Introduction: Anaesthetic  induced  impairment  of  thermoregulatory  control  and  surgical exposure  make patients  prone  to  heat  loss.  Irrigation  fluids  used  in  urologic  endoscopic  surgery  and  low operating room temperature are other factors accounting  for that loss. Passive insulation and forced  air  warming  devices  are  simple  techniques  that  can  be  used  to  prevent  it.  The  aim  of this work was to evaluate the effect of active warming in preventing  perioperative heat loss in patients submitted to urologic endoscopic surgery.
 Methods: After  Hospital  Ethics  Committe  approval,  a  prospective  audit  was  conducted  including  51 patients submitted to endoscopic urologic procedures at a tertiary hospital, from March to July 2015.  Gender,  age,  American  Society  of  Anaesthesia  Physical  Status  (ASA),  Body  Mass  Index (BMI),  type  of  anaesthesia,  duration  of  surgery,  use  of  active  warming  and  hospital  length  of stay   were   collected.   Tympanic   temperature   was   monitored   using Grado®   thermometer (RM205V  model)  on  five  moments:  Operating  Room  arrival  (T1),  after  anaesthetic induction (T2), end of surgery (T3), Post Anaesthesia Care Unit arrival (PACU) (T4) and at PACU discharge (T5). ΔT3-T2, ΔT5-T2  and ΔT5-T4  were  calculated.  Results:  number,  percentage,  mean  ± standard deviation (SD) and median. Test U Mann-Witney was used (p< 0,05) (SPSS® v.22).
 Results: 51 patients included (76% male), age between 26 and 92 years old (median 69). ASA 1: 6%; 2: 53%;  3:  41%.  BMI  was  26,11  ±  2,91  Kg/m2.  53%  submitted  to  general  anaesthesia, surgery mean duration 51 minutes (± 24). 61% (n=31) actively warmed during surgery. Hospital length stay 4,06 ± 2,67 days. T1: 36,08 ± 0,46 ºC; T2: 35,87 ± 0,57 ºC; T3: 35,12 ± 0,64 ºC; T4: 34,93 ± 0,6 ºC; T5: 35,41 ± 0,5 ºC.  We  found  statistically  significant  difference  between  patients  actively  warmed  (PW)  and patients  non-active  warmed  (PnW)  during  T5-T2  period  (p=0,001).  During surgery  procedure (T2-T3), although there was a difference in TV between PnW (-0,99 ± 0,59ºC) and PW (-0,59 ± 0,61ºC), this result was not statistically significant (p=0.09).
Conclusions: In  our  prospective  audit  study  it  seems  that  active  warming  influence  the  perioperative  heat loss.  PW  during  urologic  endoscopic  procedures  are  less  likely  to  have  heat  loss  at  PACU discharged.  This  study  let  us  think  about  the  importance  of  developing  active  warming strategies.

Urologic endoscopic procedures: does active warming matter?