Cost analysis and clinical impact of weekly ventilator circuit changes in patients in intensive care unit.

BACKGROUND: The introduction of heated circuits and sealed, single-use humidifiers has prompted some investigators to question the traditional recommendations for changing ventilator circuits. We studied the clinical and cost impact of extending the circuit change interval from 72 hours to 7 days in our two intensive care units with 17 beds. METHODS: With standard surveillance definitions from the Centers for Disease Control and Prevention and the National Nosocomial Infections Surveillance System, baseline pneumonia rates were established for a 3-month period. After the institution of weekly circuit changes, daily surveillance of intubated patients was performed during 18 of 22 weeks from May through September 1993. Standard microbiologic methods were used for the identification of patient and environmental isolates. RESULTS: Ventilator-associated pneumonia for the 72-hour circuit change group was 9.1% or 1.29 per 100 ventilator days. After the institution of weekly changes, pneumonia occurred in 9 of 146 patients (6.2% or 0.74 per 100 ventilator days chi 2 = 0.33, p = 0.44). No common bacterial isolates were recovered as judged by phenotype, biochemical, or antimicrobial susceptibility patterns. Weekly changes reduced the number of circuits used from a predicted 469 to 214. Estimating $26.46 per circuit change, annualized cost savings were $20,246.90. CONCLUSIONS: Weekly circuited changes in patients undergoing ventilation therapy in the intensive care unit are cost-effective and do not contribute to increased rates of nosocomial pneumonia.

Effect of time and temperature on inactivation of aminoglycosides by ampicillin at neonatal dosages.

The administration of gentamicin at least 1 hour before administration of ampicillin in neonates has been advocated because of in vitro inactivation of aminoglycosides by beta-lactam antibiotics. This method would cause a delay in ampicillin dosing in the treatment of serious bacterial infections and unnecessarily complicate nursing procedures. We studied the effect of varying concentrations of ampicillin (50, 100, 200, and 400 micrograms/ml) on aminoglycosidic antibiotics in vitro with the use of stock solutions diluted in pooled sera obtained from cord blood and incubated samples at 25 degrees C, 37 degrees C, and 40 degrees C. We found inactivation of aminoglycosides to be dependent on time, temperature, and ampicillin concentration, but the degree of inactivation was small and does not support temporal separation of parenteral administration of ampicillin and aminoglycosides to neonates.

A cluster of atypical skin lesions in well-baby nurseries and a neonatal intensive care unit.

We describe an epidemiologic investigation that elucidated the cause of vesicular and bullous skin lesions of the hands and feet that occurred in three otherwise well neonates during a 24-hour period. The investigation encompassed two well-baby nurseries of 28 and 17 beds and one level III neonatal intensive care unit (NICU) of 31 beds located in a 440-bed university-affiliated community hospital. Work-up for infectious causes of the skin lesions in the initial three cases had negative results. Expanded case surveillance disclosed seven additional cases that had occurred within the previous 2 weeks in the NICU. Analysis of risk factors focused attention on the insertion technique for peripheral intravenous catheters. This led to the discovery of a defective transillumination device, the tip of which reached a temperature of 88 degrees C within 20 seconds, causing thermal burns. The cause of the malfunction was the failure to install an infrared filter during the manufacture of the device. No additional cases were observed after the defective unit was removed from service. In summary, a defective transilluminating device caused a cluster of thermal burns in a newborn nursery and NICU. Epidemiologic investigation of the cluster allowed the investigators to focus on techniques of intravenous catheter insertion, which thus led to the identification of the cause of the injuries. With the increasing emphasis on health outcomes measurement, hospital epidemiologists will likely have an expanding role in investigating clusters of noninfectious adverse events.

Pneumococcal crepitant cellulitis caused by a bronchocutaneous fistula.

An elderly woman who had received radiation treatment for carcinoma of the lung presented with erythema, crepitus and pain over the scapular area. Streptococcus pneumoniae was isolated in pure culture from the subcutaneous tissues, and a bronchocutaneous fistula was demonstrated.

Reversal of infection with Mycobacterium avium intracellulare by treatment with alpha-interferon in a patient with hairy cell leukemia.

A patient with debilitating hairy cell leukemia and documented Mycobacterium avium intracellulare infection unresponsive to standard antituberculous therapy who was treated with alpha-interferon is described. A rapid clinical response with correction of underlying pancytopenia and eradication of the atypical mycobacteria infection was found. No deleterious effects from alpha-interferon therapy were found. The associated resolution of anergy and the sterilization of bone marrow suggest that the reversal of host cellular immune defects led to the eventual control of this patient's infection.

Cutaneous pseudo abscesses: an unusual presentation of severe pancreatitis.

In this report, we present a 53-yr-old man with extensive subcutaneous fat necrosis due to acute pancreatitis presenting as fluctuant collections resembling large multiple abscesses. The diagnosis was suggested by examination of the wound aspirate. Findings included absence of organisms on the gram stain, presence of fat globules on wet mount, and an elevated amylase in the wound aspirate. This dramatic presentation preceded any symptoms or signs of overt pancreatitis.

The patient with suspected meningitis.

When meningitis presents acutely, therapy should be instituted within 1 hour, based on the patient's age and risk factors. When the presentation is subacute, clinical assessment, with analysis of the cerebrospinal fluid, allows the physician to decide among empiric antimicrobial therapy, observation, or further diagnostic studies.