Patient volume per surgeon does not predict survival in adult level I trauma centers.

BACKGROUND: The 1999 American College of Surgeons resources for optimal care document added the requirement that Level I trauma centers admit over 240 patients with Injury Severity Score (ISS) > 15 per year or that trauma surgeons care for at least 35 patients per year. The purpose of this study was to test the hypothesis that high volume of patients with ISS > 15 per individual trauma surgeon is associated with improved outcome. METHODS: Data were obtained from the trauma registry of the five American College of Surgeons-verified adult Level I trauma centers in our mature trauma system between January 1, 1998, and March 31, 1999. Data abstracted included age, sex, Glasgow Coma Scale (GCS) score, intensive care unit length of stay, hospital length of stay, probability of survival (Ps), mechanism of injury, number of patients per each trauma surgeon and institution, and mortality. Multiple logistic regression was performed to select independent variables for modeling of survival. RESULTS: From the five Level I centers there were 11,932 trauma patients in this time interval; of these, 1,754 patients (14.7%) with ISS > 15 were identified and used for analysis. Patients with ISS > 15 varied from 173 to 625 per institution; trauma surgeons varied from 8 to 25 per institution; per-surgeon patient volume varied from 0.8 to 96 per year. Logistic regression analysis revealed that the best independent predictors of survival were Ps, GCS score, age, mechanism of injury, and institutional volume (p < 0.01). Age and institutional volume correlated negatively with survival. Analysis of per-surgeon patient caseload added no additional predictive value (p = 0.44). CONCLUSION: The significant independent predictors of survival in severely injured trauma patients are Ps, GCS score, age, mechanism of injury, and institutional volume. We found no statistically meaningful contribution to the prediction of survival on the basis of per-surgeon patient volume. Since this volume criterion for surgeon enpanelment and trauma center designation would not be expected to improve outcome, such a requirement should be justified by other measures or abandoned.

Primary aortoenteric fistula: computed tomographic diagnosis of an atypical presentation.

A primary aortoenteric fistula is a potentially devastating complication of untreated aortic aneurysmal disease. The clinical presentation can be confusing, leading to a delay in diagnosis. Computed tomography (CT) can greatly assist in establishing the diagnosis. An unusual case of a primary aortoenteric fistula with an atypical presentation is described. The patient presented with symptoms indicating an exacerbation of recurrent nephrolithiasis. No clinical history of an abdominal aortic aneurysm or previous history of gastrointestinal hemorrhage was reported. A CT scan demonstrated extravasation of arterial contrast into the duodenum. The aorta was repaired with an in-line prosthetic graft. A review of the literature regarding this rare entity and surgical options are presented.

Central venous injuries of the subclavian-jugular and innominate-caval confluences.

Injuries to the central venous system can result from penetrating trauma or iatrogenic causes. Injuries to major venous confluences can be particularly problematic, because the clavicle and sternum seriously limit exposure of the injury site. We report our institution's experience with central venous injuries of the subclavian-jugular and innominate-caval venous confluences. Significant injuries of the subclavian-jugular venous confluence frequently result from penetrating trauma, while injuries to the innominate-caval confluence are usually catheter-related. Median sternotomy provides adequate exposure of the innominate-caval confluence, while exposure of the subclavian-jugular venous confluence requires extension of the median sternotomy incision into the neck and resection of the clavicle. The literature is reviewed.

Pedestrian versus motor vehicle accidents: an analysis of 5,000 patients.

BACKGROUND: Pedestrian versus motor vehicle accidents are associated with substantial morbidity and mortality. Previous studies have examined pedestrian injury profiles on an individual hospital basis and have been limited by small patient populations. The objective of this study was to examine the demographics and injury profiles of pedestrian versus motor vehicle accidents in a large trauma system. STUDY DESIGN: Five thousand pedestrians injured by motor vehicles whose records were entered in a centralized county trauma database were reviewed retrospectively over 3 years. Patients were grouped by age: pediatric (less than 15 years), adult (15 to 65 years), and elderly (older than 65 years). The main outcome measures included mortality, hospital stay, ICU stay, Injury Severity Score, Glasgow Coma Scale, Revised Trauma Score, level of residual disability, and payer source. RESULTS: The pediatric group represented 38.1% of the study population, adults 53.9%, and the elderly 8.0%. Mortality was highest among the elderly (27.8%), followed by adults (8.1%) and children (3.1%). Overall, the pediatric group had the lowest Injury Severity Score (6.8 +/- 0.2, mean +/- SEM), the highest Revised Trauma Score (7.5 +/- 0.9), and the highest Glasgow Coma Scale (13.9+/-0.1). Hospital stay (4.9+/-0.2 days) and ICU stay (4.6 +/- 0.3 days) were also shortest in this age group. Among all patients, injuries included musculoskeletal (34.3%), head and neck (30.0%), external (24.4%), abdomen and pelvis (3.9%), chest (2.4%), spine (1.8%), and other (3.2%). Operations were required in 11%: orthopaedic (67%), thoracic (2%), abdominal (11%), neurosurgical or head (6%), and other (14%). At the time of discharge, 78% of patients had a temporary disability, 4% had a permanent handicap, and only 16% were functioning at preadmission capacity. Among those with identifiable payer sources, 45% were state or federal, 25% were cash or self-pay, 18% of patients belonged to an HMO or had a group carrier, and 12% were from other sources. CONCLUSIONS: This study contributes the largest database reported on motor vehicle versus pedestrian accidents and finds that these accidents are common in a large urban trauma system. Hospital stay, Injury Severity Score, Revised Trauma Score, Glasgow Coma Scale, and the mortality rate worsen with age. The high mortality rate among the elderly indicates the need for more aggressive and effective prevention efforts.

Hypothermia in trauma patients.

Hypothermia occurs commonly in severely injured patients and is associated with a high mortality rate. It perturbs the normal homeostatic response to injury and affects multiple organ systems and physiologic processes. In trauma patients, hypothermia-induced coagulopathy often leads to marked bleeding diathesis and frequently provides a challenge for the surgeon. Once hypothermia occurs, it is often difficult to correct. Efforts to prevent and treat hypothermia in trauma patients should be instituted in the field and continued as an integral part of the resuscitation process. Hospital personnel and physicians at various levels caring for trauma patients from the initial injury and thereafter should bear in mind that a patient's temperature is as important as any other vital sign. Appropriate measures for preventing and treating hypothermia should be instituted promptly and tended to with utmost vigilance.

Multiple organ failure: by the time you predict it, it's already there.

OBJECTIVE: Validate an at-risk population to study multiple organ failure and to determine the importance of organ dysfunction 24 hours after injury in determining the ultimate severity of multiple organ failure. METHODS: We evaluated 105 patients admitted to five academic trauma centers during a 1-year period who survived for more than 24 hours with Injury Severity Scores > or = 25 and who received 6 or more units of blood. Organ dysfunction was scored daily with a modified multiple organ failure scoring system made up of individual adult respiratory distress syndrome score, renal dysfunction, hepatic dysfunction, and cardiac dysfunction scores. Multiple organ failure (MOF) severity was quantitated using the maximum daily multiple organ failure score and the cumulative sum of daily multiple organ failure scores for the first 7 days (MOF 7) and 10 days (MOF 10). Independent variables included markers of tissue injury, shock, host factors, physiologic response, therapeutic factors, and organ dysfunction within the first 24 hours after admission. Data were subjected to a conditional stepwise multiple regression analysis, first excluding and then including 24-hour MOF as an independent variable. RESULTS: Of the 105 high-risk patients, 69 (66%) developed a maximum daily multiple organ failure score > or = 1; 50 (72%) did so on day 1 one and 60 (87%) did so by day 2. In multiple regression models, the multiple correlation coefficient increased from 0.537 to 0.720 when maximum MOF was the dependent variable, from 0.449 to 0.719 when maximum daily MOF was the dependent variable, from 0.519 to 0.812 when MOF 7 was the dependent variable, and from 0.514 to 0.759 when MOF 10 was the dependent variable. CONCLUSION: We have confirmed that the population of patients with Injury Severity Scores > or = 25 who received 6 or more units of blood represent a high-risk group for the development of multiple organ failure. Our data also indicate that multiple organ failure after trauma is established within 24 hours of injury in the majority of patients who develop it. It appears that multiple organ failure is already present at the time when most published models are trying to predict whether or not it will occur.

Epidemiology of major trauma and trauma deaths in Los Angeles County.

BACKGROUND: Our objective was to study population-based trauma-related injuries and deaths in the county of Los Angeles and to identify trends and progress towards meeting the "Year 2000 National Health Objectives." STUDY DESIGN: We did a retrospective study for the year 1996. Data were obtained from the Trauma Registry of the Emergency Medical Services of the Department of Health Services, and the Coroner's Department of the County of Los Angeles. Traumatic injuries and deaths per 100,000 of the population were calculated according to mechanism, race, age, and gender. RESULTS: During 1996, there were 12,136 major trauma admissions in the 13 trauma centers in Los Angeles County. Another 1,929 victims died at the scene or were certified dead at nontrauma centers and were taken to the Coroner's Department (total 14,065 victims). The overall major injury rate was 151.0 per 100,000 population and the death rate was 30.9 per 100,000. The trauma death rate per 100,000 population was 56.4 for African-Americans, 33.5 for Hispanics, 26.3 for Caucasians, and 11.6 for Asians. Homicides were the leading cause of traumatic deaths (45.3%) followed by traffic accidents (31.9% of deaths). Firearms were responsible for 3,899 major injuries or deaths (41.7 per 100,000 population). The overall homicide rate per 100,000 population was 14.0, with a much higher rate for African-Americans (40.4 per 100,000) and Hispanics (18.7 per 100,000) than Caucasians (4.0 per 100,000) or Asians (3.4 per 100,000). African-American males were at very high risk for homicide (73.3 per 100,000), and in the age group 15 to 34 years, this problem reaches epidemic proportions (164.2 per 100,000). Traffic accidents accounted for 69.0 major injuries and 9.6 deaths per 100,000 people. Males were at significantly higher risk of dying in traffic accidents than females. People over 60 years of age were at significantly higher risk of traffic-accident death than younger people, for both passenger and pedestrian groups (p < 0.01). Firearm-related suicides were responsible for 4.6 deaths per 100,000 population. Caucasian males over 65 years were at much higher risk of suicide by penetrating trauma (29.5 per 100,000) than were Hispanics (6.3 per 100,000), Asians (5.4 per 100,000), or African-Americans (no deaths) in the same gender and age group. CONCLUSIONS: Trauma remains a major health problem in the county of Los Angeles. Despite the significant reduction of intentional trauma in 1996, it still exceeds national figures and is much higher than the targeted "Year 2000 National Health Objectives." Aggressive prevention strategies need to focus on the population groups at excessive risks of injury by assault, traffic accidents, and suicides.

Laparoscopic cholecystectomy facilitated by hydrodissection.

Hydrodissection has been used in the past in open cholecystectomy to facilitate dissection in difficult cases. Injection of 50 mL of saline, with a laparoscopic cyst aspiration needle during laparoscopic cholecystectomy between the gallbladder and the liver, causes an edematous area 1-1.5 cm thick between the gallbladder and the liver. This allows dissection to be carried out prograde and retrograde with less bleeding and a much smaller chance of gallbladder perforation and the escape of stones. One hundred and thirty-three laparoscopic cholecystectomies (LC) utilizing hydrodissection were compared to 48 historical controls (HC), comparing blood loss, stone spillage, and dissection time. Blood loss was on average less than 5 mL in the LC group and 56 mL in the HC. One case of minor biliary spillage occurred in the LC group and 11 gallbladder perforations in the HC group. Time taken for the dissection was 6.4 minutes for LC and 16 minutes for HC. Laparoscopic hydrodissection was accompanied by less bleeding, fewer incidents of gallbladder damage and stone spilling, and a much faster dissection time. It can also be performed prograde, which is helpful in liver cirrhosis.

Base of skull internal carotid and internal jugular gunshot wounds treated conservatively: inadequate treatment, or was well enough left alone?

Zone three carotid injuries present problems of access in emergency situations. Not only are the methods time consuming, but they also put certain structures in the neck at risk. A patient was treated at this institution with a large calibre gunshot injury of the right internal carotid and internal jugular vein. He was neurologically intact and his bleeding had been completely controlled. A decision was made to treat him conservatively and he recovered uneventfully with no neurological deficit and no further bleeding. Emergency exposure of the distal carotid artery involves dislocating the mandible, putting the facial nerve and parotid gland at risk of injury. Base of skull carotid injuries are best treated expectantly if there is no active bleeding or progressive neurological impairment. Careful follow-up is required to diagnose and treat carotid-jugular fistulas, false aneurysms and stenoses early.

Gunshot injuries of the lower oesophagus.

We present seven cases of lower oesophageal gunshot injury cared for by one surgeon. Diagnosis was made clinically, with the help of chest X-rays and with oesophagography and oesophagoscopy. Five were treated with wide debridement and resection of the distal esophagus and oesophago-gastric anastomosis with a Nissen wrap to protect the anastomosis. Two lesser injuries were treated by primary repair. The five treated with resection and oesophago-gastric anastomosis did not leak and the patients were discharged after oesophagography 10 days postoperatively. Primary repairs in two patients were complicated by oesophageal leaks, one subclinical and one with an empyema. The oesophageal blood supply is segmental in areas and variable in the distal part. Injury due to a bullet wound may cause more damage than is evident at surgery. Additional mobilization can further devascularize the distal oesophagus and lead to anastomotic leaks. We advocate wide debridement of oesophageal gunshot injuries and resection of the distal oesophagus. Continuity is restored with a primary oesophago-gastric anastomosis (double layer) with a fundoplication to protect the anastomosis.

Blunt disruption of the abdominal aorta: report of a case and review of the literature.

A 71-year-old woman had an abdominal aortic disruption as a belted passenger in a motor vehicle accident. The diagnosis was unexpected, and the patient died during surgery. There have been 54 patients operated with this diagnosis since 1953; our patient was the fifty-fifth. This is an unusual injury, because the aorta is well protected in this position. Thoracic aortic injuries are much more common (20 times) than abdominal injuries. The causes are motor vehicle accidents, blows to the abdomen, explosions, and falls. Obstructing lesions such as thrombosis and intimal dissection are the more common presentation. False aneurysms occur occasionally. Free rupture has a very high and immediate mortality rate, and few patients arrive at the hospital alive. Diagnosis can be clinical, based on distal ischemia and neurologic abnormalities, or made with Doppler scanning, ultrasonography, computed tomography, or arteriography. Two thirds present acutely and one third subsequently months or even years after the original injury. Treatment consists of flap suture, thrombectomy, bypass grafting in more extensive injury, or extra-anatomic bypass in the face of severe contamination. Recently, endoluminal stenting has successfully been used, avoiding an abdominal operation completely.

Diagnosis and management of zone III carotid injuries.

The management of patients with extracranial carotid injury at the base of the skull (zone III) is challenging due to inaccessibility, severity, and associated injuries. In an effort to formulate a systematic approach to the evaluation and management of zone III carotid injuries, the records of 13 consecutive patients with such injuries were reviewed: nine sustained penetrating injuries and four had blunt injuries. A total of 16 arteries were injured: internal carotid (11), external carotid (four), and vertebral (one). Neurological examinations revealed a central nervous system deficit in 1/9 with penetrating injuries and in 4/4 with blunt injuries. Angiography in patients with penetrating injuries revealed pseudoaneurysm (five), intimal flap (five), transection (two), and AV fistula (one). Angiograms of patients with blunt injuries demonstrated pseudoaneurysm (2), dissection (1), and intimal flap (1). Three patients underwent operative repair of internal carotid injuries and/or ligation of external carotid injuries. Four patients were managed with endovascular balloon occlusion. The remaining patients were observed with or without anticoagulation. Neurologically the patients remained normal or had improved on follow up with the exception of one patient with a persistent hemiparesis after a blunt injury who had been observed. The conclusions are: (1) angiography at presentation is indicated, in stable patients, to delineate the injury and guide definitive management; (2) blunt injuries should generally be managed with anticoagulation. In cases of large or expanding pseudoaneurysms or when anticoagulation fails, endovascular balloon occlusion is indicated; (3) partial thickness penetrating injuries can be observed, while full thickness lesions should be managed with balloon occlusion; (4) operative vascular reconstruction should be reserved for unstable patients, patients with active bleeding, and patients requiring surgical exploration for associated injuries.

From deadly weapon to toy and back again: the danger of air rifles.

More than 30,000 air gun injuries occur annually in the United States. While in the past these injuries were usually not serious unless an eye was injured, advances in technology have created air guns with the ability to maim and kill. A recent carotid injury with embolization of the BB is presented. Modern air rifles can produce a muzzle velocity of 1,200 feet per second, faster than many low-velocity handguns and rifles. Head, chest, and abdominal injuries have lead to permanent damage and death. Federal and state laws have not kept up and air rifles are only mentioned in the laws of 28 states, and then often only to exclude them from being termed firearms or weapons. The law should take cognizance of the fact that air guns have changed and should be governed by the same laws that apply to firearms.

Gunshot injuries of the sacrum.

Gunshots to the sacrum are unusual and present several management problems. Associated injuries and particularly sacral bleeding are troublesome. Conventional methods of hemostasis are not suitable in this setting as the spinal blood supply is very complex because it is largely derived from the longitudinal spinal arteries originating intracranially. Attempts at proximal control are difficult and could lead to neurological injury. We successfully managed brisk bleeding in three patients with sacral gunshots. After the major intra abdominal hemorrhage had been controlled, attention was turned to the sacral wounds that had been packed with sponges up to that time. The sacral defect was closed with bone wax to control bleeding definitively. Methyl cellulose was then put over the bone wax and the periosteum of the sacrum and posterior peritoneum (mobilized if necessary), sutured over the methyl cellulose. Post operatively the patients are carefully monitored for developing neurological deficit that would necessitate immediate sacral laminectomy and decompression. We advocate tamponading of the sacral wound with bone wax, covered by methyl cellulose and kept in place and held firm by the periosteum and posterior peritoneum sutured over it as a successful interim or definitive form of therapy.

Comparative stress hormone changes during helium versus carbon dioxide laparoscopic cholecystectomy.

Laparoscopic surgery has been termed minimally invasive surgery by advocates of this technology. It has been demonstrated previously that using carbon dioxide for insufflation produces a respiratory acidosis due to transperitoneal absorption of gas. Insufflation with helium does not create this acidosis. We questioned whether laparoscopic surgery would elicit a stress response and whether the absence of acidosis with helium might prevent or reduce the levels of stress hormones. Sixteen female patients undergoing laparoscopic cholecystectomy were randomly assigned to helium (n = 8) or CO2 (n = 8) insufflation. Serum cortisol, epinephrine, and norepinephrine were measured preoperatively, after induction of anesthesia but before insufflation, at 45 min of surgery, and after desufflation. There were increases in epinephrine, norepinephrine, plasma cortisol, and urine cortisol at 45 min and at the conclusion of the procedure over the preoperative value. With ANOVA, each variable showed significant increases from preoperative values, at 45 min, and at the end of the case. Except for the increased epinephrine when helium was used, there were no significant differences in the other variables between helium and CO2. Laparoscopic cholecystectomy produces significant increases in stress hormone levels. Prevention of acidosis with helium insufflation does not appear to protect against increases in stress hormones. Epinephrine levels with helium insufflation are higher than with CO2, and elevations in stress hormones suggest that laparoscopic cholecystectomy is not physiologically minimally invasive.

Dependence of tissue oxygen on oxygen delivery.

The viability of tissue flaps depends on adequate blood flow and oxygenation. To help ensure oxygen delivery, increased inspired oxygen is often provided. This study uses a porcine model to measure tissue oxygen (TPO2) in a muscle flap, in response to varying levels of inspired oxygen concentration (FiO2). Six swine underwent the creation of a latissimus dorsi island flap. An ultrasonic flow probe was used to monitor afferent flow through the thoracodorsal artery, and a 20-ga fluorescence-quenching optode was employed to monitor TPO2. Additional optodes were inserted in muscle of an ipsilateral hindlimb, and in the terminal ileum. Inspired oxygen concentration was varied from 15 to 100%, and oxygen delivery variables measured. Analysis of variance and multiple linear regression were used to determine which variables had the greatest effect on TPO2. All three sites varied directly with inspired oxygen concentration. Flap TPO2 had a strong dependence on FiO2 and local oxygen delivery (r2 = 0.54). PaO2 and hemoglobin were the most significant determinants of ileal submucosal TPO2 (r2 = 0.65). A correlation between average submucosal and flap TPO2 was observed (r > 0.9, P < 0.05). We conclude that (1) muscle flap and bowel TPO2 vary directly with inspired FiO2, (2) changes in ileal submucosal TPO2 correlate with those observed in muscle, and (3) monitoring of readily accessible muscle TPO2 merits further investigation to evaluate the status of TPO2 in critical visceral beds.

Helium insufflation in laparoscopic surgery.

Carbon dioxide is the most commonly used gas for abdominal insufflation in laparoscopy today. Due to the solubility of carbon dioxide large volumes are absorbed into the circulation causing a high PCO2 and a low pH (respiratory acidosis). Carbon dioxide is also stored in several sites in the body and is released at the conclusion of the procedure prolonging the respiratory acidosis when the patient is least able to cope with this additional burden. Cardiac effects of CO2 consist of a lowering of the arrhythmia threshold, increased blood pressure, pulse and cardiac output. At a sustained high level this can lead to cardiac depression and death. These effects are particularly prone to occur in cardiac and respiratory cripples. Other gases that have been used include air, oxygen, nitrous oxide and nitrogen. Their use has been discontinued because of the danger of embolism. Air, oxygen and nitrous oxide are also not safe to use in the presence of electrosurgical instruments thereby limiting their usefulness even further. Helium has been proposed as a very promising alternative to CO2. In the laboratory and in a clinical trial, helium has not produced the respiratory acidosis associated with CO2 insufflation. This is further evidence that the acidosis is not primarily due to elevation of the diaphragm and consequent increased dead space, but to the large amount of CO2 that is absorbed directly from the peritoneal cavity. Helium would seem to be the gas of choice at this time as it comes close to fitting the criteria for an ideal insufflating gas. Helium is clear and colorless, allowing unimpeded vision to the operator. It is non toxic, not flammable or explosive and can be safely used with electrocautery and laser. Helium is easy to handle and not very soluble which decreases the amount absorbed from the peritoneal cavity and consequently the amount used. That which is absorbed is quickly cleared by the lungs. Helium is metabolically inactive (in contrast to CO2) and does not interfere with normal metabolic processes. In view of this promising initial work, further studies are indicated.

Contemporary management strategy for major inferior vena caval injuries.

Injuries of the inferior vena cava (IVC) require prompt and definitive action. To evaluate our current management strategy, we reviewed 38 patients with IVC trauma treated from 1983 through 1990. Sixteen were injured by gunshots, eight by stabs, and 14 by blunt mechanisms. Thirty of the 38 survived (79%). All were awake on presentation, although 45% were hypotensive (systolic blood pressure < 90 mmHg). The mean Injury Severity Score was 27. At laparotomy all demonstrated active retroperitoneal bleeding or an expanding hematoma. The caval injury was retrohepatic in 12 (three involving the hepatic veins), suprarenal in seven, pararenal in nine, and infrarenal in ten. Among the eight deaths, five had retrohepatic injuries, two pararenal injuries, and one had an infrarenal injury. Surgical repair was accomplished in 33, 26 (79%) via lateral venorrhaphy and seven via polytetrafluoroethylene patch repair. The right chest was entered with diaphragmatic division in 8 of 12 cases with retrohepatic injuries. Two atrial-caval shunts were used and both patients survived. Twenty follow-up studies (at > or = 3 months) were performed in which three patients demonstrated IVC occlusion, and one had a Budd-Chiari-like syndrome. We conclude that inferior vena caval injury remains a highly lethal injury. Successful outcome depends on prompt volume restoration, a stratified selective management approach, and avoidance of hypothermia. Prosthetic vena caval reconstruction represents an acceptable alternative.