Temperature and Pain in Laparoscopy (TePaLa)

A Prospective, Randomized, Controlled, Study Investigating Intraoperative Temperature and Postoperative Pain Course Following Gynaecological Laparoscopy

The aim of this investigation is to assess the impact of forced air warming, warm humidified insufflation gas and the combination of the two on intraoperative temperature maintenance and the postoperative pain course as well as the fibrinolytic activity in peritoneal fluid following laparoscopic procedures (duration > 60 min) in a prospective, randomized, controlled, mono-centric study. Therefore 150 subjects will be randomized in 3 groups of 50 subjects each. First group will be treated with forced-air warming blanket (bair hugger). Second group will be treated with warmed, humidified insufflation via the F&P HumiGard™ Surgical Humidification System. Third group will be treated with both, warming blankets and warmed, humidified insufflation. The peri-operative temperature of patients might be higher in patients of the third group with the combination of both treatments. The investigators hypothesize that VAS scores for pain (especially shoulder pain), and MEDD usage will differ between groups. Wound infection incidence and time spent in PACU are also expected to differ. Fibrinolytic activity in the peritoneal fluid is expected to be higher in patients undergoing laparoscopic procedures with humidified gas insufflation, since the trauma to the peritoneum will be less.

During the first 30 to 40 minutes of anaesthesia, a patient's temperature can drop to below 35.0°C. Reasons for this include loss of the behavioural response to cold and the impairment of thermoregulatory heat-preserving mechanisms under general or regional anaesthesia, anaesthesia-induced peripheral vasodilation, the use of cold dry insufflation gases. For these reasons, institutions employ a range of techniques to prevent hypothermia, including forced air warming (peri-operatively), use of warmed intravenous fluids, temperature monitoring and control of room temperature. Despite these interventions audits demonstrate that 20-56% of patients are hypothermic during the perioperative period. A factor often dismissed as a cause of peri-operative hypothermia during laparoscopic procedures is dry and cold insufflation gas. During laparoscopic procedures the abdomen is continuously insufflated with cold, dry CO2 resulting in desiccation and heat loss which consequently induces hypothermia in the patient. Clinical evidence suggests that the risk of hypothermia can be reduced using warm and humidified gas, as has been shown in animal models, in clinical trials and confirmed in a metaanalysis in humans. Only gas at body temperature and fully saturated with moisture will prevent loss of energy from the peritoneum surface - because it is physically not possible to evaporate fluids into a fully saturated gas. Therefore, the fluid layer will be maintained, minimizing energy loss from the body, decreasing the hypothermia induced by the evaporative losses in laparoscopic surgery and stabilizing the fibrinolytic activity of the peritoneum. The aim of this investigation is to assess the impact of forced air warming, warm humidified insufflation gas and the combination of the two on intraoperative temperature maintenance and the postoperative pain course as well as the fibrinolytic activity in peritoneal fluid following laparoscopic procedures (duration > 60 min) in a prospective, randomized, controlled, mono-centric study. Therefore 150 subjects will be randomized in 3 groups of 50 subjects each. First group will be treated with forced-air warming blanket (bair hugger). Second group will be treated with warmed, humidified insufflation via the F&P HumiGard™ Surgical Humidification System. Third group will be treated with both, warming blankets and warmed, humidified insufflation. The peri-operative temperature of patients might be higher in patients of the third group with the combination of both treatments. The investigators hypothesize that VAS scores for pain (especially shoulder pain), and MEDD usage will differ between groups. Wound infection incidence and time spent in PACU are also expected to differ. Fibrinolytic activity in the peritoneal fluid is expected to be higher in patients undergoing laparoscopic procedures with humidified gas insufflation, since the trauma to the peritoneum will be less.

Combination of forced-air warming blanket via 3M™ Bair Hugger™ and warmed, humidified insufflation via the F&P HumiGard™ Surgical Humidification System.

Intra-operative core temperature measured via oesophageal probe/urinary catheter after anaesthetic induction (baseline) but before insufflation and at 10 minute intervals until completion of surgery; hypothermia (<36 C) during the peri-operative period to be indicated by: Mild (core temperature 35.0 °C to 35.9 °C) Moderate (34.0 °C to 34.9 °C) Severe ≤33.9 °C)

Body temperature as measured by direct tympanic thermometer: Pre-operatively - 1 hour before induction and at 10 minute intervals until induction Before anesthetic induction Post-operatively at entry to recovery room and at 10 minute intervals or until normo-thermia (≥36.5 °c) is achieved. Time at which normothermia is achieved to be recorded.

VAS: Pain from abdominal area - Pain in the shoulder - Pain on movement - Pain on coughing, before transfer to ward; at arrival in recovery room; 8 a.m. + 8 p.m. until discharge; 0 - 10 Numeric Pain Rating Scale by VAS, National Institute of Pain Control - NIPCTM

MEDD usage: intraoperative, post anaesthesia care unit (PACU), Day 0, Day 1, Day 2, Day 3, Total during admission, Day on which PCA is removed if PCA is used. Start of PCA to be standardised, if possible all patient requests for PCA to be recorded by software, even if patient lockout has occurred due to too many attempts to activate PCA in a certain time.

PV to be recorded at 10 min intervals perioperatively. Volume of electrolyte solution infused to be recorded, as well as time from induction until infusion takes place.

Fibrinolytic activity in the peritoneal fluid will be determined at the beginning of surgery and Day 1. Sample will be taken from an abdominal drain.

Inclusion Criteria: Patients aged 18 years or above and aged under 70 years Written informed consent prior to study participation Patients admitted to hospital for laparoscopic surgery with a planned duration of more than 1 hour; if there is an open component to the surgery then this should be discussed, in terms of the length of the laparoscopic component BMI <35 Exclusion Criteria: Pregnancy or women without sufficient contraception Women, who are breastfeeding Alcohol or drug abuse Expected non-compliance Patients unwilling or unable to give informed consent, patients with limited ability to comply with instructions for this study Participation on another interventional study within the last 3 months Subjects who are committed to an institution and/or penitentiary by judicial or official order Employees of the investigator cooperation companies

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Wittenborn J, Mathei D, van Waesberghe J, Zeppernick F, Zeppernick M, Tchaikovski S, Kowark A, Breuer M, Keszei A, Stickeler E, Zoremba N, Rossaint R, Bruells C, Meinhold-Heerlein I. The effect of warm and humidified gas insufflation in gynecological laparoscopy on maintenance of body temperature: a prospective randomized controlled multi-arm trial. Arch Gynecol Obstet. 2022 Sep;306(3):753-767. doi: 10.1007/s00404-022-06499-z. Epub 2022 Mar 14.

Breuer M, Wittenborn J, Rossaint R, Van Waesberghe J, Kowark A, Mathei D, Keszei A, Tchaikovski S, Zeppernick M, Zeppernick F, Stickeler E, Zoremba N, Meinhold-Heerlein I, Bruells C. Warm and humidified insufflation gas during gynecologic laparoscopic surgery reduces postoperative pain in predisposed patients-a randomized, controlled multi-arm trial. Surg Endosc. 2022 Jun;36(6):4154-4170. doi: 10.1007/s00464-021-08742-1. Epub 2021 Oct 1.