Showing papers on "Hypoventilation published in 1983"

Remission of severe obesity-hypoventilation syndrome after short-term treatment during sleep with nasal continuous positive airway pressure.

Abstract: Two patients with the Pickwickian syndrome and with life-threatening sleep hypoxemia were treated with continuous positive airway pressure (CPAP) applied through the nares only during sleep periods. Each patient presented with severe daytime somnolence, disturbed sleep, nocturnal confusion, and daytime awake cardiorespiratory failure (PaCO2, 63 and 55 mmHg). Both patients demonstrated grossly abnormal breathing during sleep with severe sleep hypoxemia, the arterial oxyhemoglobin saturation (SaO2%) falling repetitively to levels below 50%. One patient had a hypoxemic convulsion during the initial sleep evaluation. Low levels (3.5 and 8.0 cm H2O) of continuous positive airway pressure, when applied via a comfortable nose mask, prevented occlusive apnea and obstructive hypopnea during sleep in both patients and maintained steady levels of arterial oxyhemoglobin saturation. There was rapid recovery of mental function and loss of cardiorespiratory failure within 3 days of treatment. After short-term treatment with nocturnal CPAP therapy (23 days and 35 days) both patients were able to sleep, unaided, without sleep-induced upper airway occlusion with arterial oxyhemoglobin levels sustained above 80%. We conclude that nasal CPAP therapy during sleep is an effective noninvasive therapy for patients with the Pickwickian syndrome, and may lead to a stable remission of the underlying severe disordered breathing in sleep.

Contribution of hypoventilation to sleep oxygen desaturation in chronic obstructive pulmonary disease

Abstract: The purpose of this study was to determine whether hypoventilation contributes to the sleep hypoxemia observed in chronic obstructive pulmonary disease (COPD) patients and to examine breathing pattern and respiratory muscle electromyographic (EMG) activity during these episodes. Seven COPD patients who experienced at least a 10% decrease in arterial O2 saturation (SaO2) during rapid-eye-movement sleep (REM) sleep, six COPD patients with a minimal fall in SaO2, and five healthy subjects were studied. An inductance vest was used to quantitate ventilation. Skin electrodes were used to estimate diaphragmatic and intercostal electromyographic activity. Minute ventilation and EMG activity decreased in all three groups during sleep. Ventilation was irregular during REM sleep in the patients. During REM sleep, desaturating patients had longer episodes of hypopneic breathing [30 +/- 8 s (SE)] than nondesaturating patients (13 +/- 1 s, P less than 0.01). Desaturating patients spent a greater proportion of REM time hypopneic (53 +/- 5 vs. 28 +/- 5%, P less than 0.01) and had a greater decrease in functional residual capacity during hypopnea (P less than 0.05). SaO2 followed the hypopneic and hyperpneic breathing in REM sleep so that desaturating patients had more time for desaturation to occur. Thus hypoventilation appears to be a primary factor in sleep O2 desaturation in these patients. Because of the fall in lung volume, maldistribution of ventilation may also contribute.

Respiratory factors limiting exercise

Abstract: The question of respiratory factors limiting exercise has been examined in terms of possible limitations arising from the function of gas exchange, the respiratory mechanics, the energetics of the respiratory muscles, or the development of respiratory muscle fatigue. Exercise capacity is curtailed in the presence of marked hypoxia, and this is readily observed in patients with chronic airflow limitation and interstitial lung disease and in some athletes at high intensities of exercise. In patients with interstitial lung disease, gas exchange abnormality--partly the result of diffusion disequilibrium for oxygen transfer--occurs during exercise despite abnormally high ventilations. In contrast, in certain athletes arterial hypoxemia has been documented during heavy exercise, apparently as a result of relative hypoventilation. During strenuous exercise the maximum expiratory flow volume curves are attained both by patients with chronic airflow limitation and by normal subjects, in particular when they breathe dense gas, so that a mechanical constraint is imposed on further increases in ventilation. Similarly, the force velocity characteristics of the inspiratory muscles may also impose a constraint to further increases in inspiratory flows that affects the ability to increase ventilation. In addition, the oxygen cost of maintaining high ventilations is large. Analysis of results from blood flow experiments reveal a substantial increase in blood flow to the respiratory muscles during exercise, with the result that oxygen supply to the rest of the body may be lessened. Alternatively, high exercise ventilations may not be sustained indefinitely owing to the development of respiratory muscle fatigue that results in hypoventilation and reduced arterial oxygen tension.

Early echocardiographic and pulmonary function findings in idiopathic scoliosis.

Abstract: Thirty-six children and adolescents with early stages of idiopathic scoliosis underwent evaluation by echocardiography and pulmonary function testing. Mildly increased pulmonary vascular resistance was inferred from an elevated ratio of right preejection period to right ventricular ejection time, an increased right ventricular dimension, and a decreased left ventricular dimension. Since neither decreased arterial oxygen saturation nor increased end-tidal expired carbon dioxide partial pressure was seen, desaturation and hypoventilation should not account for these abnormalities. Pulmonary function parameters showed no distinct patterns of abnormality. Even though the patients were divided into two groups by severity of spinal curvature, the cardiopulmonary measures did not correlate with thoracic deformity. Billowing of the mitral leaflets, termed mitral valve prolapse, was demonstrated in 25% of the subjects. Our findings suggest that cardiopulmonary and thoracic changes in idiopathic scoliosis may develop in parallel and may be expressions of a common collagen defect. However, study of sleep and exercise arterial saturation may be required to rule out intermittent hypoxemia as a precipitating factor of cor pulmonale in scoliosis.

Myoclonus, ataxia, and hypoventilation: Response to L-5-hydroxytryptophan

Abstract: Both hypoventilation and myoclonus were suppressed for 4 years with L-5-hydroxytryptophan and carbidopa in a patient with a syndrome of progressive myoclonus, ataxia, central neurogenic hypoventilation, mental retardation, motor neuropathy, and morphologic mitochondrial abnormalities in skeletal muscle.

The effect of nasal packing on arterial blood gases and acid-base balance and its clinical importance.

Abstract: Arterial blood samples were taken from adult healthy patients before and 24 hours after bilateral nasal packing. The blood samples were investigated for PO2, PCO2, HCO3, pH and Hb. It was found that there is (i) an increase of high significance of PCO2 and HCO3-, (ii)) a significant increase of percentage of Hb., (iii) a highly significant decrease of PO2 in patients after nasal packing; (iv) as regards the pH, no significant difference was found. What we suggest is that bilateral anterior nasal pack results in hypoxia and hypercapnia due to hypoventilation.

Acute Respiratory Failure in Motor Neuron Disease

Abstract: • Five patients with sudden deterioration in respiratory function were studied. In three a history of motor neuron disease was known but in two the first evidence of the disease was severe hypoventilation. No other cause for the respiratory difficulty could be detected in any, and all eventually achieved important partial or even complete independence from mechanical support. Severe hypoventilation can be the initial symptom of motor neuron disease, and not all patients with this complication of the disease have the poor prognosis usually expected.

Sleep apnea and nocturnal hypoventilation after western equine encephalitis.

Abstract: That viral encephalitis can produce daytime hypoventilation is well appreciated, but an association of this infection with the development of a prolonged disturbance of breathing during sleep once the ventilatory disorder during wakefulness has resolved, has not been reported. We describe a young male who required assisted mechanical ventilation in association with western equine encephalitis. Normal waking ventilation returned over 3 to 4 wk, but frequent apneas and severe hypoventilation persisted during sleep with a near absence of waking ventilatory response to chemical stimuli. Over 3 months there was considerable improvement in breathing during sleep associated with an increase in both hypoxic and hypercapnic ventilatory responsiveness.

Physostigmine versus naloxone in heroin - overdose

Abstract: Two groups of 10 chronically heroin addicted patients who were admitted to the Emergency Ward because of hypoventilation and coma, were treated random-aselectively with naloxone, 3 μg kg−1 BW iv, or with physostigmine salicylate 0,04 mg kg−1 BW iv. Patients in both groups completely regained consciousness and breathed spontaneously, regularly and adequately within 10 minutes. One essential difference in the treatment was that physostigmine caused no signs of acute opiate withdrawal, the patients felt fine and stayed for further control, in contrast with naloxone where the patients felt bad and occasionally escaped prematurely from the ward. Another difference is that the beneficial effect of one dose of physostigmine is shorter lived than that of naloxone. Authors emphasise the fact that treatment of heroin overdose in an addict need not jeopardize the patient's well-being by a withdrawal syndrome.

Mechanical and physical factors in lung function during work in dense environments.

Abstract: The major effects of breathing dense gas during physical exercise in hyperbaric environments can be traced to high airway resistance during inspiration and expiration and especially to an increased tendency for lung airways to become "choked" during expiration. The body's responses to the high resistance include decrease of alveolar ventilation, which leads to CO2 retention. This hypoventilation is aggravated by poor mixing in the lung because of low diffusivity of gases in the dense environment. Also, there is a tendency for the person to let the end-expired volume of the lung enlarge; this causes a marked increase of work against elastic recoil of pulmonary structures. Because the elastic work occurs during the inspiratory phase of a breath, there is a disproportionate increase of the work of the inspiratory muscles that may lead to fatigue of inspiratory musculature and consequent aggravation of the hypoventilation.

Acid maltase deficiency - treatment of respiratory insufficiency with cuirass respirator

Abstract: Three patients with the late-onset form of acid maltase deficiency showed a gradual weakening of proximal limb and trunk muscles leading to severe respiratory insufficiency. Considerable deterioration of pulmonary function occurred owing to a vicious cycle of hypoventilation and exhaustion. Treatment by nocturnal cuirass ventilation with tailor-made shells was successful. The muscle weakness still progressed very slowly but there were no more respiratory problems.

Transcutaneous gas tension monitoring in the management of intraoperative apnea.

Abstract: Periods of apnea or severe hypoventilation may occur during procedures which involve the airway or during thoracic operations. Routine vital signs and ECG monitoring of these situations are incapable of quantitating the severe tissue hypoxia and acidosis which develop under these circumstances; rather, they only reflect the morbid complications of hypoxia and acidosis (i.e., bradycardia, ectopy, and hypotension). Transcutaneous oxygen and carbon dioxide sensors directly measure tissue gas tensions with a short sensor response time. This report documents the efficacy of transcutaneous gas tension monitoring in the management of these high-risk situations.

Almitrine bismesylate in congenital central hypoventilation.

Abstract: We have carried out sequential studies of respiration and sleep state, from two weeks to two years of age in a girl with congenital central hypoventilation. When awake her minute ventilation (VE) and blood gases are normal, and when asleep she shows hypoventilation, with progressive hypoxia, hypercarbia and respiratory acidosis, most marked in NREM sleep. There has been no consistent change in VE (expressed as ml/kg/min) with age, awake or asleep, and she remains ventilator dependent when asleep. Growth and development are normal. We report a trial of almitrine bismesylate at the age of 21 months. A dose of 1.5 mg/kg/day orally for eight days produced minimal changes in VE, but when given 2.6 mg/kg/day for a further seven days there was a significant increase in VE in both NREM (27% increase) and in REM sleep (30% increase). These changes were accompanied by substantial improvements in blood gases, with PaCO2 less than 50 mmHg and PaO2 greater than 60 mmHg throughout a four hour study period asleep, off the ventilator, in air. After stopping almitrine bismesylate VE and blood gas values returned to pretreatment values. Almitrine bismesylate may be of value as an alternative to artificial ventilation in this condition.

Histological Changes of Muscle ln a Patient with Pyruvate Dehydrogenase Deficiency

Abstract: Hypoventilation during sleep in the absence of primary pulmonary, cardiac or neuromuscular disease, prompted us to make a diagnosis of Ondine's curse. This was confirmed by the immediate improvement in the blood gas level following voluntary hyperventilation, and by the lack of ventilatory response to high PC02 and low P02 levels in the blood [1]. Shannon et al reported that hypoventilation improved markedly during REM sleep in Ondine's curse [2]. On the other hand, Wells et al reported a case where ventilation was not improved during REM sleep [3]. In our case also, no significant improvement in blood gas levels was noted during REM sleep, as measured by a transcutaneous P02 monitor and PC02 monitor and by gas analysis of arterial blood. Contrary to the hypothesis of Shannon et aI, these cases suggest that non-chemoreceptor stimuli during REM sleep are not always enough to maintain normal respiration. Although some cases have been reported associated with other rare disorders [4], we have been unable to discover any previous report of a patient with both Ondine's curse and hypergonadotropic hypogonadism. Both disorders are rare, and we cannot find any explanation to link them. In the treatment of Ondine's curse respiratory stimulants seem the most applicable, although drugs such as ritalin, ethamivan, nikethamide, aminophylline and medroxyprogesterone have been tried with little success. Doxapram hydrochloride has been reported to be effective but it has to be administered parenterally and acts for only a brief period [5]. Compared with these drugs, dimfline has advantages in the treatment of Ondine's curse. It stimulates the respiratory center directly. It has a higher therapeutic index [6] and it can be administered orally. In the case reported here oral administration of dimefline brought about significant improvement of nocturnal hypoventilation. However, after the effective time of this drug PC02 elevated higher than that of no treatment. This may suggest the "exhaustion" of respiratory center. Therefore it should be tried with enough caution.

Doxapram and idiopathic hypoventilation.

Abstract: very severe spasticity and shivering in one case, but the dose was not mentioned and Dr Johnstonez asserts lack of benefit in general terms without any factual support. I suppose I have used chlorpromazine and promethazine in anaesthesia as much as anyone over the past 30 years together with halothane. Postoperative spasticity has never been a problem and I cannot recall seeing it after chlorpromazine used either as a premedicant or as part of the anaesthetic technique. Twenty five mg promethazine intravenously was very effective on one occasion. Dr Goold appears to support the idea that depression of cortical inhibition during emergence from anaesthesia allows the facilitatory centre, in the brain stem reticular formation, to exert an unremitting increase of muscle tone. If this is true, then chlorpromazine should be effective, since it was shown as long ago as 1959 that 50 mg chlorpromazine intravenously produced immediate relief of spasticity in patients spastic from upper motor neurone lesions. both electrically and myographically in 1 I out of 13 patients and marked, but incomplete, improvement in the remaining two.

Adeno-tonsillar hypertrophy as a cause of sleep apnoea syndrome.

Abstract: SUMMARY An interesting case is described here in which partial airway obstruction resulted in sleep apnoea and which was relieoed by adeno-tonsz'llectomy. Enlarged tonsils and adenoids causing upperairway obstruction represent one facet of a continuum of hypoventilation - sleep disorders and clinical examination with x-rays will help in determining patients at risk ofdeveloping these syndromes.