Hemodynamic effects of positive end-expiratory pressure. Historical perspective.

Mechanical ventilation with positive end-expiratory pressure has been known to increase arterial oxygen content for approximately 40 years. Early experiments demonstrated a diminution of cardiac output with the application of positive end-expiratory pressure, and it was not favored as a therapeutic modality until the 1960s, when it was found to be effective in the treatment of adult respiratory distress syndrome. In recent years, physiologists have methodically scrutinized the effects of positive end-expiratory pressure on each of the major determinants of cardiac output. Review of the progression of thought on this subject reinforces for today's clinician basic principles of cardiac performance and heart-lung interaction.

Hemodynamic changes in human anaphylaxis.

Human anaphylactic reactions are usually unexpected and catastrophic. Therefore, opportunities to record the physiologic changes that occur are uncommon. A patient is described who experienced an anaphylactic reaction to a penicillin drug while being monitored in an intensive care unit for ischemic heart disease. Hemodynamic monitoring indicated that the decrease in cardiac output was most likely due to a decrease in venous return. In addition, this patient's previous reactions to other penicillins demonstrated that variations in the clinical manifestations of systemic anaphylaxis can occur within the same person.

A comparison of cefpodoxime proxetil and cefaclor in the treatment of acute exacerbation of COPD in adults.

In this multicenter, observer-blinded study, 301 patients with signs and symptoms of acute bacterial exacerbation of COPD were randomized (2:1) to receive either cefpodoxime proxetil (200 mg, bid) or cefaclor (250 mg, tid) for 10 days. Clinical and microbiologic evaluations were performed before treatment, during therapy (study days 3 to 5), at the end of therapy (3 to 7 days posttreatment), and at long-term follow-up (4 weeks posttreatment). The most common pretreatment isolates were Haemophilus influenzae, Haemophilus parainfluenzae, and Streptococcus pneumoniae. Significantly (p < 0.001) more bacterial isolates were susceptible in vitro to cefpodoxime (233 of 256, 91 percent) than to cefaclor (215 of 255, 84 percent). There were no statistically significant differences between the two drug regimens in eradication of the initial pathogen (cefpodoxime, 116 of 128, 91 percent; cefaclor, 59 of 64, 92 percent) or end-of-therapy clinical response (cure + proved; cefpodoxime, 99 of 100, 99 percent; cefaclor, 45 of 49, 92 percent) rates for evaluable patients. Both drug treatments were well-tolerated, with a similar incidence of drug-related adverse events (cefpodoxime 11 percent, cefaclor 12 percent). Cefpodoxime (bid) was as safe and effective as cefaclor (tid) in the treatment of acute exacerbation of COPD. The less frequent dosing regimen of cefpodoxime may improve patient compliance compared to those antibiotics that require three or four daily doses.

Disseminated Histoplasma capsulatum infection presenting as genital ulcerations.

BACKGROUND: Histoplasma capsulatum infection in adults is most often subclinical but can result in disseminated disease with weight loss, fever, hepatosplenomegaly, and oropharyngeal ulcerations. Genital ulceration as the presenting sign of the disease has been reported rarely. CASE: A 63-year-old woman presented with multiple vaginal ulcerations due to chronic disseminated H capsulatum infection. Initial diagnosis was made by Papanicolaou and Giemsa-stained vulvar smears. Ketoconazole therapy resulted in clearing of the lesions in 5 weeks. CONCLUSION: Chronic disseminated histoplasmosis is an insidious and potentially fatal disease that can present rarely as genital mucocutaneous ulcerations in women. Prompt presumptive diagnosis can be accomplished by examination of smears obtained by ulcer abrasion, permitting institution of appropriate therapy.

Penetration of trovafloxacin into gynecologic tissues.

BACKGROUND: This randomized open-label study assessed the penetration into gynecologic tissues of trovafloxacin, a new broad-spectrum, fourth-generation fluoroquinolone with in vitro activity against anaerobes, gram-positive, gram-negative, and atypical pathogens. METHODS: Women undergoing hysterectomy or hysterectomy and adnexectomy received 200 mg trovafloxacin orally before surgery as a single dose or as multiple doses. Samples of genital tract tissue and serum were obtained simultaneously during surgery. RESULTS: In the single-dose group, trovafloxacin concentrations in genital tract tissues were measurable for up to 30 hours. Tissue concentrations of trovafloxacin after multiple doses were comparable to those after single doses. Mean tissue: serum concentration ratios after a single dose were greatest in the ovary (1.6 microg/g) and comparable in uterus, myometrium, cervix, and fallopian tubes (0.5 to 0.7 microg/g). Adverse events after a single dose were minor. CONCLUSIONS: A daily dose of 200 mg trovafloxacin produces gynecologic tissue concentrations that persist for up to 30 hours at levels necessary to prevent or treat pelvic infections. This dosing regimen is well tolerated.

Aeromedical transfer of preterm labor patients.

Obstetric patients are transported by air quite frequently. We evaluated transport times, obstetric outcomes, air-versus-ground transport costs, and related data on 22 helicopter aeromedical transports of pregnant patients with preterm labor. We found no significant differences between patients who delivered and those who did not when comparing transport time (167.1 +/- 41.9 minutes versus 177.1 +/- 56.2 minutes), air distance of transport (122.9 +/- 44.8 miles versus 143.6 +/- 23.8 miles), and other outcome measures. No deliveries occurred in flight. Air transport costs were significantly greater than estimated ground transfer ($4613.64 +/- $581.12 versus $604.02 +/- $306.38; P < .01). Two-way air transfer of preterm labor patients over moderate distances is more costly than contracted ground transfer costs at our institution.