Near-infrared spectroscopy (NIRS) in a piglet model: readings are influenced by the colour of the cover Clausen NG1,2, Spielmann N1,3, Weiss M1,3, Ringer SK4 1Children’s Research Center, University Children’s Hospital of Zurich, Switzerland; 2Department of Anaesthesiology and Intensive Care, Odense University Hospital, Denmark; 3Department of Anaesthesiology, University Children’s Hospital Zurich, Switzerland; 4Section Anaesthesiology, Vetsuisse Faculty University of Zurich, Switzerland Background and goal of study Near-infrared spectroscopy (NIRS) is used to monitor regional tissue oxygenation (rSO2) during general anaesthesia (1, 2). The measurement might have sources of error still insufficiently examined in the clinical setting. The goal of this cross-over study was to investigate the effect of differently coloured coverings on rSO2 in piglets. Materials and methods Twenty-five healthy piglets aged 4-6 weeks where anaesthetized, intubated, mechanically ventilated and fully monitored using spirometry, ecg, pulse oximetry, invasive blood pressure and rectal temperature. Neuromonitoring comprised of oxygen partial pressure (PtO2) measurement and laser doppler blood flow (CBF) in brain tissue. The rSO2 was measured by placing NIRS sensors in the supra glabellar region. In 12 animals sensors were covered with a uni-coloured pink (P) napkin and a turquoise (T) napkin in a random order (Setting A). In further 13 animals sensors were covered with blue-coloured surgical drape (SD) and a napkin with a reddish SantaClaus (SC) motive (Setting B). Uncovered (UC) baseline values were captured and measurements obtained for a period of three minutes. During measurements, the animals were kept in normoterm, normotensive, normoglycaemic and normoxic condition. Inspired oxygen fraction and ventilatory settings were kept constant. One-way ANOVA was used to compare the 3 coverage's during each part of the study (p<0.05). Results Part 1: rSO2-T differed significantly from rSO2-UC and rSO2-P (Mean ± SD rSO2-UC1: 49.7 ± 7.5; rSO2-P: 49.8 ± 8.1; rSO2-T: 45 ± 8.0 %) (p<0.05). Part 2: rSO2-SD differed significantly from rSO2-UC and rSO2-SC (rSO2-UC2: 57.4 ± 6.8; rSO2-SC: 57.5 ± 6.4; rSO2-SD: 52 ± 5.9 %) (p<0.05). CBF and PtO2 remained unchanged during measurements in part 1 and 2. Conclusion NIRS readings can be influenced by covering of the sensors. The colour of the cover seems to be of importance. This variability is likely to reflect a source of error rather than an actual change in rSO2 and should be considered, when interpreting rSO2 in a clinical setting. We suggest application of a black sensor cover to avoid the influence of light. Acknowledgement: An INVOS Oximetry monitor was provided with courtesy by Medtronic (Schweiz) AG - 3053 Münchenbuchsee | Switzerland. 1. Murphy GS, Szokol JW, Marymont JH, Greenberg SB, Avram MJ, Vender JS, et al. Cerebral oxygen desaturation events assessed by near-infrared spectroscopy during shoulder arthroscopy in the beach chair and lateral decubitus positions. Anesthesia and analgesia. 2010;111(2):496-505. 2. Sorensen H. Near infrared spectroscopy evaluated cerebral oxygenation during anesthesia. Danish medical journal. 2016;63(12). e corresponding values of cerebral regional tissue oxygenation (rSO2) (y-axis) Figure 1: Near-infrared spectroscopy (NIRS) sensor placed on the supra glabellar skin.
|Bogserie||European Journal of Anaesthesiology. Supplement|
|Udgave nummer||e-suppl. 55|
|Status||Udgivet - 2017|
|Begivenhed||European Society of Anesthesia: Annual congress - Palexpo, Geneve, Schweiz|
Varighed: 3. jun. 2017 → 5. jun. 2017
|Konference||European Society of Anesthesia|
|Periode||03/06/2017 → 05/06/2017|