The "Airmedical F.A.S.T." for trauma patients--the initial report of a novel application for sonography

BACKGROUND

While established as an initial screening tool for the evaluation of injured patients at the trauma center, sonographic evaluation of the patient in the prehospital setting remains untested. The purpose of this study was to determine the feasibility of this procedure during prehospital helicopter transport.

METHODS

Two qualified flight surgeons performed all imaging studies. Confirmatory endpoints were documented for all images obtained in flight.

RESULTS

For this preliminary study, 100 patients are presented; 84 studies were analyzed; 16 were excluded due to patient weight (8), hemodynamic instability (6), or problems with machine calibration (2). Sensitivity was 81.3%; specificity was 100%. The positive predictive value was 100%; the negative predictive value was 95.7%. The accuracy was 96.4%.

CONCLUSION

Sonographic studies obtained during air-medical transport are of similar quality and consistency as those obtained in the emergency department. The ability to detect hemoperitoneum in the field may challenge traditional algorithms for prehospital care as a result.

Single versus combination antimicrobial therapy for ventilator-associated pneumonia

The appropriate selection of definitive antimicrobial therapy is a necessary component of the overall treatment for ventilator-associated pneumonia. When possible, single-agent therapy is preferable. A combination of antibiotics is necessary to treat multiple organisms not susceptible to a single appropriate antibiotic and when antibiotic-resistant gram-negative bacteria are present. Treatment failure is more commonly the result of persistent pneumonia and the development of antibiotic resistance than to recurrence after successful antimicrobial therapy. The duration of treatment will vary depending on the severity of the underlying illness and the pneumonic process.

Emergency department discharge of patients with a negative cranial computed tomography scan after minimal head injury

OBJECTIVE

To determine the negative predictive value of cranial computed tomography (CT) scanning in a prospective series of patients and whether hospital admission for observation is mandatory after a negative diagnostic evaluation after minimal head injury (MHI).

SUMMARY BACKGROUND DATA

Hospital admission for observation is a current standard of practice for patients who have sustained MHI, despite having undergone diagnostic studies that exclude the presence of an intracranial injury. The reasons for this practice are multifactorial and include the perceived false-negative rate of all standard diagnostic tests, the belief that admission will allow prompt diagnosis of occult injuries, and medicolegal considerations about the risk of early discharge.

METHODS

In a prospective, multiinstitutional study during a 22-month period at four level I trauma centers, all patients with MHI were evaluated using the following protocol: a standardized physical and neurologic examination in the emergency department, cranial CT scanning, and then admission for observation. MHI was defined as either a documented loss of consciousness or evidence of posttraumatic amnesia and an emergency department Glasgow Coma Scale score of 14 or 15. Outcomes were measured at 20 hours and at discharge and included clinical deterioration, need for craniotomy, and death.

RESULTS

Two thousand one hundred fifty-two consecutive patients fulfilled the study protocol. The CT was interpreted as negative for intracranial injury in 1,788, positive in 217, and equivocal in 119. Five patients with CT scans initially interpreted as negative required intervention. There was one craniotomy in a patient whose CT scan was initially interpreted as negative. This patient had facial fractures that required surgical intervention and elevation of depressed intracranial fracture fragments. The negative predictive power of a cranial CT scan based on the preliminary reading of the CT scan and defined by the subsequent need for neurosurgical intervention in the population fully satisfying the protocol was 99.70%.

CONCLUSIONS

Patients with a cranial CT scan, obtained on a helical CT scanner, that shows no intracerebral injury and who do not have other body system injuries or a persistence of any neurologic finding can be safely discharged from the emergency department without a period of either inpatient or outpatient observation. Implementation of this practice could result in a potential decrease of more than 500,000 hospital admissions annually.

Comparison of methods of measurements of oxygen consumption in mechanically ventilated patients with multiple trauma: the Fick method versus indirect calorimetry

OBJECTIVE

The purpose of this study was to compare the measurements of whole body oxygen consumption determined by the Fick method and by indirect calorimetry in mechanically ventilated patients with multiple trauma.

DESIGN

A prospective, correlational, within-subjects design.

SETTING

Surgical intensive care unit of a Level I trauma center.

PATIENTS

Thirty-eight mechanically ventilated adults with multiple injuries who received a pulmonary artery catheter within 24 hrs of admission to the surgical intensive care unit.

MEASUREMENTS AND MAIN RESULTS

After the initial resuscitation, simultaneous measurements of oxygen consumption (V(O2) by the reverse Fick equation and by indirect calorimetry were performed every 6 hrs for 24 hrs in normothermic patients who were at rest for at least 30 mins. At each measurement period, the mean V(O2) values determined by indirect calorimetry were significantly greater than the mean V(O2) values determined by the Fick method (time 1: 172+/-38 vs. 125+/-47 mL/min/m2, p < .0001; time 2: 170+/-31 vs. 130+/-48 mL/min/m2, p < .0001; time 3: 170+/-32 vs. 132+/-53 mL/min/m2, p < .0001; time 4: 169+/-29 vs. 130+/-60 mL/min/m2, p < .0002). By using the Bland and Altman technique, the mean bias was 41+/-3.95 mL/min/m2. Correlation coefficients of VO2 values between methods of measurements were statistically significant (r2 = .32, p = .0001; r2 = .32, p = .0001; r2 = .33, p = .0001; r2 = .18, p = .0001).

CONCLUSIONS

Indirect calorimetry should be the preferred standard for measurement of oxygen consumption in severely injured patients.

Improved outcome after early fixation of acetabular fractures

This study was done in order to evaluate the effect of the timing of fixation for acetabular and pelvic ring fractures on patient outcome. Demographic, clinical and outcome data for 5821 trauma patients admitted from January 1993 through January 1996 were retrospectively reviewed. Pelvic fractures were classified according to Young and Burgess. Patients who had fixation within 24 h of admission were compared with those who had later operation. Main outcome measures were Multiple Organ Dysfunction Score according to Moore, hospital and intensive care unit length of stay and discharge disposition. Out of 416 patients with pelvic fractures, one hundred patients had fracture fixation [90 open reduction and internal fixation, 10 external fixation]. There were 59 acetabular fractures and 41 pelvic ring fractures. The overall mortality was 4%. Early fixation of acetabular fractures was associated with lower MODS (p < 0.006) and decreased total length of stay (p < 0.026). Length of hospital stay was also less with early fixation of pelvic ring fractures (p < 0.04). Functional outcome was improved in early fixation of acetabular fractures with a greater proportion of patients being discharged home rather than to rehabilitation or skilled care (p = 0.05). Patients who underwent early repair of acetabular and pelvic ring fractures had a shorter length of hospital stay compared to those with late fixation. Patients with early repair of acetabular fractures had significantly less organ dysfunction and exhibited improved functional outcome.

Single versus combination antimicrobial therapy for ventilator-associated pneumonia

The appropriate selection of definitive antimicrobial therapy is a necessary component of the overall treatment for ventilator-associated pneumonia. When possible, single-agent therapy is preferable. A combination of antibiotics is necessary to treat multiple organisms not susceptible to a single appropriate antibiotic and when antibiotic-resistant gram-negative bacteria are present. Treatment failure is more commonly the result of persistent pneumonia and the development of antibiotic resistance than to recurrence after successful antimicrobial therapy. The duration of treatment will vary depending on the severity of the underlying illness and the pneumonic process.

Oxygen consumption in the early postinjury period: use of continuous, on-line indirect calorimetry

OBJECTIVE

To determine the patterns of oxygen consumption (Vo2) using indirect calorimetry (IC) for the first 24 hrs after serious blunt traumatic injury.

DESIGN

Prospective, observational study.

SETTING

Surgical intensive care unit of a Level 1 trauma center.

PATIENTS

Sixty-six mechanically ventilated patients with blunt traumatic injury and Injury Severity Score >15.

INTERVENTIONS

IC for 24 hrs postinjury. Patients were resuscitated to standard parameters of perfusion.

MEASUREMENTS AND MAIN RESULTS

Mean patient age was 50.1+/-18.7 yrs with a mean Injury Severity Score 30.7+/-11.3). Mean Vo2 for all patients for the 24-hr study period was 168.5+/-29.5 mL/min/m2. The level of Vo2 was not related to Injury Severity Score, the number or combination of organ systems injured, or to the use of vasoactive agents. Patients >65 yrs of age had significantly lower Vo2 (P = .0038) compared with patients < or =50 yrs. Vo2 did not change over time after resuscitation to normal parameters of perfusion. Mean Vo2 was 156.5+/-63.2 mL/min/m2 in patients who developed multiple organ dysfunction, and 172.4+/-33.3 mL/min/m2 in those who did not develop multiple organ dysfunction (p = .16).

CONCLUSIONS

Seriously injured patients are hypermetabolic in the early postinjury period. The level of Vo2 is unrelated to injury severity or number of organ systems involved. Elderly patients can be expected to have lower levels of Vo2. Vo2 does not change significantly in response to resuscitation to normal parameters of perfusion. Vo2 measured by IC did not predict the development of multiple organ dysfunction.

Evaluation and Management of Tertiary Peritonitis

Tertiary or recurrent peritonitis can occur after any operation for secondary bacterial peritonitis. The major risk factors for the development of tertiary peritonitis include malnutrition, a high Acute Physiology and Chronic Health Evaluation II score, the presence of organisms resistant to antimicrobial therapy, and organ system failure. Most patients with tertiary peritonitis will have fever and leukocytosis, even though other signs of infection may be absent. The management of tertiary peritonitis should include the provision of appropriate physiologic support, the administration of antimicrobial therapy, and operation or intervention to control the source of contamination and to decrease the bacterial load. Antibiotic-resistant organisms and bacteremia are present more commonly and mortality is greater in patients with tertiary peritonitis. Early recognition and effective intervention are critical to achieving a successful outcome.

Evaluation and management of tertiary peritonitis

Tertiary or recurrent peritonitis can occur after any operation for secondary bacterial peritonitis. The major risk factors for the development of tertiary peritonitis include malnutrition, a high Acute Physiology and Chronic Health Evaluation II score, the presence of organisms resistant to antimicrobial therapy, and organ system failure. Most patients with tertiary peritonitis will have fever and leukocytosis, even though other signs of infection may be absent. The management of tertiary peritonitis should include the provision of appropriate physiologic support, the administration of antimicrobial therapy, and operation or intervention to control the source of contamination and to decrease the bacterial load. Antibiotic-resistant organisms and bacteremia are present more commonly and mortality is greater in patients with tertiary peritonitis. Early recognition and effective intervention are critical to achieving a successful outcome.

Optimizing the management of blunt splenic injury in adults and children

BACKGROUND

The treatment for splenic injury is evolving to an increased use of nonoperative management. We studied patients with blunt injury to the spleen to determine the overall success with splenic salvage and the reason that adults and children have different outcomes.

METHODS

Patient records were reviewed retrospectively for information and parameters that may influence outcome. Patients were categorized by age and type of management.

RESULTS

Two hundred sixty-seven patients (222 adults; 45 children < 16 years old) with blunt splenic trauma were treated over a 7.5-year period. Adults had a significantly higher injury severity score (ISS; 27.2 +/- 0.9 vs 19.9 +/- 2.0; P < .05), splenic injury score (SIS; 2.8 +/- 0.1 vs 2.3 +/- 0.1; P < .01), and mortality rate (11.7% vs 2.2%; P < .05) compared with children. Eighty-six adults and 3 children had emergent operation; 23 patients had splenorrhaphy. Nonoperative management was selected initially in 178 patients; 83% (105 adults and 42 children) were treated successfully. The ISS and SIS of patients in whom nonoperative management failed were different from those patients in whom treatment was successful (ISS, 27.5 +/- 2.1 vs 20.6 +/- 1.0; SIS, 3.6 +/- 0.2 vs 2.1 +/- 0.1; P < .05) but were similar to those patients who needed initial emergent operation. Adults and children who had successful nonoperative management had similar ISSs (21.4 +/- 1.1 vs 18.4 +/- 2.0) and SISs (2.0 +/- 0.1 vs 2.3 +/- 0.1). Overall splenic salvage was achieved in 64% of patients (57% of adults and 96 % of children). Salvage increased from 50% to 85% during the study period.

CONCLUSIONS

Splenic preservation is possible in most adults and children with blunt injury with the appropriate use of both operative salvage and nonoperative treatment. The higher salvage rate and decreased need for operation in children is due to their lower severity of overall injury and splenic injury. Operative salvage has become less common in adults because more patients are selected for nonoperative management.

Effectiveness of a 2-specialty, 2-tiered triage and trauma team activation protocol

STUDY OBJECTIVE

To determine the effectiveness, safety, and resource allocation of a 2-specialty, 2-tiered triage and trauma team activation protocol.

METHODS

We conducted a 6-month retrospective analysis of a 2-specialty, 2-tiered trauma team activation system at an urban Level I trauma center. Based on prehospital data, patients with a high likelihood of serious injury were assigned to triage category 1 and patients with a low likelihood of serious injury were assigned to category 2. Category 1 patients were immediately evaluated by both emergency medicine and trauma services. Category 2 patients were evaluated initially by emergency medicine staff with a mandatory trauma service consultation. Main outcomes measured included mortality, need for emergency procedures, need for emergency surgery, complications, and discharge disposition. Potential physician-hours saved were calculated for category 2 cases.

RESULTS

Five hundred sixty-one patients were assigned a triage classification (272 to category 1 and 289 to category 2). Category 1 patients had a higher mortality rate (95% confidence interval [CI] for difference of 15.9%, 11.1% to 20.7%, P < .0001), need for emergency surgery (10.7% versus 1.4%, 95% CI for difference of 9.3%, 5.2% to 13.4%; P < .0001), need for emergency procedures (89% of total procedures, 95% CI 83% to 95%; P < .0001), and discharges to rehabilitation facilities (95% CI for difference of 15.1%, 9.3% to 21.0%; P < .0001). The 2-tiered response system saved an estimated 578 physician-hours of time for the trauma service over the study period.

CONCLUSION

This evaluation tool effectively predicts likelihood of serious injury, mortality, need for emergency surgery, and need for rehabilitation. Patients with a low likelihood of serious injury may be initially evaluated by the emergency medicine service effectively and safely, thus allowing more efficient use of surgical personnel.

Surgical site infections

Surgical site infections are common and many are preventable. It is critical to understand the factors that influence these infections in order to create appropriate strategies to reduce this risk. Recent developments in this area and recommendations are presented.

Oxygen delivery is an important predictor of outcome in patients with ruptured abdominal aortic aneurysms

OBJECTIVE

The purpose of this study was to evaluate the relation of oxygen delivery (DO2) to the occurrence of multiple organ dysfunction (MOD) in patients with ruptured abdominal aortic aneurysms (AAA).

SUMMARY BACKGROUND DATA

Patients with ruptured AAA are at high risk for the development of MOD and death. Previous reports of high-risk general surgical patients have shown improved survival when higher levels of DO2 are achieved.

METHODS

Hemodynamic data were collected at 4-hour intervals on 57 consecutive patients (mean age, 70.5 years) who survived 24 hours after repair of infrarenal ruptured AAA. Patients were resuscitated to standard parameters of perfusion (pulse, blood pressure, urine output, normal base deficit). MOD was determined based on six organ systems. Standard parametric (analysis of variance, t tests) and nonparametric (chi square, Wilcoxon) tests were used to compare hemodynamic data, red blood cell requirements, colon ischemia, and organ failure for patients with and without MOD.

RESULTS

Patients who developed MOD had a significantly lower cardiac index and DO2 for the first 12 hours; the difference was most significant at 8 hours. Logistic regression analysis demonstrated that the strongest predictors of MOD were DO2, early onset of renal failure, and total number of red blood cells transfused.

CONCLUSIONS

DO2 is an earlier and better predictor of MOD after ruptured AAA than previously identified risk factors. Failure to achieve a normal DO2 in the first 8 hours after repair is strongly associated with the development of MOD and a high mortality. Strategies to restore normal DO2 may be useful to improve outcome in these high-risk patients.

Gastrointestinal surgery during pregnancy

Gastrointestinal surgical problems often mimic symptoms and signs of nonsurgical conditions that occur during pregnancy. This mimicry presents a particular challenge to diagnosis because avoiding a delay in treatment is critical to successful management. Some of these conditions, such as acute appendicitis and biliary colic, are common in younger women; however, the anatomic and physiologic changes of pregnancy can alter their usual manner of presentation. Many elective and urgent operations can be performed during pregnancy with minimal risk to the mother and fetus. The mother's condition should always take priority because her proper treatment usually benefits the fetus as well.

Admission or observation is not necessary after a negative abdominal computed tomographic scan in patients with suspected blunt abdominal trauma: results of a prospective, multi-institutional trial

OBJECTIVES

Hospitalization for observation is the current standard of practice for patients who have sustained blunt abdominal trauma and who do not require emergent operation, despite having undergone diagnostic studies that exclude the presence of an intra-abdominal injury. The reasons for this practice are multifactorial and include the perceived false-negative rate of all standard diagnostic tests, the belief that hospitalization will allow for the prompt diagnosis of occult injuries, and medicolegal considerations about the risk of early discharge. The focus of this study was to determine whether hospitalization for observation is necessary after a negative diagnostic evaluation after blunt abdominal trauma, to determine the negative predictive value of abdominal computed tomographic (CT) scanning in a prospective series of patients, and to identify which patients can be safely released from the emergency department without observation or hospitalization after blunt abdominal trauma.

METHODS

In a prospective, multi-institutional study over 22 months at four Level I trauma centers, all patients with blunt abdominal trauma suspected by either physical examination or mechanism of injury were evaluated using the following protocol: physical examination in the emergency department, followed by abdominal CT scanning, followed by hospitalization for observation. The standardized physical examination was repeated between 4 and 8 hours. Outcomes were measured at 20 hours and at discharge and included clinical deterioration, the need for celiotomy, and mortality. Other data collected included demographics, mechanism of injury, and findings on physical examination and abdominal CT scanning.

RESULTS

Three thousand eight hundred twenty-two consecutive patients with suspected abdominal trauma presented to the four trauma centers. Two thousand seven hundred seventy-four of these met study eligibility criteria and were prospectively enrolled. Of these, 2299 fulfilled the entire study protocol. CT scan was negative in 1,809 patients, positive for organ injury or abdominal fluid in 389 patients, and nondiagnostic in 78 patients. Abdominal tenderness or bruising was present in 1,380 patients (61%), but only 22% had a positive CT scan. Nineteen percent of patients with a positive CT scan had no tenderness. Computed tomography detected 22 of the 25 blunt intestinal injuries in this series. Free intraperitoneal fluid without solid visceral injury was present in 90 patients, and but only 7 patients had intestinal injuries. There were nine celiotomies in patients whose CT scan was initially interpreted as negative: six were therapeutic (intestine in three, bladder in one, kidney in one, and diaphragm in one), two were nontherapeutic, and one was negative. The negative predictive power of an abdominal CT scan based on the preliminary reading and as defined by the subsequent need for a celiotomy in the population fully satisfying the protocol was 99.63% (lower 95 and 99% confidence bounds of 99.31 and 99.16%, respectively).

CONCLUSION

These data indicate that abdominal tenderness is not predictive of an abdominal injury and that patients with a negative CT scan after suspected blunt abdominal trauma do not benefit from hospital admission and prolonged observation.

Inhibition of xanthine oxidase does not influence immunosuppression after hemorrhagic shock

BACKGROUND

Resuscitated hemorrhagic shock causes global ischemia reperfusion with generation of toxic oxygen metabolites. We hypothesized that the immunosuppression that follows hemorrhagic shock may be linked to this process.

METHODS

Forty-five male Sprague-Dawley rats (weight, 250-300 g) were bled to a mean arterial pressure of 30 mm Hg for 60 minutes, then were resuscitated with three times the maximum blood loss of lactated Ringer's solution. Immune response was assessed by splenocyte proliferation and interleukin-2 (IL-2) production 72 hours after hemorrhage. Allopurinol (50 mg/kg) was given after hemorrhage and immediately before resuscitation.

RESULTS

Hemorrhagic shock caused significant decreases in splenocyte proliferation (cpm: (157,880 +/- 22,068 (mean +/- SD) vs. 37,787 +/- 15,849) and IL-2 production (1/2 max U/ml: 79.6 +/- 7.9 vs. 48.0 +/- 7.7) (both p < 0.05). Hepatic xanthine oxidase was significantly increased with hemorrhage and resuscitation. Hepatic xanthine oxidase activity after hemorrhage and resuscitation was significantly decreased after treatment with allopurinol (74.2 +/- 41.7 vs. 9.2 +/- 9.40). Allopurinol did not affect splenocyte proliferation (cpm: 21,875 +/- 9,316) or IL-2 production (1/2 max U/ml: 45.0 +/- 7.1).

CONCLUSIONS

These results demonstrate that inhibition of xanthine oxidase by allopurinol after hemorrhagic shock did not affect splenocyte proliferation or IL-2 production. We conclude that the immunosuppression after hemorrhagic shock is not dependent on xanthine oxidase-induced production of toxic oxygen metabolites.

Diagnosis and management of blunt carotid artery injury in oral and maxillofacial surgery

PURPOSE

Traumatic occlusion of the internal carotid artery (ICA) is a rare complication of maxillofacial trauma or surgery. This investigation evaluated patient demographics, diagnostic methods, and effective therapeutic modalities associated with blunt carotid injury (BCI).

PATIENTS AND METHODS

This was a retrospective analysis of patient records with an ICD-9-CM diagnosis of carotid injury conducted at MetroHealth Medical Center during the 24-month period between August 1993 and July 1995. Carotid injuries attributable to penetrating trauma were excluded. Age, gender, cause of injury, Glasgow Coma Scale score, Injury Severity Score, type and location of injury, concomitant injury, diagnostic methods, treatment modalities, and outcome were identified, recorded, and analyzed.

RESULTS

During the 24-month period, 12 patients (seven males and five females) suffered BCI. These patients were divided into two groups based on cause of the problem. In group I, there were 3,214 blunt trauma patients admitted during the 2-year study, of which 10 patients had BCI, representing 0.31% of blunt trauma patients, and 1.2% of patients with head injuries. Seven patients presented with hemiplegia, two with cranial nerve palsy, and one with perceptual neglect. Ninety percent of the patients had associated injuries. Two patients had surgical intervention, three received anticoagulation, and five had only supportive care. Four of the 10 patients died, four had moderate neurologic deficits, and two survived with only minor neurologic deficits. In group II, two patients developed BCI after surgery. A 52-year-old woman had a carotid injury after right total temporomandibular joint replacement, and a 48-year-old man who underwent surgical removal of a third molar became hemiplegic postoperatively. The first patient recovered after anticoagulation, whereas the second patient, who received only supportive care, has severe neurologic deficits.

CONCLUSIONS

BCI is an uncommon entity. It is usually recognized when a patient develops an unexplained neurologic deficit, most often hemiplegia, subsequent to trauma or surgery of the head, face, or neck. In the early stages, the diagnosis can be missed by carotid ultrasound or computed tomography. The injury is unrelated to Glasgow Coma Scale score. Symptoms may not develop for days after injury in 50% of patients. Anticoagulation appears to be the most beneficial therapeutic modality.