Biomaterial Database

Acute ventilatory failure complicating obesity hypoventilation: update on a 'critical care syndrome'. 2010

Ahmed BaHammam

The University Sleep Disorders Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia. ashammam2@gmail.com

OBJECTIVE Obesity can result in serious complications, including obesity hypoventilation syndrome (OHS). OHS patients may present with acute-on-chronic ventilatory failure, necessitating acute care management. The purpose of this review is to discuss the recent literature on acute ventilatory failure in OHS patients. RESULTS Obese persons can develop acute hypercapnic respiratory failure and sleep hypoventilation due to disorders in lung mechanics, ventilatory drive, and neurohormonal and neuromodulators of breathing. Although there are no clearly defined predictors for OHS patients who are likely to develop acute hypercapnic respiratory failure, most such patients are middle-aged (mid-50s), morbidly obese, and have daytime hypercapnia, hypoxemia, and low serum pH values. Immediate ventilatory support, without sleep study confirmation, is necessary in most such patients. Patients with respiratory acidemia (pH <7.30) or altered mental status may require intensive care unit monitoring. Noninvasive application of bilevel positive airway pressure therapy is the recommended initial ventilatory support under close monitoring. Prompt initiation of noninvasive positive pressure ventilation reduces the need for invasive mechanical ventilation and rapidly improves the levels of blood gases. CONCLUSIONS Obese patients with sleep hypoventilation have an increased risk of acute hypercapnic respiratory failure. Early diagnosis and implementation of noninvasive positive pressure ventilation is recommended for these patients.

UI	MeSH Term	Description	Entries
D007362	Intensive Care Units	Hospital units providing continuous surveillance and care to acutely ill patients.	ICU Intensive Care Units,Intensive Care Unit,Unit, Intensive Care
D009765	Obesity	A status with BODY WEIGHT that is grossly above the recommended standards, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).
D010845	Obesity Hypoventilation Syndrome	HYPOVENTILATION syndrome in very obese persons with excessive ADIPOSE TISSUE around the ABDOMEN and DIAPHRAGM. It is characterized by diminished to absent ventilatory chemoresponsiveness; chronic HYPOXIA; HYPERCAPNIA; POLYCYTHEMIA; and long periods of sleep during day and night (HYPERSOMNOLENCE). It is a condition often related to OBSTRUCTIVE SLEEP APNEA but can occur separately.	Pickwickian Syndrome,Obesity-Hypoventilation Syndrome,Hypoventilation Syndrome, Obesity,Obesity-Hypoventilation Syndromes
D011175	Positive-Pressure Respiration	A method of mechanical ventilation in which pressure is maintained to increase the volume of gas remaining in the lungs at the end of expiration, thus reducing the shunting of blood through the lungs and improving gas exchange.	Positive End-Expiratory Pressure,Positive-Pressure Ventilation,End-Expiratory Pressure, Positive,End-Expiratory Pressures, Positive,Positive End Expiratory Pressure,Positive End-Expiratory Pressures,Positive Pressure Respiration,Positive Pressure Ventilation,Positive-Pressure Respirations,Positive-Pressure Ventilations,Pressure, Positive End-Expiratory,Pressures, Positive End-Expiratory,Respiration, Positive-Pressure,Respirations, Positive-Pressure,Ventilation, Positive-Pressure,Ventilations, Positive-Pressure
D012131	Respiratory Insufficiency	Failure to adequately provide oxygen to cells of the body and to remove excess carbon dioxide from them. (Stedman, 25th ed)	Acute Hypercapnic Respiratory Failure,Acute Hypoxemic Respiratory Failure,Hypercapnic Acute Respiratory Failure,Hypercapnic Respiratory Failure,Hypoxemic Acute Respiratory Failure,Hypoxemic Respiratory Failure,Respiratory Depression,Respiratory Failure,Ventilatory Depression,Depressions, Ventilatory,Failure, Hypercapnic Respiratory,Failure, Hypoxemic Respiratory,Failure, Respiratory,Hypercapnic Respiratory Failures,Hypoxemic Respiratory Failures,Respiratory Failure, Hypercapnic,Respiratory Failure, Hypoxemic,Respiratory Failures
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012307	Risk Factors	An aspect of personal behavior or lifestyle, environmental exposure, inborn or inherited characteristic, which, based on epidemiological evidence, is known to be associated with a health-related condition considered important to prevent.	Health Correlates,Risk Factor Scores,Risk Scores,Social Risk Factors,Population at Risk,Populations at Risk,Correlates, Health,Factor, Risk,Factor, Social Risk,Factors, Social Risk,Risk Factor,Risk Factor Score,Risk Factor, Social,Risk Factors, Social,Risk Score,Score, Risk,Score, Risk Factor,Social Risk Factor
D015656	Respiratory Mechanics	The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.	Breathing Mechanics,Breathing Mechanic,Mechanic, Breathing,Mechanic, Respiratory,Mechanics, Breathing,Mechanics, Respiratory,Respiratory Mechanic