Richard Kuylenstierna

Functional assessment of the pharynx at rest and during swallowing in partially paralyzed humans: simultaneous videomanometry and mechanomyography of awake human volunteers

Background: Functional characteristics of the pharynx and upper esophagus, including aspiration episodes, were investigated in 14 awake volunteers during various levels of partial neuromuscular block. Pharyngeal function was evaluated using videoradiography and computerized pharyngeal manometry during contrast bolus swallowing. Methods: Measurements of pharyngeal constrictor muscle function (contraction amplitude, duration, and slope), upper esophageal sphincter muscle resting tone, muscle coordination, bolus transit time, and aspiration under fluoroscopic control (laryngeal or tracheal penetration) were made before (control measurements) and during a vecuronium‐induced partial neuromuscular paralysis, at fixed intervals of mechanical adductor pollicis muscle train‐of‐four (TOF) fade; that is, at TOF ratios of 0.60, 0.70, 0.80, and after recovery to a TOF ratio > 0.90. Results: Six volunteers aspirated (laryngeal penetration) at a TOF ratio < 0.90. None of them aspirated at a TOF ratio > 0.90 or during control recording. Pharyngeal constrictor muscle function was not affected at any level of paralysis. The upper esophageal sphincter resting tone was significantly reduced at TOF ratios of 0.60, 0.70, and 0.80 (P < 0.05). This was associated with reduced muscle coordination and shortened bolus transit time at a TOF ratio of 0.60. Conclusions: Vecuronium‐induced partial paralysis cause pharyngeal dysfunction and increased risk for aspiration at mechanical adductor pollicis TOF ratios < 0.90. Pharyngeal function is not normalized until an adductor pollicis TOF ratio of > 0.90 is reached. The upper esophageal sphincter muscle is more sensitive to vecuronium than is the pharyngeal constrictor muscle.

The incidence and mechanisms of pharyngeal and upper esophageal dysfunction in partially paralyzed humans: pharyngeal videoradiography and simultaneous manometry after atracurium.

Background: Residual neuromuscular block caused by vecuronium alters pharyngeal function and impairs airway protection. The primary objectives of this investigation were to radiographically evaluate the swallowing act and to record the incidence of and the mechanism behind pharyngeal dysfunction during partial neuromuscular block. The secondary objective was to evaluate the effect of atracurium on pharyngeal function. Methods: Twenty healthy volunteers were studied while awake during liquid-contrast bolus swallowing. The incidence of pharyngeal dysfunction was studied by fluoroscopy. The initiation of the swallowing process, the pharyngeal coordination, and the bolus transit time were evaluated. Simultaneous manometry was used to document pressure changes at the tongue base, the pharyngeal constrictor muscles, and the upper esophageal sphincter. After control recordings, an intravenous infusion of atracurium was administered to obtain train-of-four ratios (T4/T1) of 0.60, 0.70, and 0.80, followed by recovery to a train-of-four ratio of more than 0.90. Results: The incidence of pharyngeal dysfunction was 6% during the control recordings and increased (P < 0.05) to 28%, 17%, and 20% at train-of-four ratios 0.60, 0.70, and 0.80, respectively. After recovery to a train-of-four ratio of more than 0.90, the incidence was 13%. Pharyngeal dysfunction occurred in 74 of 444 swallows, the majority (80%) resulting in laryngeal penetration. The initiation of the swallowing reflex was impaired during partial paralysis (P = 0.0081). The pharyngeal coordination was impaired at train-of-four ratios of 0.60 and 0.70 (P < 0.01). A marked reduction in the upper esophageal sphincter resting tone was found, as well as a reduced contraction force in the pharyngeal constrictor muscles. The bolus transit time did not change significantly. Conclusion: Partial neuromuscular paralysis caused by atracurium is associated with a four- to fivefold increase in the incidence of misdirected swallowing. The mechanism behind the pharyngeal dysfunction is a delayed initiation of the swallowing reflex, impaired pharyngeal muscle function, and impaired coordination. The majority of misdirected swallows resulted in penetration of bolus to the larynx.

Pharyngeal function and airway protection during subhypnotic concentrations of propofol, isoflurane, and sevoflurane: volunteers examined by pharyngeal videoradiography and simultaneous manometry

Background Anesthetic agents alter pharyngeal function with risk of impaired airway protection and aspiration. This study was performed to evaluate pharyngeal function during subhypnotic concentrations of propofol, isoflurane, and sevoflurane and to compare the drugs for possible differences in this respect. Methods Forty-five healthy volunteers were randomized to receive propofol, isoflurane, or sevoflurane. During series of liquid contrast bolus swallowing, fluoroscopy and simultaneous solid state videomanometry was used to study the incidence of pharyngeal dysfunction, the initiation of swallowing, and the bolus transit time. Pressure changes were recorded at the back of the tongue, the pharyngeal constrictor muscles, and the upper esophageal sphincter. After control recordings, the anesthetic was delivered, and measurements were made at 0.50 and 0.25 predicted blood propotol concentration (Cp50asleep) for propofol and 0.50 and 0.25 minimum alveolar concentration (MAC)awake for the inhalational agents. Final recordings were made 20 min after the end of anesthetic delivery. Results All anesthetics caused an increased incidence of pharyngeal dysfunction with laryngeal bolus penetration. Propofol increased the incidence from 8 to 58%, isoflurane from 4 to 36%, and sevoflurane from 6 to 35%. Propofol in 0.50 and 0.25 Cp50asleep had the most extensive effect on the pharyngeal contraction patterns (P < 0.05). The upper esophageal sphincter resting tone was markedly reduced from 83 ± 36 to 39 ± 19 mmHg by propofol (P < 0.001), which differed from isoflurane (P = 0.03). Sevoflurane also reduced the upper esophageal sphincter resting tone from 65 ± 16 to 45 ± 18 mmHg at 0.50 MACawake (P = 0.008). All agents caused a reduced upper esophageal sphincter peak contraction amplitude (P < 0.05), and the reduction was greatest in the propofol group (P = 0.002). Conclusion Subhypnotic concentrations of propofol, isoflurane, and sevoflurane cause an increased incidence of pharyngeal dysfunction with penetration of bolus to the larynx. The effect on the pharyngeal contraction pattern was most pronounced in the propofol group, with markedly reduced contraction forces.

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.

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.

Predictive value of malignancy grading systems, DNA content, p53, and angiogenesis for stage I tongue carcinomas.

AIM: To assess the clinical value of malignancy grading systems compared with nuclear DNA content, protein p53, and angiogenesis for predicting recurrence of stage I (UICC, 1987) tongue carcinomas. METHODS: Histopathological malignancy grading according to Jakobsson and tumour front grading according to Bryne et al were performed on haematoxylin and eosin slides. DNA analysis was performed by image cytometry. Protein p53 and angiogenesis were evaluated by immunohistochemical analysis using antibody CM1 and antibody against factor VIII related antigen, respectively. RESULTS: 49 patients with stage I carcinomas of the mobile tongue were included, all treated by local surgical excision alone. Eight patients (16%) suffered from local recurrence during follow up, and 13 (27%) had regional recurrence. Both Jakobssons malignancy grading system and p53 immunoreactivity proved to be useful predictors of regional recurrence in a Cox multivariate regression analysis. CONCLUSIONS: Histopathological malignancy grading systems provide valuable prognostic information and can still compete with current biological markers in this respect.

Tumor markers carcinoembryonic antigen, CA 50, and CA 19-9 and squamous cell carcinoma of the esophagus. Pretreatment screening.

Pretreatment serum levels of the tumor markers Carcinoembryonic antigen (CEA), CA 50, and CA 19‐9 in 95 patients with squamous cell carcinoma of the esophagus and 32 age‐matched controls were compared. Thirty‐nine percent of the cancer patients showed elevated (≥5 μg/l) serum CEA levels, 41% had elevated (≥17 U/ml) CA 50 levels, and 13% showed elevated (≥37 U/ml) CA 19‐9 levels. The tumor markers showed a considerable degree of complementarity, and combined tumor marker analysis increased the sensitivity to 59%. Raised CEA levels were found significantly more frequently in intrathoracically localized tumors than in cervical cancers. Patients surviving less than 6 months showed a higher rate of elevated CEA assays than those who survived 6 to 18 months. No certain correlation was established between tumor marker elevation and tumor stage or tumor differentiation.

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.

Radiographic diagnosis of foreign bodies in the oesophagus

In a group of patients suspected of harbouring a foreign body in the oesophagus, the diagnostic accuracy of radiographic examination is found to be high. Only 1 of 243 patients examined by radiography presented a false negative result.

Swallowing and respiratory pattern in young healthy individuals recorded with high temporal resolution

Abstract  The coordination of swallowing and respiration is essential for a safe swallow. Swallowing consists of several subsecond events. To study this, it is important to use modalities with high temporal resolution. In this study, we have examined young healthy individuals with simultaneous videofluoroscopy, videomanometry and respiratory recording, all with high temporal resolution. The onset of 13 predetermined swallowing and respiratory events and the surrounding respiratory phase pattern were studied in different body positions and during different respiratory drives. An increased respiratory drive was induced by breathing 5% CO2. The results demonstrated a highly repeatable and fixed temporal coordination of the swallowing pattern despite body position and respiratory drive. Previous studies have demonstrated a period of centrally controlled apnoea during swallowing. This apnoea period has a variable length, varying from 1 to 5 s. During increased respiratory drive, we could demonstrate a significantly shorter period of apnoea during swallowing, mainly due to an earlier resumption of respiration. The high temporal recordings in this study have revealed that swallowing during expiration is present basically in all healthy individuals. This swallowing respiratory pattern seems to be appropriate for a safe swallow. This knowledge will be used as a reference for future studies on how swallowing and respiratory coordination might be altered due to ageing and diseases.