[Dysphagia] Oximetry and aspiration - No relationship

[eripley at yahoo.com (Irene Campbell-Taylor)]

The most recent informationon this always controversial topic is:

 

 Wang TG; Chang YC; Chen SY; Hsiao TY Pulse oximetry does not reliably detect aspiration on videofluoroscopic swallowing study Arch Phys Med Rehabil 2005 ;86:730-4   

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

 

De Groof I; Dejaeger E; Goeleven A Is pulse oximetry a reliable tool for detection of aspiration Tijdschr Gerontol Geriatr 2004 Aug;35(4):153-6   

This study was designed to determine whether significant differences in saturation levels existed among patients with aspiration and patients without and wether pulse oximetry can reliably detect aspiration in patients with dysphagia. We also examined the effects of gender and disease (neurologic versus non neurologic) on saturation levels. We studied 38 patients. They all underwent a videofluoroscopic study of swallowing (VFSS). Twenty patients aspirated on videofluoroscopic study of swallowing: ten patients were solid aspirators, ten patients were liquid aspirators. In each group (liquid aspirators, solid aspirators or non aspirators) we found no significant difference in saturation levels. We found however a significant difference in saturation levels between each group before, during and after videofluoroscopic study of swallowing. Both gender and disease had an effect on saturation levels. We conclude that pulse oximetry can not serve as a screening tool for detection of
 aspiration as saturation levels are dependent on many factors. Therefore one can not reliably predict aspiration with a single saturation screening

 

Higo R; Tayama N; Watanabe T; Nito T Pulse oximetry monitoring for the evaluation of swallowing function Eur Arch Otorhinolaryngol 2003 Mar;260(3):124-7    

The aim of this study was to investigate the relationship between aspiration and oxygen desaturation and to assess the efficacy of using pulse oximetry monitoring as a clinical tool to predict or detect aspiration. The 204 subjects were divided into four groups: 63 control subjects, 110 dysphagics, 9 dysphagics with a cuffed tracheostomy tube and 22 laryngectomized subjects. Arterial oxygen saturation (SpO2) was continuously measured throughout fluorographic examination until an adequate post-examination period afterward. Then, fluorographic findings (aspiration) and SpO2 levels were compared. Eighty-five percent of aspirators showed SpO2 declines of 2% or more during swallowing procedures, but, conversely, aspiration could not be predicted or detected by an SpO2 decline because of low sensitivity and specificity (84.6% and 82.5%, respectively). SpO2 declines were also seen in laryngectomized subjects and non-aspirators with breath-holding. One patient with a cuffed tracheostomy tube
 showed a transient elevation of SpO2 following aspiration. In conclusion, aspirators show a SpO2 decline during swallowing procedures, but POM is not useful to predict or detect aspiration. Other events, such as breath-holding, posture change, coughing and compromised pulmonary functioning, may be related to oxygen desaturation.



Dr I Campbell-Taylor
Clinical Neuroscientist
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