Hypoventilation

About: Hypoventilation is a research topic. Over the lifetime, 1772 publications have been published within this topic receiving 40799 citations. The topic is also known as: respiratory depression.

Respiratory insufficiency due to high anterior cervical cord infarction

Abstract: OBJECTS AND METHODS—Respiratory dysfunction may occur as a result of lesions in the upper cervical spinal cord disturbing the descending pathways subserving automatic and volitional ventilatory control. Four patients are described who presented with acute respiratory insufficiency caused by infarction of the anterior portion of the upper cervical cord due to presumed anterior spinal artery occlusion. RESULTS—Two patients presented after respiratory arrests; they were ventilated and there was no automatic or volitional respiratory effort. Both had signs of an extensive anterior spinal cord lesion at the C2 level and this was confirmed by MRI. One patient presented with a C4 infarction and required ventilation for three months. Ventilatory recovery was characterised by the development of an automatic respiratory pattern. The fourth patient required ventilation for two months after infarction at the C3 level. On attempted weaning he had prolonged periods of hypoventilation and apnoea during inattention and sleep indicating impairment of automatic respiratory control. CONCLUSION—Infarction of the spinal cord at high cervical levels may be due to fibrocartilaginous embolism and involvement of the descending respiratory pathways may occur. Extensive lesions at C1/2 cause complete interruption of descending respiratory control leading to apnoea. Partial lesions at C3/4 cause selective interruption of automatic or voluntary pathways and give rise to characteristic respiratory patterns. The prognosis depends on the level and extent of the lesion.

Prevalence and clinical characteristics of obesity hypoventilation syndrome among individuals reporting sleep-related breathing symptoms in northern Greece

Abstract: Evidence suggests that obesity hypoventilation syndrome (OHS) is underrecognized and undertreated. Aim of this study was to evaluate the prevalence and clinical characteristics of OHS among patients reporting sleep-related breathing disorders in northern Greece. Individuals (n = 276) who consecutively underwent an attended night polysomnography, for possible obstructive sleep apnea syndrome, were recruited. OHS was defined as a combination of obesity (body mass index 30 ≥ kg/m2), daytime hypercapnia (PaCO2 ≥ 45 mmHg), and sleep-disordered breathing, without any other known cause of hypoventilation. Anthropometric and sleep characteristics, daytime sleepiness, spirometry, and arterial blood gases’ analysis in awake, were compared between OHS and non-OHS patients. OHS was identified in 38 of the 276 subjects (13.8%). Among study population, OHS patients were older, more obese, and more somnolent. They did not differ significantly in terms of pulmonary function in awake, whereas they differed, as expected, in arterial blood gases values in awake (PaO2, PaCO2). Furthermore, OHS patients displayed lower average and minimum SpO2 during sleep and spent more time in SpO2 < 90% than non-OHS patients. The most common comorbidities were arterial hypertension, diabetes mellitus, and congestive heart failure. In our study population, OHS was accounted for a significant percentage of the patients with reported breathing disorders in sleep. As obesity has become an international epidemic, it is crucial that physicians have the ability to recognize and treat obesity-associated diseases.

Neuromuscular disease and hypoventilation.

Abstract: Alveolar hypoventilation associated with neuromuscular disease can occur in acute and chronic forms. In the acute form, progressive weakness of respiratory muscles leads to rapid reduction in vital capacity followed by respiratory failure with hypoxemia and hypercarbia. Symptoms are those of acute respiratory failure, including dyspnea, tachypnea, and tachycardia. In the chronic form, impairment of the respiratory muscles affects mechanical properties of the lungs and chest wall, decreases the ability to clear secretions, and eventually may alter the function of the central respiratory centers. Symptoms include orthopnea, fatigue, disturbed sleep, and hypersomnolence. Treatment and outcome of the disease's chronic form are dependent on the underlying clinical cause of the alveolar hypoventilation. For chronic but stable diseases such as old polio, quadriplegia, or kyposcoliosis, mechanical support of minute ventilation can reverse symptoms. For chronic and progressive disease such as muscular dystrophy and amyotrophic lateral sclerosis, mechanical support of minute ventilation provides only symptomatic relief and is usually associated with deterioration to the point of complete ventilator dependency for survival. For the chronic progressive forms of alveolar hypoventilation, there is currently a need for quality randomized controlled clinical trials to define physiologic indicators and appropriate timing for mechanical support of minute ventilation.

Effects of carotid and aortic chemoreceptor denervation in newborn piglets

Abstract: The objective of the present study was to test the hypothesis that in neonatal piglets there would be no hypoventilation after sham denervation or aortic denervation (AOD) alone, but there would be transient hypoventilation after carotid body denervation (CBD) and the hypoventilation would be greatest after combined carotid and aortic denervation (CBD+AOD). There was a significant (P < 0.05) hypoventilation in CBD and CBD+AOD piglets denervated at 5, 15, and 25 days of age. The hypoventilation in CBD+AOD piglets denervated at 5 days of age was greater (P < 0.05) than that of all other groups. Conversely, sham-denervated and AOD piglets did not hypoventilate after denervation. Injections of sodium cyanide showed that aortic chemoreceptors were a site of recovery of peripheral chemosensitivity after CBD. This aortic sodium cyanide response was abolished by prior injection of a serotonin 5a receptor blocker. Residual peripheral chemosensitivity after CBD+AOD was localized to the left ventricle. We conclude that 1) aortic chemoreceptors contribute to eupneic breathing in piglets that were carotid denervated at 5 days of age and 2) there are multiple sites of residual peripheral chemosensitivity after CBD.