Superiority of aztreonam/clindamycin compared with gentamicin/clindamycin in patients with penetrating abdominal trauma

Dose-dependent association between blood transfusion and nosocomial infections in trauma patients: A secondary analysis of patients from the PAMPer trial

BACKGROUND

The Prehospital Air Medical Plasma (PAMPer) trial demonstrated a survival benefit to trauma patients who received thawed plasma as part of early resuscitation. The objective of our study was to examine the association between blood transfusion and nosocomial infections among trauma patients who participated in the PAMPer trial. We hypothesized that transfusion of blood products will be associated with the development of nosocomial infections in a dose-dependent fashion.

METHODS

We performed a secondary analysis of prospectively collected data of patients in the PAMPer trial with hospital length of stay of at least 3 days. Demographics, injury characteristics, and number of blood products transfused were obtained to evaluate outcomes. Bivariate analysis was performed to identify differences between patients with and without nosocomial infections. Two logistic regression models were created to evaluate the association between nosocomial infections and (1) any transfusion of blood products, and (2) quantity of blood products. Both models were adjusted for age, sex, and Injury Severity Score.

RESULTS

A total of 399 patients were included: age, 46 years (interquartile range, 29-59 years); Injury Severity Score, 22 (interquartile range, 12-29); 73% male; 80% blunt mechanism; and 40 (10%) deaths. Ninety-three (27%) developed nosocomial infections, including pneumonia (n = 67), bloodstream infections (n = 14), catheter-associated urinary tract infection (n = 10), skin and soft tissue infection (n = 8), Clostridium difficile colitis (n = 7), empyema (n = 6), and complicated intra-abdominal infections (n = 3). Nearly 80% (n = 307) of patients received packed red blood cells (PRBCs); 12% received cryoprecipitate, 69% received plasma, and 27% received platelets. Patients who received any PRBCs had more than a twofold increase in nosocomial infections (odds ratio, 2.15; 95% confidence interval, 1.01-4.58; p = 0.047). The number of PRBCs given was also associated with the development of nosocomial infection (odds ratio, 1.10; 95% confidence interval, 1.05-1.16; p < 0.001).

CONCLUSION

Trauma patients in the PAMPer trial who received a transfusion of at least 1 U of PRBCs incurred a twofold increased risk of nosocomial infection, and the risk of infection was dose dependent.

LEVEL OF EVIDENCE

Therapeutic/care management, level IV.

Prophylactic antibiotics for penetrating abdominal trauma: duration of use and antibiotic choice

BACKGROUND

Penetrating abdominal trauma (PAT) is a common type of trauma leading to admission to hospital, which often progresses to septic complications. Antibiotics are commonly administered as prophylaxis prior to laparotomy for PAT. However, an earlier Cochrane Review intending to compare antibiotics with placebo identified no relevant randomised controlled trials (RCTs). Despite this, many RCTs have been carried out that compare different agents and durations of antibiotic therapy. To date, no systematic review of these trials has been performed.

OBJECTIVES

To assess the effects of antibiotics in penetrating abdominal trauma, with respect to the type of agent administered and the duration of therapy.

SEARCH METHODS

We searched the following electronic databases for relevant randomised controlled trials, from database inception to 23 July 2019; Cochrane Injuries Group's Specialised Register, CENTRAL, MEDLINE Ovid, MEDLINE Ovid In-Process & Other Non-Indexed Citations, MEDLINE Ovid Daily and Ovid OLDMEDLINE, Embase Classic + Embase Ovid, ISI Web of Science (SCI-EXPANDED, SSCI, CPCI-S & CPSI-SSH), and two clinical trials registers. We also searched reference lists from included studies. We applied no restrictions on language or date of publication.

SELECTION CRITERIA

We included RCTs only. We included studies involving participants of all ages, which were conducted in secondary care hospitals only. We included studies of participants who had an isolated penetrating abdominal wound that breached the peritoneum, who were not already taking antibiotics.

DATA COLLECTION AND ANALYSIS

Two study authors independently extracted data and assessed risk of bias. We used standard Cochrane methods. We aggregated study results using a random-effects model. We also conducted trial sequential analysis (TSA) to help reduce type I and II errors in our analyses.

MAIN RESULTS

We included 29 RCTs, involving a total of 4458 participants. We deemed 23 trials to be at high risk of bias in at least one domain. We are uncertain of the effect of a long course of antibiotic prophylaxis (> 24 hours) compared to a short course (≤ 24 hours) on abdominal surgical site infection (RR 1.00, 95% CI 0.81 to 1.23; I² = 0%; 7 studies, 1261 participants; very low-quality evidence), mortality (Peto OR 1.67, 95% CI 0.73 to 3.82; I² = 8%; 7 studies, 1261 participants; very low-quality evidence), or intra-abdominal infection (RR 1.23, 95% CI 0.84 to 1.80; I² = 0%; 6 studies, 111 participants; very-low quality evidence). Based on very low-quality evidence from fifteen studies, involving 2020 participants, which compared different drug regimens with activity against three classes of gastrointestinal flora (gram positive, gram negative, anaerobic), we are uncertain whether there is a benefit of one regimen over another. TSA showed the majority of comparisons did not cross the alpha adjusted boundary for benefit or harm, or reached the required information size, indicating that further studies are required for these analyses. However, in the three analyses which crossed the boundary for futility, further studies are unlikely to show benefit or harm.

AUTHORS' CONCLUSIONS

Very low-quality evidence means that we are uncertain about the effect of either the duration of antibiotic prophylaxis, or the superiority of one drug regimen over another for penetrating abdominal trauma on abdominal surgical site infection rates, mortality, or intra-abdominal infections. Future RCTs should be adequately powered, test currently used antibiotics, known to be effective against gut flora, use methodology to minimise the risk of bias, and adequately report the level of peritoneal contamination encountered at laparotomy.

Prophylactic antibiotic use in penetrating abdominal trauma: an Eastern Association for the Surgery of Trauma practice management guideline

BACKGROUND

The use of prophylactic antibiotics in penetrating abdominal trauma has resulted in decreased infection rates. The Eastern Association for the Surgery of Trauma (EAST) first published its practice management guidelines (PMGs) for the use of prophylactic antibiotics in penetrating abdominal trauma in 1998. During the next decade, several new prospective studies were published on this topic. In addition, the practice of damage control laparotomy became widely used, and additional questions arose as to the role of prophylactic antibiotics in this setting. Thus, the EAST Practice Management Guidelines Committee set out to update the original PMG.

METHODS

A search of the National Library of Medicine and the National Institutes of Health MEDLINE databases was performed using PubMed (www.pubmed.gov) and specific key words. The search retrieved English language articles regarding the use of antibiotics in penetrating abdominal trauma published from 1973 to 2011. The topics investigated were the need for perioperative antibiotics, the duration of antibiotic therapy, the dose of antibiotics in patients presenting in hemorrhagic shock, and the appropriate duration of antibiotic therapy in the setting of damage control laparotomy.

RESULTS

Forty-four articles were identified for inclusion in this review.

CONCLUSION

There is evidence to support a Level I recommendation that prophylactic antibiotics should only be administered for 24 hours in the presence of a hollow viscus injury. In addition, there are no data to support continuing prophylactic antibiotics longer than 24 hours in damage control laparotomy.

Prevention of infections associated with combat-related thoracic and abdominal cavity injuries

Trauma-associated injuries of the thorax and abdomen account for the majority of combat trauma-associated deaths, and infectious complications are common in those who survive the initial injury. This review focuses on the initial surgical and medical management of torso injuries intended to diminish the occurrence of infection. The evidence for recommendations is drawn from published military and civilian data in case reports, clinical trials, meta-analyses, and previously published guidelines, in the interval since publication of the 2008 guidelines. The emphasis of these recommendations is on actions that can be taken in the forward-deployed setting within hours to days of injury. This evidence-based medicine review was produced to support the Guidelines for the Prevention of Infections Associated With Combat-Related Injuries: 2011 Update contained in this supplement of Journal of Trauma.

Imipenem levels are not predictable in the critically ill patient

BACKGROUND

Critically ill patients often demonstrate extremely unusual volumes of distribution (Vd) and half-lives (t1/2) of drugs. Imipenem is a widely used antibiotic in critically ill patients.

METHODS

We performed high-performance liquid chromatography analysis of imipenem in samples from 50 critically ill patients treated with either 500 or 1,000 mg.

RESULTS

Peak imipenem levels varied from 1.56 microg/mL to 58.8 microg/mL. Trough levels varied between 0.0 microg/mL and 15.62 microg/mL. Only 54% of patients maintained a trough level greater than 4 microg/mL. Both the Vd and the t1/2 of imipenem were much greater than observed in other patient populations.

CONCLUSION

The pharmacokinetic activity of imipenem in critically ill patients is different from that in other patient populations. There is a very weak correlation between dosage and serum concentrations. Therapeutic failures of imipenem may be because of unpredictable pharmacodynamics (Vd and t1/2) in critically ill surgical patients.

Randomized clinical trial to determine if delay from time of penetrating colonic injury precludes primary repair

BACKGROUND

There is often a delay of more than 12 h in transferring patients with penetrating colonic injury from outlying hospitals to a regional referral centre. The aim of this prospective study was to determine whether primary suture of a penetrating colonic injury in the presence of delayed presentation, shock, peritoneal contamination or associated injuries leads to increased morbidity and mortality rates.

METHODS

Patients with penetrating colonic injuries were randomized to primary closure or colostomy. Patients were compared with regard to interval from injury to operation, associated injuries, duration of operation, postoperative complications and hospital stay.

RESULTS

Two hundred and forty patients were seen over a 69-month period. The interval from injury to operation ranged from 3 to 56 h, and was similar in the two treatment groups. Postoperative complications were similar in the two groups but there were significant differences in operation time (mean(s.d.) 127.1(45.8) min for primary repair and 142.3(43.0) min for colostomy; P = 0.009) and length of hospital stay (mean (range) 9 (6-56) versus 26 (13-64) days respectively; P < 0.001).

CONCLUSION

Delay from time of penetrating colonic injury is not a contraindication to primary repair. :

Blood Transfusions Correlate with Infections in Trauma Patients in a Dose-Dependent Manner

Infections are a common and significant sequela of major traumatic injury. The objective of this study was to evaluate the relationship between infections in trauma patients and the transfusion of packed red blood cells (pRBCs) within the first 48 hours of admission. We hypothesized that transfusions of pRBCs were associated with an increased risk of infection in a dose-dependent manner. All adult patients admitted to the trauma service of a Level I trauma center from November 1996 to December 1999 were studied. Secondary analysis was performed on prospectively collected data. One thousand five hundred ninety-three consecutive patients were studied; of these 12.6 per cent developed at least one infection. The overall transfusion rate was 19.4 per cent. The infection rate in patients who received at least one transfusion was significantly higher ( P < 0.0001) at 33.0 versus 7.6 per cent in patients receiving no pRBCs. Transfusions per patient ranged from 0 to 46 units. There was a clear exponential correlation in patients receiving between 0 and 15 transfusions (R 2 = 0.757). Multivariate logistic regression, which was used to identify risk factors for the development of infection, demonstrated the odds ratio of receiving pRBCs to be 1.084, with a 95 per cent confidence interval of 1.028 to 1.142 ( P = 0.0028). In summary there is a clear dose-dependent correlation between transfusions of pRBCs and the development of infection in trauma patients. Multivariate analysis further demonstrated that pRBCs were an independent risk factor for the development of infections. Although transfusions are frequently indicated, they should be administered appropriately and with no more pRBCs than absolutely necessary.

Infection in Penetrating Abdominal Trauma: Risk Factors and Preventive Antibiotics

Infection remains the greatest risk for victims of penetrating abdominal injury with major infections occurring in 10 to 15 per cent. Attributable mortality is approximately 30 per cent of those who develop major abdominal infections. In addition to this morbidity infection adds approximately $43,000.00 of hospital charges per infected patients. This article addresses two significant areas: risk factors and antibiotic utilization. The most important risk factor is the presence of hollow viscus injury; colonic wounding carries the highest incidence of infection relative to intra-abdominal organs injured. Pancreatic and liver injuries significantly increase infection risk when combined with hollow viscus wounds. The degree of injury as measured by the volume of hemorrhage and the presence of shock as well as the anatomic degree of injury likewise correlates with the incidence of septic morbidity. Antibiotic utilization is addressed by the three issues of antibiotic agents of choice, duration of administration, and optimal dosing. Regimens of choice should include anaerobic coverage. Twenty-four hours of antibiotic administration is satisfactory with currently available agents. Evidence-based medicine analyses from the Eastern Association for the Surgery of Trauma have addressed those two issues. There are few data on optimal dosing. Increased volumes of distribution and rates of excretion have been demonstrated in trauma patients. This would suggest that higher-than-normal doses should be used. Laboratory studies would support such an approach. However, significant clinical research is desirable to address issues of concentration-dependent bacterial killing and time-dependent killing. Those pharmo-dynamic considerations are variable among antibiotic classes.

The "July phenomenon" and the care of the severely injured patient: fact or fiction?

BACKGROUND

The "July phenomenon," a common belief in medical academia, refers to purported errors, inefficiency, and negative outcomes during the summertime transition of the house staff. We hypothesized that care in a trauma service is consistent throughout the year and that the July phenomenon therefore is a myth.

METHODS

The records of adults admitted to a trauma service between July 1994 and September 1999 were evaluated. The care of and outcomes for patients admitted in July and August were compared with those of patients admitted in April and May.

RESULTS

Nine hundred seventeen patients were evaluated over 5 years. Patients were well matched by the Injury Severity Score, the Glasgow Coma Score, by mechanism, and by survival probability. Patients admitted in the spring were significantly older, by a mean of 5.1 years. Length of stay and intensive care unit stay were similar. Emergency department times were similar, as were resuscitation times, infection rates, and hospital costs. The mortality of patients was similar between the 2 times.

CONCLUSIONS

There was no evidence of an increase in negative outcomes early in the academic year compared with the end of the academic year. We believe that a systematic approach to the diagnosis, resuscitation, and treatment of trauma prevented a July phenomenon.

Should aminoglycoside antibiotics be abandoned?

BACKGROUND

Aminoglycosides can cause nephrotoxicity and ototoxicity. Alternatives are available.

METHODS

Surgical service antibiotic use, aminoglycoside toxicity, and perioperative culture/sensitivity results from July 1998 to June 1999 were reviewed.

RESULTS

Of 289 positive cultures in 243 patients, 92 cultures (32%) grew 151 Gram-negative rods (GNRs). Aminoglycosides were used in 26 patients and 4 of 26 (15%) suffered nephrotoxicity. Of the 112 GNRs tested against ceftazidime, 111 (99%) were sensitive to it which was significantly better than amikacin (56 of 61, 92%, P = 0.038), gentamicin (116 of 134, 87%, P <0.001), and tobramycin (67 of 81, 83%, P <0.001). The proportion sensitive to cefuroxime (26 of 30, 87%) was equivalent to the proportions sensitive to gentamicin (87%, P = NS) and tobramycin (83%, P = NS). Of the 35 GNRs that were resistant to gentamicin and/or tobramycin, 15 (43%) were Pseudomonas aeruginosa.

CONCLUSION

Aminoglycosides produce a significant rate of nephrotoxicity. There are antibiotics with equal or better sensitivity profiles than aminoglycosides against GNRs and Pseudomonas. Aminoglycoside use is rarely, if ever, indicated.

Persistent occult hypoperfusion is associated with a significant increase in infection rate and mortality in major trauma patients

OBJECTIVE

To investigate the hypothesis that occult hypoperfusion (OH) is associated with infectious episodes in major trauma patients.

METHODS

Data were collected prospectively on all adult trauma patients admitted to the Surgical/Trauma Intensive Care Unit from November of 1996 to December of 1998. Treatment was managed by a single physician according to a defined resuscitation protocol directed at correcting OH (lactic acid [LA] > 2.4 mmol/L).

RESULTS

Of a total of 381 consecutive patients, 118 never developed OH and 263 patients exhibited OH. Seventeen patients were excluded because their LA never corrected, and they all subsequently died. One hundred seventy-six infectious episodes occurred in 97 of the 364 patients remaining. The infection rate in patients with no elevation of LA was 13.6% (n = 118) compared with 12.7% (n = 110) in patients whose LA corrected by 12 hours, 40.5% (n = 79; p < 0.01 compared with all other groups) in patients whose LA corrected between 12 and 24 hours, and 65.9% (n = 57; p < 0.01 compared with all other groups) in patients who corrected after 24 hours. Among the patients with infections, there were 276 infection sites with 42% of infections involving the lung and 21% involving bacteremia. There was no difference in proportion of infections occurring at each site between groups. The mortality rate of patients who developed infections was 7.9% versus 1.9% in patients without infections (p < 0.05). Of the patients who developed infections, 69.8% versus 25.8% (p < 0.001) did not have their lactate levels normalized within 12 hours of emergency room admission. Logistic regression demonstrated that both the Injury Severity Score and OH > 12 hours were independently predictive of infection.

CONCLUSION

A clear increase in infections occurred in patients with OH whose lactate levels did not correct by 12 hours, with an associated increase in length of stay, days in surgical/trauma intensive care unit, hospital charges, and mortality.

Monobactams and carbapenems for treatment of intraabdominal infections

During the last decade improved clinical and microbiological methods have resulted in the realization that most intraabdominal infections involve both aerobic and anaerobic bacteria. Papers on the use of different antimicrobial agents directed against the polymicrobial flora of the infected site have been published. In this paper the use of monobactams and carbapenems for treatment of intraabdominal infections is reviewed. The review is based on data published since 1990. Three hundred forty-four patients participated in three trials where aztreonam combined with clindamycin was compared with other antimicrobial agents for treatment of intraabdominal infections. Eighty-six percent of the patients receiving aztreonam plus clindamycin were cured/improved, while 83% of the patients receiving the comparative drugs had favorable outcomes. Eleven trials compared imipenem/cilastatin versus other antimicrobial combinations for therapy of intraabdominal infections. One thousand three hundred seventy-five patients were evaluated in the trials. Eighty percent of patients treated with imipenem/cilastatin had favorable outcomes, while 81% of the patients receiving the comparative drugs were cured/improved. Nine studies including 1,205 patients for evaluation of meropenem versus other antimicrobial agents in the treatment of intraabdominal infections have been published. Cure/improvement was seen in 96% of the patients treated with meropenem and in 91% receiving the comparative drugs. One trial has been published comparing biapenem with imipenem/cilastatin for treatment of intraabdominal infections. Eighty-three patients participated, 65% of the patients in the biapenem group were cured/improved and 68% in the imipenem/cilastatin group.

Antibiotics for the acute abdomen

Antibiotics are only an adjunct to proper surgical therapy for the treatment of the acute abdomen associated with bacterial secondary peritonitis. Upon presentation, all patients require a preoperative dose of antibiotics for prophylaxis against infection of remaining sterile tissues. Patients found intraoperatively to have an established peritoneal infection benefit from an immediate postoperative course of therapeutic antibiotics. A regimen that adequately covers facultative and aerobic gram-negative bacilli and anaerobic organisms is essential. The duration of therapeutic antibiotics is probably best decided on an individual patient basis. The goal of antibiotics is to reduce the concentration of bacteria invading tissues. The pathogens of bacterial peritonitis are influenced by such factors as the patient's pre-existing chronic diseases, state of acute physiologic debilitation, immunocompetence, recent antibiotic use, recent hospitalization, and neutralization of gastric acidity. Intraoperative peritoneal cultures are most useful in patients suspected of having impaired local host defenses. In these patients, all identified organisms, such as Enterococcus or Candida, may be potential pathogens. The common practice of administering empiric and prolonged courses of broad-spectrum antibiotics in patients who manifest persistent signs of inflammation may be more harmful than beneficial. These patients warrant an exhaustive search for extra-abdominal and intraperitoneal sources of new infection. Otherwise, such use of antibiotics may continue to promote the selection of bacteria that are highly resistant to conventional antibiotics and permit the overgrowth of organisms commonly seen with tertiary peritonitis. The best chance of resolving bacterial peritonitis is through early, aggressive surgical management complemented by short courses of potent antibiotics and appropriate physiologic support. Through these efforts, the clinician tries to help the systemic inflammatory response to benefit the host and not become unregulated, result in MOFS, and produce a high mortality.