The TLR4 +896 polymorphism is not associated with lipopolysaccharide hypo-responsiveness in leukocytes.

Toll-like receptor 4 (TLR-4) is required for detection of Gram negative bacterial infections by binding lipopolysaccharide (LPS) and for the initiation of inflammatory signaling. Recent studies have demonstrated that a nonsynonymous single-nucleotide polymorphism (Asp299Gly, A+896G) is associated with decreased endotoxin responsiveness and poor outcomes from sepsis. We show that human carriers of this polymorphism show no deficit in LPS induced peripheral blood mononuclear cell (PBMC) mitogen-activated protein kinase (MAPK) activity, no reduction in sensitivity to endotoxin, and variable differences in whole-blood inflammatory cytokine production. These results indicate that this mutation is not a primary determinant of human endotoxin sensitivity.

Immediate effects of positive end-expiratory pressure and low and high tidal volume ventilation upon gas exchange and compliance in patients with acute lung injury.

BACKGROUND: Protective ventilation, in general, includes low tidal volume ventilation and maintaining end-inspiratory plateau pressures less than 35 cmH2O. Recent clinical studies have determined that such an approach results in improved survival in patients with moderate to severe acute lung injury and acute respiratory distress syndrome. However, experimental evidence suggests that repeated end-expiratory collapse and reexpansion contributes to ventilator-induced lung injury. We sought to determine the immediate effects of specific tidal volume-PEEP combinations upon oxygenation and static compliance in patients with moderate to severe acute lung injury. METHODS: Fourteen patients were prospectively studied and were treated with each of 10 tidal volume-PEEP combinations, applied in random order. After 5 minutes at each tidal volume-PEEP combination, PaO2/FIO2 and static compliance were recorded. Comparisons were made between low and high tidal volume ventilation as well as across five PEEP levels. RESULTS: At both low (6 mL/kg) and high (10 mL/kg) tidal volume ventilation, PaO2/FIO2 increased with increasing PEEP, up to 20 cmH2O. Similar changes in static compliance were not evident. Static compliance was highest at PEEP of 10 and 15 cmH2O, regardless of tidal volume. With PEEP set at 5 cmH2O, static compliance was significantly lower with 6 mL/kg than with 10 mL/kg tidal volumes. Overall, static compliance was lowest for both tidal volume conditions with PEEP set at 25 cmH2O. CONCLUSION: Low tidal volume ventilation with PEEP set at 5 cmH2O results in poor oxygenation and compliance in patients with moderate to severe acute lung injury. Similarly, PEEP set at 25 cmH2O did not improve oxygenation or compliance.

Plasma CD14 decreases monocyte responses to LPS by transferring cell-bound LPS to plasma lipoproteins.

CD14, a myeloid cell-surface receptor and soluble plasma protein, binds LPS and other microbial molecules and initiates the innate immune response to bacterial invasion. The blood concentration of soluble CD14 (sCD14) increases during the systemic response to infection. Although high sCD14 blood levels have correlated with increased risk of dying from severe sepsis, sCD14 can diminish cell responses to LPS. We show here that in human serum, sCD14 increases the rate at which cell-bound LPS is released from the monocyte surface and binds to plasma lipoproteins. This enhanced rate of LPS efflux is associated with a significant reduction in the ability of monocytes to produce cytokines in response to LPS. Serum from septic patients reduced the LPS-monocyte interaction by as much as tenfold, and depletion of sCD14 from the serum restored LPS-monocyte binding and release kinetics to near normal levels. In serum from septic patients, monocyte-bound LPS also moved more rapidly into lipoproteins, which completely neutralized the biologic activity of the LPS that bound to them. In human plasma, sCD14 thus diminishes monocyte responses to LPS by transferring cell-bound LPS to lipoproteins. Stress-related increases in plasma sCD14 levels may help prevent inflammatory responses within the blood.

Objective estimates of the incidence and consequences of multiple organ dysfunction and sepsis after burn trauma.

BACKGROUND: Organ dysfunction and sepsis are frequent after major burn trauma, represent quantifiable consequences of the systemic response to injury, and may be important end points by which to measure treatment effectiveness. However, standard and widely applied methods for their measurement have not been applied to burn trauma victims. Therefore, the purpose of this study was to quantify these complications after burn trauma. METHODS: Patients with > or = 20% total body surface area burns admitted to a single center were prospectively enrolled. Standard sepsis criteria and multiple organ dysfunction (MOD) scores for the pulmonary, renal, cardiovascular, hepatic, and hematologic systems were determined. The incidence and risk factors for severe MOD (cumulative MOD score > or = 6) and severe sepsis were determined. The relationships between these complications and mortality and resource utilization were examined by univariate and multivariate analyses. RESULTS: A total of 85 patients were enrolled over 1 year. Severe MOD developed in 24 (28%) and severe sepsis or septic shock developed in 12 (14%). Both were associated with increasing age and burn size and were more likely to occur in men. Most patients who developed severe MOD or severe sepsis survived (71% and 67%, respectively), and both were associated with longer intensive care unit stays and duration of mechanical ventilation. CONCLUSION: According to simple and objective scoring systems, severe MOD and severe sepsis/septic shock are both related to burn size, age, and male sex. Both are related to intensive care unit length of stay and duration of mechanical ventilation.

Indicators of fatigue and of prolonged weaning from mechanical ventilation in surgical patients.

Indicators of weaning success have been tested primarily in patients who have been ventilated for short periods of time, and they may not be as accurate in cases where support has been required for longer than a few days. In patients requiring longer periods of support it is difficult to estimate the likelihood of successful liberation. Therefore we evaluated established weaning indices for their accuracy in surgical patients who required > or = 72 hours of mechanical ventilation. Surgical patients who required mechanical ventilation for > or = 72 hours were prospectively followed (over 6 months). We obtained standard indices of ventilatory function daily once patients were ready to wean. These indices included the respiratory rate/tidal volume ratio (RSBI), the maximal inspiratory pressure, and the minute ventilation. The duration of weaning and explicitly defined episodes of fatigue were the outcomes of interest. Statistical analyses evaluated the multiple factors that might influence the duration of weaning. Ninety-five patients (66% trauma; 34% surgery) survived to begin weaning, and 93% were liberated. The median duration of mechanical ventilation prior to weaning was 4 days (range 3-16 days), and the median duration of weaning was 3 days (range 0-56 days). Fatigue occurred in 36 patients and was not reliably predicted by any of the weaning measurements. However, a RSBI of > 105 on the first day of weaning was associated with prolonged weaning. By multivariate analysis, an RSBI of > 105 on the first day of weaning predicted prolonged weaning (hazard ratio 1.9; p = 0.03). After 72 hours of mechanical ventilation, clinical fatigue and successful liberation are not reliably predicted by standard indices of respiratory muscle strength and reserve. However, an RSBI of >105 observed once the patient is ready to wean is associated with prolonged weaning.

An evaluation of risk factors for mortality after burn trauma and the identification of gender-dependent differences in outcomes.

BACKGROUND: The primary objective of this study was to determine an objective method for estimating the risk of mortality after burn trauma, and secondarily, to evaluate the relationship between gender and mortality, in the setting of a quantifiable inflammatory stimulus. Previously reported estimates of mortality risk after burn trauma may no longer be applicable, given the overall reduction in case-fatality rates after burn trauma. We expect that future advances in burn trauma research will require careful and ongoing quantification of mortality risk factors to measure the importance of newly identified factors and to determine the impact of new therapies. Conflicting clinical reports regarding the impact of gender on survival after sepsis and critical illness may in part, be from different study designs, patient samples, or failure to adequately control for additional factors contributing to the development ofsepsis and mortality. STUDY DESIGN: Data from the prospectively maintained burn registry for patients admitted to the Parkland Memorial Hospital burn unit between January 1, 1989 and December 31, 1998 were analyzed. Logistic regression was used to generate estimates of the probability of death in half of the study sample, and this model was validated on the second half of the sample. Risk factors evaluated for their relationship with mortality were: age, inhalation injury, burn size, body mass (weight), preexisting medical conditions, nonburn injuries, and gender. RESULTS: Of 4,927 patients, 5.3% died. The best model for estimating mortality included the percent of total body surface area burned; the percent of full-thickness burn size; the presence of an inhalation injury; age categories of: < 30 years, 30 to 59 years, > or = 60 years; and gender. The risk of death was approximately two-fold higher in women aged 30 to 59 years compared with men of the same age. CONCLUSIONS: We have provided a detailed method for estimating the risk of mortality after burn trauma, based on a large, contemporary cohort of patients. These estimates were validated on a second sample and proved to predict mortality accurately. We have identified an increased mortality risk in women of 30 to 59 years of age.

Identification of high-risk residents.

BACKGROUND: Identification of high-risk residents allows remediation and support for administrative action when necessary. This study characterizes differences in documentation of marginally performing residents in a general surgery residency. METHODS: High-risk residents were identified by the former program director. Twenty-four of one hundred fifteen residents over a 10-year period had one to four problematic areas: cognitive, synthetic, family/health, and interpersonal skills. Outcomes included finished (18), voluntary withdrawal (1), and involuntary withdrawal (5). A case-control study matching controls to cases by date of entry into the training program was used. Records were reviewed for demographics, preentry qualifications, American Board of Surgery In-Training Exam (ABSITE) scores, letters of complaint or praise, events of counseling, and monthly ratings. The records of 48 residents were reviewed. Ward evaluations were on eight categories with a 5-point Leikert scale (3-unacceptable to 7-outstanding). The evaluation score assigns points only to low ratings. High scores represent progressively poorer performance. A Wilcoxon signed ranks test was used to compare the cases and controls for continuous variables. The McNemar test was used in comparisons of categorical data with binary outcomes. Exact P values are reported. RESULTS: Objective data were similar for both groups. Study residents tended to score higher on monthly evaluations at Year 2 and by Year 3 this achieved significance (0.026). Study residents were more likely to have negative faculty letters (0.016) and events of counseling by a faculty member (0.017) and the program director (0.005). CONCLUSIONS: Identification of residents at risk should begin as early as possible during training. A combination of faculty evaluations and evidence of letters of counseling can detect high-risk residents. Programs may use such indicators to support decisions regarding remedial work or administrative action.

Plasma constituents regulate LPS binding to, and release from, the monocyte cell surface.

Innate immunity to Gram-negative bacteria involves regulated mechanisms that allow sensitive but limited responses to LPS. Two important pathways that lead to host cell activation and LPS deactivation involve: (i) LPS interactions with CD14 and Toll-like receptor 4 on cells (activation); and (ii) LPS sequestration by plasma lipoproteins (deactivation). Whereas these pathways were previously thought to be independent and essentially irreversible, we found that they are connected by a third pathway: (iii) the movement of LPS from host cells to plasma lipoproteins. Our data show that, in the presence of human plasma, LPS binds transiently to monocyte surfaces and then moves from the cell surface to plasma lipoproteins. Soluble CD14 enhances LPS release from cells in the presence of lipoproteins, whereas LPS binding protein and phospholipid transfer protein do not. The transfer of cell-bound LPS to lipoproteins is accompanied by reduced cell responses to the LPS, suggesting that the movement of LPS from leukocytes into lipoproteins may attenuate host responses to LPS in vivo. Preliminary data suggest that changes that occur in the plasma after trauma or during sepsis decrease LPS binding to leukocytes while greatly increasing the rate of LPS release from cells.

Evaluation of a diagnostic protocol using screening diagnostic peritoneal lavage with selective use of abdominal computed tomography in blunt abdominal trauma.

BACKGROUND: The optimal method of evaluating blunt abdominal trauma remains controversial. A combination of a sensitive screening test, diagnostic peritoneal lavage (DPL), and a specific test, abdominal computed tomography (CT), may be a safe, efficient approach to adult blunt abdominal trauma. METHODS: A prospective cohort study compared a protocol using screening DPL followed by selective use of abdominal CT (DPL/abdominal CT) and the use of abdominal CT alone in the evaluation of hemodynamically stable, adult blunt trauma patients. RESULTS: One hundred sixty-seven adult blunt trauma patients were initially evaluated by DPL (n = 71) or abdominal CT (n = 96). Emergency department evaluation required less time in the DPL/abdominal CT group than in the abdominal CT alone group (41 minutes vs. 2.5 hours; p < 0.001). There were no missed injuries in the DPL/abdominal CT group versus seven missed injuries in the abdominal CT group (p = 0.02). There were no nontherapeutic celiotomies in either study group. CONCLUSION: Screening DPL, followed by abdominal CT if positive, is a safe, efficient method of evaluating adult blunt abdominal trauma that reduces the time required to evaluate the abdomen, does not result in increased nontherapeutic celiotomies, results in fewer missed injuries, and reduces the overall use of abdominal CT.

Defining excess resource utilization and identifying associated factors for trauma victims.

BACKGROUND: Trauma system evaluation addresses aspects of the process, structure, and outcomes of trauma care. This approach may not identify all opportunities for trauma system improvement. Hospital length of stay (LOS) represents a meaningful measure of resource utilization and may help focus efforts to improve care. The purpose of this study is to estimate expected hospital LOS after trauma and determine the consequences of excessive LOS. METHODS: Patients admitted during a 2-year period (January 1, 1993 to December 31, 1994) were retrospectively reviewed, and expected LOS was estimated. Excess LOS was defined as an observed LOS > or =100% of expected. Injuries, complications, and American College of Surgeons' Committee on Trauma audit filters were compared between the groups. RESULTS: Observed LOS exceeded expected by 100% or more for 568 of 5,226 patients (10.9%), and most survived (98.3%). Complications predicted excess LOS, whereas audit filters did not. Median costs for these 568 patients were $30,315 and totaled 30% of the expenditures for the entire cohort of 5,226 patients. CONCLUSION: Prolonged LOS represents an adverse outcome. Estimation of LOS and evaluation of outliers represents an important method for the evaluation of care within established trauma systems and centers.

Ten-year trend in survival and resource utilization at a level I trauma center.

OBJECTIVE: To determine the impact of increasing trauma center experience over time on survival and resource utilization. METHODS: The authors studied a retrospective cohort at a single level I trauma center over a 10-year period, from 1986 to 1995. Patients included all hospital admissions and emergency department deaths. The main outcome measures were the case-fatality rate adjusted for injury severity, hospital length of stay, and costs. RESULTS: A total of 25,979 patients were admitted or died. The number of patients per year increased, from 2063 in 1986 to 3313 in 1995. The proportion of patients transferred from another institution increased from 16.2% to 34.4%. Although mean length of stay declined by 28.4%, from 9.5 to 6.8 days, costs increased by 16.7%, from $14,174 to $16,547. The use of specific radiologic investigations increased; the frequency of operative procedures either remained unchanged (craniotomy, fracture fixation) or decreased (celiotomy). After adjusting for injury severity and demographic factors, the mortality rate decreased over 10 years. The improvement in survival was confined to patients with an injury severity score > or =16. CONCLUSION: Over a 10-year period, the case-fatality rate declined in patients with severe injuries. Overall acute care costs increased, partially because of the increased use of radiologic investigations. Even in otherwise established trauma centers, increasing cumulative experience results in improved survival rates in the most severely injured patients. These data suggest that experience contributes to a decrease in mortality rate after severe trauma and that developing trauma systems should consider this factor and limit the number of designated centers to maximize cumulative experience at individual centers.

Imprecision in lower "inflection point" estimation from static pressure-volume curves in patients at risk for acute respiratory distress syndrome.

BACKGROUND: Static pressure-volume (PV) curves have been promoted as a tool for selecting positive end-expiratory pressure (PEEP) by identifying a lower "inflection point" (Pflex) from these curves. Their visual interpretation is subjective and difficult, however, particularly with subtle changes in the slope of the curves. This study was designed to examine the physician-to-physician variability in estimating the lower Pflex from these curves. METHODS: Static PV curves for eight patients were obtained within 24 hours of admission. Five intensivists and one respiratory therapist independently estimated the lower Pflex from these curves. RESULTS: Pflex estimates for individual patients were highly variable, ranging from 5 to 9 cm H2O. This variability was not attributable to a single discordant estimate, nor was a single physician responsible for consistently high or low estimates. CONCLUSION: Static PV curve interpretation with current methods imprecisely estimates the lower inflection point and is of limited usefulness in PEEP selection.

Accuracy of continuous jugular bulb oximetry in the intensive care unit.

OBJECTIVE: To address the accuracy of a bedside jugular bulb oxygen saturation (SjO2) catheter monitor (Baxter-Edwards, Santa Ana, CA) versus in vitro co-oximetry measurements in the intensive care unit (ICU). METHODS: By prospective protocol, we compared blood gas measurements with simultaneously recorded continuous bedside oximetric monitor values for 31 ICU patients with traumatic brain injury undergoing jugular bulb catheter monitoring. For suboptimal fiberoptic light signal quality indices, the catheter was repositioned, flushed, or both before drawing the sample for in vitro measurement. Laboratory and bedside monitor data were examined for association using the chi2 and paired t tests and a linear regression model. RESULTS: We assessed 195 samples (median, 5 per patient; range, 1-14) who were monitored an average of 3.4 (range, 1-6) days. The in vivo monitor (range, 32-94%) and in vitro co-oximetry (range, 38-93%) values had acceptable correlation (y = 0.94x + 4.4, r2 = 0.80). For bedside monitor detection of jugular bulb desaturation (SjO2 < 50% for 10 min), the kappa statistic was 0.35, the sensitivity was 45 to 50%, and the specificity was 98 to 100%. CONCLUSION: Continuous ICU SjO2 monitoring correlates significantly with in vitro values, but less so than previously described during intracranial surgery. Although sensitivity of the bedside monitor to detect confirmed desaturations remains an issue, the high specificity indicates that it is less of a concern that patients may be misdiagnosed as having desaturations resulting in unnecessary interventions. Nonetheless, suspected jugular bulb desaturation should be verified before taking therapeutic actions.

Incidence of infectious complications associated with the use of histamine2-receptor antagonists in critically ill trauma patients.

OBJECTIVE: To determine the impact of histamine2 (H2)-receptor antagonist use on the occurrence of infectious complications in severely injured patients. SUMMARY BACKGROUND DATA: Some previous studies suggest an increased risk of nosocomial pneumonia associated with the use of H2-receptor blockade in critically ill patients, but other investigations suggest an immune-enhancing effect of H2-receptor antagonists. The purpose of this study was to determine whether H2-receptor antagonist use affects the overall incidence of infectious complications. METHODS: Patients enrolled in a randomized trial comparing ranitidine with sucralfate for gastritis prophylaxis were examined for all infectious complications during their hospitalization. Data on the occurrence of pneumonia were prospectively collected, and other infectious complications were retrospectively obtained from the medical record. The relative risk of infectious complications associated with ranitidine use and total infectious complications were analyzed. RESULTS: Of 98 patients included, the charts of 96 were available for review. Sucralfate was given to 47, and 49 received ranitidine. Demographic factors were similar between the groups. Ranitidine use was associated with a 1.5-fold increased risk of developing any infectious complication (37 of 47 vs. 26 of 47; 95% confidence interval, 1.04 to 2.28). Infectious complications totaled 128 in the ranitidine-treated group and 50 in the sucralfate-treated group (p = 0.0014). These differences remained after excluding catheter-related infections (p = 0.0042) and secondary bacteremia (p = 0.0046). CONCLUSIONS: Ranitidine use in severely injured patients is associated with a statistically significant increase in overall infectious complications when compared with sucralfate. These results indicate that ranitidine should be avoided where possible in the prophylaxis of stress gastritis.

Is hypothermia in the victim of major trauma protective or harmful? A randomized, prospective study.

OBJECTIVE: The purpose of this randomized, prospective clinical trial was to determine whether hypothermia during resuscitation is protective or harmful to critically injured trauma patients. SUMMARY BACKGROUND DATA: Hypothermia has both protective and harmful clinical effects. Retrospective studies show higher mortality in patients with hypothermia; however, hypothermia is more common in more severely injured patients, which makes it difficult to determine whether hypothermia contributes to mortality independently of injury severity. There are no randomized, prospective treatment studies to assess hypothermia's impact as an independent variable. METHODS: Fifty-seven hypothermic (T < or = 34.5 C), critically injured patients requiring a pulmonary artery catheter were randomized to a rapid rewarming protocol using continuous arteriovenous rewarming (CAVR) or to a standard rewarming (SR) control group. The primary outcome of interest was first 24-hour blood product and fluid resuscitation requirements. Other comparative analyses included coagulation assays, hemodynamic and oxygen transport measurements, length of stay, and mortality. RESULTS: The two groups were well matched for demographic and injury severity characteristics. CAVR rewarmed significantly faster than did SR (p < 0.01), producing two groups with different amounts of hypothermia exposure. The patients who underwent CAVR required less fluid during resuscitation to the same hemodynamic goals (24,702 mL vs. 32,540 mL, p = 0.05) and were significantly more likely to rewarm (p = 0.002). Only 2 (7%) of 29 patients who underwent CAVR failed to warm to 36 C and both died, whereas 12 (43%) of 28 patients who underwent SR failed to reach 36 C, and all 12 died. Patients who underwent CAVR had significantly less early mortality (p = 0.047). CONCLUSION: Hypothermia increases fluid requirements and independently increases acute mortality after major trauma.

Morbid prognostic features in patients with chronic liver failure undergoing nonhepatic surgery.

BACKGROUND: Although the risk of portal decompression surgery is accurately predicted by objective scoring systems (Child classification and Pugh score), few useful prognostic criteria exist regarding nonhepatic surgery in patients with chronic liver failure. OBJECTIVE: To evaluate the clinical findings associated with perioperative mortality in patients with chronic liver failure undergoing nonhepatic surgery. DESIGN: A retrospective cohort study. SETTING: University teaching hospitals. PATIENTS: Forty consecutive patients with an International Classification of Diseases, Ninth Revision (ICD-9), diagnosis of chronic liver failure and one or more of the following: jaundice, cirrhosis, chronic hepatitis, or alcoholism. INTERVENTIONS: Forty operations, including 28 abdominal procedures, 2 coronary artery bypass grafts, 5 orthopedic procedures, and 5 miscellaneous procedures. MAIN OUTCOME MEASURES: Thirty-day mortality as related to 19 preoperative clinical and laboratory variables. RESULTS: Eleven (28%) of the patients died within 30 days of surgery. By univariate analysis, the following variables were significantly (P < .05, pearson chi 2 test for categorical data or Mann-Whitney U test for continuous data) associated with nonsurvival: encephalopathy, congestive heart failure, the need for emergent surgery, infection, hyperbilirubinemia, international normalized ratio greater than 1.6, hypoalbuminemia, and an elevated creatinine level. By multiple logistic regression analysis, an international normalized ratio greater than 1.6 and encephalopathy were associated with a greater than 10- and 35-fold increased mortality risk, respectively. Child classification and Pugh score failed to predict 30-day mortality. CONCLUSIONS: We identified 8 clinical and laboratory variables associated with death within 30 days in patients with chronic liver failure undergoing nonhepatic surgery. Two factors-international normalized ratio greater than 1.6 and encephalopathy-independently predicted mortality by multivariate analysis. Neither Child classification nor Pugh score was prognostically helpful. Nonhepatic surgery confers a substantial mortality risk in patients with chronic liver failure.

The complications of trauma and their associated costs in a level I trauma center.

OBJECTIVES: To estimate the expected costs for acute trauma care, to quantify the costs associated with the development of complications in injury victims, and to determine the deficit incurred by patients in whom complications develop. DESIGN: A retrospective, cohort design. SETTING: A referral trauma center. PATIENTS: A total of 12,088 patients admitted to a single regional trauma center during a period of 5 years. INTERVENTIONS: This is an observational study, and no interventions specific to this study are included in the design. MAIN OUTCOME MEASURES: (1) The expected costs for injury victims based on readily available clinical data. (2) The costs associated with the most important complications of trauma. (3) The effect of complications on inadequate reimbursement for trauma care. RESULTS: The expected costs were estimated using a linear model incorporating demographic variables and measures of injury severity. The expected costs averaged $14,567, and the observed costs averaged $15,032. Six complications were important predictors of cost. These included adult respiratory distress syndrome, acute kidney failure, sepsis, pneumonia, decubitus ulceration, and wound infections. For 1201 individuals with these complications, the predicted costs averaged $23,266 and the observed costs averaged $47,457. The mean excess costs for a single complication ranged from $6669 to $18,052. Multiple complications led to greater increases in excess cost, averaging $110,007 for the 62 patients with 3 or more complications. Costs exceeded reimbursement to a much greater degree in those in whom any of the 6 complications developed. CONCLUSION: Expected hospital costs can be estimated using admission clinical data. Each of 6 complications was associated with enormous increases in costs, indicating their importance as a cause of avoidable expenditures in injury victims and identifying situations in which reimbursement may not be adequate.

Thrombotic, infectious, and procedural complications of the jugular bulb catheter in the intensive care unit.

OBJECTIVE: An assessment of the thrombotic, infectious, and technical complications of continuous jugular bulb catheter monitoring in the intensive care unit (ICU) was made. METHODS: Over a 1-year period, 44 patients suffering from traumatic brain injury, subarachnoid hemorrhage, or stroke received jugular bulb catheter monitoring in the ICU. They were followed for catheter insertion complications and the development of bacteremia. In 20 patients chosen randomly, an ultrasonographic evaluation was performed after removal of the catheter for an assessment of internal jugular vein thrombosis. RESULTS: Of the 44 patients, 1 became bacteremic; the source was identified as a thoracostomy site. Among the complications related to the 44 catheter insertions, there were 2 instances of carotid artery puncture (4.5%), 1 misplaced catheter (thoracic placement), and 1 clinically insignificant hematoma. Of the 20 patients investigated with ultrasonography, 8 (40%) had nonobstructive, subclinical internal jugular vein thrombi after jugular bulb catheter monitoring (95% confidence interval, 19-61%). The median monitoring duration was 3 days (range, 1-6 d). No clinical factor was identified to be associated with thrombus formation. CONCLUSION: We conclude the following: 1) the risk of bacteremia related to the jugular bulb catheter was negligible; 2) complications related to catheter insertion were rare and clinically insignificant; and 3) the incidence of subclinical internal jugular vein thrombosis after jugular bulb catheter monitoring is considerable. Although it is worthy to note this complication, no patient with a thrombus became symptomatic in the present series. The risk-benefit assessment of this monitoring technique must include consideration of subclinical thrombosis.

New regimens in the management of posttraumatic respiratory failure.

Many individuals are now surviving their injuries to face the consequences of an activated immunoinflammatory system and the complications of supportive therapy. The pulmonary system bears the force of this insult. An understanding of the epidemiology of acute respiratory failure, as well as a greater knowledge of the cellular and subcellular mechanisms by which pulmonary dysfunction occurs, has led to novel approaches to the management of acute respiratory failure. It also appears that lung injury is caused, or at least exacerbated, by iatrogenic insults, such as positive-pressure ventilation. The purpose of this review is to discuss the etiology and pathophysiology of acute respiratory failure following severe injury and the novel therapeutic approaches. A combination of immunomodulating and mechanical ventilation strategies will likely provide the most successful approach to reducing the morbidity and mortality associated with acute respiratory failure following injury.