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Evaluation of the Parasympathetic Tone Activity (PTA) index to assess the analgesia/nociception balance in anaesthetised dogs
- Mansour, Christelle, Merlin, Tristan, Bonnet-Garin, Jeanne-Marie, Chaaya, Rana, Mocci, Rita, Ruiz, Clara Conde, Allaouchiche, Bernard, Boselli, Emmanuel, Junot, Stéphane
- Research in veterinary science 2017 v.115 pp. 271-277
- analgesia, anesthesia, dogs, heart rate, isoflurane, nociception, prediction, surgery, systolic blood pressure
- The Parasympathetic Tone Activity (PTA) is an index based on the analysis of heart rate variability that has been recently developed to assess the analgesia/nociception balance in anaesthetised animals. The present study aimed to evaluate its performance in dogs undergoing surgery.Thirty dogs admitted for elective surgeries, were anaesthetised with a standardised protocol. PTA, heart rate (HR), systolic blood pressure (SBP) and HDR (defined as an increase by >20% in HR and/or SBP within 5min) were assessed at the following predefined time-points: TStSt (steady-state, after induction of anaesthesia and before start of surgery), TClamp (clamping of surgical drapes on the skin), TCut (cutaneous incision), TPrePTA (retrospectively assessed 1min before a PTA decline of at least 20%) and TEndIso (isoflurane discontinuation). The dynamic variation of PTA over 1min (∆PTA) was calculated at each predefined time-points and its performance to predict HDR was assessed by building Receiver Operating Characteristics (ROC) curves.A significant decrease of PTA (p<0.002) was detected 1min after TClamp, TCut and TPrePTA followed by a significant increase in HR and/or SBP within 5min after the time points (p<0.01). The ΔPTA was associated with the following performance in predicting HDR: AUC ROC [95% CI]=0.80 [0.71 to 0.88] (p<0.05), with a sensitivity of 77% and a specificity of 72% for a threshold value of −18%.Although encouraging, the performance of the PTA index and its dynamic variation needs to be further evaluated, particularly in different clinical contexts.