Perioperative Fluid Management in Morbidly Obese Patients

Perioperative Fluid Management With Transthoracic Echocardiography and Pulse-contour Device in Morbidly Obese Patients

In bariatric surgery functional and feasible non- or mini-invasive modalities for monitoring, and ideal/lean body weight estimates are addressed to meet up individual variability in hydration needs, and to avoid hyperhydration.

The aim of the study is to evaluate need of perioperative hydration by comparing conventional monitoring (the control group) to a more advanced approach (individualized goal-directed therapy, IGDT) (the intervention group). In addition to conventional cardiovascular monitoring (ECG, non-invasive blood pressure, Sp02) preoperative transthoracic echocardiography (TTE) and a intraoperative perioperative mini-invasive pulse-contour device (FloTrac™) will be used for the purpose.

Study Overview

• Status: Completed
• Conditions: Hypotension; Dehydration; Anomaly; Venous Return
• Intervention / Treatment: Other: Goal directed fluid therapy

Detailed Description

The individualized goal-directed therapy (IGDT), with focus on level of venous return, will be implemented in two steps in the intervention group. First, preoperative optimizing of venous return will be performed 45 minutes before surgery in a preoperative room with TTE. Second, after induction of anaesthesia perioperative fluid therapy will be guided by utilizing the FloTrac-device.

Preoperative rehydration with 6 ml colloid fluids (Volulyte™, Fresenius Kabi Ab, Sweden) /kg estimated ideal body weight (IBW) will be administrated if low level of venous return is detected by TTE. After a colloid bolus the second TTE is performed to check the level of venous return. If remaining hypovolemia is found additional colloids 3ml/ kg IBW will be given.

In OR, before pneumoperitoneum, prophylactic i.v. antibiotics will be administrated in total 550ml crystalloids (NaCl 0.9%, Fresenius Kabi Ab, Sweden) to all patients. Infusion of buffered glucose solution (25mg/ml, Fresenius Kabi Ab, Sweden) at rate 1.5ml/kg IBW/h will be initiated to all patients. Stroke volume variation ≥ 12 % is used as a threshold for administration of additional colloids 3ml/kg/ IBW during surgery.

Postoperatively infusion of buffered glucose solution (50mg/ml) is administrated at fixed rate 100ml/h to all patients. In addition, during the stay at the postoperative ward unit 850 ml crystalloids (antibiotics, paracetamol and nonsteroidal antiinflammatory drugs) are infused.

Perioperative ephedrine and/or phenylephrine is used as i.v. injection when necessary to ensure adequate perfusion pressure (MAP ≥ 65 mmHg), cardiac index (≥ 2.0) and heart rate (≥ 50/min) in addition to i.v. fluids in both groups. In principle hemodynamic parameters will be gathered always after five minutes minimum from possible administration of i.v. ephedrine or phenylephrine. Moreover, if pre-existing systolic left ventricular failure is detected in preoperative TTE, infusion of dobutamine 3 - 4ug/kg IBW will be started 10 minutes before induction of anaesthesia.

In the control group perioperative cardiovascular monitoring will be conducted by ECG, non-invasive blood pressure and Sp02 measurements.

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Sweden
  • Lulea, Sweden, SE-97180 Lulea
    • Department of anaesthesiology and intensive care, Sunderby county hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• accepted for bariatric surgery; BMI ≥ 40 kg/m2. Written informed consent. Successful preparation by 3 weeks rapid-weight-loss diet before surgery (≥ 5% loss of weight)

Exclusion Criteria:

• Subjects with untreated systemic or pulmonary hypertension, atrial fibrillation, pacemaker, unstable angina pectoris and significant failure of heart valves.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: NON_RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: The IGDT group; 30 morbidly obese subjects scheduled for bariatric surgery by laparoscopic Roux-en-Y gastric bypass (RYGB) will be consecutively enrolled for the study. The individualized goal-directed therapy (IGDT) with focus on level of venous return will be implemented in two steps in the intervention group. First, preoperative optimizing of venous return will be performed 45 minutes before surgery in a preoperative room with TTE. Second, after induction of anaesthesia perioperative fluid therapy will be implemented by utilizing the FloTrac-device.	Other: Goal directed fluid therapy
No Intervention: The control group; 20 morbidly obese subjects scheduled for bariatric surgery by laparoscopic Roux-en-Y gastric bypass (RYGB) will consecutively be enrolled for the study. Conventional monitoring will be conducted perioperatively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Need of perioperative i.v. fluids	The primary aim of the study is to evaluate need of perioperative hydration during laparoscopic bariatric surgery. Type and amount of all perioperative fluids infused will be registered. Timing for administration of fluids will be analysed in three steps (preoperative, operating room (OR) and postoperative).	12 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
mean arterial blood pressure	Mean arterial blood pressure (MAP) will be measured before induction of anaesthesia, 5 min after endotracheal intubation, 5 min after deep reverse Trendelenburg position and pneumoperitoneum in the intervention and the control groups. In addition, MAP will be registered continuously during surgery.	1 hour

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Nt-proBNP, creatinine	A baseline for Nt-proBNP and creatinine will be taken before i.v fluids preoperatively on the day of surgery. Control samples will be gathered 12 hours postoperatively.	12 hours

Collaborators and Investigators

• Sponsor: Umeå University
• Investigators: Principal Investigator: Tomi P Poso, MD, Umeå University

Publications and helpful links

General Publications

• Poso T, Winso O, Aroch R, Kesek D. Perioperative fluid guidance with transthoracic echocardiography and pulse-contour device in morbidly obese patients. Obes Surg. 2014 Dec;24(12):2117-25. doi: 10.1007/s11695-014-1329-4.

Study record dates

Study Major Dates

• Study Start: January 1, 2011
• Primary Completion (Actual): November 1, 2013
• Study Completion (Actual): December 1, 2013

Study Registration Dates

• First Submitted: June 4, 2013
• First Submitted That Met QC Criteria: June 5, 2013
• First Posted (Estimate): June 7, 2013

Study Record Updates

• Last Update Posted (Actual): October 29, 2018
• Last Update Submitted That Met QC Criteria: October 25, 2018
• Last Verified: October 1, 2018

More Information

Terms related to this study

• Keywords: bariatric surgery; echocardiography; mean arterial blood pressure; morbid obesity; venous return
• Additional Relevant MeSH Terms: Pathologic Processes; Cardiovascular Diseases; Vascular Diseases; Metabolic Diseases; Water-Electrolyte Imbalance; Hypotension; Dehydration
• Other Study ID Numbers: 12-439-32M