Minimisation of Blood Pressure Variability and Postoperative Nausea and Vomiting

Study Overview
=================
Brief Summary
-----------------
Intraoperative hypotension is associated with postoperative nausea and vomiting (PONV). Even though the exact mechanism linking PONV and hypotension is still unclear, a reduced intestinal tissue perfusion might trigger nausea and vomiting. Still to date only limited data evaluating intraoperative blood pressure and the incidence of PONV after general anesthesia exits. Furthermore, the effect of intraoperative blood pressure variability on the incidence of PONV has not been investigated yet. Therefore, we will test our primary hypothesis that the incidence of PONV during the early (0-2h) postoperative period will be minimized by targeting intraoperative blood pressure variability to a SPB of 120±5mmHg by using a continuous vasopressor infusion in female patients undergoing elective minor to moderate risk non-cardiac surgery.

Detailed Description
-----------------
Background: Intraoperative hypotension is associated with postoperative nausea and vomiting (PONV). Even though the exact mechanism linking PONV and hypotension is still unclear, a reduced intestinal tissue perfusion might trigger nausea and vomiting. Still to date only limited data evaluating intraoperative blood pressure and the incidence of PONV after general anesthesia exits. Furthermore, the effect of intraoperative blood pressure variability on the incidence of PONV has not been investigated yet. Therefore, we will test our primary hypothesis that the incidence of PONV during the early (0-2h) postoperative period will be minimized by targeting intraoperative blood pressure variability to a SPB of 120±5mmHg by using a continuous vasopressor infusion in female patients undergoing elective minor to moderate risk non-cardiac surgery. Methods: We will include 272 women between 18 and 50 years of age undergoing minor- to moderate-risk noncardiac surgery in this randomized, double-blinded clinical trial. Patients will randomly be assigned to intraoperative management of blood pressure with a SPB of 120±5mmHg (intervention group) or standard of care intraoperative blood pressure management (control group). Our primary outcome will be the incidence of PONV during the early (0-2h) postoperative period between the groups. Nausea will be assessed in 15-min intervals in the PACU for the first two postoperative hours on a 100mm visual analog scale. A PONV episode will be defined as the occurrence of nausea (VAS 50mm or greater) or vomiting. Statistics: The primary outcome, the incidence of PONV during the early (0-2 hours) postoperative period will be compared between the intervention and control group using a Chi- Square-Test. Level of originality: Data regarding the effects of intraoperative blood pressure on PONV are very limited and mainly available from retrospective analysis. So far, the effects of blood pressure variability on PONV have not been investigated yet. As PONV is still one of the most common complications after general anaesthesia leading to delayed discharge from PACU, patient discomfort and increased medical costs, it is important to search for additional methods to manage PONV. Our patient population, being at increased risk of PONV, could therefore profit from a more rapid postoperative recovery.

Official Title
-----------------
The Effect of Minimizing Blood Pressure Variability on Postoperative Nausea and Vomiting in Women Undergoing Non-cardiac Surgery With Minor to Moderate Risk - a Prospective Randomized Clinical Trial

Conditions
-----------------
PONV, Blood Pressure, Postoperative Recovery

Intervention / Treatment
-----------------
* Other: Minimizing blood pressure variability


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Women 18-50 years of age at time of surgery ASA physical status I and II Scheduled for elective minor or moderate risk non-cardiac surgery with expected time of surgery ≥1 hour Exclusion Criteria: Patients undergoing emergency surgery Scheduled for pheochromocytoma surgery Nausea and/or vomiting on the morning before surgery Taking anti-emetic drugs Pregnancy Dysfunction of the vestibular system

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intervention Group<br>Intraoperative blood pressure management will be performed to maintain a systolic blood pressure of 120 ±5mmHg using a continuous infusion of a vasopressor starting at induction of anesthesia. | Other: Minimizing blood pressure variability<br>* Intraoperative blood pressure management will be performed to maintain a systolic blood pressure of 120 ±5mmHg using a continuous infusion of a vasopressor starting at induction of anaesthesia.<br>|
| No Intervention: Standard of Care Group<br>Intraoperative blood pressure management will be performed according to local clinical standard of care. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PONV | Incidence of postoperative nausea and vomiting within the first two postoperative hours. | First two postoperative hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Secondary Outcome 1: Late PONV | Incidence of postoperative nausea and vomiting within the first three postoperative days | First three postoperative days | 
| Secondary Outcome 2: Modified Aldrete Score | A score to assess readiness of discharge from postanesthesia care unit (PACU). Patients can achieve 0-14 points in the modified Aldrete Score. A modified Aldrete Score > 12 points signals that criteria for discharge from PACU have been fulfilled, a modified Aldrete Score < 12 points signals that patients should stay in PACU. | First two postoperative hours | 
| Secondary Outcome 3: Ready for Hospital Discharge Scale | A score to evaluate patients' subjective readiness for hospital discharge. Patients can achieve 0-80 points in the Ready for Hospital Discharge Scale. Higher scores mean that patients are ready for hospital discharge, lower scores mean that patients are not ready for hospital discharge. | First three postoperative days | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Blood Pressure Variability, Minor- to moderate-risk noncardiac surgery