None listed
Conditions
Brief summary
To date, validated depth of anaesthesia and depth of muscle relaxation monitors are available and routinely used in anaesthesia care. However, depth of analgesia has not been specifically monitored and anaesthetists tend to rely on clinical signs (i.e. blood pressure or heart rate) in order to estimate the need for intraoperative analgesics (i.e. opioids). However, the latter may be unreliable and hence a monitor for analgesia is highly desirable. Surgical Pleth Index (SPI) is a score (0-100), which is calculated from the beat-to-beat interval of the heart rate and also the peripheral pulse wave amplitude. Essentially, this data is utilized to reflect the cardiac and peripheral sympathetic tone of a patient – the latter is assumed to correlate with the depth of analgesia. The acquisition of this raw data is achieved via the standard peripheral oxygen saturation sensor and the latter is then computed into the normalized score. SPI requires no change of anaesthesia technique nor any extra monitors or consumables. It’s merely a software patch for GE monitoring systems. Though SPI has been demonstrated to reflect intraoperative stimuli (i.e. knife to skin incision), it cannot be used in awake patients as then the score is subjected to too many artefacts (e.g., arousal is a strong sympathetic stimulant). However, a recent study by Ledowski et al. at Royal Perth Hospital, Perth, Australia has shown a high positive predictive value for SPI more than 30 monitored just before patient arousal to indicate moderate-severe postoperative pain. Though this is promising, no study has yet investigated this matter in children. This observational trial proposes to prospectively investigate the association of SPI with postoperative pain in the recovery room in children from 2 to 16 years. Hypothesis: SPI during the last minutes of surgery may be predictive of moderate-severe acute postoperative pain on recovery room admission.
Interventions
Observation of Surgical Pleth Index (SPI) and State Entropy (SE, validated depth of anaesthesia monitor) 5 minutes prior to emergence from anaesthesia. Recording of postoperative pain, measured 5-minutely on an age-appropriate 0-10 pain scale for 15 minutes after recovery room admission.
All patients will receive a routine general anaesthesia with sevoflurane based maintenance/with a laryngeal mask airway or an endotracheal tube at discretion of treating anaesthetist. All patients receive stan
Observation of Surgical Pleth Index (SPI) and State Entropy (SE, validated depth of anaesthesia monitor) 5 minutes prior to emergence from anaesthesia. Recording of postoperative pain, measured 5-minutely on an age-appropriate 0-10 pain scale for 15 minutes after recovery room admission. All patients will receive a routine general anaesthesia with sevoflurane based maintenance/with a laryngeal mask airway or an endotracheal tube at discretion of treating anaesthetist. All patients receive standard anaesthesia monitoring with addition of depth of anaesthesia monitoring with SE. Clinical care will not deviate from routine practice (only children in whom an anaesthetic with sevoflurane/opioid +/- local/regional block is planned will be included, keeping MAC range between 0.8-1.3, see criteria below) for this study anaesthetic/analgesic drugs may be administered at any time during the study period (excluded medications, see below). If any of the excluded medications has to be administered, the patient will be withdrawn from the study protocol. During the anticipated last 5 minutes of the surgery (last 5 minutes prior to anticipated lightening of depth of anaesthesia to state entropy more than 60, period of only mild surgical stimulation [i.e. skin closure, application of plaster or wound dressing]), data (blood pressure, heart rate, SE, SPI) are downloaded from the anaesthesia monitors (standard anaesthesia monitor at PMH plus portable anaesthesia monitor to collect data of SPI and SE) by means of a data collection software (S5 collect, GE Healthcare) and stored on a laptop PC. After the 5-minute period, it is anticipated that the attending anaesthetist will allow state entropy rated depth of anaesthesia to become lighter (= > 60) and that the patient will finally wake up from the anaesthetic. The latter may take place in the theatre or the recovery room). No influence will be made on the speed or method of patient arousal/extubation. In the recovery room, as per routine clinical practice, a patient’s pain will be rated on a 0-10 pain scale every 5 minutes for 15 minutes (time counting from first time point a patient is deemed conscious and non-delirious. Pain will be assessed as usual at PMH via age-appropriate pain scales: Pain in the group 2-3 yrs. will be assessed using the FLACC (Face, Legs, Activity, Cry, and Consolability) score, in group 4-8 yrs. by the Revised Faces Pain Scale (FPS-R) and in group 9-16 yrs. by means of a Numeric Rating Scale (0 representing no pain and 10 the worst possible pain). Treatment of pain will not be influenced by the protocol.
Sponsors
Princess Margaret Hospital
Eligibility
Sex/Gender
All
Age
2 Years to 16 Years
Healthy volunteers
No
Inclusion criteria
Male or female patients, 2 to 16 years of age with an ASA of 1 2 or 3 who are scheduled for elective or urgent surgery under general anaesthesia (including laryngeal mask airway or endotracheal tube, state entropy monitoring) with sevoflurane.
Exclusion criteria
Lack of informed written consent and/or child assent (where appropriate), age less than 2 years or more than 16 years, poorly treated diabetes, moderate to severe intellectual disability, severe peripheral or cardiac neuropathy, pacemaker, treatment (infusion) with vasoactive medication, any pre or intraoperative treatment prior to the 5 minute observation period with ketamine, beta-receptor blockers, clonidine (as premedication, intraoperative use, or regional adjunct), beta-receptor agonists (i.e. Ventolin) or any other drug suspected to interact with the sympatho-vagal balance. Muscle relaxant reversal using neostigmine, atropine or glycopyrrolate during the 15 minute observation period. Propofol used during the 5 minute SPI observation period. Surgery requiring a tourniquet (unless already deflated at start of intra-operative data acquisition interval).
Outcome results
None listed