Evaluating Adult Patient Temperatures During Lower Spinal Surgery

Comparing Patient Temperatures in Adults During Lower Spinal Surgery Using Either a Heated Ventilator Circuit or a Standard Ventilator Circuit With a Heat-Moisture Exchanger

The purpose of this study is to evaluate patients' temperatures after using one of two ventilator circuits (breathing systems): the ANAPOD™ Heat and Humidification System (ANAPOD™ system) or the standard ventilator circuit with a heat-moisture exchanger (standard ventilator). The ANAPOD™ system will provide additional heat and humidity to patients through their breathing tube while the standard ventilator will not. The investigators are doing this research study to find out if the ventilator circuit providing additional heat and humidity will keep patients warmer during surgery and after surgery.

Study Overview

• Status: Completed
• Conditions: Hypothermia
• Intervention / Treatment: Device: Heated Ventilator Circuit; Device: Standard Ventilator Circuit

Detailed Description

Patients were randomly assigned to either the treatment group or the control group prior to surgery. Prior to induction, patients in the control group were given inspiratory gas at ambient air temperature (20-22 degrees Celsius) and patients in the treatment group were given inspiratory gas at warmed temperatures (40-41 degrees Celsius). All patients were induced with general anesthesia in the supine position and repositioned prone following endotracheal intubation and placement of an esophageal stethoscope with a temperature sensor, as per usual hospital practice. Esophageal temperatures were recorded within 30 minutes of the baseline esophageal temperature and every 10 minutes thereafter for the first hour post-induction. All patients had a blanket and forced air warming applied to their lower extremities and upper back at 43 degrees Celsius after draping. All patients had esophageal temperature measurements recorded every 30 minutes until the patient was repositioned supine. Core temperatures were recorded four hours post-induction for those patients reaching that timeframe.

• Study Type: Interventional
• Enrollment (Actual): 70
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Elective spine surgery anticipated greater than three hours in duration
• Posterior approach
• An operative site between lumbar one and sacral one
• Involving two or more levels with fusion and/or instrumentation and/or revisions
• American Society of Anesthesiologists (ASA) Status of I-III

Exclusion Criteria:

• Patients with a tracheostomy
• Preoperative temperature >38°C or <36°C on the day of surgery
• Active infection or erythema to the back
• White blood cell count greater than 10,500/microliter (mcL)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Heated Ventilator Circuit; Heated and humidified inspired gases using the ANAPOD™ Heat and Humidification System (Westmed; Tucson, Arizona, USA) circuit prior to induction of general anesthesia in addition to standard ventilation and temperature management.	Device: Heated Ventilator Circuit; active heat and humidification during anesthesia by warming inspire gases without a heat-moisture exchanger; Other Names: ANAPOD™ Heat and Humidification System
Active Comparator: Standard Ventilator Circuit; Standard ventilation and temperature management.	Device: Standard Ventilator Circuit; no active heat and humidification during anesthesia; Other Names: Thermovent 600; Portex

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Core Body Temperature	Core body temperature will be taken in the esophagus. The last recorded esophageal temperature will be used for surgeries not reaching 3 hours duration.	Approximately four hours post-induction of general anesthesia (or last recorded temperature)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraoperative Core Temperatures Post-induction	Core body temperature will be taken in the esophagus after general anesthesia induction.	Approximately 30 minutes, 60 minutes, 120 minutes post-induction of general anesthesia
Number of Subjects With Post-operative Shivering	Shivering in the post-anesthesia care unit will be assessed using the Bedside Shivering Assessment Scale. This is a 4 point scale and rate shivering as the following: absent, mild, moderate, or severe. Only the highest degree of patient shivering was used in the analysis.	Approximately 2 hours after completion of the surgery
Hospital Length of Stay	Number of days in the hospital	Surgery to hospital discharge
Overall Post-operative Temperature	Temperature at Post Anesthesia Care Unit (PACU) arrival.	PACU arrival
Number of Participants With Transfusion Within 48 Hours of Surgery	Requirement of blood transfusion within 48 hours of surgery	Within 48 hours of surgery
Estimated Blood Loss	The estimated blood loss per case was determined by the anesthesia provider by measuring the volume of blood in the suction canister while taking into account the amount of irrigation solution used.	duration of surgery

Collaborators and Investigators

• Sponsor: Mayo Clinic
• Collaborators: Westmed, Inc.
• Investigators: Principal Investigator: Jean M Guyer, DNP, Mayo Clinic

Study record dates

Study Major Dates

• Study Start (Actual): August 28, 2015
• Primary Completion (Actual): February 5, 2017
• Study Completion (Actual): February 5, 2017

Study Registration Dates

• First Submitted: February 9, 2017
• First Submitted That Met QC Criteria: February 9, 2017
• First Posted (Actual): February 13, 2017

Study Record Updates

• Last Update Posted (Actual): May 7, 2018
• Last Update Submitted That Met QC Criteria: May 3, 2018
• Last Verified: May 1, 2018

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Temperature Changes; Hypothermia
• Other Study ID Numbers: 15-001604; UL1TR000135 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes