Showing papers on "Hypoventilation published in 1996"

Sleep studies and supportive ventilatory treatment in patients with congenital muscle disorders.

Abstract: Eight ambulant children aged 6-13 years, four with congenital myopathy, two with congenital muscular dystrophy and two with the rigid spine syndrome, presented with recurrent chest infections, morning headaches, shallow breathing at night, or respiratory failure. Polysomnography confirmed the presence of nocturnal hypoxaemia with oxygen saturation on average less than 90% for 49% of sleep and less than 80% for 19% of sleep accompanied with severe hypoventilation. Additionally there was sleep disturbance characterised by an increased number of wake epochs from deep sleep (in comparison to 10 non-hypoxaemic subjects). The severity of sleep hypoxaemia did not correlate with symptoms. Treatment with night time nasal ventilation was started and repeat polysomnography showed normal overnight oxygen saturation and a reduced number of wake epochs during deep sleep. It is important to be vigilant for sleep hypoventilation in these patients and sleep studies should be part of the routine respiratory evaluation. Treatment with nasal ventilation is effective in reversing the nocturnal respiratory failure without significant disturbance to life style.

Neuronal loss in the medullary reticular formation in myotonic dystrophy: A clinicopathological study

Abstract: Article abstract-Respiratory insufficiency occurs frequently in patients with myotonic dystrophy (MyD). We have performed a quantitative study of neurons linked to respiratory function in the dorsal central medullary nucleus (DCMN), the ventral central medullary nucleus (VCMN), and the subtrigeminal medullary nucleus (SMN) in seven patients with MyD and eight age-matched controls. Alveolar hypoventilation of the central type occurred in three of the MyD patients but not in the remaining MyD patients or controls. The densities of neurons of the DCMN, the VCMN, and the SMN in MyD patients with hypoventilation were significantly lower than in MyD without hypoventilation and controls. These data suggest that the neuronal loss of the DCMN, VCMN, and SMN is associated with the presence of hypoventilation in MyD and may be an important feature of MyD. NEUROLOGY 1996;46: 228-231

A cranio-cervical malformation presenting as acute respiratory failure

Abstract: An 18-year-old, previously healthy male presented with bilateral pneumonia and acute respiratory failure with severe carbon dioxide retention. The presence of mild brainstem signs and hypoventilation led to the discovery of a platybasia, basilar invagination, and kinking of the medulla oblongata with early syrinx. He was operated upon but postoperatively was noted to have a mixed type of sleep apnea. This case illustrates the diagnostic challenge in acute respiratory failure in a previously healthy young person and the possible pathogenic mechanisms underlying it.

Permissive hypercapnia and gas exchange in lungs with high Qs/Qt: a mathematical model

Abstract: Low volume ventilation with permissive hypercapnia is becoming widely used in the treatment of acute respiratory distress syndrome. A mathematical model was developed to examine the effects of hypoventilation on pulmonary gas exchange in lungs with a range of shunt fractions. Hypoventilation did not worsen gas exchange, provided the inspired oxygen concentration was high enough to maintain PAO2 at an adequate level. In lungs with a high shunt fraction, some improvement in gas exchange may result, but these effects are small. A rightwards shift of the oxygen-haemoglobin dissociation curve induced by hypercapnia, is likely to be beneficial rather than detrimental in patients with acute respiratory distress syndrome. This analysis was limited to the direct effects of hypoventilation in lungs with constant shunt fractions, and did not encompass a number of possible secondary effects such as changes in cardiac output with PaCO2, changes in shunt fraction associated with a reduction in mean airway pressure and possible direct effects of hypercapnia on the pulmonary vasculature or airways.

Sleep-wake cycles and the management of respiratory failure.

Abstract: Sleep is characterized by many changes in the respiratory system, including a reduction in respiratory motor output associated with the loss of wakefulness, increased upper airway resistance, and blunted protective reflexes (such as load compensation), that result in reduced alveolar ventilation. The development of carbon dioxide retention appears to be linked to the exaggeration of sleep-related changes on ventilation by coexistent respiratory system disorders. Sleep-disordered breathing is becoming increasingly recognized in subjects with neuromuscular diseases, who may be prone to nocturnal respiratory events due to diaphragm and bulbar muscle weakness, abnormal central respiratory control, obesity, and sleep position restrictions. Nocturnal gas exchange deterioration may occur in patients with chronic obstructive pulmonary disease, particularly during rapid eye movement sleep when activity of the respiratory muscles other than the diaphragm is inhibited. Concurrent obstructive sleep apnea syndrome may further compromise nocturnal ventilation, thereby contributing to the development of acute or chronic respiratory failure. The use of noninvasive nocturnal ventilation at night has resulted in significant improvements in symptoms of hypoventilation and daytime carbon dioxide retention in various clinical settings, yet important questions remain about implementation of this modality.

Sleep disorders and outpatient treatment of patients with pulmonary disease.

Abstract: Patients with chronic obstructive pulmonary disease, kyphoscoliosis, and neuromuscular disorders frequently desaturate in rapid eye movement sleep. This can lead to polycythemia, pulmonary hypertension, and respiratory failure. In addition, these patients as well as those with asthma may have unsuspected coexistent obstructive sleep apnea. The detection of hypoventilation, oxygen desaturation, and obstructive sleep apnea may lead to more effective treatment of these patients.

Respiratory insufficiency in neuronopathic and neuropathic disorders

Abstract: Summary Twenty-nine patients with a neuronopathic or neuropathic disorder were referred for assessment of respiratory insufficiency between 1978 and 1994. Diagnoses included spinal muscular atrophy (6), chronic idiopathic demyelinating neuropathy (4), Vialetto-van Laere syndrome (3), hereditary motor and sensory neuropathy (3) and a miscellaneous group (5). We also describe seven patients with Guillain-Barre syndrome (GBS) who required longterm ventilatory support for over 6 months to 7 years after the initial illness. Respiratory insufficiency occurred as a consequence of respiratory muscle weakness, impaired bulbar function and restrictive lung defects. In some groups presentation was with progressive nocturnal hypoventilation culminating in acute respiratory failure. Five patients with GBS or chronic idiopathic demyelinating neuropathy were weaned from ventilatory support up to 18 months after the initial illness. The remaining 24 patients required continuous or nocturnal ventilatory support using intermittent positive-pressure ventilation (13), negative pressure ventilation (4), nasal-mask-delivered intermittent positive-pressure ventilation (4), nasal-maskdelivered continuous positive-pressure ventilation

Sleep and breathing disorders in patients with brain stem lesions

Abstract: Most information about the structures within the brain stem that modulate respiration and sleep are gathered from animal experiments. Therefore we examined 10 patients several weeks after an infarction of the brain stem by means of polysomnography and tested the chemosensitive drives of respiration. None of these patients complained about symptoms of sleep disordered breathing. In each case polysomnographic measurements and ventilatory response curves revealed pathologic findings. The respiratory response to CO2 was diminished or completely abolished in each patient. In some cases hypoventilation or disturbances of the respiratory rhythmicity could be seen. In several cases missing REM sleep, sleep fragmentation or the reduction of slow wave sleep were observed. The study indicates that on the base of results from animal research the comparison of morphological and pathophysiological data is helpful to gain a better understanding on the coupling of the respiratory system with sleep at the brain stem level as well as on the pathomechanism of sleep related breathing disorder.

Noninvasive intermittent ventilation. A prospective data collection in patients with hypoventilation syndrome

Abstract: Introduction Noninvasive intermittent ventilation is usually performed in patients with severe ventilatory pump disorder. From 1988 to 3/1995 we treated 163 patients with the aim of home mechanical ventilation (HMV). Patients and results In March 1993 115 of these 163 patients practiced HMV, 22 had already died and 26 had rejected or broken off ventilation therapy. The 115 patients were classified in three main diagnostic groups: Scoliosis or chest wall disease (n = 76), COPD (n = 11) and neuromuscular disease (n = 28). The mean pCO2 at rest of all patients before ventilation therapy was 56 (+/- 12) Torr and fell to 46 (+/- 5) Torr in the course of therapy. The maximum statical inspiration pressure PImax rose from average 3, 8 (+/- 2, 3) to 4, 9 (+/- 2, 0) kPa. There was a probability of surviving two years after onset of ventilation therapy of 85% in the scoliosis group, of 60% in the neuromuscular group and of 30% in the COPD group. Conclusions According to results of others home ventilation therapy was very successful in patients with chest wall disease. In some patients with neuromuscular disorder quality of life could be improved and life prolonged. Only half of the COPD patients could be treated successfully, whereas the other half had no benefit from noninvasive ventilation therapy.

[Obesity and hypoventilation syndrome; effects of weight loss and treatment with respiratory stimulants].

Abstract: A 32-year-old, hypertensive, morbidly obese (BMI 49 kg/m2) woman was referred to us suspected of sleep-disordered breathing. Polycythaemia, right heart and respiratory failure, restrictive ventilatory impairment, decreased hypercapnic respiratory drive, high number of very short apneas mostly of central origin (698 vs 530 obstructive), and overnight hypoxaemia were found. The diagnosis of obesity-hypoventilation syndrome was established and the treatment with almitrine, aminophylline and low-calorie diet was started. After 6 months body weight decreased significantly (BMI 38 kg/m2). RBC, spirometry, blood gas analysis, overnight oximetry, hypercapnic respiratory drive and polysomnography showed results within normal limits. Causes, pathophysiology and possible treatment of obesity-hypoventilation syndrome are discussed.

Central alveolar hypoventilation syndrome with compression of the medulla oblongata by tortuous and elongated vertebral arteries

Abstract: A 43-year-old woman was admitted to the hospital with hypoventilation, which developed when she took sedatives because of an operation on an adrenal gland tumor. Central alveolar hypoventilation syndrome was diagnosed after neurophysiological and pulmonary-function tests. Magnetic resonance imaging and vertebral angiography revealed that tortuous and elongated vertebral arteries compressed the ventral sides of the medulla oblongata, which may have caused the hypoventilation. Mechanical ventilation during sleep improved her condition. Home mechanical ventilation was prescribed and she has been well during follow up as an outpatient.

Kearns-Sayre Syndrome and Cardiac Anesthesia

Abstract: T HE KEARNS-SAYRE Syndrome (KSS) is a rare form of mitochondrial myopathy (MM) where ophthalmoplegia is associated with a variety of cardiac conduction and neural and retinal disorders. ~ There are few case reports of anesthesia for patients with KSS. 2-5 Discussed as a case of a patient with KSS who presented for cardiac surgery. The implications for anesthesia include atrioventricular node and infranodal conduction abnormalities, 6 hypoventilation secondary to ventdatory drive depression, 7 potential myopathic or neuropathic changes, 8 possible mahgnant hyperthermia susceptibility, 9 and undue sensitwity to anesthetic induction agents. 2,3

Non-invasive ventilation.

Abstract: Nasal intermittent positive pressure ventilation is an effective treatment for nocturnal hypoventilation secondary to chest wall deformity or respiratory muscle weakness. Physicians should be aware that, in these groups of patients, disabling breathlessness can be alleviated and established cor pulmonale reversed by the technique.

Long-term noninvasive ventilation for patients with thoracic cage abnormalities.

Abstract: Long-term noninvasive ventilation offers the patient with thoracovertebral deformities, including deformities that result from the severe skeletal and chest-wall sequelae of tuberculosis, what long-term oxygen therapy has offered patients with chronic obstructive pulmonary disease: improved survival and prevention or alleviation of cor pulmonale. Long-term noninvasive intermittent positive pressure ventilation, particularly nocturnal use, has little inconvenience, because ventilation during the night often suffices. Major advantages include correction of hypoventilation during autonomous breathing time that is usually sufficient to permit patients to resume their activities of daily living without need for ventilatory assistance during the day and efficacy comparable to that of intermittent positive pressure ventilation via an indwelling tracheostomy tube, without the inconveniences (tracheostomy is always available if necessary).

Intermittent nasal positive pressure ventilation with a ventilator in accordance with the Medical Device Regulation III (MedGV III). Clinical experiences with the BREAS PV 201 in 19 patients

Abstract: UNLABELLED During the period from January to September 1995, 19 patients suffering from ventilatory insufficiency were adjusted to nocturnal nasal intermittent positive pressure ventilation (nIPP) therapy with a new ventilatory apparatus conforming to German regulations governing medical equipment (MedGV III). This equipment had not been available previously. 5 patients were suffering from obstructive ventilatory disorder, 5 patients from an underlying neurological disease and 3 patients from thoracic restriction. In 6 patients the reason for their ventilatory disorder was obesity hypoventilation or disorder of central ventilatory regulation. The average age was 54 years (15-73 years). Whereas 14 patients were suffering from global respiratory insufficiency already during the day, the others had marked respiratory disorder only at night. In all cases ventilation was carried out during the whole night. RESULTS nIPPV achieved normoxia in all patients whereas in 10 patients hypercapnia was not completely eliminated. In all cases, however, the previously elevated pCO2 could be reduced. Hence, sufficient nIPPV can be achieved also with a respirator complying with the new German MedGV III regulations.

Anesthetic effects on respiratory muscles

Abstract: A NESTHESIA ALTERS BREATHING; this much is obvious to even the neophyte practitioner. Whereas other authors in this issue address those alterations resulting directly from obtundation of consciousness, we discuss the more direct effects of anesthetic agents on the neuromuscular apparatus involved in breathing. Anesthesiologists have long recognized that anesthetic drugs alter the neural control of the respiratory muscles. In 1858 John Snow observed that during chloroform anesthesia breathing was " . . . sometimes performed only by the diaphragm whilst the intercostal muscles are paralyzed," These alterations in chest wall motion were used for many years as a guide to the proper administration of anesthesia. Fortunately, the overall neural output to the respiratory muscles was relatively well preserved by early anesthetic drugs such as ether, so that anesthesia could be administered safely without assisted ventilation. However, modem drugs used during anesthesia tend to cause a more severe depression of neural output to respiratory muscles. Although anesthetic techniques have evolved to address this depression, alterations in respiratory muscle function caused by anesthesia continue to constitute a major source of morbidity and mortality in modem anesthetic practice, causing complications ranging from a mild impairment of pulmonary gas exchange to potentially catastrophic hypoventilation.

Sleep studies andsupportive ventilatory treatment inpatients withcongenital muscle disorders

Abstract: Eightambulantchildren aged6-13years, fourwithcongenital myopathy, twowith congenital musculardystrophy andtwo withtherigid spinesyndrome, presented withrecurrent chestinfections, morning headaches, shallowbreathing atnight, orrespiratory failure. Polysomnography confirmedthe presenceof nocturnal hypoxaemia withoxygensaturation on average lessthan90%for49%ofsleep and lessthan80%for19%ofsleep accompaniedwithseverehypoventilation. Additionally therewas sleepdisturbance characterised byanincreased numberof wakeepochs fromdeepsleep (incomparisonto10non-hypoxaemic subjects). The severity ofsleephypoxaemia didnotcorrelate withsymptoms.Treatmentwith nighttimenasalventilation wasstarted and repeatpolysomnography showed normalovernight oxygensaturation anda reducednumberofwakeepochsduring deepsleep. Itisimportant tobevigilant forsleep hypoventilation inthesepatients andsleepstudies shouldbepartofthe routine respiratory evaluation. Treatment withnasalventilation iseffective in reversing thenocturnal respiratory failure withoutsignificant disturbance to life style. DisChild 1996; 74:195-200)