stapling of the esophagus has been suggested as a rapid, simple means to halt variceal bleeding in such high-risk patients. This should theoretically allow a hemorrhage-free interval for resuscitation and improvement in metabolic and cardiopulmonary status before definitive shunt surgery. We tested this hypothesis in 10 high-risk patients with variceal bleeding who underwent transection of the esophagus, sometimes with splenectomy and coronary vein ligation, over a 4 year period. In our experience, esophageal transection in high-risk patients with variceal bleeding controlled acute variceal hemorrhage, was neither rapid nor free of technical misadventures, was associated with a high rate of serious postoperative complications resulting in death in nearly all patients, and consistently failed to result in sufficient metabolic improvement to permit shunt surgery.

Clinical predictors of the adult respiratory distress syndrome.

One hundred thirty-six patients meeting our criteria for one or more of eight clinical conditions were prospectively observed for the development of the adult respiratory distress syndrome. A high risk population was identified, including those with sepsis syndrome (38 percent), documented aspiration of gastric contents (30 percent), multiple emergency transfusions (24 percent), and pulmonary contusion (17 percent). The risk from multiple major fractures appeared low but contributed to the risk from other factors. The risk associated with just one factor (25 percent) was compounded by the presence of two (42 percent) and three (85 percent) simultaneous factors, and this finding was more predictive of ARDS than the injury severity score or initial arterial oxygenation. Of the ARDS cases, 76 percent occurred in the initial 24 hours after meeting the criteria. ARDS did not occur after 72 hours unless there was late development of sepsis (3 of 136 patients).

Role of intraoperative pancreatography in patients with injury to the pancreas.

Over a 10 year period, 54 patients presented with pancreatic trauma. During the first 5 years of the study, when pancreatography was not utilized for the assessment of pancreatic duct injury, 55 percent of the patients had major pancreatic complications. During the subsequent 5 years, suspected proximal duct injury was evaluated by intraoperative pancreatography. This resulted in a decrease of postoperative morbidity to 15 percent. In addition, there were not postoperative deaths during this period. The reduction in adverse sequelae after pancreatic trauma leads us to support the following principles of treatment: early recognition of pancreatic injury with immediate surgical intervention, complete exploration of the pancreas with the liberal use of intraoperative pancreatography to determine the presence of major duct injury, and the use of techniques which ensure control of duct disruption.

The role of peritoneal lavage in the management of stab wounds to the abdomen.

In a 2 year period, 237 patients presented with stab wounds to the lower chest and anterior abdomen. Ninety-six patients were discharged from the emergency room after negative findings on wound exploration. There were no apparent missed injuries but two wound infections in this group for an overall morbidity of 2.1 percent. One hundred forty-one patients underwent exploratory laparotomy. Seventy-seven required emergency laparatomy because of hemodynamic signs of blood loss or peritonitis. Sixty-four patients whose only indication for laparotomy was penetration of the anterior abdominal wall fascia by local wound exploration underwent peritoneal lavage before laparotomy. If 50,000 red blood cells/mm3 in the lavage fluid had been used to select patients for observation, the incidence of negative laparotomy would have been reduced from 58 to 3.2 percent, and only one significant visceral injury would have been missed.

Is octreotide beneficial following pancreatic injury?

BACKGROUND: Pancreatic injury is often associated with multiple complications related to uncontrolled pancreatic exocrine secretion, including pancreatic fistula, pseudocyst, and intra-abdominal abscesses. Somatostatin analogues such as octreotide have been shown to decrease pancreas-related morbidity following major pancreatic resection in patients with pancreatic neoplasms and acute severe pancreatitis. This study was conducted to determine whether or not the administration of octreotide influences the incidence and severity of abdominal complications following pancreatic injury. PATIENTS AND METHODS: Patients with intraoperative diagnosis of pancreatic injury over a 6-year period were studied retrospectively. Specific complications assessed include abdominal abscesses, pseudocyst, pancreatitis, and pancreatic fistula. Statistical analysis of qualitative variables was by chi-square analysis, and analysis of quantitative variables by Student's t-test (P < 0.05). RESULTS: Injury to the pancreas was identified in 96 patients. Sixteen early deaths (< 48 hours) and one late death occurred, for a mortality of 18%, leaving 80 patients as the study population; 21 patients received octreotide and 55 patients did not. Pancreatic fistula occurred in 32 patients (40%). When stratified by pancreatic injury severity, there was no significant difference in complication rates, although patients treated with octreotide had a higher rate of fistula formation (48% versus 40%), longer duration of fistula drainage, and longer hospital stay compared with untreated patients. CONCLUSION: Although adverse patient selection may be a factor in this retrospective survey, the magnitude of observed differences raises concerns regarding the empiric administration of octreotide to such patients pending prospective study.

Prehospital cardiopulmonary resuscitation of the critically injured patient.

Prehospital cardiopulmonary resuscitation combined with endotracheal intubation, vigorous fluid resuscitation, and rapid transport can be effective in resuscitating trauma patients in cardiopulmonary arrest. Survival does not correlate with the injury severity score or transport time once the patient has arrested but does correlate with the mechanism of injury, endotracheal intubation, and placement of intravenous lines.

Early intramedullary nailing of femoral shaft fractures: a cause of fat embolism syndrome.

Results of our retrospective review of 100 consecutive patients show that early intramedullary nailing can be accomplished in severely injured patients without increasing the risk of fat embolism syndrome. No cases of fat embolism syndrome were seen after immediate (less than 24 hours) intramedullary nailing of femoral shaft fractures. In contrast, five cases of fat embolism syndrome were found in the patients treated in the traditional manner with initial balanced skeletal traction and delayed intramedullary nailing. There was a trend toward more pulmonary complications in the immediate group. This is attributed to the greater severity of injury present in the patients selected for immediate intramedullary nailing (injury severity scores 23.2 in immediate group; 12.4 in delayed group). The incidence of critical hypoxemia in the immediate group was equivalent to that in another group of injured patients who did not have fractures, but who did have similar injury severity scores.