Comparison of liquid and semisolid consistency in the evaluation of dysphagia using cervical auscultation and pulse oximetry in post stroke individuals

Introduction

Dysphagia refers to swallowing difficulty and can be a symptom that is concomitant with other medical conditions that includes stroke, head and neck cancer, gastroesophageal reflux,

oesophageal disorders and or other systemic diseases. It is defined as difficulty in transporting saliva, liquid, or food from the oral cavity to the stomach (Tjaden, 2008). It is commonly seen

among the individuals who suffer from neurological disorder across all the age groups. (Calis et al., 2008; Martino et al., 2005). Dysphagia can manifest itself through symptoms like aspiration,

penetration, oral residue, regurgitation of liquids or solids ( Logemann, 1998) and can lead to life threatening conditions like malnutrition, dehydration, and aspiration pneumonia (Katzan, Cebul,

Husak , Dawson, & Baker, 2003). Hence a comprehensive evaluation would be essential in order to avoid the secondary complications associated with dysphagia.

The swallowing assessment is usually done using the bedside clinical swallowing evaluation reflecting only on oral phase of swallowing in most of the clinical set up. Beside the routine clinical

practice, instrumental examination is also used to assess other phases of swallowing in case of suspected dysphagia based alone with CSE. The VFSS and FEES are two widely used instrumental

methods till date (Madden, Fenton, Hughes, & Timon, 2000). Although these methods are widely used in the evaluation of dysphagia, they still persist with pros and cons. VFSS is an invasive

procedure with radiation exposure and cannot be performed on all, and aspiration being variable, it only reflects one time measure. FEES only allows for the inspection of velopharyngeal,

oropharyngeal, pharyngeal, and laryngeal functions, it does not permit any systematic evaluation of oral or esophageal components of swallowing. It is not widely available and requires skilled

personnel. (Madden et al., 2000).

During the acute period of stroke, decisions on weaning to oral feed must be based on reliable bedside evaluation. Literature over the past few years has been investigating the consistency and

strength of dysphagia screening and assessment tools. Cervical auscultation and pulse oximetry are two such tools which are being widely studied for dysphagia assessment and management.

They are being adopted in the routine clinical practice for detecting dysphagia. Cervical auscultation is used to assess the pharyngeal phase of swallowing by listening to the sounds of

swallowing and respiration during the process of swallowing. It is used to evaluate the coordination between swallowing and respiration, and to distinguish between pathological and a normal

swallow (Leslie, Drinnan, Finn, Ford, & Wilson, 2004). Recent studies also reflect on considering the pulse oximetry (PO) in identifying the signs and management of dysphagia (Rogers, Arvedson, Msall, & Demerath, 1993; Rogers, Msall, & Shucard, 1993; Zaidi et al., 1995). It is a means of providing accurate measurement of SpO2 which can ascertain variations in SpO2. Similar to cervical auscultation, the pulse oximetry is objective, noninvasive which provides constant readings that can be saved and further analysed. The

assessment and management of dysphagia seeks for a multidisciplinary approach and repeated assessments during rehabilitation (Gandolfi et al., 2014). This would be possible only if the tools

adopted are easily accessible, inexpensive, less time consuming, feasible and avoid discomfort to the individual.

Review of literature:

Literature over the past few years has been investigating the dependability and rationality of dysphagia assessment tools. Cervical auscultation and pulse oximetry are two such tools which are being widely studied for dysphagia assessment and management. They are being adopted in the routine clinical practice for detecting dysphagia. CA is developing as an area of interest for the study of dysphagia in adults, children, and infants. It is easy to use, inexpensive, and non-invasive (Greif & loughlin, 1996). The extent of its utility in evaluating the pharyngeal phase and aiding to diagnosis is a matter of debate in both research and clinical setting. Irrespective of its uncertainty, it is still considered as a useful tool in clinical evaluation, together with other methods for the speech language therapist in the assessment of dysphagia (Ferrucci, Mangilli, Sassi, Limongi, and Andrade, 2013). Zenner, Losinski, and Mills (1995) were the first ones to study cervical auscultation. They compared the reliability and validity of the cervical auscultation to that of videofluoroscopy in 50 male participants who were referred for suspected dysphagia. Overall, the study suggested that it is unclear how aspiration can be identified using cervical auscultation in the clinical swallowing assessment. Leslie et al. (2004) examined if SLPs experienced in cervical auscultation could identify aspiration by swallowing sounds alone. The results of the study evidenced that cervical auscultation can be considered as a reliable tool to identify aspiration to some extent. Santamato et al. (2009) analysed the swallowing sounds acoustically, using a microphone and computer, in healthy and individuals with dysphagia secondary to neurological diseases. The mean duration of the swallowing sounds and post swallowing apnoea were recorded. Penetration/aspiration was verified by FEES in all individuals with dysphagia. The mean duration of swallowing sounds for a liquid bolus of 10 ml water was significantly different between individuals with dysphagia and healthy participants.

Pulse oximetry provides instant information during bedside evaluation, which may be useful for recommendations regarding further investigation and feeding. The potential use of pulse oximetry as a tool for the assessment of dysphagia has been well documented. Sherman, Nisenboum, Jesberger, Morrow, and Jeberger (1999) assessed 46 participants using pulse oximetry and videofluoroscopy and found that participants who exhibited laryngeal penetration and/or aspiration without clearing (i.e. coughing) demonstrated significant drop in SpO2 level. Conversely, who penetrated and cleared or did not demonstrate penetration did not exhibit this decline. The authors suggested that with further investigation, it might be possible to identify threshold level to allow the use of pulse oximetry in routine assessment. Smith et al. (2000) compared pulse oximetry to bedside assessment and videofluoroscopy in a study of 53 patients following acute stroke. They found that combining the bedside assessment with pulse oximetry gave the best positive predictive value of 95% (with penetration +/- aspiration as end point).

Purpose:

The purpose ofthe trial is mainly to add objectivity in routine bedside swallowingevaluation. The detection of aspirationat bedside swallowing examination is complex without objective tools tending toeither over diagnose or under diagnose aspiration. The objective methods likeVideofluroscopy and FEES are invasive, expensive and time consuming, and maynot be easily performed on all individuals. Hence it is necessary to focus onincorporating simple, non-invasive evaluation methods that can be used alongwith bedside evaluation on a routine basis.

Clinical experiences have revealed abnormalfindings in SpO2 especially in brain stem stroke individuals. Despite theextensive research on SPO2 changes during swallowing and comparison of swallowacoustics across bolus consistencies, with mixed findings there has beenlimited focus on the same in the Indian context. Hence the present studyattempts to explore the feasibility of pulse oximetry with cervicalauscultation in routine bedside swallowing evaluation of post strokeindividuals.

Aim:

To compare the liquid and semisolid consistency in the evaluation of Dysphagia using cervical

auscultation and pulse oximetry in post stroke individuals.

Objectives:

To compare the swallowing across liquid and semisolid consistency using cervical

auscultation acoustically

To compare the oxygen saturation levels at baseline, during and post feed between

consistencies

Method:

This study would commence after obtaining the approvals from Institutional Research Committee (IRC) and Institutional Ethics Committee (IEC). Informed consent will be obtained from all the participants/family members.

Study setting: The study will be conducted in the premises of Kasturba Hospital, Manipal.

Proposed study design: A cross sectional research design

Sampling method: Convenience sampling will be used.

Participants: A total of N = 32 participants post stroke in the age range of 41-70 years will be enrolled in the study.

Inclusion criteria:

• Individuals with episode of stroke with GCS>8
• Individuals who are on enteral/parenteral feeding
• Level of Alertness – Must be able to respond to verbal stimuli
• Clearance from the treating Physician

Exclusion criteria:

• Unable to follow instructions (Aphasia/Cognitive problems/ Hearing loss/Other Associated conditions)
• Tracheostomy/ Ventilator/ GCS less than 8

Procedure:

All participants recruited will receive stroke specific evaluation by the neurologist and Dysphagia specific evaluation by the speech pathologist. The other findings (demographic, medical, associated problems and other significant history if any) will be documented using a proforma by the speech pathologist. A preliminary swallowing examination will be initiated using the routine clinical swallowing examination. Following, the feed trial will be initiated only if the participant is alert, conscious and able to follow commands. The participant will be made to sit in upright/ semi upright posture. The participant will be explained regarding the procedure. The feed trial will be initiated with water swallow test. The pulse oximeter will be clipped to the participant. The participant will be instructed to sip 5ml of water and will be asked to swallow it once the command is given. As the participant swallows, the SpO2 level will be monitored at baseline/ during/ and post feed. The cervical auscultation will be performed using the electronic stethoscope, placed on antero-lateral aspect of laryngeal region during the swallowing. The stethoscope will be connected to the software and the swallowing sound will be recorded. If the participant exhibits overt signs of aspiration (continuous episodes of cough, watery eyes), the procedure will be terminated. If the participants exhibits no difficulty (overt signs), the procedure will be repeated for semisolid consistency (5ml), only if the clearance of oral hygiene will be rated as fair or good on a 3 point rating scale within a duration of 30mins of the liquid feed trial. The cervical auscultation will be analysed for duration, amplitude, frequency and morphology of waveform. The participant will be monitored throughout for any overt or covert signs of aspiration.

Outcome measures:

Outcome measures for cervical auscultation includes duration, amplitude, frequency and wave morphology and pulse oximetry includes oxygen saturation levels before, during and post feed.

Benefits:The potential benefit will include preventing the participants from undergoing unnecessary, tiring,

expensive and cumbersome procedures to an extent, as the protocol will serve as a preliminary

indicator towards other investigations. It would also aid in facilitating from tube feed to oral feed

systematically.