Robert F. Buckman

Comparison of alternative methods for assessing injury severity based on anatomic descriptors.

BACKGROUND There is mounting confusion as to which anatomic scoring systems can be used to adequately control for trauma case mix when predicting patient survival. METHODS Several Abbreviated Injury Scale (AIS) and International Classification of Disease Clinical (ICD-9CM)-based methods of scoring severity were compared by using data from the Pennsylvania Trauma Outcome Study. By using a design dataset, the probability of survival was modeled as a function of each score or profile. Resulting coefficients were used to derive expected probabilities in a test dataset; expected and observed probabilities were then compared by using standard measures of discrimination and calibration. RESULTS The modified Anatomic Profile, Anatomic Profile, and New Injury Severity Score outperformed the International Classification of Disease-based Injury Severity Score. This finding remains true when AIS values are obtained by means of a conversion from International Classification of Disease to AIS. CONCLUSION Results support the integrity of the AIS and argue for its continued use in research and evaluation. The modified Anatomic Profile, Anatomic Profile, and New Injury Severity Score, however, should be used in preference to the Injury Severity Score as an overall measure of severity.

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.

URETERAL INJURIES FROM PENETRATING TRAUMA

Twelve patients with ureteral injuries from stab or gunshot wounds were evaluated. All 12 underwent surgical exploration on admission. None of the injuries were diagnosed preoperatively. Eleven of 12 injuries were diagnosed during surgical exploration. Diagnosis was delayed in one patient, until 2 weeks after injury, when a CT scan revealed a urinoma. High-dose intravenous urograms (IVUs) were nondiagnostic in nine of nine patients. Hematuria was absent in 45% of patients (5 of 11). Repair of ureteral injury was successfully performed on the proximal and middle portions of the ureter (nine patients) with stented ureteroureterostomy. Three patients sustained distal ureteral injuries. Two underwent ureteroneocystostomy and psoas hitch, and one a primary repair. Mean follow-up time after repair was 4 months in nine patients, and only two minor complications were noted. Currently available preoperative methods, including urinalysis and high-dose IVU, are not reliable for detecting penetrating ureteral injury. In addition, 1 of 12 ureteral injuries was not initially identified, despite routine surgical exploration, urinalysis, and high-dose IVU. A high index of suspicion is required to diagnose ureteral injury.

External genitalia gunshot wounds: a ten-year experience with fifty-six cases

OBJECTIVE To determine the appropriate methods for the diagnosis and management of gunshot injuries to the external genitalia. DESIGN Retrospective analysis. MATERIALS AND METHODS Fifty-six patients with gunshot wounds (GSWs) to the external genitalia were seen over the last 10 years. All patients underwent physical examination, radiographic staging, and surgical exploration, according to protocol. RESULTS There were 25 testicular, 19 scrotal soft tissue, 14 penile, 4 epididymal, 4 urethral, 4 vasal, and 3 superficial scrotal skin injuries. When possible, all injuries, except for the vasal and 1 urethral injury, were primarily repaired with excellent long-term results. Orchiectomy was required in half of testes struck by gunshots. Associated injuries with single GSWs were mostly to the proximity soft tissue and were amenable to conservative management. Major associated injuries were present in patients with multiple GSWs. In the absence of a suspected major associated injury, genital GSWs required only two diagnostic studies, a retrograde urethrogram for suspected urethral injury and a routine abdominal radiograph. Gunshot injuries to the penis or perineum, blood at the penile meatus, or gross hematuria were highly suggestive of urethral injury. CONCLUSIONS Successful management of genital GSWs is dependent upon prompt surgical exploration, conservative debridement, and primary repair.

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.

Role of flexible endoscopy in the evaluation of possible esophageal trauma after penetrating injuries

OBJECTIVE:In urban medical centers, penetrating injuries of the chest, neck, and head are frequently encountered due to the use of firearms and sharp weapons. Successful management of esophageal injury requires a high index of suspicion and prompt diagnosis. The role of flexible endoscopy, a readily available modality, has not been studied extensively in the management of potential esophageal injuries due to trauma.METHODS:A retrospective chart review of 55 patients who underwent emergent flexible endoscopy for the evaluation of suspected penetrating esophageal injuries was performed to determine if endoscopy was safe and if it yielded information that altered patient management.RESULTS:Flexible endoscopy was performed safely in all patients. It yielded a sensitivity of 100%, specificity of 92.4%, a negative predictive value of 100%, and a positive predictive value of 33.3% for detecting an esophageal injury. Although positive findings (prevalence, 3.6%) are infrequent, no esophageal injuries were missed. Endoscopy altered patient management in 38 (69.1%) patients.CONCLUSIONS:Emergent flexible endoscopic examination of the esophagus is a safe and useful diagnostic tool in the early evaluation of penetrating injuries. Flexible endoscopy resulted in four negative surgical explorations, which was deemed acceptable by the Trauma Service, as the consequences of a missed esophageal injury is likely to be devastating.

Major Bowel and Diaphragmatic Injuries Associated with Blunt Spleen or Liver Rupture

The incidence of major bowel and diaphragm injuries occurring in association with blunt spleen and liver ruptures in adults was studied. Of 142 patients with splenic injuries, five had major bowel injuries and 12 had diaphragmatic ruptures. Of 102 patients with blunt hepatic injury, 13 had either bowel or diaphragm ruptures or both. Six bowel and diaphragm injuries occurred in 42 patients with blunt ruptures of both the liver and spleen. Anatomically minor spleen injuries were associated with a 4.8% risk of bowel or diaphragm rupture. Anatomically major splenic lacerations had associated bowel or diaphragm wounds in 16.4% of cases (p = 0.024). A 20% incidence of partial-thickness bowel wounds was found in patients with hepatic or splenic injury, but the natural history of these wounds is unknown.

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.

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)

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.