Blood product transfusion and ventilator-associated pneumonia in trauma patients.

BACKGROUND: Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in trauma patients, with a high mortality rate. Blood transfusion has been identified as an independent risk factor for VAP in critically ill patients. Prior studies in trauma are limited by retrospective design, lack of multivariable analyses, and scant data on the timing of transfusion. We examined critically the relation between blood product transfusion and VAP in trauma patients. METHODS: Prospective observational cohort study of 766 trauma patients admitted to the intensive care unit (ICU), who received mechanical ventilation (MV) for >or= 48 h, and who did not have pneumonia on admission. Late-onset VAP was defined as that occurring >or= 72 h after MV. Only transfusions of red blood cell (RBC) concentrate, fresh-frozen plasma (FFP), or platelets before the onset of VAP were considered. Logistic regression analyses controlled for all variables related significantly to VAP by univariate analysis (sex, Injury Severity Score, and ventilator days and ICU length of stay prior to VAP). RESULTS: A significantly greater proportion of male patients developed VAP. Patients with VAP had a longer duration of MV: The mean number ventilator days prior to VAP was 11.1 +/- 8.0. Transfusion of blood products was an independent risk factor for VAP, and the risk increased with more units transfused. All blood products were associated with a higher risk of VAP (RBC: odds ratio [OR] 4.41; 95% confidence interval [CI] 1.00, 19.54; p = 0.05; FFP: OR 3.34; 95% CI 1.18, 9.43; p = 0.023; platelets: OR 4.19; 95% CI 1.37, 12.83; p = 0.012). CONCLUSION: Blood product transfusion is an independent risk factor for VAP in trauma, and the odds ratio is significantly higher (3.34-4.41) than in published studies of other types of ICU patients (1.89). To reduce the incidence of VAP, all efforts to reduce the transfusion of blood products to trauma patients should be implemented.

Increased intra-abdominal, intrathoracic, and intracranial pressure after severe brain injury: multiple compartment syndrome.

OBJECTIVES: Fluid therapy and/or acute lung injury may increase intra-abdominal pressure (IAP) and intrathoracic pressure, thereby increasing intracranial pressure (ICP) after traumatic brain injury (TBI). Further fluid administration to support cerebral perfusion or increasing ventilatory support to treat acute lung injury further increases ICP. This can create a cycle that ultimately produces multiple compartment syndrome (MCS). Both decompressive craniectomy (DC) and decompressive laparotomy (DL) decrease ICP. DL can also decrease IAP and ICP. We evaluated the serial application of DC and DL to treat MCS. METHODS: Data were analyzed for 102 consecutive patients with severe TBI who underwent DC alone to decrease ICP or in combination with DL to treat MCS. RESULTS: All 102 patients sustained blunt injury. Seventy percent were men with a mean age of 29.5 years, an Injury Severity Score of 34.4, and admission Glasgow Coma Scale score of 7.1. Fifty-one patients had diffuse brain injury and 51 had mass lesions. Seventy-eight patients (76%) underwent DC alone. Twenty-four (22%) had both therapies for MCS. Fifteen patients had DC before DL and nine had DL before DC. Mean time between DC and DL was 3.4 +/- 6 days. The mean IAP before DL was 28 +/- 5 mm Hg. Twenty-four-hour cumulative mean intrathoracic pressure decreased significantly after DL in the MCS group (p = 0.01). Mean ICP decreased significantly after both DC and DL (p < 0.05). CONCLUSION: Increased ICP may be from primary TBI or MCS. Patients with MCS have a higher Injury Severity Score, ICP, and fluid requirements, but no increase in mortality. Both DC and DL reduce ICP and can be used in sequence. MCS should be considered in multiply injured patients with increased ICP that does not respond to therapy.

Incidence and impact of risk factors in critically ill trauma patients.

There is a paucity of data describing the incidence of pre-existing diseases or risk factors and their effects in trauma patients. We conducted a prospective study to determine the incidence of such factors in critically ill trauma patients and to evaluate their impact on outcome. The study, performed over a 2-year period, examined the hospital course of all trauma patients admitted to the ICU. Multiple risk factors were evaluated and analyzed via multivariate regression analysis. Outcome was evaluated by infection rate, hospital length of stay, ventilator days, and mortality matched for age and Injury Severity Score (ISS). A total of 1172 patients (73% blunt injury) were enrolled over the study period. Of these, 873 (74.5%) were male. The mean age was 42.5 years with an ISS of 19.8. Tobacco use (24%) was the most common risk factor identified, followed by hypertension (HTN, 17%), coronary artery disease (9%), chronic obstructive pulmonary disease (COPD)/reactive airway disease (4%), non-insulin-dependent diabetes (NIDDM) (4%), insulin-dependent diabetes (IDDM) (3.2%), cancer (3%), liver disease (2%), and HIV/AIDS (1.4%). Of these risk factors, IDDM was found to be an independent risk factor for infection (0.004) and ventilator days (0.047), increasing age was found to be an independent risk factor for hospital length of stay (0.023) and mortality (<0.001), and HTN was found to be an independent risk factor for increased ventilator days (0.04). In addition, COPD/reactive airway disease was found to be an independent predictor of ventilator days, infection, and ICU days (P < 0.05). Thus, increased age, IDDM, COPD, and HTN are most predictive of outcome in critically ill trauma patients. With our aging population it is becoming increasingly important to identify pre-existing risk factors on admission in order to minimize their effects on outcome.

Safety of uncrossmatched type-O red cells for resuscitation from hemorrhagic shock.

BACKGROUND: Uncrossmatched type-O packed red blood cells (UORBC) are recommended for immediate transfusion in hemorrhaging trauma patients. The potential for alloimmunization with this technique is controversial, and has been reported to be as high as 80%. We examined a 1-year experience with UORBC transfusion to determine the incidence of allergic reaction and alloimmunization. METHODS: Blood Bank and Trauma Registry databases for the year 2000 were linked to determine the incidence of UORBC use and the characteristics of patients, including the incidence of transfusion reactions and seroconversion of Rh-patients. Ten units of type-O, Rh+ blood (and two units of O-blood for women of childbearing age) were available for immediate transfusion, 30 to 45 minutes sooner than type-specific or crossmatched red blood cells. UORBC were administered to any patient with signs of severe hemorrhagic shock, at the discretion of the attending physician. RESULTS: In all, 480 trauma patients (out of 5,623 admitted) received transfusions of RBC, totaling 5,203 units. Five hundred eighty-one units of UORBC were given to 161 patients. Average Injury Severity Score in the UORBC cohort was 33.8. Patients receiving UORBC received an average of 16.9 total units of red blood cells, 14 units of plasma, and 10 units of platelets. Seventy-three patients died (45%). There were no acute hemolytic transfusion reactions observed in the patients who received UORBC. Four Rh-women received UORBC, all O-. Ten Rh-men received O+ blood, and only one developed antibodies to the Rh antigen. CONCLUSION: The need for UORBC is associated with significant injury and the need for subsequent massive transfusion. In this largest reported trauma series, the use of UORBC enabled rapid administration of red cells to hemorrhaging patients, without discernible risk for transfusion-related complications. The rate of seroconversion of Rh-patients is lower than reported in the literature, perhaps due to immune suppression associated with hemorrhagic shock.

Reclassification of urinary tract infections in critically ill trauma patients: a time-dependent analysis.

BACKGROUND: Successful treatment of urinary tract infections (UTIs) in the trauma ICU requires early recognition and timely, appropriate antibiotic therapy. We evaluated the incidence and microbiology of UTIs stratified by days post-admission and risk factors. METHODS: Prospective data were collected on 1,172 trauma patients admitted to the ICU over a two-year period. Infections were classified as Community Acquired (CA, < or = 3 days), Early Nosocomial (EN, 4-6 days), Mid-Nosocomial (MN, 7-10 days) and Late Nosocomial (LN > 10 days). Criteria of the U.S. Centers for Disease Control and Prevention (CDC) were used for diagnosis. RESULTS: Two hundred twenty patients (19%) were diagnosed with a total of 235 UTIs. Thirtysix patients were diagnosed with multiple UTIs. Escherichia coli, Enterococcus sp. and Candida sp. were the most common pathogens isolated. One thousand one hundred fifty-one patients had a Foley catheter placed (mean duration, 1 +/- 11 days) with a CDC device-related infection rate (no. of catheter-associated UTIs/1000 catheter days) of 18. Patients admitted with a CA infection were significantly older (p < 0.001) and had a higher mortality rate (39% vs. 15%, p = 0.001). Unanticipated pathogens in this group included Enterococcus, Candida, and Pseudomonas. Women were more likely to be admitted with a CA infection (5% vs. 1%, p < 0.001) or acquire an NI infection (23% vs. 15%, p < 0.001). Obesity was highly predictive of increased Foley catheter days, and thus UTI, by multivariate analysis (p < 0.001). CONCLUSIONS: Escherichia coli was the most common pathogen in all nosocomial infection categories. Increased age, gender, and obesity, in addition to catheter-days, were significant risk factors for UTI in trauma patients. Specific risk factors may predispose patients to pathogens that are not ordinarily covered by usually-chosen antibiotic therapy.