Universal precautions to prevent HIV transmission to health care workers: an economic analysis.

The universal precautions recommended by the US Centers for Disease Control (CDC), Atlanta, for the prevention of HIV (human immunodeficiency virus) transmission to health care workers are widely accepted, despite little documentation of their effectiveness and efficiency. We reviewed the evidence on the risk of HIV transmission to hospital workers and the effectiveness of the universal precautions. We also evaluated the costs of implementing the recommendations in a 450-bed acute care teaching hospital in Hamilton, Ont. On the basis of aggregated results from six prospective studies the risk of HIV seroconversion among hospital workers after a needlestick injury involving a patient known to have AIDS (acquired immune deficiency syndrome) is 0.36% (upper 95% confidence limit 0.67%); the risk after skin and mucous membrane exposure to blood or other body fluids of AIDS patients is 0% (upper 95% confidence limit 0.38%). We estimated that 0.038 cases of HIV seroconversion would be prevented annually in the study hospital if the CDC recommendations were followed. The incremental cost of implementing the universal precautions was estimated to be about $315,000 per year, or over $8 million per case of HIV seroconversion prevented. If all HIV-infected workers were assumed to have AIDS within 10 years of infection the of the program would be about $565,000 per life-year saved. When less conservative, more probable assumptions were applied the best estimate of the implementation cost was $128,862,000 per case of HIV seroconversion prevented. The universal precautions implemented in the study hospital were not found to be efficacious or cost-effective. To minimize the already small risk of HIV transmission in hospitals the sources of risk of percutaneous injury should be better defined and the design of percutaneous lines, needles and surgical equipment as well as techniques improved. Preventive measures recommended on the basis of demonstrated efficacy and aimed at routes of exposure that represent true risk are needed.

Intravenous heparin for the prevention of stroke progression in acute partial stable stroke.

In a double-blind, placebo-controlled trial, 225 patients with acute partial stable thrombotic stroke were randomly assigned to receive continuous intravenous heparin therapy or placebo for 7 days for the prevention of stroke progression or death. No statistically significant difference between the two groups was found in degree of neurologic change; incidence of stroke progression after 7 days; or functional activity level of survivors at 7 days, 3 months and at 1 year after treatment. Compared with controls, a statistically significant greater number of patients in the group receiving heparin died in the year after the stroke. These deaths occurred 3 to 12 months after the initial stroke and probably were not related to treatment. Results of this study do not support the use of intravenous heparin to treat patients who have had acute partial stroke.

Heart rate response to facial immersion and apnea in quadriplegia.

Profound bradycardia is a common complication in the early posttraumatic period following cervical spinal cord damage. It is thought to be due to temporary inactivity of the sympathetic nervous system after separation from supraspinal control, coupled with unopposed parasympathetic dominance because of vagus nerve sparing. Hypoxia, underventilation, and tracheal suctioning appear to intensify the bradycardia. This study examined the effect of vagal stimulation using facial immersion and apnea on heart rate in patients with quadriplegia. Ten patients with quadriplegia (eight males and two females, mean age 25, age range 16-37) and ten healthy controls (eight males and two females, mean age 25, age range 15-37) underwent facial immersion during ECG monitoring. The patients with quadriplegia were studied at a mean of 9.4 months after injury (range, 4-26 months); cord level of injury ranged from C5 to C8; seven of the ten had had heart rates of less than 50 beats/min in the early period after injury and five of the ten had received treatment for this. No change in heart rate was seen in the quadriplegic group during facial immersion (delta = 1.5 +/- 2.7 beats/min, mean +/- SE), but a significant drop in heart rate was seen in the control group (delta = -12.2 +/- 3.7 beats/min, mean +/- SE; p less than 0.01). No significant decreases were seen in either group during apnea alone. Patients with chronic quadriplegia appear to have less sensitivity than controls to the vagal-stimulating maneuver of facial immersion and apnea.

Plasma betathromboglobulin and serum fragment E in acute partial stroke.

Plasma betathromboglobulin (BTG) and serum fragment E (FgE) were measured serially by radioimmunoassay for 7 d in 67 patients admitted with acute partial stroke. Twelve patients progressed within 7 d of admission. Plasma BTG was not different from normal in patients with acute partial stroke and did not increase significantly with stroke progression. Serum FgE was elevated in patients with acute partial stroke compared with normal values, and was significantly higher in patients who progressed compared with those who remained stable. The results indicate that fibrin formation may be more important in the process of stroke progression than activation of platelets.