Effectiveness of Forced Air Preoperative warming

Rationale: Patients undergoing surgery with general anesthesia or local regional anesthesia will have a decline in body temperature caused by redistribution of heath from the core compartment to the peripheral compartment. Intra- and postoperative hypothermia causes serious complications such as blood clotting disorders, surgical site infections, cardiac morbidity and mortality. Recent literature shows evidence to prevent patients from intra- and postoperative hypothermia and it’s resulting complications by using forced air before surgery (so called prewarming),in stead of forced air warming only during surgery (standard care)

Objective: The primary objective of the study is to determine whether the use of preoperative warming with a forced air technique leads to a reduction of the incidence of hypothermia compared to patients with standard care. Secondary objectives are the incidence of intra- and postoperative complications and cost effectiveness of implementing forced air prewarming.

Study design: Prospective randomized controlled trail. Patients will be randomized to the intervention group: 30min of prewarming in the preoperative holding and the control group: standard preoperative care.

Study population: Eligible patients are patients undergoing orthopaedic surgery for total knee – and hip arthroplasty.
Intervention (if applicable): 30 minutes preoperative warming with forced air technique (FAP) by using the ®Bair Paws gown and ®Bairhugger warming unit.

Main study parameters/endpoints: ain endpoint is hypothermia defined as a core temperature belo elsius measured with ®SpotOn non-invasive cutaneous thermometer.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Due to the observational nature of this study there are no side effects to be expected. The use of the ®SpotOn non invasive thermometer, measuring core temperature, is expected to be safe in patients under general anaesthesia or spinal anaesthesia. Measuring core temperature with ®Spot-On thermometer is a validated method, proven by literature. The use of forced air rewarming with ®Bair Paws gown and ®Bairhugger warming unit is expected to be safe.

The use of preoperative warming of patients undergoing total hip- or knee arthroplasty with a forced air technique will reduce the incidence of postoperative hypothermia.

-30 minutes preoperative

-intraoperative

-postoperative during stay on PACU

-30 day's postoperative

Patients in the FAP group will be prewarmed, 30 minutes preoperatively, in the preoperative waiting room, using a ®Bair Paws gown for 30 minutes. The ®Bair Paws perioperative single use patient gown (Arizant Healthcare, UK) is a gown developed for perioperative skin surface warming. The gown will be connected via corrugated hose to a ®Bair Hugger warming unit to provide intraoperative warming. The temperature output of the device is set on a temperature and 43 Celsius. Temperature output can be adjusted according to the patient needs.



Patients in the standard care group will receive 30 minutes preoperatively a disposable heated blanket in the preoperative waiting room area. Intra-operative a forced air warming with ®Bair Paws gown will be applied. The ®Bair Paws perioperative single use patient gown (Arizant Healthcare, UK) is a gown developed for perioperative skin surface warming. The gown will be connected via corrugated hose to a ®Bair Hugger warming unit to provide intraoperative warming. The temperature output of the device is set on a temperature and 43 degrees Celsius. Temperature output can be adjusted according to the patient needs. Furthermore administered iv fluids will be warmed by an active fluid warmer (enFlow®IV Fluid Warmer, Vital Signs A GE Healthcare company).