The effect of intravenous infusion on the rapid recovery of elderly patients treated with painless colonoscopy and the value of ultrasonic measurement of the inferior vena cava diameter in guiding intravenous infusion

Elderly patients with painless colonoscopy often complain listlessness, fatigue when they left postanesthesia care unit (PACU). These patients also commonly occur hypotension during anesthesia. However, intravenous infusion and blood volume assessment are seldom performed in elderly patients. Therefore, we aimed to observe the effect of intravenous infusion and to explore the value of inferior vena cava diameter (IVCD) measurement by ultrasound in rapid recovery.Randomized, controlled, clinical trials, elderly patients (aged ≥60 years) with painless colonoscopy were randomly divided into two groups: intravenous infusion versus no intravenous infusion was administered procedure. The primary outcome observed was the time required for complete recovery from anesthesia. Secondary outcomes included willingness to accept follow-up colonoscopy, discomfort symptoms, changes in the inferior vena cava (IVC)-related parameters. Hypotension was defined as a ≥20% decrease in systolic blood pressure (SBP) from baseline. The patients in the two groups were divided into non-hypotensive and hypotensive subgroups, respectively. Receiver operating characteristic (ROC) curves were used to determine the efficacy of the IVC-related parameters for predicting hypotension and the optimal threshold.A total of 65 patients were enrolled, including 34 patients in the infusion group and 31 patients in the conventional group. Administration of intravenous infusion reduced the time required for complete recovery and increased the willingness to accept follow-up colonoscopy and reduced discomfort symptoms. The IVC-related parameters were changed before and after bowel preparation and after reaching infusion loading dose. The ROC curve was used to predict hypotension during anesthesia. The maximum value of inferior vena cava diameter (IVCDmax) was the best predictive efficacy in the both groups [area under the ROC curve (AUC) =0.839, AUC =0.877, respectively].Intravenous infusion promotes the rapid recovery of elderly patients with painless colonoscopy. Measurement of the IVCDmax can help to guide intravenous infusion.