Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2003
Clinical TrialPulse contour analysis for cardiac output monitoring in cardiac surgery for congenital heart disease.
Conventional methods of cardiac output monitoring using pulmonary artery catheters may not be feasible in patients with congenital heart disease because of patients' small size or aberrant anatomy. We studied the accuracy of a new device, which uses pulse contour analysis to measure continuous cardiac output, in children and adults undergoing congenital heart surgery. Sixteen patients, median ages 7 yr old, were included in this prospective study. One-hundred-ninety-one data points were obtained in the pre- and postcardiopulmonary bypass periods and in the first 12 h after intensive care unit admission. We evaluated the relationship between cardiac index (CI) derived from transpulmonary thermodilution (TDCI) and CI derived from pulse contour analysis (PCCI). Bias and limits of agreement between TDCI and PCCI over all time periods were 0.1 +/- 1.94, indicating a wide dispersion of the data. Coefficient of correlation (r) between the TDCI and PCCI was 0.7. Although in previous studies, PCCI has been suggested to be accurate in adult cardiac surgery, we found it to be less reliable in our study patients, even after shunt correction. The relationships of the volume and pressure based measures of preload, intrathoracic blood volume index (ITBI), and central venous pressure with CI were also investigated. After repair, correlation (r) between PCCI or TDCI and ITBI (0.56 and 0.71, respectively) was better than that between PCCI or TDCI and CVP (0.16 and 0.11, respectively), indicating greater validity of ITBI as a measure of preload. ⋯ Our results suggest that the pulse contour analysis cardiac output (CO) monitoring in patients undergoing congenital heart surgery may not provide as accurate or reliable measures of CO as previously suggested. The volume-based variable of preload intrathoracic blood volume index (ITBI) has better correlation with cardiac index (CI) than the central venous pressure, suggesting that ITBI may be a better indicator of preload.
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Anesthesia and analgesia · Nov 2003
Comparative Study Clinical TrialWomen experience more pain and require more morphine than men to achieve a similar degree of analgesia.
Sex differences in pain perception and in response to opioids have been described, but the findings are inconsistent. We sought to determine the effect of sex on pain perception, morphine consumption, and morphine analgesia after surgery. We designed a prospective cohort study and included 423 women and 277 men who emerged from general anesthesia after surgical procedures and who reported pain intensity of >or=5 on the 0-10 numeric rating scale (NRS). We administered 2.5 mg of morphine IV every 10 min until the pain intensity was
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Anesthesia and analgesia · Nov 2003
Clinical TrialPossible overestimation of indocyanine green-derived plasma volume early after induction of anesthesia with propofol/fentanyl.
Apparently large plasma volumes derived by indocyanine green (PV-ICG) have been determined in the initial period after induction of anesthesia. We tested the hypothesis that possible overestimation of PV-ICG occurs shortly after anesthetic induction. Anesthesia was induced in 13 patients with fentanyl bolus 2 microg/kg and propofol infusion 0.5 mg x kg(-1) x min(-1) IV until patients lost consciousness and was then maintained with a propofol infusion. PV-ICG and the initial distribution volume of glucose (IDVG) were assessed at 15 min before and at 15 min after anesthetic induction. Plasma ICG and glucose concentrations were measured from serial blood samples taken before and through 7 min after injection of ICG 25 mg and glucose 5 g. PV-ICG and IDVG were calculated using a one-compartment model. PV-ICG was significantly increased by an average of 15.3% after induction, from 2.29 +/- 0.38 (SD) L to 2.64 +/- 0.31 L (P < 0.001). The mean hematocrit (Hct), concentrations of hemoglobin (Hb), and total plasma proteins at postinduction decreased compared with those at preinduction by 2.9%, 2.2%, and 2.3%, respectively (P < 0.05). Percentile increase in plasma volume calculated from Hb and Hct before and after induction was 4%. Consequently, an 11% overestimation in PV-ICG was observed. IDVG remained unchanged. Therefore, the ratio of PV-ICG/IDVG increased from 0.40 +/- 0.05 before induction to 0.48 +/- 0.06 after induction (P < 0.01). These results validate the hypothesis that possible overestimation of PV-ICG occurs during a definable period of time after propofol anesthetic induction. The present results also support the PV-ICG/IDVG ratio as a measure of possible overestimation of PV-ICG or fluid redistribution from the central to the peripheral tissues. ⋯ An approximate 11% overestimation in indocyanine green derived plasma volume was observed after induction of anesthesia using propofol and fentanyl. Simultaneous measurement of the initial distribution volume of glucose may help investigate the presence of overestimation in indocyanine green derived plasma volume.