Michael Drinnan

Assessing penetration and aspiration : how do videofluoroscopy and fiberoptic endoscopic evaluation of swallowing compare?

Objectives/Hypothesis: We aimed to investigate whether the type of dysphagia examination (fiberoptic endoscopic evaluation of swallowing [FEES] or videofluoroscopy) influences the scoring of penetration and aspiration.

Relation between heart rate and pulse transit time during paced respiration.

Pulse transit time (PTT) is a simple, non-invasive measurement, defined as the time taken from a reference time for the pulse pressure wave to travel to the periphery. PTT is influenced by heart rate, blood pressure changes and the compliance of the arteries, but few quantitative data are available describing the factors which influence PTT. The aim of this study was to investigate the relationship between the cardiac beat-to-beat interval (RR) and PTT, using paced respiration to generate changes in both variables. We analysed PTT and RR interval from 15 normal healthy subjects during paced breathing, and the cross-correlation function between PTT and RR was used to quantify their relationship. Over the 15 subjects, the maximum change in PTT ranged from 7 to 23 ms with a mean +/- standard deviation of 14 +/- 5 ms, and that in RR interval from 86 to 443 ms (241 +/- 102 ms). Examining changes over time, the best correlation (r = +0.69, p < 0.01) was obtained when PTT was advanced relative to RR, with a change in RR followed by a corresponding change in PTT 3.17 +/- 0.76 beats later. We conclude that there is a strong relationship between PTT changes and RR interval changes, but these changes are not in phase.

Reliability and validity of cervical auscultation: a controlled comparison using videofluoroscopy.

Cervical auscultation is experiencing a renaissance as an adjunct to the clinical swallowing assessment. It is a controversial technique with a small evidence base. We have aimed to establish whether cervical auscultation interpretation is based on the actual sounds heard or, in practice, influenced by information gleaned from other aspects of the clinical assessment, medical notes, or previous knowledge. We sought to determine (a) rater reliability and its impact on the clinical value of cervical auscultation and (b) how judgments compare with the “gold standard”: videofluoroscopy. Swallow sounds were computer recorded via a Littmann stethoscope. Sounds were sampled from 10 healthy control swallows with no aspiration/penetration and 10 patient swallows with aspiration/penetration, all recorded during simultaneous videofluoroscopy. The system generated sound quality similar to “live” bedside listening, a feature rarely seen in cervical auscultation studies. The 20 sound clips were classified as “normal” or “abnormal” by 19 volunteer speech–language pathologists with experience in cervical auscultation. After at least four weeks, 11 of these judges rated the sounds rerandomized on a new CD. Intrarater reliability kappa ranged from −0.12 to 0.71. Individual reliability did not correlate with years of experience, practice pattern, or frequency of use. Interrater reliability kappa = 0.17. Comparison with radiologically defined aspiration/penetration yielded 66% specificity, 62% sensitivity, and majority consensus gave 90% specificity, 80% sensitivity. There was a significant relationship between individual reliability and true positive rate (rs = 0.623, p = 0.040). The reliability of individual judges varied widely and thus, inevitably, agreement between judges was poor. Validity is dependent upon reliability: Improving the poor raters would improve the overall accuracy of this technique in predicting abnormality in swallowing. The group consensus correctly identified 17 of the 20 clips so we may speculate that the swallow sound contains audible cues that should in principle permit reliable classification.

Fibreoptic endoscopic evaluation of swallowing and videofluoroscopy: does examination type influence perception of pharyngeal residue severity?

Objectives:  The aim of the study was to investigate whether the type of instrumental swallowing examination (Fibreoptic Endoscopic Evaluation of Swallowing (FEES) or videofluoroscopy) influences perception of post‐swallow pharyngeal residue.

NONINVASIVE MEASUREMENT OF BLADDER PRESSURE BY CONTROLLED INFLATION OF A PENILE CUFF

PURPOSE A noninvasive test providing reliable objective quantification of bladder pressure during the voiding cycle would make an important contribution to the management of lower urinary tract symptoms. We developed a new noninvasive test to measure bladder pressure in males based on controlled inflation of a penile cuff during voiding. We compared the new technique with simultaneous invasive bladder pressure measurement. MATERIALS AND METHODS We evaluated 7 volunteers and 32 patients. A conventional pressure flow study was performed first. The bladder was refilled, a penile cuff was fitted and after voiding commenced the cuff was inflated in steps of 10 cm. water every 0.75 seconds until urine flow was interrupted. The cuff was rapidly deflated, allowing flow to resume, and the cycle was repeated until the end of voiding. The flow rate was graphed against cuff pressure for each interruption cycle to determine the pressure at which flow was interrupted. This pressure was compared with simultaneous invasive isovolumetric bladder pressure. RESULTS Invasive and noninvasive pressure measurements agreed well. Average cuff pressure at interruption of flow exceeded mean simultaneous isovolumetric bladder pressure plus or minus standard deviation by 14.5 +/- 14.0 cm. water. CONCLUSIONS The new method provides noninvasive quantitative information on voiding bladder pressure in males. Further study is required to assess whether the technique can contribute to the management of lower urinary tract symptoms.

International continence society guidelines on urodynamic equipment performance

These guidelines provide benchmarks for the performance of urodynamic equipment, and have been developed by the International Continence Society to assist purchasing decisions, design requirements, and performance checks. The guidelines suggest ranges of specification for uroflowmetry, volume, pressure, and EMG measurement, along with recommendations for user interfaces and performance tests. Factors affecting measurement relating to the different technologies used are also described. Summary tables of essential and desirable features are included for ease of reference. It is emphasized that these guidelines can only contribute to good urodynamics if equipment is used properly, in accordance with good practice. Neurourol. Urodynam. 33:370–379, 2014.

Cervical Auscultation Synchronized with Images from Endoscopy Swallow Evaluations

Cervical auscultation is the use of a listening device, typically a stethoscope in clinical practice, to assess swallow sounds and by some definitions airway sounds. Judgments are then made on the normality or degree of impairment of the sounds. Listeners interpret the sounds and suggest what might be happening with the swallow or causing impairment. A major criticism of cervical auscultation is that there is no evidence on what causes the sounds or whether the sounds correspond to physiologically important, health-threatening events. We sought to determine in healthy volunteers (1) if a definitive set of swallow sounds could be identified, (2) the order in which swallow sounds and physiologic events occur, and (3) if swallow sounds could be matched to the observed physiologic events. Swallow sounds were computer recorded via a Littmann stethoscope from 19 healthy volunteers (8 males, 11 females, age range = 18–73 years) during simultaneous fiberoptic laryngoscopy and respiration monitoring. Six sound components could be distinguished but none of these occurred in all swallows. There was a wide spread and a large degree of overlap of the timings of swallow sounds and physiologic events. No individual sound component was consistently associated with a physiologic event, which is a clinically significant finding. Comparisons of groups of sounds and events suggest associations between the preclick and the onset of apnea; the preclick and the start of epiglottic excursion; the click and the epiglottis returning to rest; the click and the end of the swallow apnea. There is no evidence of a causal link. The absence of a swallow sound in itself is not a definite sign of pathologic swallowing, but a repeated abnormal pattern may indicate impairment. At present there is no robust evidence that cervical auscultation of swallow sounds should be adopted in routine clinical practice. There are no data to support the inclusion of the technique into clinical guidelines or management protocols. More evaluation using imaging methods such as videofluoroscopy is required before this subjective technique is validated for clinical use by those assessing swallowing outside of a research context.

Detection of sleep apnoea from frequency analysis of heart rate variability

Sleep apnoea is a clinical condition associated with a number of serious clinical and other problems. Patients who suffer from sleep apnoea have recurrent nocturnal apnoeas. The aim of this study was to assess the ability of an automated computer algorithm to detect sleep apnoea from the characteristic pattern of its recurrence, using RR interval data. Data from 35 training and 35 test subjects supplied by PhysioNet were analysed. To produce an algorithm which did not require highly accurate QRS detection, the QRS information supplied by PhysioNet were used without checking for artifactual data. Each subjects data were converted to a sequence of beat intervals, which was then analysed by Fourier transform. The study period varied from less than 7 hours to more than 10 hours. Patients with sleep apnoea tended to have a spectral peak lying between 0.01 and 0.05 cycles/beat, with the width of the peak indicating variability in the recurrence rate of the apnoea. In most subjects the frequency spectrum immediately below that containing the apnoea peak was relatively flat. The first visual analysis of the single computed spectrum from each subject led to a correct classification score of 28/30 (93%). The ratio of the content of the two spectral regions was obtained by dividing the area under the spectral curve between 0.01 and 0.05 cycles/beat by the area between 0.005 and 0.01 cycles/beat, and then a fixed threshold (3.15) was used to classify, the subjects automatically. The automated score for the training set was 27/30 (90%), 17/20 Apnoea (A), 10/10 Normal (C). The automated score for the test set was also 27/30 (90%).

Vascularized tissue to reduce fistula following salvage total laryngectomy: a systematic review.

Pharyngocutaneous fistulae (PCF) are known to occur in nearly one‐third of patients after salvage total laryngectomy (STL). PCF has severe impact on duration of admission and costs and quality of life and can even cause severe complications such as bleeding, infection and death. Many patients need further surgical procedures. The implications for functional outcome and survival are less clear. Several studies have shown that using vascularized tissue from outside the radiation field reduces the risk of PCFs following STL. This review and meta‐analysis aims to identify the evidence base to support this hypothesis.

Exploring the relationship between severity of dysphonia and voice-related quality of life

Objectives:  To explore whether severity and/or consistency of dysphonia are linked to voice‐related quality of life.