Tip perfusion index for monitoring perioperative stress responses in patients undergoing laparoscopic...

This study aimed to characterize peri-stimulus changes in the Tip Perfusion Index (TPI) and conventional hemodynamic parameters during elective laparoscopic cholecystectomy and to compare their response dynamics among patients without major comorbidities, patients with hypertension, and patients with type 2 diabetes mellitus.

Ninety patients undergoing elective laparoscopic cholecystectomy were prospectively enrolled and classified as Control, Hypertension, or Diabetes (n = 30 each). TPI, BP, and HR were recorded at six perioperative time points (T0-T5) under standardized general anesthesia and CO2 pneumoperitoneum. In a randomly selected subcohort (n = 5 per group), plasma E, NE, and COR were measured from T0 to T4. Data were analyzed using Chi-square tests, one-way ANOVA, mixed-design repeated-measures ANOVA, and repeated-measures correlation.

Demographic and baseline parameters were comparable among the three groups (P > 0.05). Following endotracheal intubation and pneumoperitoneum, TPI decreased from the corresponding pre-stimulus values, whereas blood pressure and heart rate increased. Mixed-design repeated-measures ANOVA showed significant Group×Time interactions for DBP (P = 0.030) and HR (P = 0.002), but not for TPI (P = 0.069) or SBP (P = 0.619). Repeated-measures correlation showed inverse associations between TPI and hemodynamic parameters and stress hormones, except for cortisol in the Diabetes group, where the association did not reach statistical significance (P = 0.057). In the separate threshold-based analysis, all participants met the predefined TPI-positive response criterion during both stimuli. During pneumoperitoneum, TPI response time differed significantly among the three groups (P < 0.001), with the longest mean response time observed in the Diabetes group, whereas no significant between-group differences in response time were observed for SBP, DBP, or HR (all P > 0.05).

TPI showed consistent peri-stimulus changes during endotracheal intubation and pneumoperitoneum and may provide complementary information on peripheral vascular responses during surgical stress. The prolonged threshold-based TPI response time observed in patients with diabetes during pneumoperitoneum suggests a potential difference in response timing that warrants further investigation.