Nasogastric tube insertion using conventional versus bubble technique for its confirmation in anesthetized patients: a prospective randomized study

Abstract Background: Nasogastric tube insertion and confirmation of its position can be difficult in the anesthetized patient. The purpose of the present study was to compare the bubble technique with the conventional method for confirmation of nasogastric tube placement in these patients. Methods: Two hundred sixty adult patients, aged between 20-70 years, posted for surgeries requiring general anesthesia, tracheal intubation, and a nasogastric tube were enrolled in this study. Patients were randomized into 2 groups: Group B (Bubble group) and Group C (Control group). In Group C, a conventional technique using a lubricated nasogastric tube was positioned through the nostril with head remained neutral. In Group B, 2% lidocaine jelly was added to the proximal end to form a single bubble. The correct placement of the nasogastric tube in the stomach was confirmed by fluoroscopy by an independent observer intraoperatively. Results: The duration of nasogastric tube insertion was 57.2 ± 13.3seconds in Group B and 59.8 ± 11.9seconds in Group C (p = 0.111). The confirmation rate of the bubble technique was 76.8% (95% CI: 68.7-83.3), which was significantly better than the conventional method where the confirmation rate was 59.7% (95% CI 50.9-67.9), p< 0.001. When compared to fluoroscopy, bubble technique was found to have a sensitivity of 92.3% (95% CI: 85.6-96.1) with specificity of 81.0% (95% CI: 60.0-92.3), positive predictive value of 96.0% (95% CI: 90.2-98.4), and a moderate negative predictive value of 68.0% (95% CI: 48.4-82.8). Conclusions: The bubble technique of nasogastric tube insertion has a higher confirmation rate in comparison to the conventional technique. Trial Registry Number: Clinical Trial Registry of India (CTRI/2018/09/015864).

Preoperative assessment of inferior vena cava collapsibility index by ultrasound is not a reliable predictor of post-spinal anesthesia hypotension

Abstract Background Post-spinal anesthesia hypotension is of common occurrence, and it hampers tissue perfusion. Several preoperative factors determine patient susceptibility to hypotension. This study aimed to assess the effectiveness of the Inferior Vena Cava Collapsibility Index (IVCCI) for predicting intraoperative hypotension. Methods One hundred twenty-nine adult patients who were scheduled for elective surgical procedures after administration of spinal (intrathecal) anesthesia were included in the study. Ultrasound evaluation of the Inferior Vena Cava (IVC) was done in the preoperative area, and the patients were shifted to the Operating Room (OR) for spinal anesthesia. An independent observer recorded the change in blood pressure after spinal anesthesia inside the OR. Results Twenty-five patients developed hypotension (19.37%). Baseline systolic blood pressure and mean blood pressures were statistically higher in those patients who developed hypotension (p= 0.001). The logistic regression analysis for IVCCI and the incidence of hypotension showed r2 of 0.025. Receiver Operating Characteristic (ROC) curve analysis demonstrated the Area Under the Curve (AUC) of 0.467 (95% Confidence Interval, 0.338 to 0.597; p= 0.615). Conclusions Preoperative evaluation of IVCCI is not a good predictor for the occurrence of hypotension after spinal anesthesia.