Hypoxemia during oral feedings in adults with dysphagia and severe neurological disabilities

Comparative analysis of videofluoroscopy and pulse oximetry for aspiration identification in patients with dysphagia after stroke and non-dysphagics

PURPOSE

Dysphagia is a prevalent symptom observed in acute stroke. Several bedside screening tests are employed for the early detection of dysphagia. Pulse oximetry emerges as a practical and supportive method to augment the existing techniques utilized during bedside swallowing assessments. Desaturation levels, as measured by pulse oximetry, are acknowledged as indicative of aspiration by certain screening tests. However, the predictive capability of pulse oximetry in determining aspiration remains a subject of controversy. The objective of this study was to compare aspiration and oxygen desaturation levels by time and aspiration severity in dysphagic patients compared to healthy controls. It also aimed to evaluate the accuracy of pulse oximetry by comparing it with VFSS findings in detecting aspiration in both liquid (IDDSI-0) and semi-solid (IDDSI-4) consistencies.

MATERIALS AND METHODS

Eighty subjects (40 healthy and 40 acute stroke patients) participated. Patients suspected of dysphagia underwent videofluoroscopy as part of the stroke unit's routine procedure. Baseline SpO2 was measured before VFSS, and stabilized values were recorded. Sequential IDDSI-0 and IDDSI-4 barium tests were conducted with 5 ml boluses. Stabilized SPO2 values were recorded during swallowing and 3-min post-feeding. Patients with non-dysphagia received equal bolus monitoring. Changes in SPO2 during, before, and after swallowing were analyzed for each consistency in both groups.

RESULTS

The study revealed a statistically significant difference in SPO2 between patients with dysphagia and controls for IDDSI-4 and IDSSI-0. In IDDSI-4, 20% of patients experienced SpO2 decrease compared to 2.5% in control group (p = 0.013). For IDDSI-0, 35% of patients showed SpO2 decrease, while none in the control group did (p = 0.0001). Aspiration rates were 2.5% in IDDSI-4 and 57.5% in IDDSI-0. In IDDSI-0, SpO2 decrease significantly correlated with aspiration (p = 0.0001). In IDDSI-4, 20.5% had SpO2 decrease without aspiration, and showing no significant difference (p = 0.613). Penetration-Aspiration Scale scores had no significant association with SpO2 decrease (p = 0.602). Pulse oximetry in IDDSI-4 had limited sensitivity (0%) and positive predictive value, (0%) while in IDDSI-0, it demonstrated acceptable sensitivity (60.9%) and specificity (100%) with good discrimination capability (AUC = 0.83).

CONCLUSIONS

A decrease in SPO2 may indicate potential aspiration but is insufficient alone for detection. This study proposes pulse oximetry as a valuable complementary tool in assessing dysphagia but emphasizes that aspiration cannot be reliably predicted based solely on SpO2 decrease.

An Investigation of Pulse Oximetry Levels during Swallowing in Healthy Adults and in Individuals with Severe and Very Severe Chronic Obstructive Pulmonary Disease

To compare pulse oximetry (PO) levels during swallowing in healthy adults and adults with severe chronic obstructive pulmonary disease (COPD). Participants included two groups of 60 healthy adults, balanced for gender. The young group ranged from 18 to 38 years, and the older group from 60 to 87 years. In addition, there were 11 participants with COPD aged 43 to 82 years. PO levels were collected as each participant swallowed 10 mL of water, 10 mL of applesauce, and a piece of diced pear (three trials each). Analyses for the healthy groups revealed neither statistically significant main effects for bolus type nor interactions between gender and age. For between-subject effects, there was no main effect for gender, but there was a large main effect for age, and a gender and age interaction. In the group with COPD, there were no significant differences across bolus types; however, PO measures were consistently lower than the healthy groups for all bolus types. Healthy adults exhibited stable PO levels across bolus types. Adults with COPD, although exhibiting significantly lower PO levels, also remained stable. For clinicians who monitor PO measures, these results offer a more comprehensive understanding of the nature of these measures during swallowing in these groups.

Development of a Dysphagia Screening Test for Preterm Infants (DST-PI)

OBJECTIVE

To explore both the early prediction and diagnosis of dysphagia in preterm infants as an important developmental aspect as well as the prevention of respiratory complications, we developed the simple and-easy-to-apply Dysphagia Screening Test for Preterm Infants (DST-PI) to predict supraglottic penetration and subglottic aspiration.

METHODS

Fifty-two infants were enrolled in a videofluoroscopic swallowing study (VFSS) due to clinical suspicions of dysphagia. Thirteen items related to supraglottic penetration or subglottic aspiration were initially selected from previous studies for the DST-PI. Finally, 7 items were determined by linear logistic regression analysis. Cutoff values, sensitivity, specificity, and the area under the ROC curve (AUC) of the DST-PI for predicting supraglottic penetration or subglottic aspiration were calculated using a ROC curve. For inter-rater reliability, the kappa coefficient was calculated.

RESULTS

Seven items were selected: 'gestational age,' 'history of apnea,' 'history of cyanosis during feeding,' 'swallowing pattern,' 'coughs during or after feeding,' 'decreased oxygen saturation within 3 minutes of feeding,' and 'voice change after feeding.' The Spearman correlation coefficient between the DST-PI and the penetration-aspiration scale (PAS) was 0.807 (p<0.001). The sensitivity and specificity at different cutoff values for detecting supraglottic penetration and subglottic aspiration were 96.6% and 76.9% at 3.25, and 88.9% and 75.8% at 6.25, respectively.

CONCLUSION

The DST-PI is a valid and reliable dysphagia screening test for supraglottic penetration or subglottic aspiration in preterm infants that is easy to apply in a clinical context.

Measurement of Oxygen Desaturation Is Not Useful for the Detection of Aspiration in Dysphagic Stroke Patients

Background

Dysphagia is one of the most dangerous symptoms of acute stroke. Various screening tools have been suggested for the early detection of this condition. In spite of conflicting results, measurement of oxygen saturation (SpO₂) during clinical swallowing assessment is still recommended by different national guidelines as a screening tool with a decline in SpO₂ ≥2% usually being regarded as a marker of aspiration. This paper assesses the sensitivity of SpO₂ measurements for the evaluation of aspiration risk in acute stroke patients.

Methods

Fifty acute stroke patients with moderate to severe dysphagia were included in this study. In all patients, fiberoptic endoscopic evaluation of swallowing (FEES) was performed according to a standardised protocol. Blinded to the results of FEES, SpO₂ was monitored simultaneously. The degree of desaturation during/after swallows with aspiration was compared to the degree of desaturation during/after swallows without aspiration in a swallow-to-swallow analysis of each patient. To minimise potential confounders, every patient served as their control.

Results

In each subject, a swallow with and a swallow without aspiration were analysed. Overall, aspiration seen in FEES was related to a minor decline in SpO₂ (mean SpO₂ without aspiration 95.54 ± 2.7% vs. mean SpO₂ with aspiration 95.28 ± 2.7%). However, a significant desaturation ≥2% occurred only in 5 patients during/after aspiration. There was no correlation between aspiration/dysphagia severity or the amount of aspirated material and SpO₂ levels.

Conclusions

According to this study, measurement of oxygen desaturation is not a suitable screening tool for the detection of aspiration in stroke patients.

Cervical auscultation in the diagnosis of oropharyngeal aspiration in children: a study protocol for a randomised controlled trial

Background

Oropharyngeal aspiration (OPA) can lead to recurrent respiratory illnesses and chronic lung disease in children. Current clinical feeding evaluations performed by speech pathologists have poor reliability in detecting OPA when compared to radiological procedures such as the modified barium swallow (MBS). Improved ability to diagnose OPA accurately via clinical evaluation potentially reduces reliance on expensive, less readily available radiological procedures. Our study investigates the utility of adding cervical auscultation (CA), a technique of listening to swallowing sounds, in improving the diagnostic accuracy of a clinical evaluation for the detection of OPA.

Methods

We plan an open, unblinded, randomised controlled trial at a paediatric tertiary teaching hospital. Two hundred and sixteen children fulfilling the inclusion criteria will be randomised to one of the two clinical assessment techniques for the clinical detection of OPA: (1) clinical feeding evaluation only (CFE) group or (2) clinical feeding evaluation with cervical auscultation (CFE + CA) group. All children will then undergo an MBS to determine radiologically assessed OPA. The primary outcome is the presence or absence of OPA, as determined on MBS using the Penetration-Aspiration Scale. Our main objective is to determine the sensitivity, specificity, negative and positive predictive values of ‘CFE + CA’ versus ‘CFE’ only compared to MBS-identified OPA.

Discussion

Early detection and appropriate management of OPA is important to prevent chronic pulmonary disease and poor growth in children. As the reliability of CFE to detect OPA is low, a technique that can improve the diagnostic accuracy of the CFE will help minimise consequences to the paediatric respiratory system. Cervical auscultation is a technique that has previously been documented as a clinical adjunct to the CFE; however, no published RCTs addressing the reliability of this technique in children exist. Our study will be the first to establish the utility of CA in assessing and diagnosing OPA risk in young children.

Trial registration

Australia and New Zealand Clinical Trials Register (ANZCTR) number ACTRN12613000589785.

The use of pulse oximetry as a screening assessment for paediatric neurogenic dysphagia

PURPOSE

Early screening and intervention for dysphagia is crucial to offset potential outcomes such as compromised nutrition or reduced respiratory function. Current paediatric dysphagia screening tests are subjective with poor sensitivity and specificity. The present study examined whether an objective method, pulse oximetry (measuring oxygen saturation (SpO2) levels), could differentiate between children with and without dysphagia, in relation to (1) Average pre-feeding baseline SpO2 levels; (2) Average feeding SpO2 levels; (3) Average post-feeding SpO2 levels; and (4) The number of events of oxygen desaturation pre-, during and after feeding.

METHODS

Nine participants with chronic neurological disability (CND) (7 F, 2 M) (9; 7-15; 11 years) and nine control participants matched for age (9; 5-16; 0 years) and sex were assessed using a clinical bedside evaluation (CBE) and pulse oximetry.

RESULTS

A statistically significant difference was found in SpO2 levels between the two groups (p < 0.001) during oral feeding only (sensitivity, 88.9%; specificity, 88.9%). Only three children with dysphagia experienced 'events' of SpO2 desaturation during feeding.

CONCLUSION

Pulse oximetry may provide a useful adjunct to the CBE for dysphagia screening, with average SpO2 levels during feeding predicting those with and without dysphagia with moderate levels of sensitivity and specificity. The finding of individual variation in desaturation 'events', however, warrants the provision of further data on large homogenous populations to provide definitive criterion for pathological SpO2 levels associated with dysphagia during oral feeding.

Can pulse oximetry or a bedside swallowing assessment be used to detect aspiration after stroke?

BACKGROUND AND PURPOSE

Desaturation during swallowing may help to identify aspiration in stroke patients. This study investigated pulse oximetry, bedside swallowing assessment (BSA), and videofluoroscopy as tests for detecting aspiration after stroke.

METHODS

Swallowing was assessed in 189 stroke patients (mean+/-SD age, 70.9+/-12.3 years) within 5 days of symptom onset with a modified BSA (water replaced by radio-opaque contrast agent, followed by chest radiography to detect aspiration). Simultaneous pulse oximetry recorded the greatest desaturation from baseline for 10 minutes from modified BSA onset. Videofluoroscopy was undertaken in 54 (28%) patients.

RESULTS

Modified BSA showed a safe swallow in 98 (51.9%), unsafe swallow in 85 (45.0%), and silent aspiration in 6 (3.2%) patients. During swallowing, desaturation by >2% occurred in 27 (27.6%) and by >5% in 3 (3.1%) of the 98 safe-swallow patients on modified BSA. Of the 85 unsafe-swallow patients, only 28 (32.9%) desaturated by >2% and 6 (7.1%) by >5%. Desaturation did not occur in any of the 6 silent aspirators. With the modified BSA to detect aspiration, sensitivity and specificity, respectively, were 0.31 and 0.72 for desaturation >2% and 0.07 and 0.97 for desaturation >5%. By videofluoroscopy, sensitivity and specificity for detecting aspiration were 0.47 and 0.72 for modified BSA, 0.33 and 0.62 for desaturation >2%, and 0.13 and 0.95 for desaturation >5%. Combining a failed modified BSA with desaturation >2% or >5% did not significantly improve predictive values.

CONCLUSIONS

Modified BSA and pulse oximetry during swallowing, whether alone or in combination, showed inadequate sensitivity, specificity, and predictive values for detection of aspiration compared with videofluoroscopy in stroke patients.

Pulse oximetry does not reliably detect aspiration on videofluoroscopic swallowing study

OBJECTIVE

To examine the reliability of pulse oximetry for identifying aspiration by comparing it with the videofluoroscopic swallowing study (VFSS).

DESIGN

Nonrandomized, prospective, double-blind study.

SETTING

VFSS laboratory in a teaching hospital.

PARTICIPANTS

Sixty patients from among 130 patients with clinically diagnosed dysphagia between September and December 2002.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Simultaneously monitoring the arterial oxygen saturation (Sp o 2 ) by pulse oximetry while patients were performing VFSS. A decrease in Sp o 2 exceeding 3% was considered as significant desaturation. Bolus or portion of bolus passing through the vocal cords and entering the subglottic space was defined as aspiration on VFSS. The results of pulse oximetry and VFSS were compared.

RESULTS

No significant correlation existed between desaturation measured by pulse oximetry and aspiration on VFSS (chi 2 test, P =.87). The positive predictive rate of pulse oximetry in detecting aspiration on VFSS was 39.1%, and the negative predictive rate was 59.4%.

CONCLUSIONS

Aspiration occurring on VFSS cannot be predicted based on decrease in Sp o 2 in pulse oximetry. The application of pulse oximetry to detect aspiration during regular meals requires further investigation.

Recognition and management of respiratory dysfunction in children with tetraplegia

Children less than 15 years of age comprise approximately 3% to 5% of all new spinal injuries each year. Approximately one third of these children sustain injuries to the cervical spine. Respiratory complications of spinal cord injuries at the level of C5 and above may include diaphragm dysfunction, retained airway secretions, recurrent aspiration, nocturnal hypoventilation, and respiratory failure. Although most newly injured children with cervical injuries above the level of C5 will require mechanical ventilation acutely, many eventually will be able to be weaned from technology. Despite their ability to breathe without mechanical support, these children often develop ongoing issues associated with respiratory compromise, which interfere with daily activities and can negatively affect quality of life. Poor endurance, failure to thrive, recurrent pneumonia, and sleep-disordered breathing all may be indications of significant respiratory dysfunction. This article describes assessment tools and management strategies aimed at supporting optimal health and preventing recurrent complications associated with unrecognized or untreated respiratory dysfunction.

Physiological effects of meals in difficult-to-wean tracheostomised patients with chronic obstructive pulmonary disease

OBJECTIVES

To evaluate effects of meals in difficult-to-wean tracheostomised patients with chronic obstructive pulmonary diseases during spontaneous breathing or Inspiratory Pressure Support.

DESIGN

Prospective, crossover, randomised, and physiological study.

SETTING

Weaning centre.

PATIENTS

Sixteen COPD undergoing either decreasing levels of pressure support or increasing periods of spontaneous breathing.

MEASUREMENTS

Each patient underwent monitoring during a 30-min procedure, during and after meals either under pressure support or spontaneous breathing on two consecutive days. Inductance plethysmography was used to monitor respiratory rate and tidal volume. Tidal volume by a flow transducer, arterial oxygen saturation, pulse rate, end-tidal CO2(,) and dyspnoea by a visual analogue scale were also assessed.

RESULTS

ANOVA analysis showed a significant increase under spontaneous breathing for respiratory rate (P<0.001) and for end tidal CO(2) (P<0.03) induced by the meals. Inspiratory pressure support was associated to significantly greater tidal volume (P<0.001), lower respiratory rate (P<0.032), lower respiratory rate/tidal volume (P<0.001), and lower pulse rate (P<0.047) than spontaneous breathing. Under spontaneous breathing but not under pressure support a statistically worsening in meal-induced dispnoea (P<0.001) was found.

CONCLUSIONS

In tracheostomised difficult-to-wean COPD patients: 1) under unassisted breathing, meals may induce an increase in respiratory rate, end-tidal CO(2), and dyspnoea; 2) inspiratory pressure support ventilation prevents dyspnoea from worsening during meals.

Early assessments of dysphagia and aspiration risk in acute stroke patients

BACKGROUND AND PURPOSE

Dysphagia is common after stroke and is a marker of poor prognosis. Early identification is important. This article reviews the merits and limitations of various assessment methods available to clinicians.

METHODS

An electronic database search was performed of MEDLINE, EMBASE, and the Cochrane database using such terms as stroke, aspiration, dysphagia, and assessment; extensive manual searching of articles was also conducted.

RESULTS

Bedside tests are safe, relatively straightforward, and easily repeated but have variable sensitivity (42% to 92%), specificity (59% to 91%), and interrater reliability (kappa=0 to 1.0). They are also poor at detecting silent aspiration. Videofluoroscopy gives anatomic and functional information and allows testing of therapeutic techniques. However, swallowing is assessed under ideal conditions that are different from clinical settings, and reliability is often poor (kappa=0 to 0.75) in the absence of assessor training. Fiberoptic endoscopy allows swallow assessment and sensory testing but requires specialized staff and equipment. Oxygen desaturation during swallowing may be predictive of aspiration (sensitivity, 73% to 87%; specificity, 39% to 87%) but is more useful in combination with bedside testing than in isolation. Other methods of swallow testing are invasive and require specialized staff and equipment.

CONCLUSIONS

Although bedside tests remain an important early screening tool for dysphagia and aspiration risk, further refinements are needed to improve their accuracy.

Does feeding alter arterial oxygen saturation in patients with acute stroke?

BACKGROUND AND PURPOSE

We measured arterial oxygen saturation (SaO(2)) during eating in acute stroke patients to establish the frequency of any meal-related hypoxemia, which could further damage already vulnerable brain tissue.

METHODS

Stroke patients (</=12 days from stroke onset) classified as "safe to feed orally" were compared with elderly hospitalized (for nonneurological causes) and young healthy controls. SaO(2) was measured noninvasively at the bedside by pulse oximetry continuously for 10 minutes before the patient ate a meal, during the meal, and for 10 minutes after completion of the meal.

RESULTS

The median baseline SaO(2) was significantly lower in stroke patients (n=106, 95.7%) than elderly (n=50, 96.7%) or young control subjects (n=20, 97.9%; P:<0.001). There was a small decrease in the median SaO(2) during eating in stroke and elderly patients (95.6%, P:=0.08, and 96.3%, P:=0.004, respectively) but not in young controls. Only stroke patients had a significantly lower median SaO(2) after completion of the meal (95. 4%, P:<0.001). SaO(2) of </=90% during and after eating occurred in 24% of stroke and 16% of elderly patients but not in young controls, and it was significantly more common in those who had SaO(2) of </=90% during the baseline recordings (P:</=0.003).

CONCLUSIONS

Eating a meal was associated with a small fall in median SaO(2) among stroke and elderly patients, but only in stroke patients did this persist for at least 10 minutes after eating. A quarter of stroke patients had episodes in which the SaO(2) fell to </=90% saturation (ie, hypoxemia) during or after eating, although this rarely coincided exactly with swallowing and was more common in patients who also experienced desaturation during the baseline recordings. Further studies are required to establish whether these changes are clinically important.

Silent aspiration prominent in children with dysphagia

Children with neurologically-based dysphagia are at high risk for silent aspiration. Aspiration can lead to complications such as acute pneumonia and chronic lung disease. Thorough evaluation of the oral, pharyngeal, and esophageal phases of swallowing is crucial for patients with dysphagia. The videofluoroscopic modified barium swallow study (MBS) is the procedure of choice for children to delineate the pharyngeal and upper esophageal phases of the swallow that can only be inferred by bedside clinical assessment. This study describes attributes of aspiration and pharyngeal motility in a large sample of infants and children assessed with MBS. Aspiration was observed in 48 (26%) of 186 children, primarily on liquid before or during swallows. Aspiration was trace (less than 10% of a bolus) and silent in 94%. Relationships to clinical history and implications for management are discussed. Given the lack of objective clinical information to identify children at risk for aspiration, MBS should be considered in all children with severe dysphagia to rule out or confirm aspiration.