Surgical pleth index monitoring in perioperative pain management: usefulness and limitations / 대한마취과학회지

Surgical pleth index (SPI) monitoring is a representative, objective nociception-monitoring device that measures nociception using photoplethysmographic signals. It is easy to apply to patients and the numerical calculation formula is intuitively easy to understand; therefore, its clinical interpretation is simple. Several studies have demonstrated its efficacy and utility. Compared with hemodynamic parameters, the SPI can detect the degree of nociception during surgery under general anesthesia with greater accuracy, and therefore can provide better guidance for the administration of various opioids, including remifentanil, fentanyl, and sufentanil. Indeed, SPI-guided analgesia is associated with lower intraoperative opioid consumption, faster patient recovery, and comparable or lower levels of postoperative pain and rates of adverse events compared with conventional analgesia. In addition, SPI monitoring allows for the degree of postoperative pain and analgesic requirements to be predicted through the SPI values immediately before patient arousal. However, because patient age, effective circulating volume, position, concomitant medication and anesthetic regimen and level of consciousness may be confounding factors in SPI monitoring, clinicians must be careful when interpreting SPI values. In addition, as SPI values can differ depending on anesthetic and analgesic regimens and the underlying disease, an awareness of the effects of these variables with an understanding of the advantages and disadvantages of SPI monitoring compared to other nociception monitoring devices is essential. Therefore, this review aimed to help clinicians perform optimal SPI-guided analgesia and to assist with the establishment of future research designs through clarifying current usefulness and limitations of SPI monitoring in perioperative pain management.

Sugammadex administration in patients with end-stage renal disease: a narrative review with recommendations

Due to unknown safety concerns, sugammadex should not be administered to patients withend-stage renal disease (ESRD). However, because the supply of benzylisoquinolinium-typeneuromuscular blocking agents (NMBAs) has been discontinued, rocuronium is the onlynon-depolarizing NMBA that can be used in clinical settings in some countries, includingSouth Korea. The administration of sugammadex cannot be avoided to achieve rapid andcomplete neuromuscular recovery in patients with ESRD or renal transplantation after rocuronium administration. Although there has been a limited number of clinical studies involving the use of sugammadex in patients with ESRD, studies have shown that sugammadexcan effectively and safely reverse rocuronium-induced neuromuscular blockade (NMB) inpatients with ESRD, however recovery of neuromuscular function in patients with ESRD isslower than in patients with normal renal function. Nonetheless, safety-concerns are yet tobe addressed. Considering the small number of clinical studies, high heterogeneity amongstudies, and insufficient safety information, more extensive data on the efficacy and safetyof sugammadex in patients with ESRD are needed. In particular, it is important to securedata on safety, including residual NMB after surgery, recurarization and cardiorespiratorycomplications, anaphylactic reactions, and long-term morbidity and mortality. Furthermore,anesthesiologists should remember that performing proper quantitative neuromuscularmonitoring and neuromuscular management based on the monitoring signs are the mostessential requirements when using sugammadex in patients with ESRD.

Anesthetic management of geriatric patients / 대한마취과학회지

The number of elderly patients who frequently access health care services is increasing worldwide. While anesthesiologists are developing the expertise to care for these elderly patients, areas of concern remain. We conducted a comprehensive search of major international databases (PubMed, Embase, and Cochrane) and a Korean database (KoreaMed) to review preoperative considerations, intraoperative management, and postoperative problems when anesthetizing elderly patients. Preoperative preparation of elderly patients included functional assessment to identify preexisting cognitive impairment or cardiopulmonary reserve, depression, frailty, nutrition, polypharmacy, and anticoagulation issues. Intraoperative management included anesthetic mode and pharmacology, monitoring, intravenous fluid or transfusion management, lung-protective ventilation, and prevention of hypothermia. Postoperative checklists included perioperative analgesia, postoperative delirium and cognitive dysfunction, and other complications. A higher level of perioperative care was required for older surgical patients, as multiple chronic diseases often makes them prone to developing postoperative complications, including functional decline and loss of independence. Although the guiding evidence remains poor so far, elderly patients have to be provided optimal perioperative care through close interdisciplinary, interprofessional, and cross-sectional collaboration to minimize unwanted postoperative outcomes. Furthermore, along with adequate anesthetic care, well-planned postoperative care should begin immediately after surgery and extend until discharge.

Role of T-type Calcium Channels in Generating Hyperexcitatory Behaviors during Emergence from Sevoflurane Anesthesia in Neonatal Rats / 神经科学通报·英文版

In the current study, we sought to investigate whether T-type Ca channels (TCCs) in the brain are involved in generating post-anesthetic hyperexcitatory behaviors (PAHBs). We found that younger rat pups (postnatal days 9-11) had a higher incidence of PAHBs and higher PAHB scores than older pups (postnatal days 16-18) during emergence from sevoflurane anesthesia. The power spectrum of the theta oscillations (4 Hz-8 Hz) in the prefrontal cortex was significantly enhanced in younger pups when PAHBs occurred, while there were no significant changes in older pups. Both the power of theta oscillations and the level of PAHBs were significantly reduced by the administration of TCC inhibitors. Moreover, the sensitivity of TCCs in the medial dorsal thalamic nucleus to sevoflurane was found to increase with age by investigating the kinetic properties of TCCs in vitro. TCCs were activated by potentiated GABAergic depolarization with a sub-anesthetic dose of sevoflurane (1%). These data suggest that (1) TCCs in the brain contribute to the generation of PAHBs and the concomitant electroencephalographic changes; (2) the stronger inhibitory effect of sevoflurane contributes to the lack of PAHBs in older rats; and (3) the contribution of TCCs to PAHBs is not mediated by a direct effect of sevoflurane on TCCs.

Nociception monitoring tools using autonomic tone changes for intraoperative analgesic guidance in pediatric patients

Nociception monitoring devices using changes in autonomic nervous system activity have been developed in numerous ways. Although there have been few studies conducted on children, compared to the relatively higher number of studies on adults, most of the nociception monitors in children, as in adults, appear to be more useful than the standard clinical practice that uses hemodynamic parameters in the evaluation and treatment of intraoperative nociception (pain) during general anesthesia. Particularly, when monitoring the surgical pleth index (SPI) in anesthetized children, the application of a new target range of SPI values (≤ 40) to the SPI monitoring criteria seems to be necessary for providing a more proper intraoperative analgesia. The analgesia nociception index (ANI) shows promising results in anesthetized adults, and recently, positive results along with cardiorespiratory coherence have been reported in pediatric patients. Newborn infant parasympathetic evaluation (NIPE) could be useful for providing adequate analgesia in newborns, infants, and children under 2 years of age in anesthetized or awake states. In cases of skin conductance and pupillometry, further studies are needed. Understanding the pros, cons, and limitations of these nociception monitoring tools will provide more effective and safe intraoperative analgesia to pediatric patients undergoing general anesthesia, and it may also help to plan and conduct promising research on the use of perioperative nociception monitoring in pediatric patients in the future.

Central hyperventilation syndrome due to massive pneumocephalus after endoscopic third ventriculostomy: a case report / 대한마취과학회지

Pneumocephalus is common after brain surgeries, but usually is not substantial enough to cause serious complications. We recently encountered a case of post-operative tachypnea after an endoscopic 3rd ventriculostomy. At first, we thought that the hyperventilation was the result of residual paralysis after emergence from anesthesia, but during further evaluation we found a massive pneumocephalus. In such unusual post-operative situations, physicians should consider surgery-related complications as the possible cause as well, along with the anesthetic factors.

Consecutive anaphylaxis due to rocuronium and cisatracurium during general anesthesia: A case report

We experienced anaphylaxis during general anesthesia twice in the same patient. After the first incidence of anaphylaxis at the induction of anesthesia, we speculated that the allergen was rocuronium. Thus, we administered sugammadex as well as a vasopressor to treat the anaphylaxis and the vital signs gradually recovered to nearly normal. Thereafter, we could not avoid the administration of another muscle relaxant, cisatracurium, since the patient moved uncontrollably after the surgery was restarted. A second anaphylactic event then occurred. We speculated that the second allergen was cisatracurium and stopped using it. The results of the investigation after the surgery showed that the allergens were indeed rocuronium and cisatracurium. When we encounter anaphylaxis during general anesthesia, it is necessary to suspect all administered medicines as the cause, with the potential of two or more causes, especially with muscle relaxants.

Assessment of chloral hydrate-centered pediatric sedation performed by non-anesthesiologists

BACKGROUND: We aimed to evaluate the efficacy and safety of chloral hydrate-based pediatric sedation conducted by non-anesthesiologists. METHODS: The design and setting of this study was a single-center retrospective study performed at a tertiary university hospital between July 2012 and May 2013. A total of 519 children were enrolled in this study. We investigated the sedation medication, age of patients and type of diagnostic tests or procedures and evaluated the success rate of sedation, sedation/recovery profiles and adverse events. RESULTS: Most patients underwent moderate sedation for diagnostic tests. The most commonly used sedative drug was chloral hydrate, which was solely used for 482 patients. A combination of chloral hydrate/midazolam was used for 24 patients and midazolam only was used for 13 patients. Use of chloral hydrate resulted in a sedation success rate of 65.5% after the initial dose and a success rate of 95.2% with additional doses. The sedation failure rate in children > 6 years was significantly higher than that in children under 6 years. In all patients, the overall onset time and recovery time were too slow and long, respectively, and there was no critical complication. CONCLUSIONS: This study demonstrated that chloral hydrate-based pediatric sedation conducted by non-anesthesiologists was mostly moderate, with a high success rate and a low complication rate. However, the overall onset time and recovery time were too slow and long, respectively. Especially, alternative sedation regimens are required in children > 6 years considering the slower onset time and higher failure rate of sedation.

Comparison of clinical validation of acceleromyography and electromyography in children who were administered rocuronium during general anesthesia: a prospective double-blinded randomized study / 대한마취과학회지

BACKGROUND: Electromyography and acceleromyography are common neuromuscular monitoring devices. However, questions still remain regarding the use of acceleromyography in children. This study compared the calibration success rates and intubation conditions in children after obtaining the maximal blockade depending on each of the devices METHODS: Children, 3 to 6 years old, were randomly allocated to the TOF-Watch SX acceleromyography group or the NMT electromyography group. The induction was performed with propofol, fentanyl, and rocuronium. The bispectral index and 1 Hz single twitch were monitored during observation. The calibration of the each device was begun when the BIS dropped to 60. After successful calibration, rocuronium 0.6 mg/kg was injected. A tracheal intubation was performed when the twitch height suppressed to 0. The rocuronium onset time (time from administration to the maximal depression of twitch height) and intubating conditions were rated in a blinded manner. RESULTS: There was no difference in the calibration success rates between the two groups; and the calibration time in the electromyography group (16.7 +/- 11.0 seconds) was shorter than the acceleromyography group (28.1 +/- 13.4 seconds, P = 0.012). The rocuronium onset time of the electromyography group (73.6 +/- 18.9 seconds) was longer than the acceleromyography group (63.9 +/- 18.8 seconds, P = 0.042) and the intubation condition of the electromyography group (2.27 +/- 0.65) was better than the acceleromyography group (1.86 +/- 0.50, P = 0.007). CONCLUSIONS: Electromyography offers a better compromise than acceleromyography with respect to the duration of calibration process and surrogate for the optimal time of tracheal intubation in children.

The analgesic effect of nefopam combined with low dose remifentanil in patients undergoing middle ear surgery under desflurane anesthesia: a randomized controlled trial / 대한마취과학회지

BACKGROUND: We investigated the effects of the combined administration of nefopam, a N-methyl-D-aspartate receptor antagonist and low dose remifentanil, on early postoperative pain and analgesic requirement. METHODS: Fifty patients scheduled to undergo mastoidectomy and tympanoplasty were randomized to be given either nefopam 40 mg mixed with normal saline 100 ml (Group N) or an equal amount of normal saline (Group C) before anesthesia induction. Anesthesia was maintained with 5-6 vol% desflurane and remifentanil 0.05-0.15 microg/kg/min during the surgery. Postoperative pain was controlled by titration of ketorolac in the postanesthesia care unit (PACU) and ward. We evaluated the intraoperative remifentanil dose, recovery profiles, ketorolac demand in the PACU and ward, numeric rating scale (NRS) for pain at time intervals of every 10 min for 1 h in the PACU, 6, 12, 18 and 24 h in a ward, as well as the time to first analgesic requirement in the PACU and ward. RESULTS: Ketorolac demand and NRS in the PACU were significantly lower in Group N than Group C (P = 0.002, P = 0.005, respectively). The time to first analgesic requirement in the PACU in Group N were significantly longer than Group C (P = 0.046). There were no significant differences in intraoperative remifentanil dose, ketorolac demand, NRS, and the time to first analgesic requirement in the ward between the groups. CONCLUSIONS: Nefopam administration combined with low dose remifentanil infusion reduces pain and analgesic consumption during the immediate postoperative period in patients undergoing middle ear surgery under desflurane anesthesia.

Comparison of bispectral index scores from the standard frontal sensor position with those from an alternative mandibular position / 대한마취과학회지

BACKGROUND: The standard bifrontal application of the bispectral index (BIS) sensor interferes with the operative field in neurosurgery and plastic surgery. The aim of this study was to compare the standard frontal BIS sensor position with an alternative position across the mandible. METHODS: Two BIS(TM) Quatro sensors (Aspect Medical Systems, Newton, MA, USA) mounted on the frontal and mandibular regions were connected to BIS Vista(TM) monitors on each patient during general anesthesia. Data from each position were collected at awake, loss of consciousness, intubation, incision, every 30 minutes during the intraoperative period and emergence. These data were compared using Bland-Altman and scatter plot analyses. RESULTS: Scatter plot analysis revealed a significant correlation between BIS values of frontal and mandibular positions (R = 0.869, P = 0.000), except during emergence (R = 0.253, P = 0.077). Bland-Altman analysis revealed a negative bias of 3.2 with a limit of agreement of 16.5/-22.9, in which 3.7% of the values were outside of the limit of agreement. Additional values included -2.9 (14.1/-8.3) while patients were awake, -21.7 (14.9/-58.3) at loss of consciousness, -1.8 (9.0/-12.5) during maintenance, and -1.9 (14.9/-18.8) during emergence. CONCLUSIONS: Overall, BIS values do not agree between the standard frontal position and an alternative mandibular position. However, during the anesthesia maintenance period, the mandibular position can be availably used as an alternative position if the operative field renders the standard frontal position unavailable.

Platelet function assay to determine the optimal preoperative cessation period of aspirin

BACKGROUND: This study was conducted to assess preoperative residual antiplatelet-induced platelet dysfunction using a platelet function assay to determine the optimal cessation period of aspirin during the preoperative period. METHODS: Patients older than 20 years, who were scheduled for elective surgery under general anesthesia, were enrolled prospectively. The last ingestion of the aspirin had occurred within the previous 10 days before surgery (aspirin 100 mg per day). No history of antiplatelet intake was documented in the control group. Platelet function was assessed using a platelet function analyzer-100 (PFA-100). Receiver operating characteristic (ROC) curves were plotted to determine the ability of aspirin cessation time in order to predict platelet function as assessed by the PFA. Patients were assigned to groups according to the period of aspirin discontinuation. RESULTS: Two hundred patients were enrolled in this study (100 control group and 100 aspirin group). The mean PFA value of the control group was significantly lower than that of the treated groups. The areas under the ROC curve (0.65, P = 0.03) of aspirin cessation period to discriminate PFA prolongation were significant. There were significant decreases in PFA values when aspirin medication was discontinued for 7 days, but not when the intake was discontinued for 5 days. CONCLUSIONS: Platelet function recovered if aspirin intake was discontinued > 7 days prior to surgery; therefore, in these patients, a preoperative platelet function test is not essential. However, the residual antiplatelet effect of aspirin should be assessed using the PFA in patients who discontinue aspirin less than 7 days prior to surgery.

Management of traumatic pneumothorax with massive air leakage: role of a bronchial blocker: a case report / 대한마취과학회지

Massive air leakage through a lacerated lung produces inadequate ventilation and hypoxemia. Tube exchange from a single to double lumen endotracheal tube (DLT), and lung separation to maintain oxygenation, are challenging for seriously injured patients. In this case report, we aim to describe how a bronchial blocker (BB) makes it easier to perform a lung separation in this situation; it also increases the overall safety of the procedure. A 35-year-old female (163 cm, 47 kg) suffered from blunt chest trauma due to a traffic accident; the accident caused right-sided lung laceration with massive air leakage. Paradoxically, positive ventilation worsened SaO2 and leakage increased through a chest tube. We introduced BB while the patient was still awake: Left-side one-lung ventilation (OLV) was established and anesthesia was induced. After PaO2 was maximized with OLV, we changed the endotracheal tube to DLT without a hypoxic event. By BB placement, we maintained PaO2 at a secure level, conducted mechanical ventilation and exchanged the tube without deterioration.

Comparison of emergence agitation between sevoflurane/nitrous oxide administration and sevoflurane administration alone in children undergoing adenotonsillectomy with preemptive ketorolac / 대한마취과학회지

BACKGROUND: Sevoflurane anesthesia commonly causes emergence agitation (EA) in children. One previous study has reported that the use of nitrous oxide (N2O) during the washout of sevoflurane may reduce EA by decreasing the residual sevoflurane concentration, while many animal studies suggest that N2O poses a potential risk to children. The present study was designed to compare EA in children assigned to receive sevoflurane with N2O (group N) or sevoflurane alone (group S). METHODS: We enrolled 80 children aged 3-10 years. Anesthesia was induced with 5 mg/kg thiopental sodium, 0.6 mg/kg rocuronium and 0.5 mg/kg ketorolac, and was maintained with 50% N2O and sevoflurane in group N or with sevoflurane alone in group S. The sevoflurane concentration was adjusted with a bispectral index (BIS) of 40-60. After completion of the surgery, N2O and sevoflurane were simultaneously discontinued and replaced with oxygen (O2) at 6 L/min. End-tidal sevoflurane concentration (Et Sevo) (%), BIS at the end of surgery, Et Sevo at recovery of self-respiration and emergence profiles were recorded. EA occurrence, pain score and rescue fentanyl consumption were assessed in the postanesthesia care unit. RESULTS: Et Sevo was significantly lower in group N (1.9%) than in group S (2.3%) at the end of surgery. However, there were no differences in Et Sevo at recovery of self-respiration, emergence times, the incidence of EA, pain score or dose of rescue fentanyl between the groups. CONCLUSIONS: In children undergoing adenotonsillectomy with preemptive ketorolac, anesthetic maintenance using sevoflurane alone does not affect the incidence of EA or emergence profiles compared to anesthetic maintenance using sevoflurane with N2O.

The relationship between perioperative nausea and vomiting and serum serotonin concentrations in patients undergoing cesarean section under epidural anesthesia / 대한마취과학회지

BACKGROUND: Serotonin-also known as 5-hydroxytryptamine or 5-HT-can induce nausea and vomiting (NV) by peripheral mechanisms via the activation of 5-HT3 receptors. In this study, we observed perioperative NV, including intraoperative NV, and changes in serum 5-HT concentrations. We evaluated the relationship between perioperative NV and serum 5-HT levels in patients undergoing cesarean section under epidural anesthesia, and carried out a pilot study to determine if further studies on a larger scale were justified. METHODS: Twenty-eight patients who were scheduled for cesarean section under epidural anesthesia were included in the study. Patients were assigned to 2 groups according to the occurrence of NV after induction, i.e., an NV-positive or an NV-negative group. Serum 5-HT concentrations were measured before induction, at the time that NV occurred (in the case of the NV-positive group) or 5 min after the umbilical cord clamping (in the case of the NV-negative group) during surgery, and at 2 h postoperatively. RESULTS: NV occurred in 10 of the 28 patients. No significant differences in serum 5-HT concentrations were found within or between the two groups. CONCLUSIONS: This study suggests that there is no correlation between serum 5-HT concentration and the occurrence of perioperative NV in patients undergoing cesarean section under epidural anesthesia, and the findings do not seem to support further investigations regarding a possible relationship between serum 5-HT concentration and perioperative NV.

Combined spinal-epidural anesthesia for lumbar discectomy in a patient with asymptomatic severe aortic stenosis: a case report / 대한마취과학회지

The use of neuraxial anesthesia has traditionally been contraindicated in patients with severe aortic stenosis. However, general anesthesia can be riskier than neuraxial anesthesia for severe aortic stenosis patients undergoing spinal surgeries in the prone position as this can cause a major reduction in cardiac output secondary to diminished preload. In addition, general anesthesia, muscle relaxation, and positive-pressure ventilation can decrease venous return and reduce vascular tone, further compromising cardiac output. Combined spinal-epidural anesthesia with closely monitored, careful titration of the local anesthetic dose can be an efficient and safe anesthetic method for managing such patients. We describe the successful management of combined spinal-epidural anesthesia in an asymptomatic severe aortic stenosis patient scheduled for lumbar discectomy.

Unexpected tracheal narrowing during general anesthesia in the prone position of Duchenne muscular dystrophy patient: A report of two cases / 대한마취과학회지

Unexpected tracheal narrowing was observed in a patient with Duchenne muscular dystrophy during a corrective operation for thoracolumbar scoliosis. As the operating time progressed, peak airway pressure and end-tidal CO2 increased gradually in the prone position. We found a floppy portion of the trachea using fiberoptic bronchoscopy (FB) in the prone position. We advanced a wire-reinforced tube toward the carina beyond the lesion. This allowed correction of the ventilatory abnormalities. We encountered another patient scheduled for the same operation. We performed FB in advance before the position change and observed a narrowed portion of trachea. We advanced the tracheal tube under FB beyond the pathologic portion and then moved the patient into the prone position. The operation was done successfully without any problems.

Paroxysmal atrial fibrillation developed during perioperative periods in an adolescent without any underlying disease: A case report

Although the development of arrhythmias including atrial fibrillation (AF) is common under general anesthesia during surgery, the first episode of AF to occur during this period is rather uncommon. Moreover, most instances of AF are associated with old age, cardiopulmonary diseases as well as metabolic, endocrine, or genetic abnormalities. The occurrence of paroxysmal AF in the perioperative period in an adolescent without any underlying diseases or organic abnormalities has never been reported. Herein, we report a case of a 16-year-old adolescent whose paroxysmal AF was suspected before the anesthesia induction for strabismus surgery and diagnosed after anesthetic induction. Nevertheless, he was managed successfully with esmolol infusions during and after the surgery and thus recovered spontaneously.

Monitored anesthesia care using dexmedetomidine and remifentanil for the hip surgery in a high risk patient with brain metastasis of lung cancer, cerebral infarction, seizure and quadriplegia: A case report

To perform the major operation for high risk patients with both serious systemic diseases and major organ complications, the monitored anesthesia care could be available as a reasonable alternative for both general and regional anesthesia when it is impossible to administer; however, the choice of analgesics and sedatives is still an important and difficult task. We present a high risk patient who suffers from neurologic complications including decreased consciousness caused by brain metastasis of lung cancer, cerebral infarction, quadriplegia and seizure as well as decreased respiratory function and bleeding tendency. When performing the operation on hip joints, we administered both dexmedetomidine as a major sedative, and remifentanil as an adjunct analgesic; as a result, we could successfully perform the monitored anesthesia care without any complications including cardiovascular instability, respiratory depression, and seizure.

Sufentanil infusion before extubation suppresses coughing on emergence without delaying extubation time and reduces postoperative analgesic requirement without increasing nausea and vomiting after desflurane anesthesia / 대한마취과학회지

BACKGROUND: Coughing, hypertension, tachycardia, and even laryngospasm can occur due to airway irritation during emergence from anesthesia. We investigated the effect of maintaining a sufentanil infusion during emergence from anesthesia by evaluating the incidence of cough and recovery profiles at extubation. METHODS: In total, eighty-four patients undergoing an elective laparoscopic hysterectomy were randomly divided into two sufentanil groups and a control group. During emergence, sufentanil was administered in the sufentanil groups at a rate of 0.2 microg/kg/hr (Group S1) or 0.3 microg/kg/hr (Group S2), and saline was administered to the control group. Cough score, hemodynamic changes, and recovery profiles, such as duration from skin closure to a bispectral index of 80, to eye opening at verbal command, to tracheal extubation and the total duration of study solution infusion, were recorded. The pain score, the total volume of administered patient-controlled analgesia (PCA), and the postoperative nausea and vomiting (PONV) score were evaluated 1, 6, and 24 hours after surgery. RESULTS: Groups S1 and S2 showed significantly lower cough scores and smaller hemodynamic changes on extubation compared to Group C. Recovery profiles showed no significant differences among the three groups. Pain score, PONV at 1 hour postoperatively, and the total volume of PCA administered at all evaluation times were significantly lower in Groups S1 and S2 than in the control group. However, pain score, and PONV at 6 hours and 24 hours postoperatively showed no significant differences. CONCLUSIONS: A sufentanil infusion (0.2-0.3 microg/kg/hr) during emergence from desflurane anesthesia may suppress coughing on extubation in patients with body mass indexes (BMI) of 21-26 without delaying extubation time. It may also reduce the postoperative analgesic requirement without increasing PONV.