| Title: | An Investigation into the Utility of Serum Bicarbonate as a predictor of Obstructive Sleep Apnoea in a Sleep Clinic Population. |
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| Author(s): | Campbell, C D.[1] Doherty, M [1] Baker, L [1] Finan, K [1] [1]Respiratory Department, Sligo University Hospital, Sligo. |
| Institution: | Sligo University Hospital |
| Poster: | Click to view poster |
| Category: | General Respiratory and Sleep |
| Abstract: | Obstructive Sleep Apnoea is characterised by partial or complete upper airway obstruction during sleep, leading to hypoxia and sleep fragmentation. It is a highly prevalent disorder, affecting an estimated 4% of adult males and 2% of adult females.Many screening questionnaires are available and in wide use. The utility of serum bicarbonate has also been proposed as an additional screening tool. We checked serum bicarbonate in all new patients referred for sleep studies in Sligo University Hospital. 22 individuals proceeded for sleep studies and were included in the final analysis. Average age ws 51.6years ( 28 - 73years), average BMI 35.6kg/m2 (28 - 44.3) and average Epworth Sleepiness Score was 9. Limited sleep study results showed 3 patients had a normal study, 5 had mild, 4 moderate and 10 severe obstructive sleep apnoea syndrome. Using a cut off of 28 mmmol/L to determine a high serum bicarbonate, a serum bicarbonate had a positive predictive value of 92.9% for any grade of obstructive sleep apnoea, negative predictive value of 38%, sensitivity of 73% and specificity of 75%. Serum bicarbonate above 28mmol/L has a high positive predictive value for obstructive sleep apnea syndrome in a sleep clinic population, but lower sensitivity and specificity. Its use could be combined with pre-existing screening tools to triage patients awaiting sleep studies.Obstructive Sleep Apnoea is characterised by partial or complete upper airway obstruction during sleep, leading to hypoxia and sleep fragmentation. It is a highly prevalent disorder, affecting an estimated 4% of adult males and 2% of adult females.Many screening questionnaires are available and in wide use. The utility of serum bicarbonate has also been proposed as an additional screening tool. We checked serum bicarbonate in all new patients referred for sleep studies in Sligo University Hospital. 22 individuals proceeded for sleep studies and were included in the final analysis. Average age ws 51.6years ( 28 - 73years), average BMI 35.6kg/m2 (28 - 44.3) and average Epworth Sleepiness Score was 9. Limited sleep study results showed 3 patients had a normal study, 5 had mild, 4 moderate and 10 severe obstructive sleep apnoea syndrome. Using a cut off of 28 mmmol/L to determine a high serum bicarbonate, a serum bicarbonate had a positive predictive value of 92.9% for any grade of obstructive sleep apnoea, negative predictive value of 38%, sensitivity of 73% and specificity of 75%. Serum bicarbonate above 28mmol/L has a high positive predictive value for obstructive sleep apnea syndrome in a sleep clinic population, but lower sensitivity and specificity. Its use could be combined with pre-existing screening tools to triage patients awaiting sleep studies.Obstructive Sleep Apnoea is characterised by partial or complete upper airway obstruction during sleep, leading to hypoxia and sleep fragmentation. It is a highly prevalent disorder, affecting an estimated 4% of adult males and 2% of adult females.Many screening questionnaires are available and in wide use. The utility of serum bicarbonate has also been proposed as an additional screening tool. We checked serum bicarbonate in all new patients referred for sleep studies in Sligo University Hospital. 22 individuals proceeded for sleep studies and were included in the final analysis. Average age ws 51.6years ( 28 - 73years), average BMI 35.6kg/m2 (28 - 44.3) and average Epworth Sleepiness Score was 9. Limited sleep study results showed 3 patients had a normal study, 5 had mild, 4 moderate and 10 severe obstructive sleep apnoea syndrome. Using a cut off of 28 mmmol/L to determine a high serum bicarbonate, a serum bicarbonate had a positive predictive value of 92.9% for any grade of obstructive sleep apnoea, negative predictive value of 38%, sensitivity of 73% and specificity of 75%. Serum bicarbonate above 28mmol/L has a high positive predictive value for obstructive sleep apnea syndrome in a sleep clinic population, but lower sensitivity and specificity. Its use could be combined with pre-existing screening tools to triage patients awaiting sleep studies.Obstructive Sleep Apnoea is characterised by partial or complete upper airway obstruction during sleep, leading to hypoxia and sleep fragmentation. It is a highly prevalent disorder, affecting an estimated 4% of adult males and 2% of adult females.Many screening questionnaires are available and in wide use. The utility of serum bicarbonate has also been proposed as an additional screening tool. We checked serum bicarbonate in all new patients referred for sleep studies in Sligo University Hospital. 22 individuals proceeded for sleep studies and were included in the final analysis. Average age ws 51.6years ( 28 - 73years), average BMI 35.6kg/m2 (28 - 44.3) and average Epworth Sleepiness Score was 9. Limited sleep study results showed 3 patients had a normal study, 5 had mild, 4 moderate and 10 severe obstructive sleep apnoea syndrome. Using a cut off of 28 mmmol/L to determine a high serum bicarbonate, a serum bicarbonate had a positive predictive value of 92.9% for any grade of obstructive sleep apnoea, negative predictive value of 38%, sensitivity of 73% and specificity of 75%. Serum bicarbonate above 28mmol/L has a high positive predictive value for obstructive sleep apnea syndrome in a sleep clinic population, but lower sensitivity and specificity. Its use could be combined with pre-existing screening tools to triage patients awaiting sleep studies. |
