Gastric-Lavage
Introduction
Tuberculosis continues to be a significant problem with a major proportion of morbidity and mortality in the children. Likewise, making a bacteriological diagnosis remains a challenge due to difficulty in obtaining samples in children. As most children have difficulty in expectorating sputum, gastric aspirates are frequently required to AFB detection/ culture the organism in pediatric patients. Additional problems in the pediatric age group are the pauci-bacillary forms and an increasing incidence of drug-resistant strains.
During sleep, the muco-ciliary mechanism sweeps mucus up the airways into the throat. This mucus is swallowed and unless the stomach empties, a pool of mucus in the stomach may serve to provide adequate sample to isolate TB organism. Gastric aspiration is thus a technique to collect gastric contents that can be used in the diagnosis of tuberculosis.
Procedure :
- Insertion of Naso gastric (NG) tube
- It is preferably performed early in the morning, after an overnight fasting (minimum 4-6 hours).
- Use as large a bore NG tube as is comfortable for the child (minimum 10 french).
Collection of the Sample
It can be either an inpatient or outpatient procedure and should be performed in two consecutive days.
Transport to laboratory
- This should be done immediately with strict aseptic precautions.
- In the laboratory, gastric lavage samples are then digested and decontaminated, centrifuged and sediments are then stained by Ziehl-Neelsen technique for the detection of acid-fast bacilli.
- Its accuracy ranges from 20% to 52%.
Investigations
Sample can be processed for AFB Smear , Culture, and CBNAAT or Xpert TB
Conclusion
GL can be effective for diagnosis of patients who have suspicious tuberculosis symptoms and are unable to produce sputum especially in resource limited areas.