Trial of short-course antimicrobial therapy for intraabdominal infection.

BACKGROUND: The successful treatment of intraabdominal infection requires a combination of anatomical source control and antibiotics. The appropriate duration of antimicrobial therapy remains unclear. METHODS: We randomly assigned 518 patients with complicated intraabdominal infection and adequate source control to receive antibiotics until 2 days after the resolution of fever, leukocytosis, and ileus, with a maximum of 10 days of therapy (control group), or to receive a fixed course of antibiotics (experimental group) for 4±1 calendar days. The primary outcome was a composite of surgical-site infection, recurrent intraabdominal infection, or death within 30 days after the index source-control procedure, according to treatment group. Secondary outcomes included the duration of therapy and rates of subsequent infections. RESULTS: Surgical-site infection, recurrent intraabdominal infection, or death occurred in 56 of 257 patients in the experimental group (21.8%), as compared with 58 of 260 patients in the control group (22.3%) (absolute difference, -0.5 percentage point; 95% confidence interval [CI], -7.0 to 8.0; P=0.92). The median duration of antibiotic therapy was 4.0 days (interquartile range, 4.0 to 5.0) in the experimental group, as compared with 8.0 days (interquartile range, 5.0 to 10.0) in the control group (absolute difference, -4.0 days; 95% CI, -4.7 to -3.3; P<0.001). No significant between-group differences were found in the individual rates of the components of the primary outcome or in other secondary outcomes. CONCLUSIONS: In patients with intraabdominal infections who had undergone an adequate source-control procedure, the outcomes after fixed-duration antibiotic therapy (approximately 4 days) were similar to those after a longer course of antibiotics (approximately 8 days) that extended until after the resolution of physiological abnormalities. (Funded by the National Institutes of Health; STOP-IT ClinicalTrials.gov number, NCT00657566.).

Prevalence and Course of Atrial Fibrillation in Critically Ill Trauma Patients.

Atrial fibrillation (AF) is the most common cardiac dysrhythmia. Its prevalence, risk factors, course, and complications are not well described in critically ill trauma patients. This was a retrospective, single-center, cohort study at an academic, level 1 trauma center. Trauma patients >18 years, identified from the trauma registry and admitted to the intensive care unit (ICU), were sequentially screened for AF. A matched cohort was created by selecting patients consecutively admitted before and after the patients who experienced AF. Of 2591 patients screened, 191 experienced AF, resulting in a prevalence of 7.4%. There was no difference in injury severity score (ISS) between those with and without AF, but patients with AF had higher observed mortality (15.5% vs 6.7%, P < .001). Patients with a history of AF (n = 75) differed from new-onset AF (n = 106) in their mean age, 78.9 ± 8.4 versus 69.2 ± 17.9 years; mean time to AF onset, 1.1 ± 2.3 versus 5.2 ± 10.2 days; median duration of AF, 29.8 (1-745.2) versus 5.9 (0-757) hours; and rate of AF resolution, 28% versus 82.1%, respectively. Despite a higher ISS, Sequential Organ Failure Assessment and length of stay, the new-onset AF group experienced a similar rate of mortality compared to the history of AF group (14.7% vs 16.0%). Patients with AF had a higher mortality when compared to those in sinus rhythm. The course of AF in the new-onset AF group occurred later was shorter and was more likely to convert; however, these patients had a longer ICU stay when compared to those who had a history of AF.

Effect of Delay and Disruption in Venous Thromboembolism Prophylaxis in Trauma Patients: Case-Control Study.

BACKGROUND: Trauma patients are at high risk for venous thromboembolism (VTE) and bleeding. The purpose of this study was to characterize percentage of VTE chemoprophylaxis given to trauma patients with and without a VTE. STUDY DESIGN: This retrospective case-control study evaluated trauma patients admitted to a Level I trauma center. Adult patients were included when hospitalized at least 2 days and had a head abbreviated injury score of 1 or less. Non-VTE patients were matched by decade of life and injury severity score (ISS). The primary outcome was percentage of VTE chemoprophylaxis received over the first 14 days of admission. Descriptive statistics, chi-squared test, Student's t-test, and Cox proportional hazard were used for analysis. RESULTS: A total of 44 VTE patients were included with 125 matched non-VTE patients. Baseline demographics included age in years (50.7 ± 19.6 vs 49.6 ± 19.4), ISS (18.9 ± 11.3 vs 19 ± 11.6), and lower extremity fracture (54.5% vs 40%), for VTE and non-VTE groups, respectively. The primary outcome of VTE chemoprophylaxis doses given was significantly lower for VTE patients than non-VTE patients (49.3% vs 59.3%, p = 0.0069). Significant predictors of VTE were percentage of VTE chemoprophylaxis doses given (p < 0.0001) and weight (p = 0.0042) based on regression analysis. Notably, there was a 7% decrease in the hazard for VTE for every 1% increase in VTE chemoprophylaxis given. CONCLUSIONS: Patients who developed VTE were more likely to have delays and disruptions in VTE chemoprophylaxis, even after controlling for age, sex, ISS, lower extremity fractures, and number of operations.

Making your geriatric and palliative programs a strength: TQIP guideline implementation and the VRC perspective.

BACKGROUND: Older patients compose approximately 30% of trauma patients treated in the USA but make up nearly 50% of deaths from trauma. To help standardize and elevate care of these patients, the American College of Surgeons (ACS) Trauma Quality Improvement Program's best practice guidelines for geriatric trauma management was published in 2013 and that for palliative care was published in 2017. Here, we discuss how palliative care and geriatrics quality metrics can be tracked and used for performance improvement and leveraged as a strength for trauma verification. METHODS: We discuss the viewpoint of the ACS Verification, Review, and Consultation and three case studies, with practical tips and takeaways, of how these measures have been implemented at different institutions. RESULTS: We describe the use of (1) targeted educational initiatives, (2) development of a consultation tool based on institutional resources, and (3) application of a nurse-led frailty screen. DISCUSSION: Specialized care and attention to these vulnerable populations is recommended, but the implementation of these programs can take many shapes.Level of evidence V.

Necrotizing soft tissue infections in the intensive care unit.

Necrotizing soft tissue infection is a severe illness that is associated with significant morbidity and mortality. It is often caused by a wide spectrum of pathogens and is most frequently polymicrobial. Care for patients with necrotizing soft tissue infection requires a team approach with expertise from critical care, surgery, reconstructive surgery, and rehabilitation specialists. The early diagnosis of necrotizing soft tissue infection is challenging, but the keys to successful management of patients with necrotizing soft tissue infection are early recognition and complete surgical debridement. Early initiation of appropriate broad-spectrum antibiotic therapy must take into consideration the potential pathogens. Critical care management components such as the initial fluid resuscitation, end-organ support, pain management, nutrition support, and wound care are all important aspects of the care of patients with necrotizing soft tissue infection. Soft tissue reconstruction should take into account both functional and cosmetic outcome.

Blunt splenic injury.

PURPOSE OF REVIEW: To review the current care of the patient with an injured spleen. RECENT FINDINGS: The initial care of the patient with splenic injury is dictated by their hemodynamic presentation and the institution's resources. Although most high-grade injuries require splenectomy, up to 38% are successfully managed nonoperatively. Angioembolization has increased splenic salvage with a minimum of complications. In the absence of injuries that mandate longer hospital stays, patients with low-grade injuries are successfully discharged in 1-2 days and high-grade injuries in 3-4 days. Delayed splenic hemorrhage remains a feared complication, but fortunately the 180-day readmission rate for splenectomy is low with the majority of those returning within 8 days of injury. SUMMARY: Nonoperative management (NOM) is the standard of care for the hemodynamically stable patient with an isolated blunt splenic injury. Splenic salvage can be safely increased, even in higher grade injuries, with the use of angioembolization. Patients managed nonoperatively are successfully discharged as early as 1-2 days for low-grade injuries and as early as 3-4 days for higher grade. Safe management of the patient with blunt splenic injury requires careful selection for NOM, meticulous monitoring and follow-up.

Effect of Flumazenil on Hypoactive Delirium in the ICU: A Double-Blind, Placebo-Controlled Pilot Study.

To determine whether the use of flumazenil reverses hypoactive delirium and increases delirium-free days in critically ill patients who were exposed to benzodiazepine therapy during the ICU admission. DESIGN: This was a single-center, double-blinded, randomized placebo-controlled pilot study. SETTING: Adult ICUs at a large academic medical center in the United States. PATIENTS: Adult, critically ill patients with benzodiazepine exposure and hypoactive delirium based on the Confusion Assessment Method-ICU and Richmond Agitation Sedation Scale assessments were considered for enrollment. INTERVENTIONS: Patients received a test dose of flumazenil starting at 0.1 mg intravenously and titrated up every 5 minutes by 0.1 mg increments up to a maximum total dose of 2 mg. Patients who demonstrated a Richmond Agitation Sedation Scale score increase of greater than 1 point were considered responders and randomized to flumazenil (0.05-0.3 mg/hr) or placebo infusion for up to 72 hours. Confusion Assessment Method-ICU scores were assessed twice daily for resolution of delirium. MEASUREMENTS AND MAIN RESULTS: The trial was stopped early based on the observed size effect and power analysis. Twenty-two of the 25 patients responded to the flumazenil test dose (88%). The median number of delirium-free days alive without coma within 14 days of enrollment was similar between the two infusion groups (12.7 vs 9.2; p = 0.19). There was no difference in the probability of delirium resolution within the first 14 days with 90% versus 70% in the flumazenil and placebo groups, respectively (p = 0.2). There was no statistical difference (odds ratio, 0.17; 95% CI, 0.022-1.23; p = 0.079) in delirium- and coma-free days at the end of the study drug infusion. There was no difference between groups in ICU length of stay (7.8 ± 4.8 vs 7 ± 8; p = 0.74). No serious adverse events occurred. CONCLUSIONS: This study found that flumazenil test dose and infusion present a potential option for hypoactive delirium associated with benzodiazepine exposure; however, the possible benefit is unknown. Larger studies are warranted to further evaluate these findings.

Effect of early and focused benzodiazepine therapy on length of stay in severe alcohol withdrawal syndrome.

Objective: Current evidence supports symptom-triggered therapy for alcohol withdrawal syndrome (AWS). Early, escalating therapy with benzodiazepines (BZD) appears to decrease ICU length of stay (LOS); however, the effect on hospital LOS remains unknown. The hypothesis of this study is that focused BZD treatment in the first 24 h will decrease hospital LOS. Design: Pre-post cohort study. Setting: Academic medical center. Patients: This study included patients with severe AWS. The pre-intervention cohort (PRE) was admitted between January and November 2015. The post-intervention cohort (POST) was admitted between April 2016 and March 2017. Severe AWS was defined as patients requiring diazepam doses of >30 mg. Focused treatment was defined as >50% of total diazepam usage within the first 24 h of recognition of AWS. Intervention: In the PRE group, patients received symptom-triggered, escalating doses of diazepam and phenobarbital based on their Richmond Agitation-Sedation Scale (RASS). In the POST group, patients received a revised, time-limited course of therapy: escalating doses of BZD and phenobarbital were given during a 24-h loading phase, and all therapy was discontinued after a 72-h tapering phase. The SHOT scale was used as an adjunct to RASS to assess non-agitation symptoms of AWS and guide additional diazepam doses. Measurements and main results: The primary outcome was hospital LOS; secondary outcomes included ICU LOS, BZD use, and ventilator-free days. Five hundred thirty-two patients were treated using the AWS protocol; 113 experienced severe AWS. The PRE (n = 75) and POST (n = 38) groups were evenly matched in age, sex, history of AWS, and severity of illness. There was a substantial difference in POST patients who received focused treatment (51.3% vs. 73.7%, p = .03). The POST group had a significant decrease in hospital LOS (14.0 vs. 9.8 days, p = .03) and ICU LOS (7.4 vs. 4.4 days, p = .03). Conclusion: Early, focused management of severe AWS was associated with a decrease in ICU and hospital LOS.

Trauma and acute care surgeons report prescribing less opioids over time.

INTRODUCTION: Confronted with the opioid epidemic, surgeons must play a larger role to reduce risk of opioid abuse while managing acute pain. Having a better understanding of the beliefs and practices of trauma and acute care surgeons regarding discharge pain management may offer potential targets for interventions beyond fixed legal mandates. METHODS: An Institutional Review Board-approved electronic survey was sent to trauma and acute care surgeons who are members of the American Association for the Surgery of Trauma, and trauma and acute care surgeons and nurse practitioners at a Level 1 trauma center in February 2018. The survey included four case-based scenarios and questions about discharge prescription practices and beliefs. RESULTS: Of 66 respondents, most (88.1%) were at academic institutions. Mean number of opioid tablets prescribed was 20-30 (range 5-90), with the fewest tablets prescribed for elective laparoscopic cholecystectomy and the most for rib fractures. Few prescribed both opioid and non-opioid medications (22.4% to 31.4 %). Most would not change the number/strength of medications (69.2%), dose (53.9%), or number of tablets of opioids (83.1%) prescribed if patients used opioids regularly prior to their operation. The most common factors that made providers more likely to prescribe opioids were high inpatient opioid use (32.4%), history of opioid use/abuse (24.5%), and if the patient lives far from the hospital (12.9%). Most providers in practice >5 years reported a decrease in opioids (71.9%) prescribed at discharge. CONCLUSION: Trauma and acute care surgeons and nurse practitioners reported decreasing the number/amount of opioids prescribed over time. Patients with high opioid use in the hospital, history of opioid use/abuse, or who live far from the provider may be prescribed more opioids at discharge. LEVEL OF EVIDENCE: Level IV.

Multimodal Analgesia and Opioid Use in Critically Ill Trauma Patients.

BACKGROUND: Opioids are the mainstay of pain management in critically ill trauma patients. However, the risks of opioid use mandate a different approach. Multimodal analgesia employs a combination of opioid and nonopioid agents using different mechanisms that have synergistic effects in treating pain. This study examines the effects of multimodal analgesia on the opioid requirements of critically ill trauma patients. STUDY DESIGN: This was a pre-post cohort study of adult trauma ICU patients before and after implementation of a multimodal pain management order set. Patients were excluded if their hospital stay was less than 5 days, head Abbreviated Injury Scale score was greater than 1, or pre-injury medications included methadone or buprenorphine. The total oral morphine equivalent (OME) dose was calculated for each 24-hour period on days 2 through 5 of admission and the last 24 hours before discharge using standardized ratios. The primary endpoint was cumulative OME doses over the second through fifth days of admission. RESULTS: There were 65 patients in the pre-group and 62 in the post-group. Median cumulative OME dose was significantly lower in the post-group (125.6 mg, interquartile range [IQR] 45.0 to 415.0 mg) compared with the pre-group (481.5 mg, IQR 174.8 to 881.3 mg), p < 0.001. Patients who received 3 or more multimodal agents had a lower cumulative OME dose (116.3 mg, IQR 52.5 to 496.5 mg) compared with those who were on 1 to 2 multimodal agents (363 mg, IQR 115.5 to 743 mg) or 0 multimodal agents (479 mg, IQR 185 to 736.5 mg), p = 0.024. There were no differences between pre-group and post-group mean pain scores on hospital day 5 (4.48 ± 0.34 vs 3.50 ± 0.38, p = 0.058) or at hospital discharge (3.43 ± 0.34 vs 3.56 ± 0.32, p = 0.789). CONCLUSIONS: Implementation of a multimodal pain management strategy significantly reduced opioid use in critically ill trauma patients without compromising patient comfort.

Challenges to the care of the critically ill: novel staffing paradigms.

The current shortage in intensive care unit (ICU) physician staffing coupled with Leapfrog initiatives has lead to novel ICU staffing paradigms including the use of nonsurgeon intensivists in surgical ICUs, increased development of telemedicine, and ICU regionalization.

Gastric alkalinization after major trauma.

BACKGROUND: Gastric function in trauma patients is poorly understood. In animals, shock causes gastric luminal alkalinization and bile reflux. In trauma patients, studies of stress gastritis prophylaxis demonstrated with continuous gastric pH monitoring that the stomach became alkaline even without antisecretory therapy. Therefore, we hypothesized that trauma patients have an alkaline gastric environment that may be because of bile reflux. METHODS: A prospective observational study at an urban Level I trauma center was performed. All major torso trauma patients (severe head injuries excluded) who met the criteria for standardized shock resuscitation were eligible for inclusion. A 12.5 Fr silastic pH probe (Sandhill Scientific) was placed in the stomach and the gastric pH continuously monitored for 7 days. Patients received no stress gastritis prophylaxis. Gastric samples were obtained each day and assayed for total bile acids and pH. RESULTS: Twelve patients were entered into the study. Mean age was 31 years +/- 4 years, 67% men, 75% blunt mechanism of injury, and mean Injury Severity Score 28 +/- 3. Three patients (25%) developed multiple organ failure and four acquired ventilator-associated pneumonia. During the first day of continuous pH monitoring, 9 of 12 patients had a gastric pH >4 for the majority of the day with 7 patients having essentially no acid production. During subsequent days, gastric pH began to drop and by the 4th day the majority of each day was spent at a pH <4. Additionally, gastric pH of patients with ventilator-associated pneumonia or multiple organ failure tended to be more alkaline. Bile acid was present in the gastric fluid of all patients in varying amounts. However, there was no significant correlation between gastric pH and bile acid concentration. CONCLUSIONS: Traumatic injury causes gastric luminal alkalinization that may be related, only in part, to bile acid reflux. Other alkalinizing factors remain to be elucidated.

Nonocclusive mesenteric ischemia in patients with methamphetamine use.

BACKGROUND: Data suggest that methamphetamine may increase the risk of nonocclusive mesenteric ischemia (NOMI). We describe patterns of presentation and outcomes of patients with methamphetamine use who present with NOMI to a single institution. METHODS: This is an observational study of patients from January 2015 to September 2017 with methamphetamine use who presented with NOMI at an academic medical center in Northern California. We summarize patient comorbidities, clinical presentation, operative findings, pathologic findings, hospital course, and survival. RESULTS: Ten patients with methamphetamine use and severe NOMI were identified. One patient was readmitted with a perforated duodenal ulcer, for a total of 11 encounters. Most presented with acute (n = 3) or acute-on-chronic (n = 4) abdominal pain. Distribution of ischemia ranged from perforated duodenal ulcer (n = 3), ischemia of the distal ileum (n = 1), ischemia of entire small bowel (n = 2), and patchy necrosis of entire small bowel and colon (n = 5). Six patients died, three within 1 week of admission and three between 3 months and 8 months. CONCLUSION: Methamphetamine use may be associated with significant microvascular compromise, increasing the risk of mesenteric ischemia. Providers in areas with high prevalence of methamphetamine use should have a high index of suspicion for intestinal ischemia in this patient population. Patients with methamphetamine use admitted for trauma or other pathology may be at particular risk of ischemia and septic shock, especially in the setting of dehydration. Use of vasoconstrictors in this patient population may also exacerbate intestinal ischemia. LEVEL OF EVIDENCE: Therapeutic Case series study, level V.

Acute lower extremity compartment syndrome (ALECS) screening protocol in critically ill trauma patients.

BACKGROUND: Acute lower extremity compartment syndrome (ALECS) is a devastating complication that often presents silently in critically injured patients; therefore, we developed a protocol to screen high-risk patients. METHODS: This prospective observational study included all Shock Trauma intensive care unit patients who met specific high-risk criteria including pulmonary artery catheter-directed shock resuscitation, open or closed tibial shaft fracture, major vascular injury below the aortic bifurcation, abdominal compartment syndrome, or pelvic or lower extremity crush injury. Patients were screened at admission and every 4 hours thereafter for the first 48 hours of admission. Screening included physical examination (PE) and anterior or deep posterior calf compartment pressure measurements when PE was suspicious or unreliable. A positive screening, defined as a DeltaP <30 mm Hg (where DeltaP is the difference between the diastolic blood pressure and the compartment pressure), mandated a four-compartment fasciotomy. RESULTS: During a 6-month period, the incidence of ALECS in screened patients was surprisingly high at 20% (9 patients). With diligent screening, it was diagnosed early in the patient's Shock Trauma intensive care unit course. These were patients with severe injuries with an Injury Severity Score of 32.0 +/- 12.5 who exhibited significant volume depletion, with a base deficit of 12.9 +/- 5.9 mEq/L and a lactate level of 13.0 +/- 5.2 mmol/L, requiring large volume resuscitation. Although aggressive fasciotomy resulted in no limb loss, ALECS was associated with an exceedingly high mortality rate at 67%. CONCLUSIONS: ALECS is an important clinical entity in critically injured patients with trauma associated with significant mortality. Aggressive screening may provide some diagnostic insight to those at risk.

Informed consent-It's more than a signature on a piece of paper.

Informed consent is an ethical concept that is codified in the law and is in daily practice at every health care institution. Three fundamental criteria are needed for clinical informed consent: the patient must be competent, adequately informed and not coerced. Physician-patient interaction is rooted in the ethical concept of beneficence, but over the 19th and 20th centuries, case law and societal changes brought respect for autonomy and with it--informed consent. This article briefly reviews the basics of informed consent, when is it required, how did informed consent evolve into what it is today and what can the surgeon do to truly achieve informed consent.

Antibiotics vs. Appendectomy for Acute Uncomplicated Appendicitis in Adults: Review of the Evidence and Future Directions.

BACKGROUND: Acute appendicitis is the most common abdominal surgical emergency in the United States, with a lifetime risk of 7%-8%. The treatment paradigm for complicated appendicitis has evolved over the past decade, and many cases now are managed by broad-spectrum antibiotics. We determined the role of non-operative and operative management in adult patients with uncomplicated appendicitis. METHODS: Several meta-analyses have attempted to clarify the debate. Arguably the most influential is the Appendicitis Acuta (APPAC) Trial. RESULTS: According to the non-inferiority analysis and a pre-specified non-inferiority margin of -24%, the APPAC did not demonstrate non-inferiority of antibiotics vs. appendectomy. Significantly, however, the operations were nearly always open, whereas the majority of appendectomies in the United States are done laparoscopically; and laparoscopic and open appendectomies are not equivalent operations. Treatment with antibiotics is efficacious more than 70% of the time. However, a switch to an antimicrobial-only approach may result in a greater probability of antimicrobial-associated collateral damage, both to the host patient and to antibiotic susceptibility patterns. A surgery-only approach would result in a reduction in antibiotic exposure, a consideration in these days of focus on antimicrobial stewardship. CONCLUSION: Future studies should focus on isolating the characteristics of appendicitis most susceptible to antibiotics, using laparoscopic operations as controls and identifying long-term side effects such as antibiotic resistance or Clostridium difficile colitis.

Management and Novel Adjuncts of Necrotizing Soft Tissue Infections.

Necrotizing soft tissue infections (NSTI) have been recognized for millennia and continue to impose considerable burden on both patient and society in terms of morbidity, death, and the allocation of resources. With improvements in the delivery of critical care, outcomes have improved, although disease-specific therapies are lacking. The basic principles of early diagnosis, of prompt and broad antimicrobial therapy, and of aggressive debridement have remained unchanged. Clearly novel and new therapeutics are needed to combat this persistently lethal disease. This review emphasizes the pillars of NSTI management and then summarizes the contemporary evidence supporting the incorporation of novel adjuncts to the pharmacologic and operative foundations of managing this disease.

Longer-Duration Antimicrobial Therapy Does Not Prevent Treatment Failure in High-Risk Patients with Complicated Intra-Abdominal Infections.

BACKGROUND: Recent studies have suggested the length of treatment of intra-abdominal infections (IAIs) can be shortened without detrimental effects on patient outcomes. However, data from high-risk patient populations are lacking. We hypothesized that patients at high risk for treatment failure will benefit from a longer course of antimicrobial therapy. METHODS: Patients enrolled in the Study to Optimize Peritoneal Infection Therapy (STOP-IT) trial were evaluated retrospectively to identify risk factors associated with treatment failure, which was defined as the composite outcome of recurrent IAI, surgical site infection, or death. Variables were considered risk factors if there was a positive statistical association with treatment failure. Patients were then stratified according to the presence and number of these risk factors. Univariable analyses were performed using the Kruskal-Wallis, χ2, and Fisher exact tests. Logistic regression controlling for risk factors and original randomization group, either a fixed four-day antimicrobial regimen (experimental) or a longer course based on clinical response (control), also was performed. RESULTS: We identified corticosteroid use, Acute Physiology and Chronic Health Evaluation II score ≥5, hospital-acquired infection, or a colonic source of IAI as risk factors associated with treatment failure. Of the 517 patients enrolled, 263 (50.9%) had one or two risk factors and 16 (3.1%) had three or four risk factors. The rate of treatment failure rose as the number of risk factors increased. When controlling for randomization group, the presence and number of risk factors were independently associated with treatment failure, but the duration of antimicrobial therapy was not. CONCLUSIONS: We were able to identify patients at high risk for treatment failure in the STOP-IT trial. Such patients did not benefit from a longer course of antibiotic administration. Further study is needed to determine the optimum duration of antimicrobial therapy in high-risk patients.