Time-kill profiles of Enterococcus to antibiotics used for intravitreal therapy.

BACKGROUND AND OBJECTIVE: To determine and then compare the time-kill profiles of Enterococcus to antibiotics used for intravitreal therapy. PATIENTS AND METHODS: The time-kill profiles of four endophthalmitis isolates of Enterococcus faecalis, one vancomycin-resistant E. faecalis isolate, and three vancomycin-resistant isolates of E. faecium were determined against vancomycin, amikacin, cefazolin, gentamicin, ampicillin, ciprofloxacin, ceftazidime, clindamycin, and the combinations of vancomycin and amikacin, vancomycin and ceftazidime, vancomycin and gentamicin, vancomycin and ampicillin, cefazolin and gentamicin, and ampicillin and gentamicin. RESULTS: No single antibiotic or combination was bactericidal (defined as 99.9% kill) to all isolates of Enterococcus. Gentamicin was bactericidal to all E. faecalis isolates. None of the tested antibiotics were bactericidal to vancomycin-resistant E. faecium. CONCLUSIONS: The time-kill profiles demonstrated that vancomycin and ceftazidime did not produce a 99.9% kill for E. faecalis in this small study. Gentamicin combined with either cefazolin or ampicillin had somewhat better bactericidal activity and should be considered as an alternative therapy. Novel therapy may be necessary to treat endophthalmitis because of vancomycin-resistant Enterococcus, depending on the susceptibility patterns of the individual isolate and the response to initial therapy.

Influence of patient position on withdrawal forces during removal of lumbar extradural catheters.

We have investigated the force required to remove lumbar extradural catheters from 88 parturients to determine the effects of patient positioning at removal, relative to the position at insertion. Parturients were allocated randomly to one of four groups: LS (lateral insertion, sitting withdrawal), LL (lateral insertion, flexed lateral withdrawal), SL (sitting insertion, lateral withdrawal) or SS (sitting insertion, sitting withdrawal). In both positions, the lumbar spine was kept maximally flexed. The force required to remove the catheter was measured at withdrawal. We found that the withdrawal force was influenced by the relationship between the position at removal and that at insertion, and we recommend that for ease of removal, patients should be placed in the same position as they were at the time of insertion. Compared with all other groups, the withdrawal force in patients in group LS was significantly greater (P < 0.05).

AIDS and the eye.

The AIDS pandemic has finally emerged from the big cities to the small towns of this country, as patients with this disease are returning home to spend their last months and days in the care of their families. No physician will be spared from caring for patients with AIDS. This multisystem disease crosses the boundaries of primary and specialty medicine, and with its various manifestations, presents to virtually all health care professionals. This infection has an enormous impact on our society: economically, socially, and medically. The seriousness of this condition is reflected in the medical school curriculum at the University of Pittsburgh. AIDS education begins the first day of the first year for our medical students.

Coagulopathy with the use of hetastarch in the treatment of vasospasm.

The use of colloid agents to achieve hypervolemia in the prevention and treatment of postsubarachnoid hemorrhage (post-SAH) vasospasm is included in the standard of care at many institutions. Risk profiles are necessary to ensure appropriate use of these agents. In a series of 85 patients with recent aneurysmal SAH, 26 developed clinical symptoms of vasospasm. Fourteen of the 26 were treated with hetastarch for volume expansion while the other 12 received plasma protein fraction (PPF). Clinically significant bleeding pathologies were noted in six patients who received hetastarch as a continuous intravenous infusion. Hetastarch increased partial thromboplastin time from a mean of 23.9 seconds to a mean of 33.1 seconds (p < 0.001) in all patients who received infusions of this agent, while no effect was noted in the 12 patients who received PPF infusions. No other coagulation parameters were altered. This study shows an increase in coagulopathy with the use of hetastarch as compared with the use of PPF for the treatment of postaneurysmal vasospasm.