1. SKIN CONDUCTANCE AS A MEASURE OF DISCOMFORT IN ARTIFICIAL VENTILATED CHILDREN Gjerstad AC*, Wagner K**, Henriksen T***, Hellerud BC*, Storm H*, Skills training centre, Medical Faculty, University of Oslo, The National Hospital*, Intensive care unit for children, Department of Anaesthesia, The National Hospital**, Intensive care unit for children, Ullevaal University hospital***, Norway. INTRODUCTION Skin conductance shows the emotional state as reflected in changes in the sympathetic nervous system. Each time this part of the sympathetic nervous system is activated, the palmar and plantar sweat glands are filled up, and the skin conductance increases before the sweat is removed and the skin conductance decreases. Thus, when an outgoing sympathetic nervous burst occurs, changes of skin conductance will follow. An increase in the number of skin conductance fluctuations can therefore be interpreted as increased activity in this part of the sympathetic nervous system. This method is specific for the stimuli that induce the stress response. Skin conductance fluctuations have been used to evaluate the pain response in preterm infants. The pain stimuli induced an immediate increase in emotional sweating and skin conductance fluctuations, and when the pain stimuli terminated, the skin conductance fluctuations decreased immediately. Unlike heart rate and blood pressure changes, emotional sweating is not influenced by circulatory changes. Skin conductance changes may therefore be more specifically linked to pain responses than blood pressure and heart rate at least in patients that are circulatory unstable. PURPOSE The purpose of the study was to find out how the changes of skin conductance fluctuations, blood pressure and heart rate are associated to the changes in the COMFORT sedation score during suction from tracea in artificial ventilated children that are circulatory stable. MATERIALS AND METHODS Subjects 20 artificial ventilated children that were circulatory stable, were studied. The skin temperature was more than 25 o C. The children were more or less sedated with paracetamol, morphine and midazolam. Table 1: Sex Age WeightDiagnosis F 6 months 6,7 kgReflux-operated F 5 months 7,5 kgLiver-transplanted M 3.5 months 3,0 kgIleum-resection F 5 days 4,1 kgTransposition of great vessels M 2.5 months 5,3 kgMycoplastic aorticarch F 7 years 27,6 kgAV-malformation-operated M 1 month 3,8 kgAVSD-operated F 2 days 1,7 kgGastrochise-operated F 7 months 6.0 kgAVSD-operated M 1 1/2 year 8,7 kgASD II-operated F 3 months 3,2 kgAortastenosis-operated F 2 months 3,8 kgOesophagusatresia-operated M 1 day 3,5 kgPulmonalatresia-operated M 8 days 4,1 kgVSD-ASD-operated M 8 years 27,6 kgHypoplastic aorticarch-operated M 6 years 22,0 kgLiver-transplanted F 9 months 6,4 kgLung-infection F 5 years 12,5 kgEBV-pneumonia M 18 days 2,6 kgPleura-drainage F 2 years 11,7 kgLung-atelectasis Apparatus The skin conductance equipment, developed by Med-Storm as, was connected to a portable PC. The software progam analysed the skin conductance data off-line in 30 seconds periodes. The thresholds for the skin conductance fluctuations were 0.015 microsiemens, equipment from Siemens. The bloodpressure was measured online by an intra arterial line. The heart rate was also measured online, equipment form Siemens. Procedure The study was conducted in the ICU in children that were artificial ventilated. Skin conductance (number of fluctuation, amplitude of fluctuation and mean skin conductance level), bloodpressure, heart rate and COMFORT sedation score (Alertness, Calmness, Respiratory response, Physical movement, Muscle tone and Facial tension) were registrated for 2 minutes before, during and 2 minutes after suction from tracea. The maximum skin conductance level, bloodpressure, heart rate and COMFORT sedation score were calculated for these periods of time. Statistical analysis Linear regression analysis was used to correlate the changes in skin conductance, heart rate, blod pressure and COMFORT sedation score from before to during and from during to after suction of tracea. Moreover, non-parametric tests for related samples, with Bonferoni correction, were used to test if the different variables increased from before to during and decreased from during to after suction of tracea. Results The number and amplitude of skin conductance fluctuations (fig. 1), the mean skin conductance level (fig. 1), the blood pressure and the COMFORT sedation score increased statistical significant during suction from tracea, different from the heart rate (table 2). Fig. 1 Skin conductance before, during and after suction from tracea. Linear regression on the different variables showed only a statistical significant correlation between COMFORT and Number of skin conductance fluctuations from before to during r2 = 0.66 p=0.000, and from during to after r2=0.51 p=0.000. Table 2: No sc fl from before to during p=0.002 No sc fl from during to after p=0.004 Ampl sc fl from before to during p=0.006 Ampl sc fl from during to after p=0.002 Mean sc level from before to during p=0.002 Mean sc level from during to after p=0.072 COMFORT from before to during p=0.000 COMFORT from during to after p=0.000 Blood pressure from before to during p=0.000 Blood pressure from during to after p=0.004 Heart rate from before to during p=0.092 Heart rate from during to after p=0.084 Abbrevations: No - number, sc – skin conductance, fl – fluctuations, Conclusion Increase in number of skin conductance fluctuation during suction from tracea correlates with increase in COMFORT sedation score different from blod pressure and heart rate and therefore seems to be a better measure than blood pressure and heart rate to monitor discomfort in artificial ventilated children in circulatory stable patients.