Marc J. Shapiro

The CRIT Study: Anemia and blood transfusion in the critically ill--current clinical practice in the United States.

ObjectiveTo quantify the incidence of anemia and red blood cell (RBC) transfusion practice in critically ill patients and to examine the relationship of anemia and RBC transfusion to clinical outcomes. DesignProspective, multiple center, observational cohort study of intensive care unit (ICU) patients in the United States. Enrollment period was from August 2000 to April 2001. Patients were enrolled within 48 hrs of ICU admission. Patient follow-up was for 30 days, hospital discharge, or death, whichever occurred first. SettingA total of 284 ICUs (medical, surgical, or medical-surgical) in 213 hospitals participated in the study. PatientsA total of 4,892 patients were enrolled in the study. Measurements and Main ResultsThe mean hemoglobin level at baseline was 11.0 ± 2.4 g/dL. Hemoglobin level decreased throughout the duration of the study. Overall, 44% of patients received one or more RBC units while in the ICU (mean, 4.6 ± 4.9 units). The mean pretransfusion hemoglobin was 8.6 ± 1.7 g/dL. The mean time to first ICU transfusion was 2.3 ± 3.7 days. More RBC transfusions were given in study week 1; however, in subsequent weeks, subjects received one to two RBC units per week while in the ICU. The number of RBC transfusions a patient received during the study was independently associated with longer ICU and hospital lengths of stay and an increase in mortality. Patients who received transfusions also had more total complications and were more likely to experience a complication. Baseline hemoglobin was related to the number of RBC transfusions, but it was not an independent predictor of length of stay or mortality. However, a nadir hemoglobin level of <9 g/dL was a predictor of increased mortality and length of stay. ConclusionsAnemia is common in the critically ill and results in a large number of RBC transfusions. Transfusion practice has changed little during the past decade. The number of RBC units transfused is an independent predictor of worse clinical outcome.

Prospective Study of Blunt Aortic Injury: Multicenter Trial of the American Association for the Surgery of Trauma

BACKGROUND Blunt aortic injury is a major cause of death from blunt trauma. Evolution of diagnostic techniques and methods of operative repair have altered the management and posed new questions in recent years. METHODS This study was a prospectively conducted multi-center trial involving 50 trauma centers in North America under the direction of the Multi-institutional Trial Committee of the American Association for the Surgery of Trauma. RESULTS There were 274 blunt aortic injury cases studied over 2.5 years, of which 81% were caused by automobile crashes. Chest computed tomography and transesophageal echocardiography were applied in 88 and 30 cases, respectively, and were 75 and 80% diagnostic, respectively. Two hundred seven stable patients underwent planned thoracotomy and repair. Clamp and sew technique was used in 73 (35%) and bypass techniques in 134 (65%). Overall mortality was 31%, with 63% of deaths being attributable to aortic rupture; mortality was not affected by method of repair. Paraplegia occurred postoperatively in 8.7%. Logistic regression analysis demonstrated clamp and sew (p = 0.002) and aortic cross clamp time of > or = 30 minutes (p = 0.01) to be associated with development of postoperative paraplegia. CONCLUSIONS Rupture after hospital admission remains a major problem. Although newer diagnostic techniques are being applied, at this time aortography remains the diagnostic standard. Aortic cross clamp time beyond 30 minutes was associated with paraplegia; bypass techniques, which provide distal aortic perfusion, produced significantly lower paraplegia rates than the clamp and sew approach.

Multiple organ failure in trauma patients.

SUMMARY BACKGROUND As care of the critically ill patient has improved and definitions of organ failure have changed, it has been observed that the incidence of organ failure and the mortality associated with organ failure appear to be decreasing. In addition, many early studies included large heterogeneous populations of both medical and surgical patients that may have influenced the incidence and outcome of organ failure. The purpose of this study is to establish the current incidence and mortality of organ failure in a homogenous population of critically ill trauma patients. METHODS All trauma patients admitted to the intensive care unit (ICU) at an urban Level I trauma center were prospectively studied. Patients were evaluated for the presence of organ failure using definitions proposed by Knaus and by Fry. Newer definitions of organ failure incorporating organ dysfunction and severity-of-illness scores were also obtained in all patients in an attempt to predict outcome. These included lung injury scores (acute respiratory distress syndrome scores), Acute Physiology and Chronic Health Evaluation (APACHE) II and III scores, Injury Severity Score (ISS), and multiple organ dysfunction scores. Primary outcomes assessed were death and the occurrence of organ failure by the various definitions. RESULTS Eight hundred sixty-nine trauma patients were admitted to the ICU and survived longer than 48 hours. Mean APACHE II and APACHE III scores at admission to the ICU and ISS were 12.2 +/- 22, 30.5 +/- 22.7, and 19 +/- 10, respectively. Single organ failure (SOF) occurred in 163 patients (18.7%) and multiple organ failure occurred in 44 patients (5.1%). All SOF was caused by respiratory failure. Respiratory failure occurred first in the majority of patients with multiple organ failure. Mortality was 4.3% with one organ system failure, 32% with two, 67% with three, and 90% when four organ systems failed. None of the patients with SOF died secondary to respiratory failure. Multiple stepwise regression analysis was performed to determine which of the following risk factors are associated with the occurrence of organ failure: mechanism of injury, lactate at 24 hours, ISS, APACHE II, APACHE III, acute respiratory distress syndrome score at admission, multiple organ dysfunction score at admission and total blood products transfused in 24 hours. Of these factors, APACHE III, lactate at 24 hours, and total blood products transfused in 24 hours were associated with the occurrence of organ failure. CONCLUSION The overall incidence of organ failure in a homogeneous trauma population appears to be lower than that reported in studies performed in heterogeneous patient populations in the 1980s. Mortality for SOF is low and appears to be related primarily to the patients underlying injuries and not to organ failure. Mortality for two or three organ system failures is lower than reported 15 to 20 years ago. Mortality for patients with four or more organ system failures remains high, approaching 100%.

Penetrating esophageal injuries: Multicenter study of the American Association for the Surgery of Trauma

OBJECTIVE The purpose of this study was to define the period of time after which delays in management incurred by investigations cause increased morbidity and mortality. The outcome study is intended to correlate time with death from esophageal causes, overall complications, esophageal related complications, and surgical intensive care unit length of stay. METHODS This was a retrospective multicenter study involving 34 trauma centers in the United States, under the auspices of the American Association for the Surgery of Trauma Multi-institutional Trials Committee over a span of 10.5 years. Patients surviving to reach the operating room (OR) were divided into two groups: those that underwent diagnostic studies to identify their injuries (preoperative evaluation group) and those that went immediately to the OR (no preoperative evaluation group). Statistical methods included Fishers exact test, Students T test, and logistic regression analysis. RESULTS The study involved 405 patients: 355 male patients (86.5%) and 50 female patients (13.5%). The mean Revised Trauma Score was 6.3, the mean Injury Severity Score was 28, and the mean time interval to the OR was 6.5 hours. There were associated injuries in 356 patients (88%), and an overall complication rate of 53.5%. Overall mortality was 78 of 405 (19%). Three hundred forty-six patients survived to reach the OR: 171 in the preoperative evaluation group and 175 in the no preoperative evaluation group. No statistically significant differences were noted in the two groups in the following parameters: number of patients, age, Injury Severity Score, admission blood pressure, anatomic location of injury (cervical or thoracic), surgical management (primary repair, resection and anastomosis, resection and diversion, flaps), number of associated injuries, and mortality. Average length of time to the OR was 13 hours in the preoperative evaluation group versus 1 hour in the no preoperative evaluation group (p < 0.001). Overall complications occurred in 134 in the preoperative evaluation group versus 87 in the no preoperative evaluation group (p < 0.001), and 74 (41%) esophageal related complications occurred in the preoperative evaluation group versus 32 (19%) in the no preoperative evaluation group (p = 0.003). Mean surgical intensive care unit length of stay was 11 days in the preoperative evaluation group versus 7 days in the no preoperative evaluation group (p = 0.012). Logistic regression analysis identified as independent risk factors for the development of esophageal related complications included time delays in preoperative evaluation (odds ratio, 3.13), American Association for the Surgery of Trauma Organ Injury Scale grade >2 (odds ratio, 2.62), and resection and diversion (odds ratio, 4.47). CONCLUSION Esophageal injuries carry a high morbidity and mortality. Increased esophageal related morbidity occurs with the diagnostic workup and its inherent delay in operative repair of these injuries. For centers practicing selective management of penetrating neck injuries and transmediastinal gunshot wounds, rapid diagnosis and definitive repair should be made a high priority.

The Use of Oxygen Consumption and Delivery as Endpoints for Resuscitation in Critically III Patients

OBJECTIVE Oxygen consumption (VO2I) and delivery (DO2I) indices have been stated to be superior to conventional parameters as endpoints for resuscitation. However, another interpretation of published data is that inability to increase VO2I/DO2I given adequate volume resuscitation reflects inadequate physiologic reserve and poor outcome. DESIGN Fifty-eight critically ill patients were randomized to two groups. In group 1 (27 patients) attempts were made to maintain VO2I > or = 150 or DO2I > or = 600 mL/min/m2. If DO2I was > 600, no attempt was made to increase VO2I even if it was < 150. Group 2 (31 patients) was resuscitated based on conventional parameters. Volume resuscitation protocols and goals for pulmonary capillary wedge pressure were the same in both groups. VO2I/DO2I were recorded in group 2, but physicians were blinded to this data. Age, Injury Severity Score, and Acute Physiology and Chronic Health Evaluation (APACHE II) score were not different between groups. MAIN RESULTS Three patients in group 1 and two patients in group 2 died of organ failure (OF). One additional patient in group 2 died of refractory shock within 24 hours. Two of the patients in group 1 who died failed to meet VO2I/DO2I goals within 24 hours despite maximal resuscitation. Mortality was not different between the groups even with exclusion of the group 1 patients who failed to meet VO2I/DO2I goals (p = 0.66). After exclusion of the patient in group 2 who died of refractory shock, OF occurred in 18 of 27 (67%) in group 1 and in 22 of 30 (73%) in group 2 (p = 0.58). Length of ventilator support, intensive care unit stay, and hospital stay were not different between groups. When all patients were assessed, no difference was found in the incidence of OF between patients who attained the VO2I goal and those who did not. OF occurred in 20 of 34 (59%) patients who maintained a mean DO2I > or = 600 during the first 24 hours of the study and in 21 of 24 (88%) of those who did not (p < 0.02). CONCLUSIONS No difference was found in the incidence of OF or death in patients resuscitated based on oxygen transport parameters compared to conventional parameters. These data suggest that given adequate volume resuscitation, oxygen-based parameters are more useful as predictors of outcome than as endpoints for resuscitation.

Outcome and utility of scoring systems in the management of the mangled extremity

BACKGROUND The role of scoring systems as predictors of amputation and functional outcome in severe blunt extremity trauma was examined. METHODS All severe extremity injuries treated over a 10-year period were scored retrospectively using four scoring systems: Mangled Extremity Syndrome Index (MESI), Mangled Extremity Severity Score (MESS), Predictive Salvage Index (PSI), and Limb Salvage Index (LSI). RESULTS Twenty-three upper (UE) and 51 lower extremity (LE) injuries were evaluated. Sensitivity and specificity, respectively, were MESI 100% and 50%, MESS 79% and 83%, PSI 96% and 50%, and LSI 83% and 83%. For each system, there were no differences between patients with good and poor functional outcomes. CONCLUSION All of the scoring systems were able to identify the majority of patients who required amputation. However, prediction in individual patients was problematic. None of the scoring systems were able to predict functional outcome.

Cardiovascular evaluation in blunt thoracic trauma using transesophageal echocardiography (TEE)

Blunt chest trauma can result in significant cardiothoracic injury, which can include cardiac contusion, aortic injury, and myocardial valvular injury. Nineteen patients with no prior history of cardiac abnormalities who sustained severe blunt chest trauma and had widening of the mediastinum on chest radiographs were prospectively evaluated using transesophageal echocardiography (TEE). In each instance TEE was performed without difficulty, excellent images were obtained of the aorta and heart, and no complications were noted. Abnormalities were seen in 12 (63%) patients, with hypokinetic regional wall motion consistent with cardiac contusion demonstrated in five (26%) patients. Tricuspid regurgitation was found in three (16%) patients, and aortic and mitral regurgitation in one (5%) patient each. Aortic wall hematomas were seen in two patients, one of whom had an intimal tear on aortography, and a pericardial effusion was seen in one patient with an aortic intimal tear confirmed angiographically. Thus TEE can be performed safely in the acute setting of patients sustaining severe blunt chest trauma and yield useful information with respect to cardiovascular function and the aorta.

The unreliability of CT scans and initial chest radiographs in evaluating blunt trauma induced diaphragmatic rupture

OBJECTIVE There is no gold standard for early and reliable diagnosis of traumatic diaphragmatic rupture (TDR). The purpose of this study is to correlate CT scans, chest radiographs, and intubation on the ability to diagnosis traumatic diaphragmatic rupture. MATERIALS AND METHODS Twenty patients with blunt trauma induced diaphragmatic rupture were identified from a five year review of a Level 1 Trauma Registry. RESULTS Ten of the 20 (50%) patients had TDR on initial chest X-ray, all on the left side. Twelve patients had both chest X-rays and a chest and abdominal CT scan; however, only five (42%) of the CT scans were diagnostic. Of the 12 patients initially intubated, TDR was diagnosed in only four (33%) patients on initial chest X-ray and in one (14%) of seven patients having chest and abdominal CT scans and being intubated. CONCLUSION The early diagnosis of blunt traumatic diaphragmatic rupture, especially in intubated patients, continues to be a diagnostic dilemma. There is a significantly better possibility of identifying left over right-sided TDR (P < or = 0.05). Diagnosing TDR is also facilitated by extubation. If the suspicion exists, a post extubation chest radiograph should be performed to evaluate for TDR.

Computed tomography in the diagnosis of blunt thoracic injury

BACKGROUND Computed tomography (CT) is an important diagnostic modality in the evaluation of blunt head and abdominal injuries, but it has not been routinely used to evaluate blunt chest trauma. METHODS One hundred seventy stable patients with blunt thoracic trauma were evaluated with chest x-ray (CXR), and subsequently by CT. RESULTS Of a total of 131 fractures, 53% were identified on initial CXR, 39% on CT, and 26% were not seen on either study. Twenty-one pneumothoraces were seen on CT but not on CXR. Chest tubes were placed in 8 patients and 12 patients were observed without incident. One hemothorax identified by CT scan alone required treatment. Four of 6 diaphragmatic injuries were seen on CT and 2 on CXR. Parenchymal abnormalities were apparent in 189 lung fields on CT and in 66 lung fields on CXR. Most represented atelectasis and did not require treatment. Altogether, CT scanning resulted in changes in management for 11 patients (6%). CONCLUSIONS Although CXR is less sensitive in detecting parenchymal and pleural injuries than CT, the majority of the injuries identified by CT alone are minor and require no treatment. CXR remains the primary modality for diagnostic evaluation of blunt thoracic trauma.

Anemia and blood transfusion in trauma patients admitted to the intensive care unit

BACKGROUND Anemia is a common occurrence in the intensive care unit (ICU). Although resuscitation, including the use of blood, is a mainstay of early treatment of trauma victims, the safety and efficacy of red blood cell (RBC) transfusion has come under scrutiny recently. The issue of blood use in critically injured patients requires evaluation. METHODS This was a post hoc analysis of a subset of trauma patients (> or =18 years in age) from a prospective, multicenter, observational, cohort study in the United States. Patients were enrolled within 48 hours after ICU admission and followed for up to 30 days, or until hospital discharge or death. RESULTS Five hundred seventy-six patients from 111 ICUs in 100 hospitals were enrolled between August 2000 and April 2001. At baseline, mean age was 44.1 +/- 20.2 years, 73.6% were men, and mean APACHE II score was 16.9 +/- 8.2. Mean baseline hemoglobin was 11.1 +/- 2.4 g/dL and patients remained anemic throughout the study either with or without transfusion; 55.4% of patients were transfused (mean, 5.8 +/- 5.5 units) during the ICU stay and 43.8% of patients had an ICU length of stay > or = 7 days. Mean pretransfusion hemoglobin was 8.9 +/- 1.8 g/dL. Mean age of RBCs transfused was 20.1 +/- 11.4 days. As compared with the full study population, patients in the trauma subset were more likely to be transfused and received an average of 1 additional unit of blood. CONCLUSION Anemia is common in critically injured trauma patients and persists throughout the duration of critical illness. These patients receive a large number of RBC transfusions during their ICU course with aged blood.