Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020440 (hypercapnia)
 7,939 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to study the effects of PaCO2 and PaO2 on the laryngeal closure reflex, changes in laryngeal resistance of the isolated cat larynx were measured before and during the stimulation of the superior laryngeal nerve (SLN) at various levels of PaCO2 and PaO2. The results showed that laryngeal resistance before SLN stimulation [LR (baseline)] increased slightly during hypocapnia. SLN stimulation produced laryngospasm which was defined as a sharp rise in the laryngeal resistance. Hypercapnia alone and hypoxia alone increased ventilation but decreased the degree and duration of laryngospasm due to SLN stimulation. On the other hand, hypocapnia augmented and prolonged the duration of this laryngospasm. These results suggest that PaCO2 and PaO2 regulate the laryngeal closure reflex in a way such that the degree of laryngospasm changes in inverse proportion to the activity of the respiratory center.
 ...
PMID:Modification of laryngospasm in response to changes in PaCO2 and PaO2 in the cat. 679 29

The frequency and pattern of laryngeal mask airway (LMA) usage in a regional general hospital has been studied. Data were collected prospectively by means of a standardized record sheet which was completed at the time of anesthetic administration. During a 19-month period 10,150 patients underwent surgical procedures requiring general or regional anesthesia, of which 1,096 (men/ women: 791/305, ASA 3 or 4: 350, mean age: 64 years) were managed with the LMA. A clinically pattern airway was provided in 99.75% of occasions of whom 44.4% breathed spontaneously and 55.3% underwent positive pressure ventilation. The monthly frequencies of LMA usage increased significantly during the second year of the survey (25.1% vs 12.8%). Problems were recorded in 16.3% of cases: air leak 8.0%, laryngospasm 1.8%, desaturation (SpO2 < or = 90%) 1.8%, severe hypercarbia (PETCO2 > or = 50 mmHg) 1.0%, regurgitation 0.09%, sore throat 3.4%. No patient required intensive care management postoperatively. There were five cases of failed intubation managed with the LMA. This survey has shown that LMA has a well established role in anesthetic practice. Use of this device is equally safe and effective for both controlled and spontaneous ventilation in a wide range of starve patients undergoing most types of surgery.
 ...
PMID:The laryngeal mask airway: a survey of its usage in 1,096 patients. 903 36

The cuffed oropharyngeal airway (COPA) was compared with the laryngeal mask airway (LMA) with respect to airway quality and respiratory adverse events in 140 spontaneously breathing patients undergoing procedures of duration more than 1 h. Patients were allocated randomly to receive either a COPA (n = 72) or a LMA (n = 68) for airway management during anaesthesia induced with propofol and maintained with sevoflurane, nitrous oxide and oxygen. Groups were similar when comparing the first-time successful insertion rates (COPA: 94.5%, LMA: 95.6%), but airway manipulations (head tilt, chin lift, jaw thrust) were reported more frequently in the COPA group, 27.8% vs. LMA, 4.4%; P = 0.0005. During the post-induction apnoeic period, all patients were ventilated manually and although, mean (SD) leak pressure was lower in the COPA group (18 (4) cm H2O vs. LMA, 22 (3) cm H2O; P < 0.0001), the tidal volumes achieved did not differ in both groups: COPA, 9.5 (4) mL kg-1 vs. LMA, 10.5 (4.5) mL kg-1. The incidences of intra-operative coughing, gagging, laryngospasm, oxygen desaturation and hypercarbia were similar in both groups. Although both devices are equivalent with respect to the overall respiratory problems during spontaneous breathing anaesthesia of intermediate or prolonged duration, the LMA was associated with fewer airway quality problems, suggesting that it is more efficacious in securing the airway.
 ...
PMID:Comparative evaluation of the prolonged use of the cuffed oropharyngeal airway and the laryngeal mask airway in spontaneously breathing anaesthetized patients. 1043 64

The most common sleep disorder in children is obstructive sleep apnea syndrome (OSAS). The majority of children with OSAS improve following tonsillectomy and adenoidectomy (T&A). T&A as an outpatient procedure in children is very common. Young age in considered risk factors for postoperative respiratory complications. The purpose of this study is to analyze our experience with postoperative T&A complications in patients younger than 2 years of age. A total of 39 T&A were performed in children younger than 2 years of age. OSAS diagnosis was confirmed by overnight polysomnography (PSG). All the patients were hospitalized and monitored by overnight pulse oximetry monitoring. Post-operatively there was marked improvement in respiratory function in all the patients comparing pre- and post-operative nadir oxygen saturation (P<0.05). Complications were documented in seven patients (20%). Five of the complications occurred in children older than 1 year of age. Bleeding occurred in two patients (5.7%). Three patients (8.6%) had dehydration, one patient (2.9%) had hypercarbia and one patient had laryngospasm. In this study there was a low incidence of peri- and post- operative respiratory complications in children younger than 2 years of age who undergo T&A for OSAS. Identification of OSAS severity may be an important factor in determining the risk of T&A in a young child.
 ...
PMID:Complications of adenotonsillectomy in children with OSAS younger than 2 years of age. 1288 Jun 63

The causes of obstruction to airflow in the pediatric upper airway include craniofacial disorders, subglottic stenosis, choanal atresia, syndromes associated with neuromuscular weakness, and the most common, hypertrophy of the tonsils and adenoids. Abnormal breathing can adversely affect craniofacial growth, and abnormal craniofacial development can promote upper airway obstruction. Chronic upper airway obstruction often presents with evidence of obstructive sleep apnea syndrome; in severe cases these children also present with pulmonary hypertension and cor pulmonale. The development of pulmonary hypertension and right heart dysfunction from chronic upper airway obstruction is complex. Hypoxemia and hypercarbia-induced respiratory acidosis are potent mediators of pulmonary vasoconstriction that can lead to reversible and irreversible chronic changes in the pulmonary vasculature. It is likely that production of various neurohumoral factors in response to hypoxemia and respiratory distress may further promote pulmonary hypertension, right ventricular dysfunction, and consequent impairment of systemic cardiac output. The anesthetic considerations for children undergoing adenotonsillectomy for chronic airway obstruction are significant. These children are at high risk for complications such as laryngospasm, desaturation, stimulation of pulmonary hypertension and cardiac dysfunction, pulmonary edema, postoperative upper airway obstruction, and respiratory arrest. Because of underlying condition(s) (facial abnormalities, neuromuscular disease, etc.), successful adenotonsillar surgery may not improve upper airway obstruction significantly, especially in the immediate postoperative period when edema, bleeding and the effects of anesthetics and analgesics are present.
 ...
PMID:Chronic upper airway obstruction and cardiac dysfunction: anatomy, pathophysiology and anesthetic implications. 1471 77

Permanent tracheotomy was the first surgical procedure proposed for the treatment of severe obstructive sleep apnoea syndrome and is still the only surgical option that ensures, even in very severe cases, complete elimination of apnoea and, in turn, clinical remission. Improved knowledge of the causes of obstructive sleep apnoea syndromes and the increasing therapeutic options (instrumental, medical and surgical) have resulted in cases requiring tracheotomy as the only indispensable therapeutic option becoming more rare. At present, the only indications are in very occasional conditions of life-threatening obstructive sleep apnoea syndromes and in patients on whom continuous positive airway pressure is not tolerated or is not effective (severe deoxygenation or hypercapnia, severe respiratory disorder index, severe obstructive sleep apnoea syndrome-related arrhythmias, severe excessive daytime sleepiness, heart diseases or ischaemic encephalopathy exacerbated by obstructive sleep apnoea syndromes, obstructive pneumopathy exacerbated by obstructive sleep apnoea syndromes, severe obstructive sleep apnoea syndromes with few chances of resolution with other surgical procedures or failure of the latter). Moreover, it is the only therapeutic solution in rare nocturnal laryngeal stridor due to multisystemic atrophy (in which obstructive sleep apnoea syndrome is due to nocturnal laryngospasm of neurologic origin). Therapeutic tracheotomy must be permanent (tracheostomy) and, therefore, preferably carried out with a specific technique (skin-lined tracheotomy), able to guarantee greater stability, less risk of granulation tissue, wider opening of the tracheostomy, sufficient reversibility. In our experience, very few patients (10 cases) withsleep disorder breathing have been submitted to skin-lined tracheotomy. Of these, the majority were submitted to surgery for severe apnoea due to nocturnal laryngospasm on account of multisystemic atrophy (n = 7), while only 3 cases of obstructive sleep apnoea syndromes were submitted to skin-lined tracheotomy, i.e., 0.7% of the 424 patients operated on for obstructive sleep apnoea syndrome and 1.7% of the 175 operated on for severe, or very severe, obstructive sleep apnoea syndromes (RDI > 40). Skin-lined tracheotomy was not followed by important complications and expected results were achieved with immediate disappearance of daytime symptoms and considerable improvement in nocturnal apnoea. Besides sleep-related disorders, numerous clinical situations with indications for a permanent tracheotomy may benefit from the skinlined technique, such as severe laryngeal or tracheal stenoses, laryngeal diplegias, miasthenia gravis, lateral amyotrophic sclerosis, intractable aspiration, severe emphysema.
 ...
PMID:Role of skin-lined tracheotomy in obstructive sleep apnoea syndrome: personal experience. 1546 94