Hypoventilation alveolar

General Alveolar Hypoventilation A Syndrome of Respiratory and Cardiac Failure in Patients with Normal Lungs. Quart. J. Med. (1966), 35, 261 - 275. 

Breathing-Reiated Sieep Disorders. The breathing-related sleep disorders include obstructive sleep apnea, central sleep apnea, and alveolar hypoventilation. Of these three, obstructive sleep apnea is by far the most common. The patient with sleep apnea usually breathes normally when awake and only stops breathing while asleep. Occasional episodes of apnea are normal, but five or more episodes of apnea per hour are usually considered diagnostic of the disorder. 

Central alveolar hypoventilation, which most commonly occurs in very overweight individuals... 

Mobius syndrome in association with congenital central alveolar hypoventilation has been described in Brazil (38). 

Nunes ML, Friedrich MA, Loch LF. Association of misoprostol, Moebius syndrome and congenital central alveolar hypoventilation. Case report. Arq Neuropsiquiatr 1999 57(1) 88-91. 

Pieters T, Amy JJ, Burrini D, Aubert G, Rodenstein DO, Collard Ph. Normal pregnancy in primary alveolar hypoventilation treated with nocturnal nasal intermittent positive pressure ventilation. Eur Respir J 1995 8 1424—1427. 

If sodium bicarbonate is used instead of acetate, no such fixation of metabolic C02 occurs and the gaseous C02 loss through the dialyzer is too small to cause significant hypocapnia and reciprocal hypoventilation and hypoxemia. However, a high bath bicarbonate concentration or the use of high-flux dialyzers will cause a large bicarbonate influx and rapid alkalemia, which would lead to alveolar hypoventilation and hypoxemia (C2). 

In human populations, it is estimated that 10-15% of young and more than 30% of aged (above 50 years) high-altitude permanent residents (>2500 m) are at risk to develop chronic mountain sickness (47,48). Some of the major features of chronic mountain sickness are chronic alveolar hypoventilation associated with low... 

Hypercapnic respiratory failure is due to failure of the ventilatory pump caused by acute (drug overdose, acute neuromuscular diseases) or chronic (chest wall abnormalities, chronic neuromuscular diseases) disorders. It is characterized by alveolar hypoventilation, which leads to hypercapnia with coexistent, usually mild, hypoxemia. The central drive may be globally reduced with the fall in Pa02 resulting from the increase in alveolar CO2. More commonly, the drive remains high, but the mechanical load on the respiratory systan is too great or the capacity of the muscles too low to ensure efficient CO2 elimination (Fig. 1). 

Mixed ventilatory disorders Bronchiectasis Sequelae of tuberculosis Nonpulmonary diseases Dysfunction of respiratory centers Primary alveolar hypoventilation Obesity hypoventilation syndrome Depressant drugs Myxoedema Lesion of brainstem Neuromuscular diseases Poliomyelitis... 

Achincloss JH, Cook E, Renzetti AD. Clinical and physiological aspects of a case of polycythemia and alveolar hypoventilation. J Clin Invest 1955 34 1537-1545. 

Specific conditions such as idiopathic central alveolar hypoventilation syndrome (Ondine s curse) or central alveolar hypoventilation syndrome secondary to neurological lesions (trauma, infections, infarction. Shy Drager syndrome) can cause or contrihute to long-term ventilator dependence (40). In most ventilator-dependent patients, however, estimations of respiratory drive indicate that drive is increased and not decreased (18,41-43). 

A large number of conditions can result in chronic ventilatory failure and patients with these conditions may benefit from home ventilation. Typically, patients with restrictive disorders have decreased compliance of the chest wall, resulting from a thoracic cage deformity or from respiratory muscle involvement (1). In patients with severe obstructive pulmonary disorders, respiratory muscle fatigue and alveolar hypoventilation, especially during sleep, are thought to contribute to respiratory failure (2,3) (Table 1). 

Bach JR, Robert D, Leger P, et al. Sleep fragmentation in kyphoscoliotic individuals with alveolar hypoventilation treated by NIPPV. Chest 1995 107 1552-1558. 

Careful patient selection prevents unsafe levels of alveolar hypoventilation with subsequent hypoxemia and hypercapnea, especially if the tidal volume leakage is >20%. Any compensatory increase in respiratory rate and shortened expiratory time, attributable to the air leakage, may aggravate dynamic hyperinflation, especially among patients with airflow obstruction (15). Ventilator-supported speech has been reported in patients with neuromuscular diseases (NMD) and intact bulbar function (16-19). The physiologic characteristics that enable this population to tolerate ventilator-supported speech include little or no decrease in chest wall or lung compliance and the absence of airflow obstmction. Therefore, patients with NMD may be ventilated with a deflated or cuffless tracheostomy tube accepting the modest compromise in alveolar ventilation (16,20-22). Patient populations, such as those with chronic obstructive pulmonary disease may be able to tolerate cuff deflation for short periods provided there is adequate supervision. 

Careful patient selection is important if diaphragmatic pacing is to be effective. The main indications are SCI above C3, central alveolar hypoventilation, which may be idiopathic or secondary to brain stem injury, or other conditions that affect daytime or nocturnal ventilatory control. Whereas patients with high SCI require 24-hour ventilation, those with hypoventilation may only require support for part of this cycle. 

This patient with primary alveolar hypoventilation did not sense her underlying respiratory failure—either initially, when she would turn blue and lose consciousness, or subsequently, when, after many years of stability, a pacing wire failed. 

The respiratory patient evaluation includes a survey for symptoms of chronic and/or acute alveolar hypoventilation, medical history, physical examination, cough evaluation, and simple pulmonary function tests. Measurement of mucous transport through the bronchial tree by radiolabeled tracers is a technique that has been used above all to study mucociliary clearance, as well as the measurement of the volume of expectorated mucous (32). 

The first example is of a 48-year-old woman with alveolar hypoventilation consequent upon syringomyelia in whom bilateral pacers were inserted at the age of 29. Her VC was 69% predicted, FEVx/FVC was 104% predicted, her MIP was 75% predicted, and MEP 44% predicted. 

Garray SM, Turino GM, Goldring RM. Sustained reversal of chronic hypercapnia in patients with alveolar hypoventilation syndromes. Long term maintenance with non-invasive nocturnal mechanical ventilation. Am J Med 1981 70 269-274. 

Burwell CS, Robin ED, Whaley R, et al. Extreme obesity associated with alveolar hypoventilation. A Pickwickian syndrome. Am J Med 1956 21 811-816. 

In a recent study, 25 patients with ALS became dependent on NIPPV, including 13 who became continuously dependent for 19.7 16.9 months without developing acute respiratory distress or oxyhemoglobin desaturation. For another 76 patients, the daytime Sa02 baseline persistently decreased to <95%, 78 times because of some combination of alveolar hypoventilation and airway congestion. For 41 patients, the baseline was corrected by some combination of NIPPV and MAC for 11.1 8.7 months before desaturation recurred in 27. Of the latter, 11 underwent tracheostomy, 14 died in less than two months, and two were again corrected by the addition of MAC to NIPPV. Thirty-three of the 35 patients for whom the Sac>2 could not be normalized required tracheostomy or died within two months. The difference between the patients who could be spared respiratory... 

Obstruction of the upper or lower airways may cause an increase in respiratory load. Obstructive sleep apnea (OSA) is less common in children than in adults. In this age group, enlarged tonsils and adenoids play a predominant role (3). Noninvasive continuous positive airway pressure (CPAP) ventilation has proved its efficacy and is proposed as a first therapeutic option if tonsillectomy and adenoidectomy are not able to relieve upper airway obstruction (4,5). Congenital abnormalities of the upper airways, such as laryngomalacia, tracheomalacia, or Pierre Robin syndrome, may also cause severe upper airway obstruction (6). Even in young infants, noninvasive CPAP may correct the alveolar hypoventilation (7). 

The general point of view is that NPPV is preferred over invasive mechanical ventilation as the first therapy of chronic respiratory failure. However, NPPV is inadequate in some circumstances, which are listed in Table 2. The inability to correct the alveolar hypoventilation... 

These improvements in nocturnal alveolar hypoventilation translate into a decrease in dirrmal hypercapnia among patients with OSA and NMD (38,39). This benefit may be due to the combined effects of several interrelated processes. Reduced cerebrospinal fluid bicarbonate concentration resets the ventilatory response to CO2 and increases respiratory drive. Improved sleep quality influences the ventilatory response to CO2 and improved... 

Most children are managed with NPPV (1,50). However, some require invasive ventilation through a tracheostomy. The main indications for a tracheostomy in children are airway abnormalities such as tracheobronchomalacia or tracheal stenosis, chronic disease of prematurity, and NMD (1,51,52). The indications for a tracheostomy are comparable to those of the adult population. They include the persistence of hypercapnia despite NPPV and additional measures such as daytime mouthpiece ventilation, aspiration, and bulbar dysfunction (53). In children, NPPV is more difficult to perform in those who might be 24-hour dependent, than in adults. Infants with primaiy alveolar hypoventilation (Ondine s curse) are preferentially ventilated by means of a tracheostomy (18). Tracheostomy ventilation favors airway inflammation (54) and may affect speech and language development (55). In children with progressive NMD, the decision of a tracheostomy has to be discussed on an individual basis, taking into account the familial environment and the parent s and child s perspective (52,56). In any case, sending children home with invasive ventilation is more difficult than when noninvasive ventilation is used (52). 

Nielson DW, Black PG. Mask ventilation in congenital central alveolar hypoventilation syndrome. Pediatr Pulmonol 1990 9 44-45. 

Ellis ER, McCauley VB, Mellis C, et al. Treatment of alveolar hypoventilation in a six-year-old girl with intermittent positive jncssure ventilation through a nose mask. Am Rev Respir Dis 1987 136 188-191. 

In the case of a 62-year-old woman with bilateral carotid body paraganglioma (19) and central alveolar hypoventilation—who received mechanical ventilation in 1990 with negative pressure through a poncho wrap and subsequently NIPPV through a nasal mask— two months after treatment symptoms, signs of right ventricular failure and daytime blood gases all improved. She has successfully been ventilated for 16 years. 

Montiel GC, Roncoroni AJ, Quadrelli SA, et al. Central alveolar hypoventilation with cor pulmonale successful treatment by non-invasive intermittent positive pressure ventilation. Medicina (B Aires) 1994 54 343-348. 

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