The characteristics of five patients with obstructive sleep apnea whose apnea-hypopnea index deteriorated after uvulopalatopharyngoplasty.

The objective of this retrospective, consecutive, case series design study was to determine the number of unselected patients with obstructive sleep apnea (OSA) who deteriorated after uvulopalatopharyngoplasty (UPPP). Sixteen of 27 patients at the Sleep Clinic at Veterans Affairs Medical Center who underwent UPPP for OSA and who completed both a pre- and postpolysomnogram were studied. After comparing the apnea-hypopnea index (AHI) before and after UPPP, three groups of patients were identified: deteriorators, unchanged, and improvers.

Effects of sodium bicarbonate administration on the exercise tolerance of normal subjects breathing through dead space.

Study Objective: The purpose of this study was to determine whether the administration of sodium bicarbonate to normal individuals would increase their PaCO2 and thereby decrease the ventilatory requirements at a given workload.

Design: In this double-blind crossover study, six normal men ingested either 3 mEq/kg NaHCO3 or 1 mEq/kg NaCl once a day for 5 days, in addition to 40 mg of furosemide and 40 mEq KCl. After each 5-day treatment, the subjects underwent a symptom-limited maximal bicycle ergometer exercise test while breathing through external dead space (with a volume of approximately 50% of their FEV1), a second exercise test without any external dead space, and an assessment of their respiratory response to hypercapnia.

On-line arterial blood gas analysis with optodes: current status.

Objectives: To summarize the rationale for and the principles of blood gas and pH measurement with photochemical sensors (optodes) placed in the arterial line--either intravascularly (in vivo) or extravascularly (ex vivo). To review the specific problems that occur with in vivo measurement; the clinical data that have been obtained with continuous intravascular and on-demand extravascular systems; and, the role of this technology in the intensive care unit.

Methods And Results: The principles of absorbance and fluorescent optical sensors are described.

Acute hemorrhagic leukoencephalitis during treatment for disseminated tuberculosis in a patient with AIDS.

A 45-year-old man with the acquired immune deficiency syndrome (AIDS) developed disseminated Mycobacterium tuberculosis infection and was started on isoniazid, rifampin, pyrazinamide and ethambutol. The treatment was interrupted because of side effects. On resumption of treatment be developed a rapidly progressive neurological illness characterized by left hemiparesis, right gaze preference, convulsions, coma, evidence of cerebral edema on computed tomography scan and death 9 days later.

Breathing pattern during acute respiratory failure and recovery.

The objective of this study was to compare the breathing pattern of patients who failed to wean from mechanical ventilation to the pattern during acute respiratory failure. We hypothesized that a similar breathing pattern occurs under both conditions. Breathing pattern, mouth occlusion pressure (P[0.