The effect of culture-positive influenza type A on resource use and adverse events in nursing home residents

OBJECTIVES: To determine adverse clinical events and resource utilization associated with culture-positive influenza A in nursing home residents. DESIGN: A retrospective cohort study with cases and controls. SETTING: Seven hundred twenty-one-bed skilled nursing facility. PARTICIPANTS: One hundred fifty-four residents (21% of all residents) from whom influenza A was isolated during the 1997/98 season and matched controls. MEASUREMENTS: Baseline parameters, staff interventions, diagnostic tests, and adverse events were recorded from 60 days before to 60 days after specimen collection. The difference between each individual's before and after measurements determined excess utilization secondary to influenza. Controls were studied to determine time series effects. RESULTS: Baseline Minimum Data Set and nutritional parameters demonstrated significantly greater (P <.05) feeding dependency and lower serum albumin in the control group. Time series effects in the control group were negligible. Among cases, there were nine deaths within 30 days; among controls, there were four (chi2 P =.26). Within 30 days of onset, an average excess of 18 notations by nursing staff, one phone call to the physician, and one to family was noted per case. In half of cases, a nonscheduled physician visit was required. There was a 20% excess in physician orders for oxygen and bronchodilators. Chest x-rays were performed in half of the cases, and antibiotics were prescribed to half. Sixteen percent of cases had radiographic pneumonia, and 2% had congestive heart failure. The average cost for excess chest x-rays, laboratory services, antimicrobials, ambulance calls, hospital days, and emergency room and physician visits was $943.44. This does not include efforts by nursing home staff who accommodate functional decline on-site. CONCLUSION: An unexpected finding was that there were more impaired individuals who were less likely to have influenza detected or less likely to acquire influenza in the control group than in the influenza group. The morbidity, mortality, excess staff effort, and measured expenditure justify efforts to prevent influenza.     

Reducing the incidence of surgical fires: supplying nasal cannulae with sub-100% O2 gas mixtures from anesthesia machines

In June 2003, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) recommended: "As a general policy, use air or FiO2 at < or =30% for open delivery (consistent with patient needs)" to prevent surgical fires. One way to interpret JCAHO's recommendation is that 100% O2 should not be indiscriminately used, and anesthesia providers should have the ability, consistent with patient needs and their clinical judgment, to deliver sub-100% O2 with nasal cannulae. An auxiliary O2 flowmeter has a barbed outlet connector that offers a convenient means to connect a cannula to an anesthesia machine and is routinely used for open delivery of 100% O2. The auxiliary O2 flowmeter provides only 100% O2 and thus does not allow titration of the O2 concentration to patient needs and may increase the risk of surgical fires. This report clarifies the JCAHO recommendation and describes different means of addressing it that are based primarily on using the anesthesia machine to blend a sub-100% O2 gas mixture and delivering it via a nasal cannula. The options presented depend on the model and manufacturer of the anesthesia machine and allow delivery via nasal cannula of O2 concentrations that range from 21% to 100%.     

Increased pulmonary artery perforating potential of pulmonary artery catheters during hypothermia

The rate of major complications from the use of pulmonary artery (PA) catheters has been reported to be as high as 9%, 0.2% of which may be attributed to PA perforation, a catastrophe with a fatal outcome more than 50% of the time. Although an uncommon event generally, more than one third of catheter-related PA perforations occur during cardiac surgery. Several factors act to advance the balloon-tipped PA catheter into the distal PA, where, during hypothermia, the catheter hardens and, thus, may be more likely to perforate the vessel. The relative contribution of hypothermia, itself, to the perforating potential of previously used, triple-lumen PA catheters (n = 5) was examined in vitro by mounting them in a temperature-controlled testing chamber, at a 90 degrees incident angle to a polyethylene membrane, which represented the PA wall. The membrane was made to pulsate 80 times/min against the PA catheter until it was perforated. Each catheter was tested 5 times each at 3 temperatures. At 35 degrees C, 30 degrees C, and 25 degrees C, the number of pulsations to produce perforation (perforation rate) was 488 +/- 280, 309 +/- 242, and 97 +/- 234, respectively. The perforation rates differed significantly between temperatures (P less than 0.01), but not between catheters or tests at the same temperature. This study demonstrates that perforation of a model PA by a triple-lumen PA catheter is 500% more likely during hypothermia.     

The Stealth Station Image Guidance System may interfere with pulse oximetry

PURPOSE: Interference on pulse oximetry can come from many sources. We found an additional source of interference from the Stealth Station. This article gives an overview of sources of pulse oximeter interference so that clinicians can better prevent them.Technical features: This article discusses the infrared disturbances caused by the Stealth Station. The Stealth Station is a frameless stereotactic positioning system that utilizes a three dimensional location system to measure the position of the patient and the surgical tools, and to relate those positions to previously recorded imaging. To understand the disturbance caused by the Stealth Station, we discuss its operation and that of pulse oximeter monitors. Pulse oximeter interference can come from volume artifacts, electrical and light noise, and can be caused by issues related to the patient. Because the passive Stealth Station contains a strong infrared light source, interference caused by light is a likely reason for the interference we noted. Pulse oximeters rely on the time-variant light signal modulated by arterial volume variations in the finger. Although relatively immune to static light sources, pulse oximeters are extremely sensitive to time-varying light sources. The light emitted by the passive Stealth Station is time-varying at 4 Hz and this is causing the pulse oximeter to provide invalid results. Shielding can generally be used to stop the light from the Stealth Station from being picked up by the pulse oximeter sensor. CONCLUSION: Infrared light interference can be very common, but is easily dealt with if one is aware of it.