Stephen O. Heard

Guidelines for the Prevention of Intravascular Catheter–Related Infections

Naomi P. O’Grady, Mary Alexander, E. Patchen Dellinger, Julie L. Gerberding, Stephen O. Heard, Dennis G. Maki, Henry Masur, Rita D. McCormick, Leonard A. Mermel, Michele L. Pearson, Issam I. Raad, Adrienne Randolph, and Robert A. Weinstein National Institutes of Health, Bethesda, Maryland; Infusion Nurses Society, Cambridge, and University of Massachusetts Medical School, Worcester, and The Children’s Hospital, Boston, Massachusetts; University of Washington, Seattle; Office of the Director, Centers for Disease Control and Prevention (CDC), and Division of Healthcare Quality Promotion, National Center for Infectious Diseases, CDC, Atlanta, Georgia; University of Wisconsin Medical School and Hospital and Clinics, Madison; Rhode Island Hospital and Brown University School of Medicine, Providence, Rhode Island; MD Anderson Cancer Center, Houston, Texas; and Cook County Hospital and Rush Medical College, Chicago, Illinois

A Comparison of Two Antimicrobial-Impregnated Central Venous Catheters

BACKGROUND The use of central venous catheters impregnated with either minocycline and rifampin or chlorhexidine and silver sulfadiazine reduces the rates of catheter colonization and catheter-related bloodstream infection as compared with the use of unimpregnated catheters. We compared the rates of catheter colonization and catheter-related bloodstream infection associated with these two kinds of antiinfective catheters. METHODS We conducted a prospective, randomized clinical trial in 12 university-affiliated hospitals. High-risk adult patients in whom central venous catheters were expected to remain in place for three or more days were randomly assigned to undergo insertion of polyurethane, triple-lumen catheters impregnated with either minocycline and rifampin (on both the luminal and external surfaces) or chlorhexidine and silver sulfadiazine (on only the external surface). After their removal, the tips and subcutaneous segments of the catheters were cultured by both the roll-plate and the sonication methods. Peripheral-blood cultures were obtained if clinically indicated. RESULTS Of 865 catheters inserted, 738 (85 percent) produced culture results that could be evaluated. The clinical characteristics of the patients and the risk factors for infection were similar in the two groups. Catheters impregnated with minocycline and rifampin were 1/3 as likely to be colonized as catheters impregnated with chlorhexidine and silver sulfadiazine (28 of 356 catheters [7.9 percent] vs. 87 of 382 [22.8 percent], P<0.001), and catheter-related bloodstream infection was 1/12 as likely in catheters impregnated with minocycline and rifampin (1 of 356 [0.3 percent], vs. 13 of 382 [3.4 percent] for those impregnated with chlorhexidine and silver sulfadiazine; P<0.002). CONCLUSIONS The use of central venous catheters impregnated with minocycline and rifampin is associated with a lower rate of infection than the use of catheters impregnated with chlorhexidine and silver sulfadiazine.

Laboratory models of sepsis and septic shock

That there are so many models of sepsis and septic shock is tacit evidence that none of them are perfect. Although sepsis presents in many forms clinically, most clinicians would probably agree that virtually all severely septic patients manifest respiratory failure and ventilator dependence. Furthermore, failure of organs other than the lungs typically occurs days to weeks after the onset of the septic process. Although early deaths occur commonly in some situations (e.g., meningococcemia, pneumococcal bacteremia in asplenic individuals, Gram-negative bacteremia in the setting of profound granulocytopenia), most deaths due to sepsis occur after a protracted course in an intensive care unit. Thus, for certain important experiments, there is a need for an animal model of severe chronic sepsis characterized by these features: persistent hypermetabolism, low systemic vascular resistance, respiratory failure severe enough to require mechanical ventilation, late (nonpulmonary) organ system failure, and death. Obviously, creation of such a model will require a major commitment of resources, because it will require, in essence, the creation of an animal intensive care unit. Nevertheless, we believe that progress in sepsis-related research would be substantially facilitated were such a model available. Even without such a model, progress will continue in this field. A wide variety of good animal models are already available to investigators. In the next decade, as new methods, such as the powerful tools of molecular biology, are applied to problems related to the sepsis syndrome, these models will be invaluable in improving our understanding of pathophysiology and in developing new and more effective approaches toward therapy.

Practice parameters for hemodynamic support of sepsis in adult patients: 2004 update

Objective:To provide the American College of Critical Care Medicine with updated guidelines for hemodynamic support of adult patients with sepsis. Data Source:Publications relevant to hemodynamic support of septic patients were obtained from the medical literature, supplemented by the expertise and experience of members of an international task force convened from the membership of the Society of Critical Care Medicine. Study Selection:Both human studies and relevant animal studies were considered. Data Synthesis:The experts articles reviewed the literature and classified the strength of evidence of human studies according to study design and scientific value. Recommendations were drafted and graded levels based on an evidence-based rating system described in the text. The recommendations were debated, and the task force chairman modified the document until <10% of the experts disagreed with the recommendations. Conclusions:An organized approach to the hemodynamic support of sepsis was formulated. The fundamental principle is that clinicians using hemodynamic therapies should define specific goals and end points, titrate therapies to those end points, and evaluate the results of their interventions on an ongoing basis by monitoring a combination of variables of global and regional perfusion. Using this approach, specific recommendations for fluid resuscitation, vasopressor therapy, and inotropic therapy of septic in adult patients were promulgated.

Report of a National Conference on Donation after cardiac death.

A national conference on organ donation after cardiac death (DCD) was convened to expand the practice of DCD in the continuum of quality end‐of‐life care.

Treatment of severe pneumonia in hospitalized patients: results of a multicenter, randomized, double-blind trial comparing intravenous ciprofloxacin with imipenem-cilastatin. The Severe Pneumonia Study Group.

Intravenously administered ciprofloxacin was compared with imipenem for the treatment of severe pneumonia. In this prospective, randomized, double-blind, multicenter trial, which included an intent-to-treat analysis, a total of 405 patients with severe pneumonia were enrolled. The mean APACHE II score was 17.6, 79% of the patients required mechanical ventilation, and 78% had nosocomial pneumonia. A subgroup of 205 patients (98 ciprofloxacin-treated patients and 107 imipenem-treated patients) were evaluable for the major efficacy endpoints. Patients were randomized to receive intravenous treatment with either ciprofloxacin (400 mg every 8 h) or imipenem (1,000 mg every 8 h), and doses were adjusted for renal function. The primary and secondary efficacy endpoints were bacteriological and clinical responses at 3 to 7 days after completion of therapy. Ciprofloxacin-treated patients had a higher bacteriological eradication rate than did imipenem-treated patients (69 versus 59%; 95% confidence interval of -0.6%, 26.2%; P = 0.069) and also a significantly higher clinical response rate (69 versus 56%; 95% confidence interval of 3.5%, 28.5%; P = 0.021). The greatest difference between ciprofloxacin and imipenem was in eradication of members of the family Enterobacteriaceae (93 versus 65%; P = 0.009). Stepwise logistic regression analysis demonstrated the following factors to be associated with bacteriological eradication: absence of Pseudomonas aeruginosa (P < 0.01), higher weight (P < 0.01), a low APACHE II score (P = 0.03), and treatment with ciprofloxacin (P = 0.04). When P. aeruginosa was recovered from initial respiratory tract cultures, failure to achieve bacteriological eradication and development of resistance during therapy were common in both treatment groups (67 and 33% for ciprofloxacin and 59 and 53% for imipenem, respectively). Seizures were observed more frequently with imipenem than with ciprofloxacin (6 versus 1%; P = 0.028). These results demonstrate that in patients with severe pneumonia, monotherapy with ciprofloxacin is at least equivalent to monotherapy with imipenem in terms of bacteriological eradication and clinical response. For both treatment groups, the presence of P. aeruginosa had a negative impact on treatment success. Seizures were more common with imipenem than with ciprofloxacin. Monotherapy for severe pneumonia is a safe and effective initial strategy but may need to be modified if P. aeruginosa is suspected or recovered from patients.

Guidelines for the prevention of intravascular catheter-related infections.

BACKGROUND Although many catheter-related bloodstream infections (CRBSIs) are preventable, measures to reduce these infections are not uniformly implemented. OBJECTIVE To update an existing evidenced-based guideline that promotes strategies to prevent CRBSIs. DATA SOURCES The MEDLINE database, conference proceedings, and bibliographies of review articles and book chapters were searched for relevant articles. STUDIES INCLUDED Laboratory-based studies, controlled clinical trials, prospective interventional trials, and epidemiologic investigations. OUTCOME MEASURES Reduction in CRBSI, catheter colonization, or catheter-related infection. SYNTHESIS The recommended preventive strategies with the strongest supportive evidence are education and training of healthcare providers who insert and maintain catheters; maximal sterile barrier precautions during central venous catheter insertion; use of a 2% chlorhexidine preparation for skin antisepsis; no routine replacement of central venous catheters for prevention of infection; and use of antiseptic/antibiotic-impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (ie, education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis). CONCLUSION Successful implementation of these evidence-based interventions can reduce the risk for serious catheter-related infection.

The hemodynamic and adrenergic effects of perioperative dexmedetomidine infusion after vascular surgery.

UNLABELLED We tested dexmedetomidine, an alpha(2) agonist that decreases heart rate, blood pressure, and plasma norepinephrine concentration, for its ability to attenuate stress responses during emergence from anesthesia after major vascular operations. Patients scheduled for vascular surgery received either dexmedetomidine (n = 22) or placebo (n = 19) IV beginning 20 min before the induction of anesthesia and continuing until 48 h after the end of surgery. All patients received standardized anesthesia. Heart rate and arterial blood pressure were kept within predetermined limits by varying anesthetic level and using vasoactive medications. Heart rate, arterial blood pressure, and inhaled anesthetic concentration were monitored continuously; additional measurements included plasma and urine catecholamines. During emergence from anesthesia, heart rate was slower with dexmedetomidine (73 +/- 11 bpm) than placebo (83 +/- 20 bpm) (P = 0.006), and the percentage of time the heart rate was within the predetermined hemodynamic limits was more frequent with dexmedetomidine (P < 0.05). Plasma norepinephrine levels increased only in the placebo group and were significantly lower for the dexmedetomidine group during the immediate postoperative period (P = 0.0002). We conclude that dexmedetomidine attenuates increases in heart rate and plasma norepinephrine concentrations during emergence from anesthesia. IMPLICATIONS The alpha(2) agonist, dexmedetomidine, attenuates increases in heart rate and plasma norepinephrine concentrations during emergence from anesthesia in vascular surgery patients.

Summary of Recommendations: Guidelines for the Prevention of Intravascular Catheter-related Infections

These guidelines have been developed for healthcare personnel who insert intravascular catheters and for persons responsible for surveillance and control of infections in hospital, outpatient, and home healthcare settings. This report was prepared by a working group comprising members from professional organizations representing the disciplines of critical care medicine, infectious diseases, healthcare infection control, surgery, anesthesiology, interventional radiology, pulmonary medicine, pediatric medicine, and nursing. The working group was led by the Society of Critical Care Medicine

Gastric tonometry in healthy volunteers: effect of ranitidine on calculated intramural pH.

ObjectiveTo determine if intraluminal production of CO2 leads to underestimation of gastric intramural pH (pHi) by tonometry. DesignNonrandomized controlled study. PatientsHealthy volunteers. InterventionsNG tonometers were placed in healthy volunteers. Some of the volunteers (n = 11) were pretreated with ranitidine to prevent secretion of protons into the gastric lumen. Others (n = 13) were untreated (i.e., gastric acid secretion was uninhibited). Measurements and Main ResultsGastric pHi was calculated from the arterial (HCO3) and the tonometrically determined intraluminal Pco2 using the Henderson-Hasselbalch equation. Intraluminal Pco2 was significantly higher in the control group (54 ± 14 torr [7.2 ± 1.9 kPa]) than in the ranitidine-treated group (42 ± 4 torr [5.6 ± 0.4 kPa], p = .02). Mean gastric luminal pH was 1.9 ± 0.6 in the control group as compared with 6.7 ± 0.7 in volunteers treated with ranitidine (p < .01). Mean calculated gastric pHi was 7.30 ± 0.11 in the untreated group and 7.39 ± 0.03 in the ranitidine-treated group (p < .03). ConclusionsThese data suggest that intraluminal production of CO2 from the titration of gastric HCO−3 by secreted H+ can result in the underestimation of gastric pHi by tonometry. This phenomenon can be eliminated by H2-receptor blockade. (Crit Care Med 1991; 19:271)