Ellis S. Caplan

Infection surveillance and control in the severely traumatized patient

Among severely traumatized patients, infection is second only to head trauma as the leading cause of death. Few studies have defined the infections that occur, the risk factors involved, or the appropriate means of evaluating these patients. In our trauma unit, daily infection surveillance included clinical evaluation of every patient and all microbiologic data. In addition, prophylactic and therapeutic antibiotics were directly under our control. Over a two period 2,368 patients were admitted, most arriving directly from the scene by patients were admitted, most arriving directly from the scene by helicopter. The over-all mortality was 20 percent. In this setting, 639 nosocomial infections occurred in 381 patients of whom 14 percent died of their infection. Sites of infection in percent of total and of bacteremia (given in parentheses) were urinary tract 18 (3), pneumonia 15 (19), empyema 11 (11), phlebitis 12 (17), primary bacteremia 10 (21), surgical wound 19 (8), intraabdominal 8 (11), CNS 7 (5), sinusitis 5 (0), arterial lines 2 (4) and other 3 (1). Over-all 44 percent of infections were bacteremia. Organisms involved in nosocomial infections as percent of total and in bacteremias given in parentheses) were coagulase-positive Staphylococcus 24 (39), other gram-positive cocci 13 (8), Escherichia coli 13 (9), Proteus 4 (5), anaerobes 3 (1) and other organisms 12 (8). Most infections were directly related to an invasive procedure.

Circulating thyroid hormone changes in acute trauma: prognostic implications for clinical outcome.

Alterations in circulating thyroid hormone concentrations occur in a variety of nonthyroidal disease states. In the present study, thyroid hormone levels were measured every 8 to 12 hours in 19 otherwise healthy individuals suffering acute severe trauma necessitating admission to the Maryland Institute for Emergency Medical Services Systems. Four fatalities occurred within 48 hours of admission. The mean total T3 level fell rapidly after the onset of trauma and remained low throughout the observation period. Reverse T3 rose concurrent with the fall in T3 but gradually returned to normal in the survivors. Total and free T4 levels remained normal in the survivors but fell below normal in the fatalities on the samples obtained preceding death. Changes in free T4 were consistent in three separate radioimmunoassay systems. Pharmacologic doses of glucocorticoids administered to seven of the 15 survivors and to the four fatalities did not result in an acute depression in total and free T4 levels in the survivors. Post-mortem examination of three fatalities did not reveal evidence of significant thyroid or pituitary disease. These results suggest that in acutely traumatized patients: 1) T3 declines rapidly and remains depressed throughout the illness; 2) continued fall of T4 to subnormal levels is associated with a poor prognosis; and 3) steroid therapy alone cannot explain the acute changes observed in hormone levels.

Seroprevalence of human immunodeficiency virus, hepatitis B virus, hepatitis C virus, and rapid plasma reagin in a trauma population. Discussion

We evaluated the presence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and rapid plasma reagin (RPR) among patients admitted to our trauma unit from April 15 to June 30, 1993. Of 984 patients tested, we found 255 (26%) had evidence of exposure to one or more of these agents: HIV, 4%; HBV, 20%; HCV, 14%; and RPR, 1%. Thirty-eight percent of patients had more than one positive serology, 75% of the HIV patients, 49% of the HBV patients, and 66% of the HCV patients. There was no difference between penetrating and nonpenetrating trauma with respect to any of the viruses. The risk factors for HIV-positive patients were non-White race, positive drug screen, positive alcohol screen, and city resident. Risk factors for HBV patients were non-White race, positive drug screen, and city resident. Risk factors for HBC patients were male sex, non-White race, positive alcohol screen, positive drug screen, and city resident. The risk of blood-borne infections in this group of patients is substantial.

Identification and treatment of infections in multiply traumatized patients

Trauma is the leading cause of death among young adults, and infection is a leading complication in multiply traumatized patients. All antibiotic use and all infections among 1,009 patients admitted to the Maryland Institute for Emergency Medical Services Systems over a six-month period were reviewed. The vast majority of patients had sustained high-speed automobile trauma and had blunt injuries. All antibiotics were given by the infectious diseases consultants under predetermined protocols. During this time period, 175 infections and 76 bacteremias were identified. Thirty-three percent of the antibiotic use was for prophylaxis. Prophylactic antibiotics were used for open fractures, in which a cephalosporin was used; for abdominal trauma, in which an aminoglycoside and clindamycin or cefoxitin alone was used; and for penetrating open fractures of the oral cavity, in which penicillin was used. As therapy, the aminoglycosides were used in 25 percent, the cephalosporins in 21 percent, the penicillins in 39 percent, and other antibiotics in 15 percent of the cases. The organisms identified as causing infection were Staphylococcus aureus (25 percent), Escherichia coli (18 percent), Enterobacter species (17 percent), Pseudomonas species (12 percent), and Klebsiella species (11 percent). The sites of infections were primary bacteremia (11 percent), vascular lines (21 percent), the central nervous system (3 percent), the lower respiratory tract (13 percent), the paranasal sinuses (6 percent), the urinary tract (19 percent), surgical wounds (11 percent), the abdomen (7 percent), and other sites (9 percent). More than 82 percent of the infections that occurred were nosocomial in origin and were related to the various procedures used for monitoring and therapy in these critically ill patients. Infections of the abdominal cavity and the lower respiratory tract accounted for eight of the 10 infection-related deaths in these patients.

Ciprofloxacin pharmacokinetics in critically III trauma patients

The steady-state pharmacokinetics of ciprofloxacin 200 mg intravenously every 12 hours was examined in 10 critically ill trauma patients. The mean parameter estimates for total clearance, renal clearance, non-renal clearance, and volume of distribution were 30.08 liters/hour/1.73 m2, 16.62 liters/hour/1.73 m2, 13.46 liters/hour/1.73 m2, and 2.10 liters/kg. Although the mean values were similar to those previously reported, significant individual differences were observed, with the coefficient of variation ranging from 41 to 61 percent. Non-renal clearance appeared to have a bimodal distribution. The dosage studied appeared to provide adequate serum concentration profiles to treat most pathogens found in infected trauma patients. However, the use of higher doses and more frequent dosing may be required to treat patients with Staphylococcus aureus and Pseudomonas aeruginosa infections.

Prospective use of optimal sampling theory: Steady‐state ciprofloxacin pharmacokinetics in critically ill trauma patients

We examined the use of optimal sampling theory to determine a sparse sampling design to estimate pharmacokinetic parameters of ciprofloxacin in patients who had sustained trauma. Two serum sampling strategies, consisting of six sampling times each, were derived on the basis of the patients renal function (patients with creatinine clearance ≥ 6 L/hr/1.73 m2 and patients with creatinine clearances < 6 L/hr/1.73 m2). Two additional serum samples were obtained for other aspects to the study. A timed urine collection was also obtained. Pharmacokinetic parameter estimates were determined by comodeling the serum and urine data with a three‐compartment open model (parameterized as microconstants) with a bayesian algorithm and by noncompartmental analysis. Bayesian‐derived parameter estimates were total body clearance of drug from plasma, 29.8 L/hr/1.73 m2; renal clearance, 17.0 L/hr/1.73 m2; and nonrenal clearance, 12.7 L/hr/1.73 m2 and were not significantly different from noncompartmentally derived parameters (p = 0.80, p = 0.65 and p = 0.333, respectively). The study demonstrates the use of optimal sampling theory to determine an informative yet relatively sparse sampling strategy for a drug with a complex pharmacokinetic model.

Double-blind, prospective, multicenter trial comparing ceftazidime with moxalactam in the treatment of serious gram-negative infections.

Ceftazidime is a new antimicrobial agent possessing excellent in vitro activity against most members of the family Enterobacteriaceae and against Pseudomonas aeruginosa. We conducted a double-blind, prospective, multicenter trial to compare ceftazidime with moxalactam in the treatment of serious gram-negative infections. The overall favorable response rates for the two regimens were similar (93 of 106 [88%] and 84 of 97 [86%], respectively). Among these, the response rates of the 56 gram-negative bacteremias and the 23 P. aeruginosa infections were comparable. Both groups had similar incidences of subsequent infections with P. aeruginosa, enterococci, and yeasts. A total of 13% of the patients in the moxalactam group developed a prolonged prothrombin time (P less than 0.01), and three patients demonstrated clinical bleeding. These results suggest that although the overall efficacy of both regimens was similar, treatment with moxalactam resulted in a higher incidence of prolongation of prothrombin time with an attendant risk of bleeding. In nonneutropenic patients, ceftazidime as a single agent is safe and effective in gram-negative bacillary infections.

Impact of community-acquired infection on acquisition of nosocomial infection, length of stay, and mortality in adult blunt trauma patients.

The incidence of community-acquired infections (CA) and how it relates to the incidence of nosocomial infections (NI) in the adult blunt trauma population is unknown. We evaluated this incidence and assessed the impact of age on morbidity and mortality. Prospective data were collected on blunt trauma patients admitted >48 h over a 2-year period. Each patient was screened for infection by an infectious disease specialist. The Centers for Disease Control and Prevention (CDC) guidelines were used to diagnose infection. Of the 2,645 patients admitted, 86% were <65 years of age and 14% were > or =65 years of age. There was not a significant difference in Injury Severity Score (ISS) between the two groups. A total of 201 (8.8%) of the younger patients were diagnosed with CA; of these, 52.2% acquired a NI. Additionally, 65 (17.4%) of the older patients were diagnosed with a CA; of these, 57% acquired a NI. The combination of CA and NI led to the most significant increases in intensive care (ILOS), hospital (HLOS) length of stay, and mortality. Patients with the CA had a significantly greater risk of obtaining an NI in both age groups. The relative risk (RR) of an older patient presenting with a CA was two times greater than in patients <65 years old. The greatest relative risk of mortality (RRM) was demonstrated with the combination of CA and NI, and age. However, once infected with both CA and NI, younger patients had a greater RRM (5.0 vs. 3.9) in the group-specific comparison. CA significantly increases the risk of blunt trauma patients acquiring an NI. The combination of CA and NI led to the most significant increases in HLOS, ILOS, and mortality. Increased age is associated with a significantly higher incidence of CA, ILOS, HLOS, and mortality. Once infected with both CA and NI, younger patients have a greater risk of mortality.

Cefoxitin-Resistant Facultative or Aerobic Gram-Negative Bacilli in Infections Associated with the Gastrointestinal Tract

Excerpt Infections associated with the gastrointestinal tract, such as intra-abdominal abscesses, are usually caused by a mixture of facultative or aerobic gram-negative bacilli and anaerobic organ...