Authors (including presenting author) :
Chiu GS (1), Leung MY (2), CHAN E (1), Lee WM (1), Wong KYZ (1), Wong W (1), Wong SCM (1), Jalal K (1), SIU HY (2), Chow YK (2), Chan W (2), Wong KYK (3), Chan HYI (3).
Affiliation :
(1) Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital. (2) Department of Anaesthesia, Pain and Perioperative Medicine, Queen Mary Hospital (3) Department of Surgery, Queen Mary Hospital
Introduction :
Very low birth weight (VLBW) babies are at risk of hypothermia as they have inadequate subcutaneous fat and under-developed thermoregulatory mechanism. This risk is increased when the infant undergoes surgery in the operating theatre due to the cool environmental setting and the general anaesthesia procedure. Definition of hypothermia according to WHO, is axillary temperature <36.5℃. Hypothermia is also stratified as mild (36℃-36.4℃), moderate (32℃-35.9℃) and severe (≤32℃, and <35℃ in extreme low birth weight (ELBW) babies). In November 2021, two ELBW infants’ temperature had recorded significant hypothermia with axillary temperature < 35oC upon arrival to NICU after operation. These had brought the attention to the clinical team. A quality improvement project aimed at reducing hypothermia in neonates throughout the process of pre-/ intra-/ post-operation and on arrival from OT to NICU was conducted.
Objectives :
1. To reduce incidence of perioperative hypothermia for very low birth weight babies 2. To implement improvement strategies to maintain the temperature within normal range in neonates requiring operation through cross-departmental collaborative efforts. 3. To standardize the workflow for enhancing the thermoregulation of neonates in both NICU and Operating theatre
Methodology :
A Quasi-Experimental design study was conducted to evaluate the effectiveness of implementing the standardized workflow and checklist on reducing perioperative hypothermia. Retrospective chart reviews from electronic clinical information system in OT and NICU were performed during the pre-intervention review period (1/1/2019 till 8/11/2021) and post-intervention review period (16/11/2021 till 6/7/2022). The definition of hypothermia by WHO was adopted and the post-operative temperature measurement method was axillary. Multi-disciplinary team discussions were held to identify possible gaps leading to intra-operative hypothermia prior to interventions. Interventions: Educational activities in enhancing OT nurses’ awareness in neonatal thermoregulation, nurse initiatives in developing and implementing standardized workflow and checklist to guide thermal care in both NICU and OT. Outcome measurement: Demographics data was collected and recorded. Primary outcome was patient’s post-operative axillary temperature within 30 minutes on arrival to NICU from OT. Secondary outcome included intraoperative temperature, relationship between patient or clinical characteristics and hypothermia. Data was input and analysed using IBM SPSS version 26. Descriptive analysis was performed, including means, standard deviations (SD)for continuous variables, and frequencies and percentage for categorical variables. Mean difference of the pre- and post-interventions temperatures between subjects and control were analysed with the unpaired samples t-test.
Result & Outcome :
81 episodes (pre-intervention) and 27 episodes (post-intervention) of neonatal surgeries were reviewed and analysed. Episodes of postoperative hypothermia were significant decreased from 57% to 11% (p<0.0001). Moreover, the mean temperature significantly increased from 36.3℃ (pre-intervention) to 36.9℃ (post-intervention). Body weight at operation was break down into 4 groups for calculation and significant relationship shown between body weight at OT and/or intra-operative blood transfusion and hypothermia. There was 5/27 episodes (19%) of intraoperative hypothermia captured during post-intervention period, and 2/27 episodes (7.4%) found post-operative hyperthermia (>37.5 ℃), thus, the relationship between intra-operative hypothermia and post-op temperature was inconclusive. The hypothermia risk is increased in VLBW infants undergone major operation requiring intra-operative blood transfusion. Hypothermia may have detrimental effect in neonates especially ELBW infants. However, perioperative hypothermia could be significantly reduced by implementing the improvement strategies through multidisciplinary collaboration.
