Showing papers on "Hypoventilation published in 1988"

Control of nocturnal hypoventilation by nasal intermittent positive pressure ventilation.

Abstract: Ten patients with respiratory failure and nocturnal hypoventilation were treated for three to nine months by nasal intermittent positive pressure ventilation. Four patients had chronic obstructive lung disease (median FEV1 19% predicted) and six restrictive chest wall disorders (median FVC 25% predicted); eight of the patients also had cardiac failure. The median daytime arterial oxygen tension, measured before and after at least three months' treatment, increased from 6.2 (range 5.4-9.6) to 9.1 (7.1-9.8) kPa in those with restrictive disease (p less than 0.05), and from 6.0 (5.7-6.5) to 7.1 (6.3-7.7) kPa in the four with airflow limitation (NS). Median values for arterial carbon dioxide tension over the same time fell from 8.2 (range 6.7-9.8) to 6.5 (6.0-6.9) kPa in the group with restrictive disease (p less than 0.05) and from 8.2 (7.0-9.2) to 7.1 (4.9-7.7) kPa in those with airflow limitation (p less than 0.02). Total sleep time while patients were using nasal positive pressure ventilation varied from 155 to 379 (median 341) minutes, and included 4-26% rapid eye movement sleep (median 14%). The percentage of monitored time during the night in which the arterial oxygen saturation was less than 80% fell from a median (range) of 96 (3-100) to 4 (0-9) in the six patients with restrictive disease and from 100 (98-100) to 40 (2-51) in those with airflow limitation. There were no changes in spirometric values but exercise tolerance improved in all patients. The technique may prove an acceptable alternative to long term domiciliary oxygen therapy in selected patients.

Effect of posttraumatic hypoventilation on cerebral energy metabolism.

Abstract: Cerebral energy metabolism was studied in cats subjected to fluid-percussion brain trauma followed immediately by 30 minutes of controlled hypoventilation for the purpose of simulating a more realistic model of human head injury. The cerebral blood flow (CBF) and cerebral metabolic rates of oxygen (CMRO2) and glucose (CMRGl) were measured, with simultaneous phosphorus-31 magnetic resonance spectroscopy quantifications of cerebral tissue pH, phosphocreatine (PCr), and inorganic phosphate (Pi). Hypoventilation alone did not produce marked changes in CMRGl, tissue pH, or PCr:Pi ratios. When hypoventilation was combined with trauma, marked alterations in CBF, CMRGl, PCr:Pi ratio, and tissue pH were seen, indicating relative ischemia. The alterations of cerebral energy metabolism produced by combining trauma and hypoventilation are more severe than those caused by fluid-percussion trauma alone, and may provide a more realistic model of human head injury.

Delayed muscular rigidity and respiratory depression following fentanyl anesthesia.

Abstract: • A delayed effect of fentanyl used for anesthesia may be respiratory distress several hours after surgery. The findings are muscular rigidity, fall in chest wall compliance, hypoventilation, respiratory acidosis, and hypotension. In the past, to our knowledge, this complication was exclusively reported in patients undergoing cardiac surgery, when large fentanyl dosages are employed. This article describes three general surgical patients in whom respiratory distress developed three to five hours following colon surgery when a moderate dose of fentanyl citrate, 55 to 75 μg/kg, was used. Initially, all patients had a normal recovery from anesthesia. Later, respiratory distress was successfully treated with a fentanyl antagonist and ventilatory assistance. This delayed toxic phenomenon is thought to be due to the reentry of fentanyl into plasma from deposits in adipose tissue, muscle, and the gastrointestinal tract, leading to a secondary rise in the plasma concentration. It is more likely to be encountered when hypothermia, rewarming, and acidosis are present in the postoperative period. This life-threatening complication is treacherous, since it may occur when the patient has been transferred to the surgical ward and is less closely monitored. (Arch Surg1988;123:66-67)

Delayed respiratory depression following fentanyl anesthesia for cardiac surgery.

Abstract: High-dose fentanyl anesthesia is widely used in cardiac surgery. Its immediate side-effects are well known. However, its late adverse effect manifested by extreme truncal rigidity, decreased chest wall compliance, hypoventilation, respiratory acidosis and hemodynamic instability is not sufficiently appreciated. Of 380 patients who underwent aortocoronary artery bypass under high-dose (100 micrograms/kg) fentanyl anesthesia, 29 (7.6%) developed the sudden onset of extreme thoracic and abdominal rigidity, leading to respiratory depression 2 to 6 h postoperative, after an apparently normal recovery from the anesthesia. In 15 patients, a high plasma level of fentanyl (5.2 to 7.8 ng/ml) correlated with the clinical events. Administration of naloxone or a muscle relaxant rapidly reversed this late complication of fentanyl, thought to be due to re-entry of fentanyl into plasma from deposits in adipose tissue, muscle and the GI tract, leading to a secondary peak in plasma fentanyl. It is more likely to be encountered when hypothermia, rewarming, and acidosis occur in the postoperative period. Awareness of this life-threatening complication is critical in patients undergoing surgery with fentanyl anesthesia.

Prostaglandin E2 causes hypoventilation and apnea in newborn lambs

Abstract: To test the hypothesis that prostaglandin (PG) E2 is a respiratory depressant in the newborn lamb, 12 chronically catheterized, unanesthetized lambs (age 2-6 days) were infused with progressively increasing doses of PGE2 (0.1, 0.5, 1.0, and 5.0 micrograms.kg-1.min-1; 30 min for each dose) into the ascending aorta. PGE2 caused significant progressive decreases in ventilation (due to decreased tidal volume and breathing rate), heart rate, blood pressure, and percent of the time spent in low-voltage electrocortical activity (LVA). PGE2 also caused respiratory acidosis, hypoxemia, and increased frequency and duration of apneic events (greater than 3 s). During the infusion there was a dose-related increase in plasma concentration of PGE2. At 30 min postinfusion, all measured variables showed recovery, although arterial pH, CO2 tension, and plasma PGE2 remained significantly different from control values, and the percent time in LVA was even higher than during control. Infusion of the vehicle alone (n = 5) caused no significant changes in any of the measured variables. The results, taken in combination with previous fetal studies, indicate that PGE2 has marked inhibitory effects on breathing movements both before and after birth.

Intermittent positive pressure ventilation by nasal mask: technique and applications.

Abstract: Intermittent positive pressure ventilation delivered non-invasively through a well-fitting nasal mask has been used to control nocturnal hypoventilation in three patients with severe, combined cardio-respiratory and skeletal disease. The advantages of this approach to domiciliary ventilation are described and the requirements of the ventilator are defined.

Gas exchange during xylazine-ketamine anesthesia in neonatal calves.

Abstract: Ten neonatal calves were anesthetized with xylazine and ketamine intramuscularly and breathed air spontaneously. Drug injection was repeated after 45 minutes. Each injection resulted in a rapid and sustained increase in respiratory rate, but arterial carbon dioxide tension (PaCO2) increased, indicating hypoventilation. Arterial hypoxemia, primarily caused by hypoventilation, developed within 15 minutes of each injection, but gradually disappeared. Acidemia was primarily respiratory in origin. Heart rate and arterial blood pressure decreased for the duration of anesthesia (90 minutes). This form of anesthesia is a satisfactory alternative to inhalation anesthesia of neonatal calves.

Arnold-Chiari Malformation and Paralysis of the Diaphragm

Abstract: A woman aged 17 years presented with symptoms of somnolence. A bilateral diaphragmatic paralysis and an Arnold-Chiari malformation were diagnosed. Lung function tests revealed a marked restrictive defect and a blunted ventilatory response to hypercapnia and hypoxia. A sleep study also showed central apneas, an irregular pattern of breathing and marked hypoventilation.

Delayed respiratory depression following fentanyl anesthesia for cardiac surgery

Abstract: High-dose fentanyl anesthesia is widely used in cardiac surgery. Its immediate side-effects are well known. However, its late adverse effect manifested by extreme truncal rigidity, decreased chest wall compliance, hypoventilation, respiratory acidosis and hemodynamic instability is not sufficiently appreciated. Of 380 patients who underwent aortocoronary artery bypass under high-dose (100 micrograms/kg) fentanyl anesthesia, 29 (7.6%) developed the sudden onset of extreme thoracic and abdominal rigidity, leading to respiratory depression 2 to 6 h postoperative, after an apparently normal recovery from the anesthesia. In 15 patients, a high plasma level of fentanyl (5.2 to 7.8 ng/ml) correlated with the clinical events. Administration of naloxone or a muscle relaxant rapidly reversed this late complication of fentanyl, thought to be due to re-entry of fentanyl into plasma from deposits in adipose tissue, muscle and the GI tract, leading to a secondary peak in plasma fentanyl. It is more likely to be encountered when hypothermia, rewarming, and acidosis occur in the postoperative period. Awareness of this life-threatening complication is critical in patients undergoing surgery with fentanyl anesthesia.

Cervicomedullary Cord Compression in Young Children with Achondroplasia: Value of Comprehensive Neurologic and Respiratory Evaluation

Abstract: While the majority of individuals with achondroplasia have few serious complications, affected infants and children are at risk for both respiratory and neurologic complications due to certain anatomic characteristics of the disorder (1–3). In the young child, the ribs are short and straight, causing a constricted thoracic cage with a flattened anteroposterior diameter. Dysplasia of the cranial base and upper cervical spine result in a shortened and narrowed nasopharynx as well as a constricted craniocervical junction (Fig. 1). Both restrictive lung disease and obstructive sleep apnea have been documented in young children with achondroplasia (3,4). Compression of the upper cervical spinal cord and distal medulla because of a stenotic foramen magnum is well documented as a cause of quadriplegia in achondroplasia (5), but has been recently reemphasized as a cause of respiratory compromise, apnea and sudden death in infants with the disorder (6). Compression of the anterior spinal artery, traction on the medullary respiratory center and paresis of respiratory muscles have each been suggested as causes of hypoventilation in infants with cervicomedullary compression (5,6). Some young patients with documented cord compression have had findings suggesting a chronic respiratory disorder, such as right ventricular hypertrophy, but have had few, if any, upper motor neuron signs (1). Because both primary and neurogenic respiratory problems may coexist, interpretation of respiratory problems in a given patient is difficult, especially when there are few neurologic signs. We hypothesized that respiratory problems in some achondroplastic infants and children might be due to occult cervicomedullary compression, and that some patients with signs of compression might have occult respiratory abnormalities. We therefore undertook a prospective clinical study to evaluate achondroplastic infants and children for both respiratory and neurologic abnormalities.

Hypoventilation caused by ventilator valve rupture.

Abstract: Following an uneventful induction of anesthesia and tracheal intubation in a 20-year-old, 60-kg man scheduled for aortic valve replacement, ventilation was controlled with a Drager AV-E@, standing bellows ventilator. The fresh gas flow was oxygen 6 Limin, and the ventilator was set to deliver tidal volume 750 ml at rate 10/min, with inspiratory to expiratory ratio 1:2. The minimum ventilatory pressure alarm was set at 8 cm H,O. Peak airway pressure was 10 cm H,O, and arterial blood analysis revealed pH of 7.32, PCO, 57 mmHg, and PO, 460 mmHg. Neither the volumeter reading of the exhaled tidal volume nor filling of the bellows during exhalation were noted. The oxygen gas flow was reduced to 3 L/min, tidal volume was increased to 850 mlhreath, and ventilatory rate was increased to 12/min. Within a minute the minimum ventilatory pressure alarm sounded. Peak airway pressure was 7 cm H,O, exhaled tidal volume was 200 mlhreath, and the ventilator bellows did not fill completely during exhalation. Arterial blood gases revealed pH 7.30, PCO, 60 mmHg, and PO, 481 mmHg. The patient was ventilated manually without difficulty, and no leak in the breathing circuit was detected. When mechanical ventilation was reinstituted, however, the bellows did not rise completely during exhalation. The anesthesia ventilator was

Conditioning of the diaphragm by phrenic nerve pacing in primary alveolar hypoventilation

Abstract: A patient with respiratory muscle weakness due to alveolar hypoventilation was treated with nocturnal bilateral phrenic nerve pacing for one year. Treatment was associated with a progressive increase in diaphragmatic strength and endurance.

Delayed muscular rigidity and respiratory depression following fentanyl anesthesia

Abstract: • A delayed effect of fentanyl used for anesthesia may be respiratory distress several hours after surgery. The findings are muscular rigidity, fall in chest wall compliance, hypoventilation, respiratory acidosis, and hypotension. In the past, to our knowledge, this complication was exclusively reported in patients undergoing cardiac surgery, when large fentanyl dosages are employed. This article describes three general surgical patients in whom respiratory distress developed three to five hours following colon surgery when a moderate dose of fentanyl citrate, 55 to 75 μg/kg, was used. Initially, all patients had a normal recovery from anesthesia. Later, respiratory distress was successfully treated with a fentanyl antagonist and ventilatory assistance. This delayed toxic phenomenon is thought to be due to the reentry of fentanyl into plasma from deposits in adipose tissue, muscle, and the gastrointestinal tract, leading to a secondary rise in the plasma concentration. It is more likely to be encountered when hypothermia, rewarming, and acidosis are present in the postoperative period. This life-threatening complication is treacherous, since it may occur when the patient has been transferred to the surgical ward and is less closely monitored. (Arch Surg1988;123:66-67)

Partial reversal of the obesity hypoventilation syndrome with weight reduction.

Abstract: 2. Quan L, Smith DW. The Vater association vertebral defects, anal atresia, tracheo-osophageal fistula with esophageal atresia, radial and renal dysplasia; a spectrum of associated defects. J Pediatr 1973; 82:104-6. 3. Temtamy SA, Miller JD. Extending the scope of the Vater association: definition of the Vater syndrome. J Pediatr 1974; 85:345-9. 4. Paes BA, De Sa DJ, Hitch DA. Fatal malformations of the larynx and upper trachea. Laryngoscope 1984; 94: 1477-81. 5. Sankaran K, Bhagirath CP, Duncan WJ, et al. Congenital tracheal occlusion in neonates: a mini review. West J Med 1985; 142:348-51.

Control of breathing in the central alveolar hypoventilation syndrome with and without a phrenic pacemaker

Abstract: Primary central alveolar hypoventilation (CAHV) is a rare disorder described in newborns, children, and adults. We report a 2 9/12 year old child with CAHV of unknown etiology. The evaluation of her ventilatory control system showed abnormalities awake and in the different sleep states. Hypoventilation was found to be more severe during non-REM sleep than during REM sleep and awake state. She had central apnea, an irregular respiratory rhythm in the non-REM sleep too, and diminished ventilatory response to inhaled 5%-6% CO2 in both REM and non-REM sleep. Her ventilation decreased when she was breathing 50% and 100% oxygen. During breathing 15% oxygen she did not arouse in spite a transcutaneous pO2 of 10 mmHg. She was first treated with mechanical ventilation during sleep and has now received bilateral simultaneous phrenic pacemaker support during quiet sleep for about one year. With the phrenic pacemaker she has normal minute volume and transcutaneous blood gases during sleep. During a respiratory infection she needed again mechanical ventilation via her tracheostoma 24 hours a day for one week. This case of a CAHV demonstrates a dysfunction of the central and partially also of the peripheral chemoreceptors. The abnormalities of the ventilation were demonstrable not only in the non-REM sleep but also in the REM sleep and awake state.

Periodic nocturnal ventilation using an Emerson chest respirator as an alternative to permanent tracheostomy with positive pressure ventilation in patients with idiopathic scoliosis and severe global respiratory insufficiency

Abstract: Sustained success was achieved in treating a 40-year-old patient who had had severe progressive thoracic kyphoscoliosis since childhood and developed cardiorespiratory failure with terminal alveolar hypoventilation and hypoxemia due to acute pulmonary infection On emergency admission to this hospital mechanically controlled ventilation by tracheostomy tube produced a remarkable improvement in cardiorespiratory function Weakness of the respiratory muscles made complete disconnection from ventilatory support impossible Instead of positive pressure ventilation by tracheostomy tube with resultant patient invalidity, nighttime external negative pressure ventilation with an Emerson chest respirator was started leaving the patient free for daytime activity This type of ventilation is a simple, effective and well tolerated long-term treatment at low cost The patient has been using it nightly at home for over 6 months and no problems have arisen These findings show that intensive care is indicated in patients with severe thoracic kyphoscoliosis and cardiorespiratory failure since long-term treatment of terminal hypoventilation and cardiorespiratory failure is possible with a cheap and simple nocturnal ventilation system

Methods of Increasing FRC in Acute Respiratory Failure

Abstract: The goal of respiratory therapy to increase functional residual capacity (FRC) is not only to improve oxygenation, so important this effect may be, but to reestablish pertinent and normal ventilation of all regions of the lung. In acute respiratory failure (ARF), ventilation is endangered by destabilization of alveoli [1, 2]. Apart from interstitial edema the clinical picture will be determined by the pathophysiological consequences of increased pulmonary retraction and decreased lung volume leading to reduced compliance, hypoventilation, shunting, and hypoxemia. In addition fluid balance is disturbed and extravasation will increase further [3] (Fig. 1). Respiratory therapy at increased FRC does not influence the initial or the causative mechanisms of ARF, but it will confine their influence on pulmonary volume and therefore mechanics and gas exchange because it counteracts volume loss and prevents it becoming a causative factor per se. From that point of view ventilation with increased FRC is a struggle against progressive pulmonary retraction. The improvement of gas exchange that usually results is important and a useful monitor of successful therapy, however it is not indispensable for justification of ventilatory patterns with increased FRC.

Electrical stimulation of the phrenic nerve in dogs

Abstract: Respiratory parameters have been studied by electrical stimulation of phrenic nerves (EPN) in 12 dogs. The optimal parameters of an electrical stimulus were found for long-term EPN. EPN increased minute respiratory volume, when respiratory rate raised to 18 per min, and decreased, when respiratory rate diminished to 6 per min. Another parameter--oxygen utilization index--diminished at high respiratory rate and increased at low one, which reflected hyper- or hypoventilation status, respectively. The data obtained indicate that controlled lung ventilation may maintain living status of dogs for a long time without alteration of general respiratory parameters.