Analysis of prognostic factors for postoperative complications and mortality in elderly patients undergoing emergency surgery for intestinal perforation or irreversible intestinal ischemia

Purpose@#Because the global geriatric population continues to increase, the assessment of emergency surgical outcomes in elderly patients with acute peritonitis will become more important. @*Methods@#A retrospective review was conducted on the data of 174 elderly patients who underwent emergency surgery for intestinal perforation or intestinal infarction between June 2010 and November 2022. We conducted an analysis of the risk factors associated with postoperative complications and mortality by evaluating the characteristics of patients and their surgical outcomes. @*Results@#In our study, most patients (94.3%) had preexisting comorbidities, and many patients (84.5%) required transfer to the intensive care unit following emergency surgery. Postoperative complications were observed in 84 individuals (48.3%), with postoperative mortality occurring in 29 (16.7%). Multivariate analysis revealed preoperative acute renal injury, hypoalbuminemia, and postoperative ventilator support as significant predictors of postoperative mortality. @*Conclusion@#When elderly patients undergo emergency surgery for intestinal perforation or infarction, it is important to recognize that those with preoperative acute renal injury, hypoalbuminemia, and a need for postoperative ventilator support have a poor prognosis. Therefore, these patients require intensive care from the early stages of treatment.

Anesthetic Management of a Patient with Type II Alexander Disease: A Case Report

Patients with type II Alexander disease have white matter dysplasia, which may cause various symptoms due to nerve conduction impairment. When providing anesthesia to a patient with Alexander disease, careful and patient-specific individualized risk evaluation must be preceded by planning the method of anesthesia and anesthetic drugs. This is the first case report of a patient with type II Alexander disease who underwent general anesthesia. We performed general anesthesia on a 45-year-old male with type II Alexander disease for laparoscopic cholecystectomy, using remimazolam, remifentanil, and rocuronium. Despite the use of reversal agents including flumazenil, naloxone, and sugammadex, the patient manifested a delay in emergence but successfully recovered from anesthesia without postoperative complications. In consideration of the possibility that leukodystrophy may have altered responses to anesthetics, the action of an anesthetic agent may be prolonged or delayed in patients with type II Alexander disease. We recommend using drugs with a short duration of action and which can be reversed immediately by a reversal agent.

Perforation on the superior side of duodenum is a risk factor of laparoscopic primary repair for duodenal ulcer perforation

Purpose@#Primary repair is the standard surgical method for treating duodenal ulcer perforations, with very good results usually anticipated because of the simplicity of the associated surgical techniques. Therefore, this study aimed to analyze the risk factors that affect laparoscopic primary repair outcomes for duodenal ulcer perforation. @*Methods@#Between June 2010 and June 2020, 124 patients who underwent laparoscopic primary repair for duodenal ulcer perforations were reviewed. Early surgical outcomes were evaluated and risk factors for postoperative complications were assessed. @*Results@#All surgeries were performed laparoscopically without open conversion. Multivariate analysis showed that the elderly (over 70 years), and perforations that needed more than 2 stitches for closure were risk factors for overall postoperative complications. Perforations that needed more than 2 stitches and perforations on the superior side of the duodenum were major risk factors for severe postoperative complications. Severe postoperative complications occurred in 6 of the patients, and 1 of them died of multiorgan failure. @*Conclusion@#Based on our results, we suggest that laparoscopic primary repair can be safely performed in duodenal ulcer perforation. However, more careful surgery and postoperative care are needed to improve the surgical outcomes of patients who need more than 2 stitches to close their perforation or who have perforations on the superior side of the duodenum.

Perforation on the superior side of duodenum is a risk factor of laparoscopic primary repair for duodenal ulcer perforation

Purpose@#Primary repair is the standard surgical method for treating duodenal ulcer perforations, with very good results usually anticipated because of the simplicity of the associated surgical techniques. Therefore, this study aimed to analyze the risk factors that affect laparoscopic primary repair outcomes for duodenal ulcer perforation. @*Methods@#Between June 2010 and June 2020, 124 patients who underwent laparoscopic primary repair for duodenal ulcer perforations were reviewed. Early surgical outcomes were evaluated and risk factors for postoperative complications were assessed. @*Results@#All surgeries were performed laparoscopically without open conversion. Multivariate analysis showed that the elderly (over 70 years), and perforations that needed more than 2 stitches for closure were risk factors for overall postoperative complications. Perforations that needed more than 2 stitches and perforations on the superior side of the duodenum were major risk factors for severe postoperative complications. Severe postoperative complications occurred in 6 of the patients, and 1 of them died of multiorgan failure. @*Conclusion@#Based on our results, we suggest that laparoscopic primary repair can be safely performed in duodenal ulcer perforation. However, more careful surgery and postoperative care are needed to improve the surgical outcomes of patients who need more than 2 stitches to close their perforation or who have perforations on the superior side of the duodenum.

Surgical Outcomes and Survival Prognostic Factors for Palliative Gastrectomies in Stage IV Resectable Gastric Cancer Outlet Obstruction Patients

Purpose@#Currently, there is no clear evidence to support any specific treatment as a principal therapy for stage IV gastric cancer outlet obstruction (GCOO) patients. This study evaluated the outcomes of palliative gastrectomies and survival prognostic factors in patients with stage IV resectable GCOO. @*Materials and Methods@#We retrospectively reviewed the medical records of 48 stage IV GCOO patients who underwent palliative gastrectomies between June 2010 and December 2019.Palliative gastrectomies were performed only in patients with resectable disease. Early surgical outcomes and prognostic factors were analyzed using univariate and multivariate analyses. @*Results@#There were no specific risk factors for postoperative complications, except for being underweight. Severe postoperative complications developed in five patients, and most of the patients underwent interventional procedures and received broad-spectrum antibiotics for intra-abdominal abscesses. The multivariate survival analysis showed that palliative chemotherapy is a positive prognostic factor, while the specific type of hematogenous and lymphatic metastasis is a negative prognostic factor. @*Conclusions@#We recommend that the treatment method for stage IV GCOO should be selected according to each patient's physical condition and tumor characteristics. In addition, we suggest that palliative gastrectomies can be performed in stage IV resectable GCOO patients without unfavorable prognostic factors (types of hematogenous and lymphatic metastases).

Surgical Outcomes and Survival Prognostic Factors for Palliative Gastrectomies in Stage IV Resectable Gastric Cancer Outlet Obstruction Patients

Purpose@#Currently, there is no clear evidence to support any specific treatment as a principal therapy for stage IV gastric cancer outlet obstruction (GCOO) patients. This study evaluated the outcomes of palliative gastrectomies and survival prognostic factors in patients with stage IV resectable GCOO. @*Materials and Methods@#We retrospectively reviewed the medical records of 48 stage IV GCOO patients who underwent palliative gastrectomies between June 2010 and December 2019.Palliative gastrectomies were performed only in patients with resectable disease. Early surgical outcomes and prognostic factors were analyzed using univariate and multivariate analyses. @*Results@#There were no specific risk factors for postoperative complications, except for being underweight. Severe postoperative complications developed in five patients, and most of the patients underwent interventional procedures and received broad-spectrum antibiotics for intra-abdominal abscesses. The multivariate survival analysis showed that palliative chemotherapy is a positive prognostic factor, while the specific type of hematogenous and lymphatic metastasis is a negative prognostic factor. @*Conclusions@#We recommend that the treatment method for stage IV GCOO should be selected according to each patient's physical condition and tumor characteristics. In addition, we suggest that palliative gastrectomies can be performed in stage IV resectable GCOO patients without unfavorable prognostic factors (types of hematogenous and lymphatic metastases).

Ketamine Anesthesia for Maintenance of Spontaneous Breathing during Video-Assisted Thoracic Surgery

If you have conventional general anesthesia using muscle relaxants for video-assisted thoracic surgery, one lung ventilation with double lumen tube could be dangerous when residual lung volume of non-operated lung could be lacking, and positive pressure ventilation for maintenance of proper minute ventilation could be impossible when there could be too much air leakage. Also, if the abnormal bleeding tendency is, thoracic epidural anesthesia for maintenance of spontaneous breathing could be difficult to perform. A 66-year-old male with a consolidative lesion in involving right middle and lower lobe, and left pneumothorax and pleural effusion successfully underwent video-assisted thoracic bullectomy using ketamine with remifentanil for maintenance of spontaneous breathing and intermittent positive pressure support ventilation within 10 cmH2O for protection of excessive air leakage.

Ultrasound-guided greater occipital nerve block with botulinum toxin for patients with chronic headache in the occipital area: a randomized controlled trial / 대한마취과학회지

BACKGROUND: Ultrasound-guided greater occipital nerve (GON) block has been frequently used to treat various types of headaches, and botulinum toxin has recently begun to be used in patients with headache. Our study presents the long-term effect of botulinum toxin on GON block using ultrasound in patients with chronic headache in occipital area. METHODS: Patients with occipital headache were divided into two groups (bupivacaine: BUP group [n = 27], botulinum toxin: BTX group [n = 27]), and ultrasound-guided GON block was performed at the C2 level. GON was detected with ultrasound and distance from GON to midline, from the skin surface to GON, and size of GON were measured in both groups. Visual analogue scale (VAS) scores and Likert scale were assessed at pretreatment and at 1, 4, 8, and 24 weeks after treatment in both groups. RESULTS: The distance from GON to midline was 18.9 ± 4.4 mm (right) and 17.3 ± 3.8 mm (left). The depth from the skin was 12.9 ± 1.5 mm (right) and 13.4 ± 1.6 mm (left). GON size was 3.1 mm on both sides. The VAS score and patient satisfaction score (Likert scale) in 4, 8, and 24 weeks after injection were superior for the BTX than the BUP group. CONCLUSIONS: Ultrasound-guided GON block using BTX is effective in reducing short-term and long-term pain in patients with chronic headache in the occipital area.

Alternative anesthetic management of video-assisted thoracic surgery for spontaneous breathing / 대한마취과학회지

No abstract available.

Anesthetic Management for an Eye Surgery in a Patient with Stevens-Johnson Syndrome

The Stevens-Johnson syndrome is a severe manifestation of erythema multiforme associated with multisystem involvement. It is extremely unusual for patients with this syndrome to present with indications for eye surgery. Respiratory tract involvement can make the management of the airway and tracheal intubation difficult. We describe herein the perioperative management of a patient with this disease who underwent surgery for amniotic membrane transplantation.

Ultrasound-guided greater occipital nerve block with botulinum toxin for patients with chronic headache in the occipital area: a randomized controlled trial / 대한마취과학회지

BACKGROUND@#Ultrasound-guided greater occipital nerve (GON) block has been frequently used to treat various types of headaches, and botulinum toxin has recently begun to be used in patients with headache. Our study presents the long-term effect of botulinum toxin on GON block using ultrasound in patients with chronic headache in occipital area.@*METHODS@#Patients with occipital headache were divided into two groups (bupivacaine: BUP group [n = 27], botulinum toxin: BTX group [n = 27]), and ultrasound-guided GON block was performed at the C2 level. GON was detected with ultrasound and distance from GON to midline, from the skin surface to GON, and size of GON were measured in both groups. Visual analogue scale (VAS) scores and Likert scale were assessed at pretreatment and at 1, 4, 8, and 24 weeks after treatment in both groups.@*RESULTS@#The distance from GON to midline was 18.9 ± 4.4 mm (right) and 17.3 ± 3.8 mm (left). The depth from the skin was 12.9 ± 1.5 mm (right) and 13.4 ± 1.6 mm (left). GON size was 3.1 mm on both sides. The VAS score and patient satisfaction score (Likert scale) in 4, 8, and 24 weeks after injection were superior for the BTX than the BUP group.@*CONCLUSIONS@#Ultrasound-guided GON block using BTX is effective in reducing short-term and long-term pain in patients with chronic headache in the occipital area.

Comparison of several dosing schedules of intravenous dexmedetomidine in elderly patients under spinal anesthesia

BACKGROUND: Many clinicians have probably used subjective, unscientific methods for dose reduction to avoid overdose in elderly patients. The aim of this study was to compare several dosing schedules of intravenous dexmedetomidine (DEX) to identify the appropriate dosing schedule within the therapeutic dose range for adequate sedation of elderly patients under spinal anesthesia. METHODS: After administration of spinal anesthesia, a loading dose of DEX was injected over 10 min in three groups with the following dosages: group A, 1.0 μg/kg of actual body weight; group B, 1.0 μg/kg of ideal body weight (IBW); and group C, 0.8 μg/kg of IBW. Then, a maintenance infusion (0.5 μg/kg of each BW/h) was administered. The bispectral index score (BIS), the time required to reach BIS 80, airway obstruction score, and the occurrence of bradycardia were recorded. RESULTS: The changes in the BIS among the groups over time were found to have statistically significant differences (P < 0.001). The times required to reach BIS 80 were 6.1 ± 5.3 min, 5.0 ± 3.6 min, and 11.0 ± 8.6 min in groups A, B, and C, respectively (P < 0.001). The airway obstruction score and the frequency of bradycardia did not have statistically significant differences among the groups. CONCLUSIONS: An initial loading dose of DEX that is 0.8 μg/kg of IBW over 10 min, followed by an infusion rate of less than 0.5 μg/kg of IBW/h may be adequate for sedation in elderly patients receiving spinal anesthesia.

Comparison of several dosing schedules of intravenous dexmedetomidine in elderly patients under spinal anesthesia

BACKGROUND: Many clinicians have probably used subjective, unscientific methods for dose reduction to avoid overdose in elderly patients. The aim of this study was to compare several dosing schedules of intravenous dexmedetomidine (DEX) to identify the appropriate dosing schedule within the therapeutic dose range for adequate sedation of elderly patients under spinal anesthesia. METHODS: After administration of spinal anesthesia, a loading dose of DEX was injected over 10 min in three groups with the following dosages: group A, 1.0 μg/kg of actual body weight; group B, 1.0 μg/kg of ideal body weight (IBW); and group C, 0.8 μg/kg of IBW. Then, a maintenance infusion (0.5 μg/kg of each BW/h) was administered. The bispectral index score (BIS), the time required to reach BIS 80, airway obstruction score, and the occurrence of bradycardia were recorded. RESULTS: The changes in the BIS among the groups over time were found to have statistically significant differences (P < 0.001). The times required to reach BIS 80 were 6.1 ± 5.3 min, 5.0 ± 3.6 min, and 11.0 ± 8.6 min in groups A, B, and C, respectively (P < 0.001). The airway obstruction score and the frequency of bradycardia did not have statistically significant differences among the groups. CONCLUSIONS: An initial loading dose of DEX that is 0.8 μg/kg of IBW over 10 min, followed by an infusion rate of less than 0.5 μg/kg of IBW/h may be adequate for sedation in elderly patients receiving spinal anesthesia.

A loading dose of 1 µg/kg and maintenance dose of 0.5 µg/kg/h of dexmedetomidine for sedation under spinal anesthesia may induce excessive sedation and airway obstruction

BACKGROUND: For many drugs, dosing scalars such as ideal body weight (IBW) and lean body mass are recommended over the use of total body weight (TBW) during weight-based dose calculations. Doses based on TBW are frequently used, and this may cause under- or over-dosing. Because dexmedetomidine (DEX) overdosing could increase the incidence of side effects, and spinal anesthesia may increase sensitivity to a sedative agent, determining an appropriate dose is critical. METHODS: Eighty patients were randomly divided into 2 groups, the IBW and TBW groups. Patients received a loading dose of DEX 1 µg/kg IBW or TBW for 10 min, followed by a continuous infusion at 0.5 µg/kg/h IBW or TBW after the induction of spinal anesthesia. The patients' vital signs, bispectral index (BIS), peripheral capillary oxygen saturation, time to reach a BIS of 80, airway obstruction score, and coughing were monitored and recorded at 0, 10, 30, and 50 min after the start of the loading dose injection. RESULTS: The changes in BIS, airway obstruction score, the incidence of side effects, and time to reach a BIS of 80 did not show statistically significant differences between the two groups. However, airway obstruction and/or coughing occurred in both groups, and the average BIS in both groups was lower than the target BIS of 60-80 at 30 and 50 min. CONCLUSIONS: A loading dose of DEX 1 µg/kg for 10 min, and a maintenance dose of DEX 0.5 µg/kg/h of either IBW or TBW, may induce excessive sedation, airway obstruction, and/or coughing under spinal anesthesia.

A unilateral large bronchopleural fistula caused by rupture of bulla with coexisting bilateral giant bullae: A case report

A patient with a large bronchopleural fistula presents several intraoperative challenges for the anesthesiologist, particularly if bullae coexist bilaterally. Ideally, a double lumen tube is inserted while the patient is conscious or breathing spontaneously under general anesthesia to prevent possible tension pneumothorax in the contralateral lung due to positive-pressure ventilation and the possibility of inadequate ventilation due to an air leak from the fistula. However, we inserted a single lumen tube instead of a double lumen tube, because this patient had multiple giant bullae bilaterally and the contralateral lung tissue was almost completely compressed and destroyed. We report the use of a single lumen tube under volatile general anesthesia with synchronized intermittent mandatory ventilation with small tidal volume. In addition, we used permissive hypercapnia to further minimize barotraumas. Due to permissive hypercapnia, there were no cardiovascular consequences.

End-tidal concentration of sevoflurane for reducing rocuronium-induced withdrawal reactions in adult patients: a comparison between male and female patients / 대한마취과학회지

BACKGROUND: In this study, we assessed the 50% effective concentration (EC50) of sevoflurane for reducing a rocuronium-induced reaction, based on the Dixon's up-and-down method. We also assessed the 50 and 95% effective end-tidal concentration of sevoflurane (ETsev), based on the probit regression curve of the probability of nonwithdrawal reaction. METHODS: We conducted a prospective, double-blind study in 23 males and 24 females. After using 2.5% thiopental sodium (4 mg/kg), anesthesia was induced in the patients. The patients then inhaled sevoflurane with 5 vol% in 6 L/min of oxygen. When the target ETsev was achieved, a nurse injected the intubating dose of rocuronium (0.6 mg/kg) for 5-10 s under the free flow of intravenous fluid. After the nurse evaluated the response, the nurse recorded the maximum heart rate during 30 s and the mean arterial pressure after rocuronium injection. RESULTS: Based on Dixon's up-and-down method, the EC50 of sevoflurane was 2.5 alpha 0.5 vol% in males and 2.5 alpha 0.3 vol% in females. The probit regression curve of the probability of nonwithdrawal reaction showed that in males the 50% effective ETsev was 2.4 vol% (95% confidence interval [CI], 1.5-3.1 vol%) and the 95% effective ETsev was 3.5 vol% (95% CI, 2.9-11.0 vol%); in females, the 50% effective ETsev was 2.4 vol% (95% CI, 2.1-2.7 vol%) and the 95% effective ETsev was 3.0 vol% (95% CI, 2.7-4.5 vol%). CONCLUSIONS: The inhalation of sevoflurane during the induction period may provide a simple and reliable means of reducing rocuronium-induced reactions without adverse hemodynamic changes. There was no significant difference between males and females.

End-tidal concentration of sevoflurane for preventing rocuronium-induced withdrawal of the arm in pediatric patients / 대한마취과학회지

BACKGROUND: During induction of general anesthesia, the intravenous injection of rocuronium is often associated with withdrawal movement of the arm due to pain, and this abrupt withdrawal may result in dislodgement of the venous catheter, injury, or inadequate injection of rocuronium. We performed this study to evaluate the 50 and 95% effective end-tidal concentrations of sevoflurane (ETsev) for preventing rocuronium-induced withdrawal of the arm. METHODS: We conducted a prospective double-blind study in 31 pediatric patients. After free flow of lactated Ringer's IV fluid was confirmed, anesthesia was induced in the patients by using 2.5% thiopental sodium (4 mg/kg) and sevoflurane (4 vol%) with 6 L/min of oxygen. When the target ETsev was reached, preservative-free 1% lidocaine (1.5 mg/kg) was intravenously injected during manual venous occlusion and rocuronium (0.6 mg/kg) was injected after lidocaine injection under free-flow intravenous fluid. A nurse who was an investigator and was blinded to the ETsev injected the rocuronium. The nurse evaluated the response. RESULTS: Non-withdrawal movement was observed in 5 out of 11 patients with ETsev 3.0 vol% and in 5 out of 6 patients with ETsev 3.5 vol%. By Dixon's up-and-down method, the 50% effective concentration (EC50) of sevoflurane for non-withdrawal movement at rocuronium injection was 3.1 +/- 0.4 vol%. A logistic regression curve of the probability of non-withdrawal movements showed that the 50% effective ETsev for abolishing withdrawal movement at rocuronium injection was 2.9 vol% (95% confidence interval [CI] 2.4-3.8 vol%) and the 95% effective ETsev was 4.3 vol% (95% CI 3.6-9.8 vol%). CONCLUSIONS: This study showed that the 50 and 95% effective ETsev that prevent withdrawal movement at rocuronium injection are 2.9 and 4.3 vol%, respectively.

Antioxidant effects of methylprednisolone and hydrocortisone on the impairment of endothelium dependent relaxation induced by reactive oxygen species in rabbit abdominal aorta / 대한마취과학회지

BACKGROUND: The reperfusion following ischemia produces reactive oxygen species (ROS). We studied the influences of methylprednisolone (MPD) and hydrocortisone (CRT) on ROS effects using the endothelium of rabbit abdominal aorta. METHODS: Isolated rabbit aortic rings were suspended in an organ bath filled with Krebs-Henseleit (K-H) solution. After precontraction with norepinephrine, changes in arterial tension were recorded following the cumulative administration of acetylcholine (ACh). The percentages of ACh-induced relaxation of aortic rings before and after exposure to ROS, generated by electrolysis of K-H solution, were used as the control and experimental values, respectively. The aortic rings were pretreated with MPD or CRT at the same concentrations, and the effects of these agents were compared with the effects of ROS scavenger inhibitors: superoxide dismutase inhibitor, diethylthiocarbamate (DETCA), and the catalase inhibitor, 3-amino-1,2,4-triazole (3AT). RESULTS: Both MPD and CRT maintained endothelium-dependent relaxation induced by ACh in a dose-related manner in spite of ROS attack. The restored ACh-induced relaxation of MPD and CRT group was not attenuated by pretreatment of 3AT and DETCA. CONCLUSIONS: MPD and CRT preserve the endothelium-dependent vasorelaxation against the attack of ROS, in a dose-related manner. Endothelial protection mechanisms of MPD and CRT may be not associated with hydrogen peroxide and superoxide scavenging.

Peri-operative ketamine with the ambulatory elastometric infusion pump as an adjuvant to manage acute postoperative pain after spinal fusion in adults: a prospective randomized trial / 대한마취과학회지

BACKGROUND: In this study, we assessed the effectiveness of ketamine as an alternative to non-steroidal anti-inflammatory drugs (NSAID), to manage acute postoperative pain after spinal fusion when given intravenously via a patient-controlled analgesia (PCA) pump in which the dose was proportional to that of fentanyl. METHODS: Forty patients undergoing 1-2 level spinal fusion were enrolled in this study. Patients were intraoperatively randomized into two groups to receive intravenous PCA consisting either of fentanyl 0.4 microg/ml/kg (control group) or fentanyl 0.4 microg/ml/kg with ketamine 30 microg/ml/kg (ketamine group) after intravenous injection of a loading dose. The loading dose in the control group was fentanyl 1 microg/kg with normal saline equal to ketamine volume and in the ketamine group it was fentanyl 1 microg/kg with ketamine 0.2 mg/kg. The verbal numerical rating scale (NRS), fentanyl and ketamine infusion rate, and side effects were evaluated at 1, 24, and 48 hours after surgery. RESULTS: There were no significant differences in patient demographics, duration of surgery and anesthesia or intra-operative opioids administration. We did not find any significant differences in the mean infusion rate of intraoperative remifentanil or postoperative fentanyl or in the side effects between the groups, but we did find a significant difference in the NRS between the groups. CONCLUSIONS: Based on our results, we conclude that a small dose of ketamine (0.5-2.5 microg/kg/min) proportional to fentanyl is not only safe, but also lowers postoperative pain intensity in patients undergoing spinal fusion, although the opioid-sparing effects of ketamine were not demonstrated.

Remifentanil used as adjuvant in general anesthesia for spinal fusion does not exhibit acute opioid tolerance / 대한마취과학회지

BACKGROUND: Although acute tolerance to opioids, especially to remifentanil, has been demonstrated consistently in animal studies, the results of clinical trials in humans are controversial. The aim of this study was to determine whether intraoperative infusions of remifentanil used as an adjuvant in general anesthesia result in acute tolerance, an event manifested by increased postoperative pain and a higher opioid requirement than usual. METHODS: Sixty patients who underwent surgery under general anesthesia for spinal fusion were randomly assigned to receive sevoflurane-nitrous oxide-oxygen (group SO, n = 20), sevoflurane-remifentanil-nitrous oxide-oxygen (group SR, n = 20), or propofol-remifentanil-oxygen (group PR, n = 20) in a double-blinded manner. All patients within 1 hour after induction received PCA (fentanyl 0.4 microg/kg/ml and ondansetron 16 mg) administered intravenously at a basal infusion rate of 1 ml/h, after being intravenously injected with a loading dose of fentanyl (1 microg/kg). Data for fentanyl requirement, verbal Numerical Rating Scale (NRS) pain score at rest, and presence of nausea or vomiting were collected at 1, 24, and 48 hours after surgery. RESULTS: We did not find any significant difference in postoperative PCA fentanyl requirements, NRS or side effects among the groups. CONCLUSIONS: Remifentanil as an adjuvant to sevoflurane or propofol in general anesthesia for adults having surgery for spinal fusion does not appear to cause acute opioid tolerance or hyperalgesia in patients. However, further studies are needed to elucidate whether sevoflurane and propofol exert a clinically significant effect on opioid-induced tolerance or hyperalgesia and whether this effect is related to the age of the patient, the dose and duration of remifentanil given and the intensity of pain experienced postoperatively.