Nutritional gain versus financial gain: The role of metabolic carts in the surgical ICU.

BACKGROUND: Adequate nutritional replacement of critically ill and injured patients is of paramount importance, as it decreases infectious morbidity and mortality. However, multiple methods of determining nutritional requirements exist, including mathematical formulas, weight based calculations, and the use of metabolic cart measurements, the latter of which is associated with significant labor and equipment costs. We hypothesized that metabolic cart measurements, despite increasing the cost of care, would more accurately determine nutritional requirements in a critically ill population than formulaic or weight-based calculations. METHODS: Consecutive metabolic cart measurements were prospectively obtained on 59 critically ill surgery and trauma patients, and compared with predicted values as determined by the Harris-Benedict equation and weight-based calculations. Comparison was made to actual resting energy expenditure data acquired via indirect calorimetry data obtained from serial metabolic carts. RESULTS: There were 59 patients who formed the study population, with 37% of the population having two or more metabolic cart readings (total number of cart readings was 106). There was no statistically significant difference between the metabolic cart results, the predicted resting energy expenditure as calculated by the Harris-Benedict equation adjusted with a factor of 1.5, and a weight based calculation at 30 kcal/kg adjusted body weight. Metabolic requirements were stable over time (4-48 days) without significant variation. Nutritional parameters, as evaluated by the visceral proteins prealbumin and transferrin significantly increased with time in injured patients. CONCLUSIONS: Either 30 kcal/kg adjusted body weight or the resting energy expenditure calculated from the Harris-Benedict equation multiplied by 1.5 adequately predicts the nutritional requirements of critically ill surgery and trauma patients. The addition of metabolic cart data does not provide any additional information in the determination of caloric needs in the critically ill and injured patient. In this population, omission of metabolic cart data would have saved 33,000 dollars without adversely affecting patient outcome.

Ventilator-associated pneumonia after combined burn and trauma is caused by associated injuries and not the burn wound.

An increased risk of ventilator-associated pneumonia (VAP) has previously been demonstrated in trauma patients urgently intubated in the prehospital (ie, field) and emergency department (ED) settings. This study investigated the impact of urgent intubation on subsequent VAP in patients who sustained both a burn injury and a traumatic injury. We undertook a retrospective review of both trauma registry data and medical records for all patients with combined thermal and traumatic injuries admitted to a single verified burn center and level I trauma center. Patients undergoing field or ED intubation during the 5-year period ending December 2002 were identified and studied. Data abstracted included admission demographics and vital signs, presence of inhalation injury, location at the time of intubation, presence of associated injury, percentage TBSA burn, hospital and intensive care unit length of stay, and hospital day of VAP diagnosis. Seventy-eight of the 3388 patients (2.3%) admitted during the study period sustained a combination of burn wounds and trauma and underwent urgent field or ED intubation. The majority of patients were men (71%), with a mean age of 46 +/- 24 years. There was one failed oral intubation, which required cricothyroidotomy. The location of the patient at the time of intubation was ED, 66%; burn center ED, 17%; and field, 17%. Eighty percent of all patients were diagnosed with an inhalation injury. VAP was diagnosed in 39 patients (50%), with a mean time to diagnosis of 10 +/- 9 days. TBSA burn, smoke inhalation, and time (in days) to diagnosis of VAP were not independent risk factors for the occurrence of pneumonia in any of the 3 groups. However, those intubated at the initial ED were more likely to develop VAP (P = .028) compared to those intubated in the field or in the burn center. The incidence of associated injuries was significantly greater (P < .0001) in the initial ED group. Only a small percentage of burn patients also sustain blunt trauma. VAP occurs in 50% of the patients requiring urgent intubation. Independent risk factors appear to be intubation at an initial ED before transfer and associated injuries.

Ventilator-associated pneumonia, like real estate: location really matters.

INTRODUCTION: Previous work has demonstrated an increased risk of ventilator-associated pneumonia (VAP) in trauma patients after prehospital (field) intubation as compared with emergency department (ED) intubations. However, this population was not compared with patients intubated as inpatients, making data interpretation difficult. We sought to further examine predictors for the development of VAP after trauma. METHODS: A 10-year retrospective review of all patients mechanically ventilated greater than 24 hours after injury was performed. RESULTS: In all, 1,628 patients were identified, of which 1,213 (75%) were intubated as inpatients and 415 were emergently intubated (353 ED, 62 field). Overall, those intubated emergently were younger (p = 0.03) and less injured as seen by higher Glasgow Coma Scale scores (p = 0.0002), lower Injury Severity Scores (p = 0.01) and higher Revised Trauma Scores (p < 0.0001). Despite a lower injury severity, those patients emergently intubated were more likely to develop pneumonia as 22% of ED intubations and 15% of field intubations developed pneumonia, as compared with the inpatient rate of 6.5%. Pneumonia after field intubation was more likely to be community-acquired (p < 0.0001) with a significantly lower percentage of infecting enteric gram-negative rods (p < 0.0001) as compared with the inpatient and ED groups. Forward logistic regression analysis (with VAP = 1) identified inpatient intubation as protective against VAP (odds ratio 0.28, 95% CI = 0.2-0.4). Backwards logistic regression analysis further identified both field airway (odds ratio 2.29, 95% CI = 1.1-4.9) and ED airway (odds ratio 3.61, 95% CI = 2.5-5.2) as predictive of VAP. CONCLUSIONS: Compared with a population of trauma patients as inpatients, and excluding those patients mechanically ventilated less than 24 hours, patients intubated in the ED or field have a higher incidence of pneumonia, despite equivalent or lower injury severity.

Half-a-dozen ribs: the breakpoint for mortality.

BACKGROUND: We hypothesized that the number of rib fractures independently impacted patient pulmonary morbidity and mortality. METHODS: The National Trauma Data Bank (NTDB, v. 3.0 American College of Surgeons, Chicago, IL) was queried for patients sustaining 1 or more rib fractures. Data abstracted included the number of rib fractures by International Classification of Diseases-9 code, Injury Severity Score, the occurrence of pneumonia, acute respiratory distress syndrome, pulmonary embolus, pneumothorax, aspiration pneumonia, empyema, and associated injuries by abbreviated injury score, the need for mechanical ventilation, number of ventilator days, intensive care unit (ICU) length of stay (LOS), hospital LOS, mortality, and use of epidural analgesia. Statistical analysis was performed using the Student t test and linear regression analysis. Statistical significance was defined as a P value of less than .05. RESULTS: The NTDB included 731,823 patients. Of these, 64,750 (9%) had a diagnosis of 1 or more fractured ribs. Thirteen percent (n = 8,473) of those with rib fractures developed 13,086 complications, of which 6,292 (48%) were related to a chest-wall injury. Mechanical ventilation was required in 60% of patients for an average of 13 days. Hospital LOS averaged 7 days and ICU LOS averaged 4 days. The overall mortality rate for patients with rib fractures was 10%. The mortality rate increased (P < .02) for each additional rib fracture. The same pattern was seen for the following morbidities: pneumonia (P < .01), acute respiratory distress syndrome (P < .01), pneumothorax (P < .01), aspiration pneumonia (P < .01), empyema (P < .04), ICU LOS (P < .01), and hospital LOS for up to 7 rib fractures (P < .01). An association between increasing hospital LOS and number of rib fractures was not shown (P = .19). Pulmonary embolism also was not related to the number of rib fractures (P = .06). Epidural analgesia was used in 2.2% (n = 1,295) of patients with rib fractures. A reduction in mortality with epidural analgesia was shown at 2, 4, and 6 through 8 rib fractures. The use of epidural analgesia had no impact on the frequency of pulmonary complications. When stratifying data by Injury Severity Score and the presence or absence of rib fractures the mortality rates were similar. CONCLUSIONS: Increasing the number of rib fractures correlated directly with increasing pulmonary morbidity and mortality. Patients sustaining fractures of 6 or more ribs are at significant risk for death from causes unrelated to the rib fractures. Epidural analgesia was associated with a reduction in mortality for all patients sustaining rib fractures, particularly those with more than 4 fractures, but this modality of treatment appears to be underused.

Old fashion clinical judgment in the era of protocols: is mandatory chest X-ray necessary in injured patients?

BACKGROUND: The ATLS Course advocates that injured patients have a chest x-ray (CXR) to identify potential injuries. The purpose of this study was to correlate clinical indications and clinician judgment with CXR results to ascertain if a selective policy would be beneficial. METHODS: Patients treated at a Level I trauma center over 12 months were prospectively evaluated. Before obtaining a CXR, signs, symptoms, and history suggestive of thoracic injury were identified. Additionally, a trauma surgeon (TS) recorded whether in their judgment a CXR was clinically indicated. These findings were compared with final CXR diagnoses. The sensitivity of individual clinical indicators, combinations of clinical indicators, and TS judgment for CXR abnormalities were calculated with a 95% confidence interval. RESULTS: During the twelve-month study period, data were acquired on 772 patients (age 0-102 years). Seventy percent were male and 86.0% were injured by blunt force. Only 29% (N = 222) of the patients manifested one or more of the clinical indicators (signs and symptoms). The negative predictive value for the TS judgment was 98.2% which was superior to the clinical indicators. Reliance on the opinion of the TS to determine the need for a CXR would have eliminated 49.9% of CXRs and avoided hospital and radiologist reading charges totaling $100,078.22. CONCLUSION: Mandatory CXR for all trauma patients has a low yield for abnormal findings. A selective policy relying on surgical judgment guided by clinical indicators is safe and efficacious while reducing cost and conserving resources.

Ventilator-associated pneumonia in injured patients: do you trust your Gram's stain?

BACKGROUND: The results of sputum or bronchoalveolar lavage (BAL) fluid Gram's stain have been used to guide presumptive antibiotic therapy for ventilator-associated pneumonia (VAP) in injured patients, despite reported variability in sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Our aim was to evaluate the utility of Gram's stain of BAL fluid in the diagnosis of VAP. METHODS: We conducted a retrospective chart review of all mechanically ventilated trauma patients who developed pneumonia over a 5-year period in whom Gram's stain and final culture data were available. RESULTS: One hundred fifty-five records with complete data sets were reviewed. VAP was diagnosed by Centers for Disease Control and Prevention criteria and confirmed by BAL and quantitative culture in all patients. Overall accuracy of Gram's stain in diagnosing VAP for any organism was 88% (137 true-positives). When assessed for the ability to predict pneumonia caused by a specific organism, the accuracy decreased significantly, with only 63% of Gram-negative VAPs and 72% of Gram-positive VAPs accurately identified by Gram's stain. However, the absence of Gram-positive organism of Gram's stain excludes Gram-positive VAP in 80% of patients. CONCLUSION: All trauma patients should be covered presumptively for gram-negative organisms, as they encompass 70% of infections, but are not reliably identified by Gram's stain. As 88% of VAP can be identified by the presence of any organism on Gram's stain, it may be useful in the early diagnosis of VAP but cannot reliably be used to guide presumptive therapy.

Reasons to omit digital rectal exam in trauma patients: no fingers, no rectum, no useful additional information.

BACKGROUND: Performance of digital rectal examination (DRE) on all trauma patients during the secondary survey has been advocated by the Advanced Trauma Life Support course. However, there is no clear evidence of its efficacy as a diagnostic test for traumatic injury. The purpose of this study is to analyze the value of a policy mandating DRE on all trauma patients as part of the initial evaluation process and to discern whether it can routinely be omitted. METHODS: Prospective study of patients treated at a Level I trauma center. Clinical indicators other than DRE (OCI) denoting gastrointestinal bleeding (GIB), urethral disruption (UD), or spinal cord injury (SCI) were sought and correlated with DRE findings suggesting the same. Impression of the examining physician as to the need and value of DRE was also studied. Patients with a Glasgow Coma Scale Score (GCS) of 3 and pharmacologically paralyzed were excluded from the SCI analyses. UD analysis included only males. RESULTS: In all, 512 cases were studied (72% male, 28% female) ranging in age from 2 months to 102 years. Thirty index injuries were identified in 29 patients (6%), 17 SCI (3%), 11 GIB (2%), and 2 UD (0.4%). DRE findings agreed positively or negatively with one or more OCI of index injuries in 93% of all cases (92% seeking SCI, 90% seeking GIB, 96% seeking UD). Overall, negative predictive value of DRE was the same as that of OCI, 99% (SCI 98% versus 99%, GIB, 97% versus 99%, UD both 100%). Positive predictive value for DRE was 27% and for OCI 24% (SCI 47% versus 44%, GIB 15% versus 18%, UD 33% versus 6%). Efficiency of DRE was 94% and OCI was 93%. For confirmed index injuries, indicative DRE findings were associated with 41% and OCI 73% (SCI 36% versus 79%, GIB 36% versus 73%, UD 50% versus 100%). OCIs were present in 81% of index injury cases. In all index injury cases where OCIs were absent, positive DRE findings were also absent. DRE was felt to give additional information in 5% of all cases and change management in 4%. In cases where the clinician felt DRE was definitely indicated (29%) it reportedly gave no additional information in 85% and changed management in 11%. CONCLUSION: DRE is equivalent to OCI for confirming or excluding the presence of index injuries. When index injuries are demonstrated, OCI is more likely to be associated with their presence. DRE rarely provides additional accurate or useful information that changes management. Omission of DRE in virtually all trauma patients appears permissible, safe, and advantageous. Elimination of routine DRE from the secondary survey will presumably conserve time and resources, minimize unpleasant encounters, and protect patients and staff from the potential for further harm without any significant negative impact on care and outcome.

Ten year experience of burn, trauma, and combined burn/trauma injuries comparing outcomes.

BACKGROUND: Percent total body surface area (TBSA) burn, inhalation injury (INH), and age all have been shown to be independent predictors of mortality in burn victims. Little is known regarding patients sustaining combined thermal and mechanical injuries in relation to either injury sustained in isolation or with regard to these variables. This descriptive study profiles the 10-year experience of a single American Burn Association/American College of Surgeons verified Level I trauma and burn center and the treatment of this patient population. METHODS: A retrospective review of all burn and trauma patients admitted between 1990 and 2000. Patients were divided into three groups; Burn only (B), Trauma only (T), and combined Burn/Trauma (B/T). Groups were compared with respect to age, TBSA burn, length of stay (LOS), Injury Severity Score (ISS), INH and mortality. These groups were then compared with B, T and B/T patients from the National Burn Repository (NBR) and National Trauma Data Bank (NTDB). Student's t test and chi tests were performed, as well as multiple logistic regression to identify independent predictors of mortality. p <0.05 was considered significant. RESULTS: Through our trauma registry, 24,093 patients were identified (T=22,284, B=1717 and B/T=92). When comparing B and T, there was no difference in age, LOS, ISS, or mortality to those patients in the NBR or NTDB. B/T patients showed significantly increased percentage with INH (B/T=44.5% versus 11%), increased LOS (B/T=18 days versus 13.7 B and 5.3 T) and increased mortality (B/T=28.3% versus 9.8% B and 4.3% T). B/T were also significantly older (B/T=40.1 years versus 31.0 B and 35.1 T). When these variables are compared with the NBR and the NTDB benchmarks, mortality (28.3% versus 11.6% NBR and 7.0% NTDB) and ISS (23 versus 11.7 NTDB) were significantly higher with no difference in age (40.1 versus 33.4 NTDB, 35.9 NBR), LOS (18 days versus 23.3 NBR) or TBSA (20.8% versus 19.5% NBR). Multiple logistic regression comparing TBSA, age, ISS and INH of survivors versus non-survivors identified only ISS as an independent predictor of mortality. CONCLUSION: B combined with T presents a rare injury pattern that has a synergistic effect on mortality. Physicians and caregivers should be aware of a 2-3 fold increase in the incidence of INH in this population, and increased mortality despite similar TBSA burned when compared with patients with B as the sole mechanism; ISS appears to be an independent predictor of mortality in this combined injury pattern.

Urgent airways after trauma: who gets pneumonia?

BACKGROUND: Several risk factors, including emergent intubation, severe head injury, shock, blunt trauma, and high severity of injury, have been identified as risk factors for the development of pneumonia after trauma. This study assesses the contribution of emergent intubation to the development of pneumonia after injury. METHODS: A retrospective review of all trauma patients requiring intubation or cricothyroidotomy in the Emergency Department (ED) or in the pre-hospital area (field) over a 41/2 year period. RESULTS: 571 patients comprised the study population. Of these, 80% had airways established in the ED, while 20% were intubated in the field. Field intubation was associated with a lower Glasgow Coma Scale (GCS) score (p <0.0001) and more severe injury (p <0.0001), particularly to the chest and extremities.Twenty-five percent of the population developed pneumonia. Patients diagnosed with pneumonia were older (p=0.009), and had a higher ISS (p <0.0001), lower GCS score, (p <0.008), longer ICU and hospital length of stay (p < 0.0001). Injuries to the head, thorax and extremities were more common (p < 0.05) and more severe (p <0.05) in patients developing pneumonia. The incidence of pneumonia after field airway was significantly higher (35% versus 23%, p=0.048).Multiple logistic regression analysis identified field intubation, age, AIS-head, and AIS-extremity as independent risk factors for pneumonia. CONCLUSION: Pre-hospital but not ED intubation is an independent risk factor for the development of post-traumatic pneumonia. Other predictors include the severity of injury, specifically head and extremity injuries.

Burn injury and pulmonary sepsis: development of a clinically relevant model.

BACKGROUND: Despite improvements in the early resuscitation of the critically injured, mortality from multiple organ failure has remained stable, with the lung often the first organ to fail. Early intubation and mechanical ventilation predispose patients to the development of pneumonia and respiratory failure. Our objective was to establish a murine model of combined injury, consisting of burn/trauma and pulmonary sepsis with reproducible end-organ responses and mortality. METHODS: Male B6D2F1 mice were divided into four groups: burn/infection (BI), burn (B), infection (I), and sham (S). Burned animals had a full-thickness 15% dorsal scald burn. BI and I groups were inoculated intratracheally with Pseudomonas aeruginosa (3-5 x 103 colony-forming units). S and B animals received saline intratracheally. All animals were resuscitated with 2 mL of intraperitoneal saline. Mortality was recorded at 24, 48, and 72 hours. Bacterial sepsis was confirmed by tissue Gram's stain of the lungs and positive organ and blood cultures for Pseudomonas aeruginosa. Femoral bone marrow cells were collected at 72 hours from surviving animals. Clonogenic potential was assessed by response to macrophage (M) colony-stimulating factor (CSF) and granulocyte-macrophage (GM) CSF in a soft agar assay and the data were represented as colonies per femur. Isolated alveolar macrophages and whole lung tissue were assayed for levels of the inflammatory cytokines tumor necrosis factor-alpha and interleukin-6. RESULTS: Mortality at 72 hours was 30% in BI, 12% in I, and <10% in B and S groups. Pneumonia was documented in all infected animals at 24 hours by Gram's stain and positive tissue cultures for Pseudomonas aeruginosa. Systemic sepsis as confirmed by blood, and remote organ cultures was seen in BI animals only. Significantly increased responsiveness to M-CSF stimulations was noted in all groups (BI, 8,291 +/- 1,402 colonies/femur; B, 6,357 +/- 806 colonies/femur; and I, 8,054 +/- 1,112 colonies/femur; p < 0.05) relative to sham (3,369 +/- 883 colonies/femur, p < 0.05). Maximal responsiveness to GM-CSF stimulation was noted in the BI group (11,932 +/- 982 colonies/femur, p < 0.05), and similar GM responsiveness was noted in all other groups (B, 7,135 +/- 548 colonies/femur; I, 7,023 +/- 810 colonies/femur; and S, 6,829 +/- 1,439 colonies/femur). Alveolar macrophage release of the proinflammatory cytokines tumor necrosis factor-alpha and interleukin-6 increased in all animals, but the magnitude of increase was not proportional to the strength of the inciting stimulus. CONCLUSION: Although minimal perturbations were seen after burn or pulmonary infection alone, the combined insult of burn and pulmonary sepsis resulted in statistically significant hematopoietic changes with increased monocytopoiesis. Only the combined injury resulted in systemic sepsis and significantly increased mortality. We have developed a clinically relevant model of trauma and pulmonary sepsis that will allow further clarification of the inflammatory response after injury and infection.

Mechanism of injury does not predict acuity or level of service need: field triage criteria revisited.

BACKGROUND: Trauma systems use specific criteria based on physiologic, anatomic, and mechanistic factors for field triage. The purpose of this study was to evaluate the emergency department disposition of patients not meeting mandatory criteria (ie, physiologic or anatomic factors) for triage to a trauma center and the potential for over- or undertriage. METHODS: This was a retrospective review of trauma admissions from July 1999 to June 2001, to a level I trauma center. Triage criteria were classified as physiologic factors (n=300), anatomic factors (n=115), or mechanistic factors (n=414), according to the criteria of the American College of Surgeons Committee on Trauma. Physiologic and anatomic factors were combined and compared with mechanistic factors. RESULTS: There were 1253 admissions during the study period. Sixty-six percent (n=830) met study inclusion criteria. Fifty percent (n=413) were admitted to the intensive care unit or operating room. Approximately 50% of each group (physiologic/anatomic, 52%; mechanistic, 47%; P=.08) were admitted directly to the operating room or to the intensive care unit. CONCLUSIONS: Patients not meeting mandatory criteria for transfer to a trauma center often have serious injuries that require a higher level of care. The inclusion of all or select mechanistic criteria for evaluation at a trauma center is appropriate to achieve an acceptable rate of clinical undertriage, as well as resource undertriage and its subsequent complications.

Blunt aortic injury with concomitant intra-abdominal solid organ injury: treatment priorities revisited.

BACKGROUND: Patients with blunt aortic injury (BAI) often have concomitant liver or spleen (L/S) injuries. With increasing use of cardiopulmonary bypass with heparinization in repair of BAI, many advocate operative management of the L/S injury before aortic repair to eliminate risk of hemorrhage. We evaluated the safety of nonoperative management (NOM) of blunt L/S injuries in patients undergoing acute BAI repair with bypass. METHODS: All patients admitted over a 6-year period with BAI were identified from the registry of our Level I trauma center. Patients with isolated L/S injuries without BAI admitted over the same period served as controls. Groups were compared with regard to demographics, injury characteristics, hospital course, and mortality. RESULTS: Eighty-four patients were diagnosed with BAI from 1994 to 2000; 28 (33%) also had blunt abdominal trauma. Three patients with severe brain injury did not undergo BAI repair, and five required laparotomy before BAI repair for other intra-abdominal injuries (two for hemodynamic instability with splenic injury, and three for concomitant bowel injury). Therefore, 20 of 28 (71.4%) BAI patients with grade I or II L/S injury (Aorta L/S group) underwent planned NOM. All BAIs were repaired using partial bypass with full heparinization. These 20 patients are compared with 894 patients with grade I or II L/S injuries with no BAI (L/S group) over the same time period. There was no difference in the nonoperative failure rate of the Aorta L/S group versus the L/S group (0% vs. 1.7%). Both groups had similar complication rates. The Aorta L/S group was also compared with 56 BAIs without solid organ injury (Aorta group). Although the Aorta L/S group was more severely injured than the Aorta group (Injury Severity Score of 35.3 vs. 26.8, < 0.0001), transfusion rates (5.7 U of packed red blood cells vs. 8.0 U of packed red blood cells, p = NS), hospital days (17.9 vs. 19.1, p = NS) and mortality (10% vs. 9%, p = NS) were similar. CONCLUSION: NOM of patients with grade I or II L/S injury who undergo systemic anticoagulation with heparin for repair of BAI is safe and associated with transfusion rates similar to BAI alone. Patients with low-grade liver or spleen injuries do not require laparotomy before BAI repair using partial bypass.