A clinical trial of a novel emulsion for potential use as a saliva substitute in patients with radiation-induced xerostomia.

Researchers have recently developed a novel oily formulation for potential use as a saliva substitute for the treatment of dry mouth. The aim of this randomised, crossover study was to compare this new formulation to a currently available saliva substitute and a control of water on measures of mastication, subjective feeling of oral dryness and product acceptability. Forty participants treated with radiotherapy to the head and neck and experiencing xerostomia were invited to participate in the trial. Each participant trialled all three products in a randomised order. The effect of each product was measured using the Test of Masticating and Swallowing Solids (TOMASS), the Shortened Xerostomia Inventory (SXI) and a questionnaire designed to test patient acceptability of each product. Outcome data were gathered in a single session after the first administration of each product to evaluate immediate effects and after 7 days of use to evaluate longer-term effects. Statistical analyses consisted of repeated-measures analysis of variance and mixed models. There was no evidence that application of the three formulations had an effect on any of the TOMASS measures, either immediately or after one week of use (P > 0·05). There was a significant main effect of formulation on the SXI score (P = 0·02). Application of the novel emulsion resulted in a clinically small but significant improvement in SXI score (P < 0·01); however, application of methylcellulose (P = 0·21) and water (P = 0·81) resulted in no significant difference. There was no difference in participant acceptability between the three products (P = 0·32). The novel oily emulsion showed no clinically significant benefit over two existing products for relief of xerostomia. Indeed, none of the three products demonstrated significant change in patient outcomes.

The effect of titrated fentanyl on suppressed cough reflex in healthy adult volunteers.

Cough suppression is part of the pharmacodynamic profile of opioids. We investigated the impact of clinical doses of fentanyl on suppressing the cough reflex. Thirteen volunteers received 2 µg.kg(-1) of fentanyl in a divided administration protocol. Three minutes after each administration and at 10 min intervals during washout, suppressed cough reflex testing with nebulised citric acid was performed and compared with fentanyl effect-site concentration. Mean (SD) citric acid concentration provoking cough increased from 0.5 (0.28) mol.l(-1) at baseline to 1.2 (0.50) mol.l(-1) after 2 µg.kg(-1) of fentanyl (p = 0.01). Mean (SD) fentanyl effect-site concentration after the final dose of fentanyl was 1.89 (0.05) ng.ml(-1) . A strong positive correlation was found between suppressed cough reflex thresholds and fentanyl effect-site concentrations during both fentanyl administration and washout phases of the study (r(2) = 0.79, p = 0.01). The mean (SD) length of time for return of suppressed cough response was 44.6 (18.8) min. Clinically relevant doses of fentanyl produced cough reflex suppression in healthy volunteers.

Characterization and correction of pressure drift in the ManoScan(™) high-resolution manometry system: In vitro and in vivo.

BACKGROUND: A substantial pressure drift in high-resolution manometry (HRM) has been reported; however, fundamental questions remain regarding the origin and management of this drift. The aim of this study was to provide critical in-depth analyses of ManoScan(™) HRM drift in vitro and in vivo. METHODS: A total of sixteen 15-min studies and twelve 5-h studies were performed in a water bath at 37 °C at 4.0 cm depth (2.9 mmHg) with ESO and ESO Z catheters. Six 5-h in vitro studies were performed similarly at a depth of 9.0 cm (6.6 mmHg). Eight 15-min studies and nine 8-h in vivo studies were performed with healthy participants. Two correction methods - thermal compensation (TC) and interpolated thermal compensation (ITC) - were tested. KEY RESULTS: Overall pressure drift varied both between studies (p < 0.01) and within sensors (p < 0.01). Drift resulted from thermal shock, an initial pressure change at intubation, and baseline drift, a linear drift over time (R(2)  > 0.96). Contrary to previous reports, there was no correlation between drift and average (r = -0.02) or maximum pressure exposure (r = -0.05). Following data correction, ITC had the lowest median error but persisted with a maximum error of 2.5 mmHg (IQR = 3.0). CONCLUSIONS & INFERENCES: The substantial drift in the ManoScan(™) HRM system is highly variable and not corrected via the standard operating instructions. ITC has superior performance but requires communication with the manufacturer to enable this option. This has a substantial impact on clinical diagnosis, utility of existing normative data, and future research of HRM.

The influence of taste on swallowing apnea, oral preparation time, and duration and amplitude of submental muscle contraction.

Prior research has documented a modulating effect of taste on swallowing. We hypothesized that presentation of tastant stimuli would be a significant variable in swallowing-respiratory coordination, duration of oral bolus preparation, and submental muscle contraction. Twenty-three healthy females were presented with 1-cm(3) gelatin samples flavored with 4 tastants of increasing intensities. Visual analogue scale ratings of perceived intensity of each were used to identify relative equivalent concentrations across the 4 tastants. Data were then collected during ingestion of 5 trials of the 4 equivalent tastants using measurements of nasal airflow and submental surface electromyography (sEMG) to record biomechanical measures. Chi-square analysis failed to identify a statistically significant influence of taste on the phase location of swallowing apnea. Repeated measures analysis of variance demonstrated significant taste effects for oral preparation time, submental sEMG amplitude, and duration (P < 0.02). Sweet tastants were prepared for a shorter time when compared with bitter tastants. Swallow duration for sour, salty, and bitter tastants were longer than sweet and neutral tastants. Sour tastants resulted in the greatest amplitude of submental muscle contraction during swallowing. This study supports existing research that found that sour substances were swallowed with more effort when compared with other tastes.

Outcomes of swallowing rehabilitation in chronic brainstem dysphagia: A retrospective evaluation.

This study examines the functional and physiologic outcomes of treatment in a group of 10 patients with chronic dysphagia subsequent to a single brainstem injury. All patients participated in a structured swallowing treatment program at a metropolitan teaching hospital. This program differs from more traditional swallowing treatment by the inclusion of surface electromyography biofeedback as a treatment modality and the completion of 10 hr of direct treatment in the first week of intervention. A retrospective analysis of medical records and patient questionnaires was used to gain information regarding medical history, site of lesion, prior interventions, and patient perception of swallowing recovery. Physiologic change in swallowing treatment, as measured by severity ratings of videofluoroscopic swallowing studies, was demonstrated in nine of 10 patients after 1 week or 10 sessions of treatment. Functional change was measured by diet level tolerance after 1 week of treatment, at 6 months, and again at 1 year posttreatment. Eight of the 10 patients were able to return to full oral intake with termination of gastrostomy tube feedings, whereas two demonstrated no long-term change in functional swallowing. Of the eight who returned to full oral intake, the average duration of tube feedings following treatment until discontinuation was 5.3 months, with a range of 1-12 months. Six patients who returned to oral intake maintained gains in swallowing function, and two patients returned to nonoral nutrition as the result of a new unrelated medical condition.