***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Abstract . Objective : Pulse oximetry ( SpO2 ) is a st and ard monitoring device in intensive care units ( ICUs ) , currently used to guide therapeutic interventions . Few studies have evaluated the accuracy of SpO2 in critically ill patients . Our objective was to compare pulse oximetry with arterial oxygen saturation ( SaO2 ) in such patients , and to examine the effect of several factors on this relationship . Design : Observational prospect i ve study . Setting : A 26-bed medical ICU in a university hospital . Patients : One hundred two consecutive patients admitted to the ICU in whom one or serial arterial blood gas analyses ( ABGs ) were performed and a reliable pulse oximeter signal was present . Interventions : For each ABG , we collected  SaO2 , SpO2 , the type of pulse oximeter , the mode of ventilation and requirement for vasoactive drugs .  Measurements and results : Three hundred twenty-three data points were collected . The mean difference between SpO2 and SaO2 was –0.02 % and st and ard deviation of the differences was 2.1 % . From one sample to another , the fluctuations in SpO2 to arterial saturation difference indicated that SaO2 could not be reliably predicted from SpO2 after a single ABG . Subgroup analysis showed that the accuracy of SpO2 appeared to be influenced by the type of oximeter , the presence of hypoxemia and the requirement for vasoactive drugs . Finally , high SpO2 thresholds were necessary to detect significant hypoxemia with good sensitivity . Conclusion : Large SpO2 to SaO2 differences may occur in critically ill patients with poor reproducibility of SpO2 . A SpO2 above 94 % appears necessary to ensure a SaO2 of 90 % Bolus manipulation is a primary treatment strategy in the management of oral-pharyngeal dysphagia . The use of thickening agents to alter bolus rheology is particularly commonplace ; however , the precise effects of these alterations on swallowing remain uncertain . The purpose of our study , a prospect i ve , double-blind clinical trial ( Level 1b ) , was to investigate the effects of viscosity on aspiration .  One hundred patients with dysphagia were prospect ively evaluated with fluoroscopic swallow studies performed across three st and ardized and r and omized conditions : thin liquid barium ( THIN ) , liquid barium thickened with a starch-based agent ( STARCH ) , and liquid barium thickened with a gum-based agent ( GUM ) . Outcome measures included the prevalence of aspiration and score on the Penetration-Aspiration Scale . A total of 23 out of 100 patients exhibited 56 episodes of aspiration . Twenty patients aspirated on THIN , 15 on STARCH , and 11 on GUM bolus conditions ( P<0.05 , thin vs gum ) . There were 28 instances of aspiration on THIN , 16 on STARCH , and 12 on GUM . Mean Penetration-Aspiration Scale score ± st and ard deviation was 2.11 ± 2.22 for THIN , 1.76 ± 1.88 for STARCH , and 1.42 ± 1.47 for GUM conditions , respectively ( P<0.001 , THIN vs GUM ) . A clinical ly significant reduction in the incidence of penetration and aspiration was observed for gum-thickened barium compared with thin liquid barium BACKGROUND AND PURPOSE The aim of the present study was to examine the value of pulse oximetry in the diagnosis of aspiration by comparing it with the gold st and ard , videofluoroscopy , by use of a prospect i ve , controlled , single-blind study design . METHODS Pulse oximetry was performed simultaneously with videofluoroscopy in 54 consecutive dysphagic stroke patients .  Oxygen saturation measurements were taken before the video-fluoroscopic examination ( baseline ) , on swallowing and continuously for 2 minutes after swallowing , and 10 minutes later . RESULTS Pulse oximetry reliably predicted aspiration or lack of it in 81.5 % of cases . The predictive value of the test was low in patients aged > or = 65 years and possibly those with chronic lung disease . One smoker also had a false-negative pulse oximetry result , ie , normal oxygen saturation despite radiological evidence of aspiration . CONCLUSIONS Pulse oximetry is a reliable method of diagnosis of aspiration in most dysphagic patients . However , careful interpretation of pulse oximetry data is necessary in older subjects , possibly those with chronic pulmonary disease , and smokers . The method is noninvasive , simple , and quick , and can be used routinely in the clinical assessment of dysphagic patients Increasing bolus viscosity of thin liquids is a basic therapeutic strategy to protect patients with oropharyngeal dysphagia ( OD ) from aspiration . However , conventional starch thickeners increase post‐deglutitive residue OBJECTIVE To examine the reliability of pulse oximetry for identifying aspiration by comparing it with the videofluoroscopic swallowing study ( VFSS ) . DESIGN Nonr and omized , prospect i ve , double-blind study . SETTING VFSS laboratory in a teaching hospital . PARTICIPANTS Sixty patients from among 130 patients with clinical ly 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 can not 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 
    Output:
    
The majority of studies failed to demonstrate an association between observed aspiration and oxygen desaturation .
Current evidence does not support the use of pulse oximetry to detect aspiration