Effects of morphine and midazolam on pharyngeal function, airway protection, and coordination of breathing and swallowing in healthy adults.

BACKGROUND: Drugs used for sedation in anesthesia and intensive care may cause pharyngeal dysfunction and increased risk for aspiration. In this study, the authors investigate the impact of sedative doses of morphine and midazolam on pharyngeal function during swallowing and coordination of breathing and swallowing. METHODS: Pharyngeal function, coordination of breathing and swallowing, and level of sedation were assessed by manometry, videoradiography, measurements of respiratory airflow, and a visual analog scale in 32 healthy volunteers (age 19 to 35 yr). After baseline recordings, morphine (0.1 mg/kg) or midazolam (0.05 mg/kg) was administered intravenously for 20 min, followed by recordings at 10 and 30 min after the end of infusion. RESULTS: Pharyngeal dysfunction, seen as misdirected or incomplete swallowing or penetration of bolus to the airway, increased after morphine infusion to 42 and 44% of swallows compared with 17% in baseline recordings. Midazolam markedly increased incidence of pharyngeal dysfunction from 16 to 48% and 59%. Morphine prolonged apnea before swallowing, and midazolam increased the number of swallows followed by inspiration. CONCLUSION: Morphine and midazolam in dosages that produce sedation are associated with increased incidence of pharyngeal dysfunction and discoordinated breathing and swallowing, a combination impairing airway protection and potentially increasing the risk for pulmonary aspirations.

Pharyngeal function and breathing pattern during partial neuromuscular block in the elderly: effects on airway protection.

BACKGROUND: Intact pharyngeal function and coordination of breathing and swallowing are essential for airway protection and to avoid respiratory complications. Postoperative pulmonary complications caused by residual effects of neuromuscular-blocking agents occur more frequently in the elderly. Moreover, elderly have altered pharyngeal function which is associated with increased risk of aspiration. The purpose of this study was to evaluate effects of partial neuromuscular block on pharyngeal function, coordination of breathing and swallowing, and airway protection in individuals older than 65 yr. METHODS: Pharyngeal function and coordination of breathing and swallowing were assessed by manometry and videoradiography in 17 volunteers, mean age 73.5 yr. After control recordings, rocuronium was administered to obtain steady-state train-of-four ratios of 0.70 and 0.80 followed by spontaneous recovery to greater than 0.90. RESULTS: Pharyngeal dysfunction increased significantly at train-of-four ratios 0.70 and 0.80 to 67 and 71%, respectively, compared with 37% at control recordings, and swallowing showed a more severe degree of dysfunction during partial neuromuscular block. After recovery to train-of-four ratio of greater than 0.90, pharyngeal dysfunction was not significantly different from the control state. Resting pressure in the upper esophageal sphincter was lower at all levels of partial neuromuscular block compared with control recordings. The authors were unable to demonstrate impaired coordination of breathing and swallowing. CONCLUSION: Partial neuromuscular block in healthy elderly individuals causes an increased incidence of pharyngeal dysfunction from 37 to 71%, with impaired ability to protect the airway; however, the authors were unable to detect an effect of partial neuromuscular block on coordination of breathing and swallowing.

Co-ordination of spontaneous swallowing with respiratory airflow and diaphragmatic and abdominal muscle activity in healthy adult humans.

Co-ordination of breathing and swallowing is essential for normal pharyngeal function and to protect the airway. To allow for safe passage of a bolus through the pharynx, respiration is interrupted (swallowing apnoea); however, the control of airflow and diaphragmatic activity during swallowing and swallowing apnoea are not fully understood. Here, we validated a new airflow discriminator for detection of respiratory airflow and used it together with diaphragmatic and abdominal electromyography (EMG), spirometry and pharyngeal and oesophageal manometry. Co-ordination of breathing and spontaneous swallowing was examined in six healthy volunteers at rest, during hypercapnia and when breathing at 30 breaths min(-1). The airflow discriminator proved highly reliable and enabled us to determine timing of respiratory airflow unambiguously in relation to pharyngeal and diaphragmatic activity. During swallowing apnoea, the passive expiration of the diaphragm was interrupted by static activity, i.e. an 'active breath holding', which preserved respiratory volume for expiration after swallowing. Abdominal EMG increased throughout pre- and post-swallowing expiration, more so during hyper- than normocapnia, possibly to assist expiratory airflow. In these six volunteers, swallowing was always preceded by expiration, and 93 and 85% of swallows were also followed by expiration in normo- and hypercapnia, respectively, indicating that, in man, swallowing during the expiratory phase of breathing may be even more predominant than previously believed. This co-ordinated pattern of breathing and swallowing potentially reduces the risk for aspiration. Insights from these measurements in healthy volunteers and the airflow discriminator will be used for future studies on airway protection and effects of disease, drugs and ageing.

Popliteal pterygium syndrome (PPS) with intra-alveolar syngnathia: a discussion of anesthetic and surgical considerations.

Popliteal pterygium syndrome (PPS) is a rare genetic disorder that involves the association of a popliteal web with a combination of craniofacial, genitourinary and extremity malformations. In this article, we describe a patient with PPS complicated with multiple intra-alveolar syngnathia. We discuss the anesthetic and the surgical management of this case and review the literature regarding PPS and intra-alveolar syngnathia.

OK-432 therapy for lymphatic malformation in 32 patients (28 children).

BACKGROUND/PURPOSE: Operating lymphatic malformation (LM) may lead to nerve damage with permanent cosmetic disturbance. Even sclerosants as ethanol and Sotradecol may sometimes harm more than cure. The purpose with this study was to evaluate the effect of a relatively new drug for intralesional injections, OK-432. METHODS: The diagnosis of LM was made clinically by means of ultrasound and MRT and/or CT. Thirty-two patients (28 children) with LM were consecutively enrolled in the study. Twenty-nine (27 children) had not been treated previously: 17 (15 children) had macrocysts (MAC), four microcysts (MIC) and eight had combined cysts (CC). Three patients (one child) had got previous treatment without any curative effect. All patients got intralesional injections with OK-432 at intervals according to a previously published protocol (Läkartidningen, 95 (1998) 2074). RESULTS: No serious adverse effects were seen. The results obtained were excellent in all with macrocysts but in one, who was pretreated with ethanol, where no LM-regression was seen. None of four with MIC-LM required further therapy; for two of them the results were excellent. Of 10 with CC, seven showed excellent results. Only one required surgery. CONCLUSION: OK-432 is effective and is proposed to be the first choice of treatment for LM.