Parent-Controlled Analgesia in Children Undergoing Cleft Palate Repair

The aims of this study were to find an optimal basal infusion dose of fentanyl for parent-controlled analgesia (PrCA) in children undergoing cleft palate repair and the degree of parents' satisfaction with PrCA. Thirty consecutive children between 6 months and 2 yr of age were enrolled. At the end of surgery, a PrCA device with a basal infusion rate of 2 mL/hr and bolus of 0.5 mL with lockout time of 15 min was applied. Parents were educated in patient-controlled analgesia (PCA) devices, the Wong Baker face pain scoring system, and monitoring of adverse effects of fentanyl. Fentanyl was infused 0.3 microgram/kg/hr at first, and we obtained a predetermined fentanyl regimen by the response of the previous patient to a larger or smaller dose of fentanyl (0.1 microgram/kg/hr as the step size), using an up-and-down method. ED50 and ED95 by probit analysis were 0.63 microgram/kg/hr (95% confidence limits, 0.55-0.73 microgram/kg/hr) and 0.83 microgram/kg/hr (95% confidence limits, 0.73-1.47 microgram/kg/hr), respectively. Eighty seven percent of the parents were satisfied with participating in the PrCA modality. PrCA using fentanyl with a basal infusion rate of 0.63 microgram/kg/hr can be applied effectively for postoperative pain management in children undergoing cleft palate repair with a high level of parents' satisfaction.

The Relationship of the Anthropometric Variables to the Infusion Rate of Rocuronium in the Elderly

We have determined the infusion rates of rocuronium in the elderly and young adult patients during sevoflurane and nitrous oxide anesthesia. The correlation of some anthropometric predictors with infusion rate of rocuronium was also investigated for both elderly and young adult. Participating patients were assigned to one of two groups: 1) young adult patients aged 20 to 50 years (n = 30) ; 2) elderly patients aged over 65 years (n = 30). The anthropometric variables such as height, weight, ratio of weight to body surface area, subscapularis and suprailiac skin folds, body surface area, body mass index and % ideal body weight were evaluated as predictors for infusion rate. The infusion rate in elderly patients was significantly less compared with that in young adult patients (p < 0.05). In elderly patients, no anthropometric predictor was related to the infusion rate of rocuronium. This suggests that the infusion rate of rocuronium for an elderly patient needs to be individualized by monitoring neuromuscular transmission to avoid excessive dose.

Hemodynamic Effects of Modified Ultrafiltration (MUF) in Adult Patients Undergoing Valvular Heart Surgery / 대한마취과학회지

BACKGROUND: Modified ultrafiltration (MUF) has been demonstrated to have beneficial effects in children undergoing cardiac surgery with cardiopulmonary bypass (CPB). In adults, the hemodynamic effects of MUF are little known. The purpose of this investigation is to evaluate the hemodynamic effects of MUF in adult patients undergoing valvular heart surgery. METHODS: 30 patients scheduled for elective mitral valvular surgery were randomized into either Ultrafiltration (U) or Control (C) group. In the U group, MUF was performed just after termination of CPB for 20 minutes, and not in the C group. Measurements of hemodynamic variables including right ventricular ejection fraction (RVEF) measured by thermodilution technique and hematocrit were performed before induction, just after termination of CPB, after completion of MUF and after sternal closure. Measurement after MUF in the C group was performed at 20 minutes after the termination of CPB. After transfer to ICU, same measurements were performed at postoperative 6 and 12 hrs. RESULTS: After MUF, RVEF (P < 0.05) and hematocrit (P < 0.01) increased in the U group, compared to the corresponding values measured just after termination of CPB. However, the variables were not statistically different between the two groups throughout the intraoperative procedures and during ICU stay. CONCLUSIONS: Conclusively, MUF was demonstrated to have the transient beneficial effect of improving the right heart function and hemoconcentration immediately after termination of CPB.

Effect of Thiopental Sodium on Hearing Outcomes Following Microvascular Decompression Surgery / 대한마취과학회지

BACKGROUND: The use of intraoperative brainstem auditory evoked potential (BAEP) has reduced the incidence of sensorineural hearing loss (SNHL) after microvascular decompression (MVD). This complication occurs due to direct compressive and/or stretching injury of the cochlear nerve or to indirect compression of the perineural vasculature during cerebellar retraction. The aim of this study was to evaluate the effect of thiopental sodium on SNHL after MVD for hemifacial spasm. METHODS: 94 hemifacial spasm patients with normal hearing function preoperatively and who underwent MVD under intraoperative BAEP monitoring were enrolled in this study. Patients were randomly divided into two groups. 52 patients were administered placebo (control group) and 42 patients were administered thiopental sodium 5 mg/kg intravenously 5 minutes before cerebellar retraction (thiopental group). The effects of thiopental on intraoperative BAEP changes and postoperative hearing functional outcomes were sought. Incidence and degree of postoperative SNHL were evaluated by pure tone audiometry threshold analysis. RESULTS: Maximal changes in intraoperative BAEP parameters did not differ between the two groups, and neither did the incidence nor degree of SNHL. In the control group, 4 transient and 4 permanent postoperative SNHL, including 2 deaf patients, occurred with an overall incidence of 15.4%. In the thiopental group, 2 transient and 1 permanent postoperative SNHL occurred, with an overall incidence of 7.1%. CONCLUSIONS: Thiopental sodium administered prior to cerebellar retraction might reduce the incidence of postoperative hearing loss.

The Validity of Intraoperative Brainstem Auditory Evoked Potentials (BAEPs) for the Postoperative Hearing Impairments in Microvascular Decompression (MVD) / 대한마취과학회지

BACKGROUND: Intraoperative brainstem auditory evoked potentials reduced the sensorineural hearing loss (SNHL) after microvascular decompression (MVD) This study was performed to evaluate the validity of BAEP parameters of latency or amplitude to SNHL. METHODS: 557 patients out of 930 hemifacial spasm patients performed MVD, who were free from hearing impairment preoperatively, were enrolled in this study. Maximal changes of BAEPs wave V latency and amplitude during MVD were retrospectively sought according to postoperative SNHL. Sensitivity, specificity and positive predictability of wave V latency and amplitude were also sought according to the postoperative SNHL with a critical value of 1.0 msec prolongation and 40% decrease, respectively. RESULTS: Wave V latency of BAEPs prolonged less in patients with normal hearing outcome (0.44 +/- 0.63 msec) than in the patients with temporary or permanent SNHL (1.23 +/- 0.56 msec, 1.33 +/- 0.33 msec). Wave V amplitude also decreased less in the patients with normal hearing outcome (5.4 +/- 15.8%) than in the patients with transient or permanent SNHL (42.8 +/- 31.7%, 60.0 +/- 34.7%). While sensitivity, specificity and predictability of prolongation of wave V latency at a value of 1.0 msec for SNHL, were 52.5%, 76.4% and 14.7%, respectively, those of decrease in the amplitude of wave V for SNHL at a value of 40% were 35.0%, 93.6% and 29.8%, respectively. CONCLUSIONS: Decrease of the amplitude of wave V seems to have higher specificity, predictability and lower sensitivity for SNHL than the prolongation of wave V latency.

Comparison of Radial and Femoral Arterial Pressure in Pediatric Patients Undergoing Open Heart Surgery / 대한마취과학회지

BACKGROUND: It has been known that a reversal of usual relationship between aortic and radial artery pressures(RAP) can occur in adult patients following cardiopulmonary bypass(CPB). The phenomenon of a pressure gradient between RAP and femoral artery pressure(FAP) were evaluated in pediatric patients before and after CPB. METHODS: 141 perdiatric patients undergoing open heart surgery were allocated into 2 groups. Group 1(n=77): infant's body weight was below 10kg. Group 2(n=64): child's body weight was between 10 and 20kg. After induction of anesthesia RAP was measured through 22G(1 inch) or 24G(3/4 inch) catheters and FAP was measured through 20G(2 inch) or 22G(1 inch) catheters using calibrated transducers. Hematocrit, rectal and nasopharyngeal temperature and left atrial pressure(LAP) were recorded 10 min after induction, immediately, l5, 30 and 60 min after CPB. Values are expressed as mean+/-SD and analysed using paired and unpaired t-test; p<0.05 was considered significant. RESULT: Systolic femoral arterial pressure(SFAP) was higher than radial arterial pressure(SRAP) before CPB in both groups. After CPB, the pressure gradient persisted in group 2 but was reversed with statistical significance in group l. CONCLUSION: When hypotension occurs during cardiac surgery, a comparison is recommended between radial and femoral or aortic pressure before treatment for hypotension is contemplated.

Comparison of Radial and Femoral Arterial Pressure in Pediatric Patients Undergoing Open Heart Surgery / 대한마취과학회지

BACKGROUND: It has been known that a reversal of usual relationship between aortic and radial artery pressures(RAP) can occur in adult patients following cardiopulmonary bypass(CPB). The phenomenon of a pressure gradient between RAP and femoral artery pressure(FAP) were evaluated in pediatric patients before and after CPB. METHODS: 141 perdiatric patients undergoing open heart surgery were allocated into 2 groups. Group 1(n=77): infant's body weight was below 10kg. Group 2(n=64): child's body weight was between 10 and 20kg. After induction of anesthesia RAP was measured through 22G(1 inch) or 24G(3/4 inch) catheters and FAP was measured through 20G(2 inch) or 22G(1 inch) catheters using calibrated transducers. Hematocrit, rectal and nasopharyngeal temperature and left atrial pressure(LAP) were recorded 10 min after induction, immediately, l5, 30 and 60 min after CPB. Values are expressed as mean+/-SD and analysed using paired and unpaired t-test; p<0.05 was considered significant. RESULT: Systolic femoral arterial pressure(SFAP) was higher than radial arterial pressure(SRAP) before CPB in both groups. After CPB, the pressure gradient persisted in group 2 but was reversed with statistical significance in group l. CONCLUSION: When hypotension occurs during cardiac surgery, a comparison is recommended between radial and femoral or aortic pressure before treatment for hypotension is contemplated.