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.

Frequency and predictors of obesity hypoventilation in hospitalized patients at a tertiary health care institution

Abstract: Objectives: Patients with obesity hypoventilation syndrome (OHS) have significant morbidity and mortality. Early diagnosis and treatment is important and there are limited data on its prevalence and predictive factors. The objective of this observational study was to determine the frequency and predictors of OHS in hospitalized patients at a tertiary health care institution. Materials and Methods: All blood gas analyses of hospitalized adult (age over 18 years) patients were prospectively recruited from the biochemistry laboratory at a tertiary health care center between August 2009 and July 2010. Patients who had hypercapnia (PaCO 2 ≥ 45 mmHg) while breathing room air were included and clinical and laboratory data were obtained from hospital records. A standard questionnaire was also filled by face-to-face interview with patients and/or relatives. Results: A total of 9480 patients' arterial blood gases were evaluated and 330 patients (3.4%) who met the selection criteria were included in the analysis during the study period. Hypoventilation was associated with acute diseases in 64.2% and chronic diseases in 35.8% of the patients. Of the chronic hypoventilation patients, 24.4% had OHS. Univariate logistic regression analysis showed that, female gender, body mass index (BMI), smoking, PaO 2 , SaO 2 and a PaCO 2 /BMI 35 kg/m 2 , SaO 2 Conclusions: OHS is a common cause of chronic alveolar hypoventilation. A careful examination PaCO 2 /BMI ratio may prevent misdiagnoses among hypercapnic patients.

Carbon dioxide levels during polygraphy in children with sleep-disordered breathing.

Abstract: The recent scoring rules of the American Academy of Sleep Medicine (AASM) define hypoventilation in children as a carbon dioxide (CO2) level of >50 mmHg for >25 % of total sleep time (partial pressure of CO2 (PCO2) > 50[>25 %]). As there is no validated level of nocturnal hypoventilation with regard to end-organ damage in children, we evaluated the prevalence of hypoventilation with the AASM definition but also with a lesser degree of elevated CO2 in children with sleep-disordered breathing (SDB). Transcutaneous CO2 (PtcCO2) was recorded during overnight polygraphy (PG). Hypoventilation was defined according to four definitions: the AASM score (PCO2 > 50[>25 %]), the peak value of PtcCO2 > 50 mmHg (PtcCO2 > 50[peak]), a percentage of PtcCO2 > 50 mmHg > 2 % of nighttime recording (PtcCO2 > 50[>2 %]) or a nocturnal PtcCO2 > 10 mmHg above waking baseline level (PtcCO2[>10 mmHg]). PtcCO2 indices were correlated to the apnoea–hypopnoea index (AHI) and oxygenation indices. PGs from 221 children with suspicion of obstructive sleep apnoea (72 %), neuromuscular diseases (21 %), and lung diseases (7 %) were analysed. The prevalence of hypoventilation according to PCO2 > 50[>25 %], PtcCO2 > 50[peak], PtcCO2 > 50[>2 %] and PtcCO2[>10 mmHg] were 16, 27, 31 and 52 %, respectively, and did not differ between the three diagnostic groups. Significant but weak correlations were observed between hypoventilation and AHI and oxygenation indices. Nocturnal hypoventilation occurs in a large number of children referred for SDB, independent of the underlying disease, when more stringent criteria than those of the AASM are used. The poor correlation between hypoventilation and AHI or oxygenation indices is in favour of CO2 being a supplemental index of SDB.

Classification and definition of respiratory disorders during sleep.

Abstract: Growing interest in sleep disorders has led to increased research in this direction. Increasingly sophisticated instrumental tests have disclosed new breathing patterns and complex syndromes. The initial identification of obstructive apneas was followed by studies characterizing snoring, hypopneas, respiratory effort-related arousal and flow limitation events. Since Pickwickian syndrome, an historical term currently deemed obsolete and confusing, sleep investigations have differentiated secondary hypoventilation, central hypoventilation and syndromes resulting from narrowing of the upper airways (snoring, upper airway resistance syndrome, obstructive sleep apnea-hypopnea syndrome). Inevitably, this has given rise to some confusion in the classification of events and syndromes which recent studies have attempted to clarify.

Respiratory abnormalities due to craniovertebral junction compression in rheumatoid disease.

Abstract: OBJECTIVE--To assess the extent and severity of respiratory insufficiency associated with severe rheumatoid atlantoaxial dislocation and its relation to compression of the neuraxis. METHODS--Twelve patients with severe atlantoaxial dislocation due to rheumatoid disease were studied. Detailed clinical, CT myelography and respiratory assessment including nocturnal oximetry, were performed on all patients. RESULTS--All patients were severely disabled by their underlying disease but none had symptoms of hypoventilation. All the patients with C1 compression had myelopathic features. Those with medullary deformation (moulding and/or stretch) had abnormal noctural oximetry whilst no significant desaturations were seen in the remaining patients. Post-operative studies showed resolution of noctural desaturations. CONCLUSION--This study suggests that clinically unsuspected respiratory insufficiency may be common in patients with severe medullary compression associated with rheumatoid atlantoaxial dislocation. It emphasises the importance of careful respiratory monitoring including nocturnal oxygen saturation in patients with major atlantoxial dislocation due to rheumatoid disease.