Positional treatment vs continuous positive airway pressure in patients with positional obstructive sleep apnea syndrome.

OBJECTIVES: The aim of this study was to compare the relative efficacy of continuous positive airway pressure (CPAP) and positional treatment in the management of positional obstructive sleep apnea (OSA), using objective outcome measures. DESIGN: A prospective, randomized, single blind crossover comparison of CPAP and positional treatment for 2 weeks each. SETTING: A university teaching hospital. PATIENTS: Thirteen patients with positional OSA, aged (mean+/-SD) 51+/-9 years, with an apnea-hypopnea index (AHI) of 17+/-8. MEASUREMENTS: (1) Daily Epworth Sleepiness Scale scores; (2) overnight polysomnography, an objective assessment of sleep quality and AHI; (3) maintenance of wakefulness testing; (4) psychometric test battery; (5) mood scales; (6) quality-of-life questionnaires; and (7) individual patient's treatment preference. RESULTS: Positional treatment was highly effective in reducing time spent supine (median, 0; range, 0 to 32 min). The AHI was lower (mean difference, 6.1; 95% confidence interval [CI], 2 to 10.2; p = 0.007), and the minimum oxygen saturation was higher (4%; 95% CI, 1% to 8%; p = 0.02) on CPAP as compared with positional treatment. There was no significant difference, however, in sleep architecture, Epworth Sleepiness Scale scores, maintenance of wakefulness testing sleep latency, psychometric test performance, mood scales, or quality-of-life measures. CONCLUSION: Positional treatment and CPAP have similar efficacy in the treatment of patients with positional OSA.

Continuous positive airway pressure requirement during the first month of treatment in patients with severe obstructive sleep apnea.

OBJECTIVES: (1) To compare the continuous positive airway pressure (CPAP) requirement at the time of diagnosis (T0), after 2 weeks (T2), and after 4 weeks (T4) of CPAP treatment, in patients with severe obstructive sleep apnea (OSA); and (2) to assess whether any alteration in CPAP requirement over the first 4 weeks of CPAP treatment would influence daytime alertness, subjective sleepiness, or mood. DESIGN: A prospective, controlled, single-blind crossover study. SETTING: University teaching hospital. PATIENTS: Ten patients with newly diagnosed and previously untreated severe OSA (aged 52+/-9 years, apnea hypopnea index [AHI] of 99+/-31) and subsequently 10 control patients (aged 52+/-11 years, AHI 85+/-17). MEASUREMENTS: Overnight polysomnography with CPAP titration to determine the CPAP requirement, which was standardized for body position and sleep stage, on all three occasions (T0, T2, T4). Objective sleep quality, daytime alertness, subjective sleepiness (Epworth Sleepiness Scale), and mood (Hospital Anxiety and Depression Scale). RESULTS: CPAP requirement decreased from T0 to T2 (median difference, 1.5 cm H2O, 95% confidence interval [CI], 1.1 to 2.7 cm H2O, p=0.0004) and did not differ between T2 and T4. Use of the lower CPAP pressure during T2 to T4 was associated with a decrease in Epworth scale (mean difference, 2.6, 95% CI, 1.2 to 4; p=0.01) and anxiety (median change, 2; 95% CI, 0.5 to 2.9, p=0.03) scores, as compared with the first 2 weeks. Daytime alertness did not differ between T0 to T2 and T2 to T4. CONCLUSION: CPAP requirement falls within 2 weeks of starting CPAP treatment. A change to the lower required CPAP was not associated with any deterioration in daytime alertness but was associated with small subjective improvements in sleepiness and mood.

Surface tension forces in sleep apnea: the role of a soft tissue lubricant: a randomized double-blind, placebo-controlled trial.

Upper airway obstruction in patients with sleep apnea may occur in the absence of a negative intraluminal upper airway pressure. We hypothesized that surface tension forces may play a role in the pathogenesis of obstructive sleep apnea (OSA), and that a topical soft tissue lubricant might reduce the severity of OSA. Ten male patients (age 49 +/- 10 yr [mean +/- SD]; body mass index [BMI] 31 +/- 5 kg/m2) with OSA (apnea-hypopnea index [AHI] 17 +/- 9) were studied. The arousal index was lower with the lubricant treatment than with placebo (mean difference 8; 95% CI 4 to 11 arousals/h; p = 0.001). The AHI was lower, in each of the 10 patients, on the lubricant treatment than the placebo (mean change 10, 95% CI 6 to 13; p = 0.0003). The lower AHI with lubricant as compared with placebo was present in both supine (mean difference 13; 95% CI 5 to 20; p = 0.006) and nonsupine (mean difference 6; 95% CI 0 to 12; p = 0.05) positions. There was no significant difference in sleep architecture between the lubricant and placebo treatments. Application of a topical lubricant consistently reduced the severity of OSA. This implies a pathogenetic role for surface tension forces in OSA, and a potential role for surface tension-reducing agents in the treatment of OSA.

The morphology of the sensory neuron in the cockroach femoral tactile spine.

1. The cockroach femoral tactile spine contains a single bipolar sensory neuron. The mechanosensitive dendrite in the wall of the spine leads through the spine lumen to a cell body, and then to an axon that proceeds proximally along the femur. The ultrastructure of the sensory ending has been examined before with electron microscopy. However, the morphology of the complete neuron and its relationship to the general spine structure have not been described before. 2. The tactile spine neuron has been extensively used in electrophysiological studies, including intracellular recordings. Action-potential amplitudes and thresholds were variable and inversely related in intracellular recordings, which could be caused by variability in the location of the action-potential initiation region, the position of the recording electrode, or the neuronal morphology. Attempts to observe the complete neuronal morphology by dye injection were hampered by the opaque and autofluorescent cuticle surrounding the neuron. 3. We examined 10 tactile spine neurons, and their surrounding structures, by taking serial 1-micron sections through the base of the spine, normal to its long axis. The sections were examined with light microscopy, digitized by tracing onto a graphics tablet, and then reassembled with the use of computer software. Reconstructions were made of the borders of the spine cuticle, neuron, neuronal nucleus, glial wrappings, and the main trachea in the spine lumen. 4. There was considerable variability in the size and shape of the neuronal cell body, although the sensory dendrite and axon had more consistent morphologies.(ABSTRACT TRUNCATED AT 250 WORDS)

Glial swelling in ischemia: a hypothesis.

On the basis of experiments with primary cultures of mouse astrocytes with conventional K(+)-sensitive intracellular microelectrodes involving 'chemical ischemia' (antimycin a and sodium fluoride treatment), a model of ischemia is presented. According to this model, ischemia has no significant direct effect during the first 10 min on astrocytes; neurones, however, lose a major part of their K+ into the ECS. This leads to an astrocytic depolarization, which in turn activates astrocytic anion channels. This will result in passive, Donnan-mediated K+, Cl- and HCO3- fluxes into astrocytes, which in turn causes swelling and a collapse of the ECS. Arguments are put forward that this may explain the swelling of astrocytic endfeet, which occurs very early in an ischemic insult.

[Unusual health improvement in a patient with pulmonary heart disease in kyphosis and scoliosis after home treatment with oxygen]. / Niezwykla poprawa stanu zdrowia chorego z sercem plucnym w przebiegu kyfoskoliozy po domowym leczeniu tlenem.

Male obese patient, aged 35 years with kyphoscoliosis due to poliomyelitis was admitted in respiratory and cardiac failure. Severe desaturations during sleep were found. After successful hospital treatment patient was submitted to the long-term oxygen therapy. Reduction of weight and smoking cessation was suggested. Patient stopped smoking, lost 14 kg in 12 months and breathed oxygen for 12 hours per day (mainly at night). Treatment resulted in a significant improvement in ventilatory reserves, blood gases and normalization of pulmonary arterial pressure.

[Evaluation of the effectiveness of medical consultation regarding smoking cessation]. / Ocena skutecznosci porady lekarskiej na porzucenie nalogu palenia.

Smoking habits were assessed by a questionnaire in workers of a small factory during their prophylactic medical check-up. In all subjects spirometry and CO levels in expired air were determined. In the studied group 43.8% were smokers. Respiratory indices were decreased in smokers in comparison to ex- and non-smokers. In all smokers higher (3x) levels of CO were found. After a year 5 subjects ceased to smoke (15.6% of the smokers).

Prospective study of metabolic abnormalities in patient with continent Kock pouch urinary diversion.

Metabolic alterations as a result of bowel being employed in the urinary tract are well documented. To investigate this phenomenon in the continent ileal reservoir urinary diversion, 106 patients who had undergone Kock pouch surgery were followed in a prospective study at the University of Southern California between 1985 and 1987. Serum chemistries and urine osmolality determinations were performed approximately every three months for a year. Mean patient values for each time period were then compiled and compared with the norms and with the preoperative values. The mean serum electrolyte values were found to be within normal limits during all follow-up periods. Fourteen patients were identified, however, as having values falling intermittently outside of the normal range. These patients were investigated and found to be abnormal during episodes of acute renal failure usually secondary to dehydration or obstruction at which time they usually became acidotic and occasionally hyperchloremic. These problems disappeared when the renal failure was corrected. This study corroborated our previously reported findings that hyperchloremic acidosis or other metabolic alterations requiring replacement therapy do not routinely occur in this population.

[Extremely severe respiratory failure complicated by lactic acidosis]. / Skrajnie ciezka niewydolnosc oddychania powiklana kwasica mleczanowa.

A case of a 48-year male patient with chronic cor pulmonale is presented. Exacerbation of the chronic respiratory failure was caused by pneumonia. The patient was treated with artificial ventilation for 22 days and stimulating aggressive antibacterial therapy. An improvement was achieved. Indications to the use of respirator in the exacerbated chronic respiratory failure have been discussed together with problem of the potential reversibility of the cause, gas and lactic acidosis and an important clinical problem of the respiratory muscles exhaustion.

Amplitude discriminator for biological impulses.

A simple amplitude discriminator with two ways of triggering DC-level monitoring is described. This system is based on easily available inexpensive integrated circuits.