Yield & accuracy of Gastric Lavage in non-expectorating adults with Suspected Pulmonary Tuberculosis

To determine the yield of Gastric lavage (GL) in non-expectorating adults with suspected Pulmonary Tuberculosis (PTB) and accuracy of GL-AFB smear with GL-GeneXpert (GXP) by taking AFB culture as gold standard.

Cross-sectional study on suspected PTB patients was done at Ojha Institute of Chest Diseases during period 16^th July 2020 till 15^th January 2021. Adult patients of either gender suspected to have PTB and not expectorating were included. GL was performed and sent for AFB smear, GXP and AFB culture. Odds ratio, sensitivity and specificity were calculated.

After informed written consent, 206 patients, mean age was 38.17 ±17.30 years were inducted, including 89 (43.2%) males and 117 (56.8%) females. Gene Xpert, AFB smear & AFB culture were positive in 83(40%), 50 (24%) & 72 (35%) respectively in GL samples. Odds of PTB were 3.95 times higher among patients with ≤1 month of duration of symptoms (aOR 3.95, 95% CI 1.82-8.57, p-value 0.001), 6.24 times higher among patients with weight loss (aOR 6.24, 95% CI 3.03-12.84, p-value <0.001), and 4.22 times higher among patients with cavitation (aOR 4.22, 95% CI 1.99-8.93, p-value <0.001). GL-AFB smear showed sensitivity 63.89%, specificity 97.01%, positive predicted value 92%, negative predicted value 83.3%, and overall diagnostic accuracy 85.4%. Whereas GL-GXP showed sensitivity 94.4%, specificity 88.81%, positive predicted value 81.93%, negative predicted value 96.75%, and overall diagnostic accuracy 90.78%.

Yield of GL significant to detect PTB in suspected cases who are not expectorating. GL-GXP diagnostic accuracy and sensitivity is higher than GL-AFB smear.