Emergence Cough Research Articles

Effects of age on effect-site concentration of remifentanil for suppressing anesthetic emergence cough in male patients undergoing laparoscopic cholecystectomy.

BackgroundRemifentanil infusion during emergence lowers cough. Effect-site concentration (Ce) of remifentanil using target-controlled infusion (TCI) has been evaluated in previous studies. Recent studies revealed the existence of sex-related differences in remifentanil Ce in young and elderly patients. Thus, there was the need to re-evaluate the effect of age in single sex. We investigated the remifentanil Ce for suppressing emergence cough in young and elderly male patients and evaluated the age-related differences.Patients and methodsIn total, 25 young (ages between 20 and 50 years) and 24 elderly (ages between 65 and 75 years) male patients undergoing laparoscopic cholecystectomy were enrolled. Anesthesia was implemented with remifentanil using TCI and sevoflurane. The remifentanil Ce for suppressing emergence cough was estimated for each group using Dixon’s up-and-down method and isotonic regression method with a bootstrapping approach.ResultsThe remifentanil Ce for suppressing emergence cough in 50% (EC50) and 95% (EC95) of the patients was comparable between the young and elderly patients. Isotonic regression demonstrated that the EC50 (83% confidence interval [CI]) of remifentanil was 2.56 (2.39−2.75) ng/mL in the young patients and 2.15 (1.92−2.5) ng/mL in the elderly patients. The EC95 (95% CI) of remifentanil was 3.33 (2.94−3.46) ng/mL in the young patients and 3.41 (3.18−3.48) ng/mL in the elderly patients. Dixon’s up-and-down method also demonstrated that the EC50 was comparable between the two groups (2.69±0.32 ng/mL vs 2.39±0.38 ng/mL, P=0.132).ConclusionThe remifentanil Ce for suppressing emergence cough following extubation during general anesthesia was comparable between young and elderly male patients. It indicates that age-related differences in remifentanil requirement for suppressing emergence cough did not exist in male sex.

Alkalinized Lidocaine Preloaded Endotracheal Tube Cuffs Reduce Emergence Cough After Brief Surgery: A Prospective Randomized Trial.

Alkalinized lidocaine in the endotracheal tube (ETT) cuff decreases the incidence of cough and throat pain on emergence after surgery lasting more than 2 hours. However, alkalinized lidocaine needs 60-120 minutes to cross the ETT cuff membrane; therefore, its usefulness in shorter duration surgery is unknown. This prospective double-blind randomized controlled trial tested the hypothesis that alkalinized lidocaine would reduce the incidence of emergence cough after surgeries lasting <120 minutes. After local ethics board approval, American Society of Anesthesiologists I-III patients consented to be randomized into 1 of 2 groups receiving either alkalinized lidocaine (group AL) or saline (group S) to inflate the ETT cuff. Cuffs were prefilled >90 minutes before intubation with either 2 mL of 2% lidocaine and 8 mL of 8.4% bicarbonate (group AL) or 10 mL of normal saline (group S). Cuffs were emptied immediately before intubation. After intubation, either 2 mL of 2% lidocaine (AL) or 2 mL of saline (S) were injected into the cuff. Additional 8.4% bicarbonate (AL) or saline (S) was injected into the cuff until there was no air leak. Anesthesia was maintained using desflurane, rocuronium, and either fentanyl or sufentanil to maintain vital signs within 20% of baseline values. Opioids administered in prophylaxis of extubation cough were proscribed. A standardized "no touch" emergence technique was used. A blinded assessor noted any cough above 0.2 minimum alveolar concentration (MAC) of expired desflurane. At 0.2 MAC, once every 30 seconds, the patient was instructed to open his eyes and extubation occurred once a directed response was noted. A total of 213 patients were randomized and 100 patients in each group completed the experimental protocol. The incidence of extubation cough in group AL was 12%, significantly lower (1-sided P = .045) than the 22% incidence in group S. The 1-tailed risk ratio for cough in group AL was 0.55 (0-0.94, P = .045). Total amount of opioids administered (P = .194), ETT cuff preloading times (P = .259), and extubation times (P = .331) were not significantly different between groups. The average duration of surgery was 59 ± 28 minutes in group AL and 52 ± 29 minutes in group S (P = .057). Alkalinized lidocaine in the ETT cuff significantly decreased general anesthesia emergence cough after surgeries with an average duration of slightly <1 hour.

Sex-related differences in effect-site concentration of remifentanil for preventing anesthetic emergence cough in elderly patients.

PurposeCough on anesthetic emergence should be prevented considering its dangerous complications. Target-controlled infusion (TCI) of remifentanil can reduce emergence cough effectively, and sex-related differences in effect-site concentration (Ce) of remifentanil have been evaluated in young patients. In this study, we determined the Ce of remifentanil for preventing emergence cough following extubation in male and female elderly patients and evaluated the sex-related difference.Patients and methodsTwenty-three male and 22 female elderly patients aged between 60 and 75 years were enrolled. Anesthesia was maintained with sevoflurane and remifentanil TCI. The Ce of remifentanil for preventing emergence cough was determined for each sex using isotonic regression method with a bootstrapping approach, following Dixon’s up-and-down method.ResultsThe Ce of remifentanil for preventing emergence cough in 50% (EC50) and 95% (EC95) of the population was significantly lower in females than in males. Isotonic regression revealed the EC50 (83% confidence interval [CI]) of remifentanil was 1.67 (1.55–1.83) ng/mL in females and 2.60 (2.29–2.91) ng/mL in males. The EC95 (95% CI) of remifentanil was 2.30 (2.02–2.62) ng/mL in females and 3.41 (3.27–3.58) ng/mL in males. Dixon’s up-and-down method indicated that the mean EC50 in females was lower than in males (1.56±0.26 ng/mL vs 2.56±0.37 ng/mL, P<0.001).ConclusionThe remifentanil requirement for preventing emergence cough was lower in female than in male elderly patients, indicative of sex-related differences in Ce of remifentanil. Sex should be considered when using remifentanil TCI for preventing emergence cough in elderly patients.

Study of sevoflurane/remifentanil coadministration on improving emergence and recovery characteristics of patients following general anaesthesia with sevoflurane

Objective: To investigate the effects of remifentanil infusion on emergence and recovery characteristics of patients with thoracoscopic lobectomy following general anaesthesia with sevoflurane. Methods: One hundred patients, who were aged 37 to 65 years with American Society of Anesthesiologists (ASA) physical status 1-2, and scheduled for elective thoracoscopic lobectomy under general anaesthesia in National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, from February 2016 to August 2016, were allocated to receive sevoflurane maintenance regimen(group S, n=50)or sevoflurane/remifentanil maintenance regimen(group SR, n=50)by random digital table. After routine induction and intubation, anaesthesia was maintained with 2% sevoflurane in group S and 1.5% sevoflurane/remifentanil(continuous intravenous injection at rate of 4 μg·kg(-1)·h(-1))coadministration in group SR respectively, with intermittent intravenous infusion of sulfentanil. Haemodynamic variables were collected at different time points and compared between two groups. Awaking time and extubation time, incidences of serious coughing and agitation were evaluated during emergence.Postoperative pain, nausea and cather-related bladder discomfort(CRBD)were evaluated in post anesthesia care unit. Results: Compared with group S, the arterial blood pressure and heart rate were significantly lower in group SR at extubation(all P<0.05). Time to awaking and to extubation in group SR were (4.2±2.1) min and (4.8±3.1)min respectively, in group S were (12.7±3.4) min and (15.4±4.1)min.The difference between two groups were statistically significant (t=-15.040, 14.582, all P<0.05). The incidences of serious coughing and agitation in group S were 48% and 58%, which were greater than those of group SR(6% and 10%). The difference were statistically significant(χ(2)=20.294, 23.574, all P<0.05). The NRS and incidence of complaining CRBD were similar in both groups(all P>0.05). Conclusion: Compared with sevoflurane maintenence, coadministration of remifentanil and sevoflurane maintenance regimen provides better emergence and recovery which are characterized by faster awakening and extubation with a lower incidence of emergence coughing and agitation.

Staggering the dose of sugammadex lowers risks for severe emergence cough: a randomized control trial

BackgroundCough on emergence has been reported as a common adverse reaction with sugammadex reversal. We investigated if staggering the dose of sugammadex will reduce emergence cough in a single-center, randomized, double-blinded study.MethodsA hundred and twenty ASA 1–3 adults were randomly reversed with 1 mg/kg sugammadex prior to extubation followed by another 1 mg/kg immediately after extubation (staggered group), single dose of 2 mg/kg sugammadex (single bolus group) or neostigmine 0.02 mg/kg with glycopyrrolate (neostigmine group).ResultsWe found 70% of patients (n = 28) reversed with single boluses of sugammadex had Grade 3 emergence cough compared to 12.5% (n = 5) in the staggered sugammadex group and 17.5% (n = 7) in the neostigmine group (p < 0.001). Besides cough, emergence agitation also appeared highest in the single bolus sugammadex group (n = 14, 35%, p = 0.005). On the other hand, staggering sugammadex lowered risks of developing severe cough (RR 0.2, p < 0.001) and agitation (RR 0.43, p = 0.010) on emergence in addition to cough (RR 0.25, p = 0.039) and early sore throat (RR 0.70, p = 0.036) in the post-anesthetic care unit. The risks for severe emergence cough (RR 0.86, p = 0.762), severe cough in the post-anesthetic care unit (RR 1.0, p = 1.000) and sore throat (RR 1.17, p = 0.502) were also not different between the staggered sugammadex group and control given neostigmine. In terms of timing, there was no delay in time taken from discontinuing anesthetic agents to reversal and extubation if sugammadex was staggered (emergence time 6.0 ± 3.2 s, p = 0.625 and reversal time 6.5 ± 3.5, p = 0.809).ConclusionsStaggering the dose of sugammadex for reversal will effectively decrease common emergence and early postoperative complications.Trial registrationANZCTR Number ACTRN12616000116426. Retrospectively registered on 2nd February 2016.

Effects of low-dose propofol vs ketamine on emergence cough in children undergoing flexible bronchoscopy with sevoflurane-remifentanil anesthesia: a randomized, double-blind, placebo-controlled trial

Study ObjectiveTo determine the effects of low-dose ketamine and propofol on cough during emergence and the recovery period when administered at emergence in children undergoing fiberoptic bronchoscopy for bronchoalveolar lavage (FOBL) with sevoflurane-remifentanil anesthesia. DesignRandomized, double-blind, placebo-controlled trial. SettingOperating room, postoperative recovery area. PatientsSixty-eight children aged 1 to 8 years old undergoing elective diagnostic FOBL. InterventionsAfter discontinuation of anesthetics at the end of FOBL, patients were randomly divided into 3 groups: in group K, children were administered 0.5 mg/kg of ketamine; in group P, 0.5 mg/kg of propofol; and in group C, 0.1 mL/kg of normal saline. MeasurementsAnesthesia time, procedure time, emergence time, and recovery time were recorded. Coughing and delirium scores were recorded as the patient fully emerged from anesthesia (time 0) and 5, 10, 15, and 20 minutes later. Main ResultsThe percentage of children with moderate or severe cough during emergence was similar in all groups. Mean delirium scores at emergence (T0) were significantly lower in group K than those in group P and in group C (P = .0001 and P = .02). Mean delirium score at 5 minutes in group K (6 [5-10]) was significantly lower than that of group C (P = .02) and similar to that of group P. The recovery time of group K was significantly longer than that of group C and group P (P = .01 and P = .03, respectively). ConclusionsKetamine or propofol given at the end of sevoflurane-remifentanil general anesthesia in children undergoing FOBL did not decrease cough more than normal saline during the emergence period. Ketamine and propofol, compared to normal saline, had a beneficial effect on decreasing the incidence of emergence delirium. Ketamine lengthened recovery time.

A Randomized Comparison of Remifentanil Target-Controlled Infusion Versus Dexmedetomidine Single-Dose Administration

Remifentanil target-controlled infusion and dexmedetomidine single-dose administration are known to reduce airway response and hemodynamic stimulation during anesthetic recovery. We compared the effects of 2 drugs on the prevention of cough during emergence. We enrolled 70 female patients aged 20-60 years with American Society of Anesthesiologists (ASA) I-II who underwent general anesthesia for elective thyroidectomy. The patients were randomly assigned to remifentanil (group R) or dexmedetomidine (group D). Anesthesia was maintained with sevoflurane and effect-site target-controlled infusion of remifentanil. In group D, remifentanil was discontinued, and dexmedetomidine 0.5 μg/kg was given 10 minutes before the end of surgery. In group R, remifentanil target-controlled infusion at an effective-site concentration of 2.0 ng/mL was maintained during emergence until extubation. The cough grade, hemodynamic values, respiration, and other recovery profiles were evaluated during the periextubation period. The proportion of patients with no cough or just a single cough during extubation was significantly higher in group R than in group D (96.8% vs. 55.9%). The change of mean arterial pressure and heart rate were not significantly different during extubation in both groups. Respiratory rate and the incidence of residual sedation after extubation were lower in group R. There were no desaturation events and no differences in time to extubation or duration of postanesthesia care unit stay in both groups. Remifentanil target-controlled infusion reduces emergence cough from general anesthesia more effectively than single-dose dexmedetomidine. However, a single-dose of dexmedetomidine has the effect with respect to respiratory and hemodynamic stability during emergence.

Effect of Endotracheal Tube Lidocaine Instillation in Prevention of Smokers Emergence Coughing: Sample of Iraqi Patients Undergoing Emergency Appendectomy

Background: Cough reflex is normal protective reflex but cause various complication during emergence from general anaesthesia especially to smokers. Objective: To evaluate the effect of instillation 0.5% lidocaine through the endotracheal tube to reduce the smokers coughing during emergence from general anaesthesia. Methods: 300 patients of both sex enrolled in this study to have open emergency appendectomy. Patients divided into 4 groups. 50 non-smoker patients as control group. 50 smokers patient received no per operative efforts to reduce the incidence of postoperative cough, 100 smokers patient received 20 ml of 0.5% lidocaine dropped slowly into the endotracheal tube throughout the procedure, and 100 smoker patient received 20 ml normal saline dropped slowly into the endotracheal tube throughout the procedure. At the end of surgery, after extubation, the patient was considered to have cough if develops irritating cough or have 3 or more bucking. Result: Incidence of cough significantly decreased (p ≤ 0.05) among smoking patients treated with lidocaine in relation to patients treated with normal saline, smokers without intervention. Conclusion: Instillation of lidocaine to endotracheal tube is effective method in reduction of smokers cough during emergence from general anaesthesia.

Determination of EC95 of remifentanil for smooth emergence from propofol anesthesia in patients undergoing transsphenoidal surgery.

In patients undergoing pituitary surgery using a transsphenoidal approach, anesthesia emergence should be smooth with minimal coughing. Recent studies demonstrated that a target-controlled infusion of remifentanil effectively suppresses coughing induced by the endotracheal tube. We investigated the EC95 of remifentanil for smooth emergence without coughing from propofol anesthesia in patients undergoing transsphenoidal hypophysectomy. A total of 41 patients undergoing transsphenoidal hypophysectomy, aged 20 to 65 years, with an ASA physical status of I or II, were enrolled. For all participants, anesthesia was induced and maintained with a target-controlled infusion of remifentanil and propofol using predicted effect-site concentration (Ce). A biased coin design up-and-down sequential allocation and isotonic regression method were used to determine the remifentanil EC95 to prevent emergence coughing. In addition, we observed recovery profiles after anesthesia. According to the study design, 19 patients received remifentanil 2.6 ng/mL Ce and 22 patients received a lower Ce, ranging from 1.0 to 2.2 ng/mL. The EC95 of remifentanil to prevent coughing was estimated as 2.51 ng/mL (95% confidence interval, 2.28-2.57 ng/mL). Despite the exclusion of 1 case because of delayed emergence, 17 of 18 patients receiving 2.6 ng/mL of remifentanil had bradypnea (<10 breaths/min) until 3 minutes after extubation. However, end-tidal carbon dioxide was maintained below 55 mm Hg during anesthetic emergence and respiratory rate recovered within 20 minutes of admission to the postanesthetic care unit. The EC95 of remifentanil for smooth emergence from anesthesia was 2.51 ng/mL after transsphenoidal hypophysectomy.

Effect of single-dose dexmedetomidine on recovery profiles after sevoflurane anesthesia with spontaneous respiration in pediatric patients undergoing cleft lip and palate repair

To explore the effect of single-dose dexmedetomidine on recovery period after sevoflurane anesthesia with spontaneous respiration in pediatric patients undergoing cleft lip and palate repair. A total of 60 American Society of Anesthesiologists (ASA) I-II pediatric patients undergoing cleft lip and palate repair from October to December 2013 were randomly divided into groups D and C (n = 30 each) . Dexmedetomidine 0.5 µg/kg (group D) or an equal volume of normal saline (group C) was ad ministered intravenously over a period of 10 min at 30 min before the end of surgery. Anesthesia was induced and maintained with sevoflurane under spontaneous ventilation. Heart rate, mean arterial pressure (MAP), hemoglobin oxygen saturation (SpO2), respiratory rate, tidal volume (VT) and pressure of end-tidal carbon dioxide (PETCO2) were recorded at the time before induction (T0), 30 min before the end of surgery (T1) , 20 min before the end of surgery (T2), 15 min before the end of surgery (T3), 10 min before the end of surgery (T4), the end of surgery (T5), extubation (T6), 5 min after transferal into post-anesthesia care unit (PACU) (T7) , 1 h after surgery (T8) , extubation time, length of PACU stay, fentanyl consumption and adverse events were all recorded. The incidence and severity of coughing and emergence agitation were assessed. Compared to T0, MAP and heart rate at T1 to T5 all decreased in two groups (P < 0.05). MAP and heart rate at T6 both increased in two groups and group C was higher than group D (P < 0.05). No inter-group differences existed in SpO2, respiratory rate, VT or PETCO2. The incidence of coughing and emergence agitation (30% and 13.3%), fentanyl consumption of group D (0.8 ± 2.1 µg) were all significantly lower than that of group C [(66.7% vs 56.7%) and (4.9 ± 6.50) µg, P < 0.05]. Length of PACU stay in group D was shorter than that in group C [(15 ± 6) vs (23 ± 19) min, P < 0.05]. No inter-group difference existed in extubation time or adverse events. A single intravenous dose of dexmedetomidine is effective in reducing emergence agitation and coughing, shortening length of PACU stay and improving the quality of recovery period after sevoflurane anesthesia in pediatric patients undergoing cleft lip and palate repair.

Sevoflurane/propofol coadministration provides better recovery than sevoflurane in combined general/epidural anesthesia: a randomized clinical trial

A classic general anesthesia is performed by induction with an intravenous hypnotic (such as propofol) and maintenance with a volatile anesthetic (such as sevoflurane). The aim of the present study was to compare the effects of a propofol/sevoflurane maintenance regimen with that of a sevoflurane regimen on recovery profiles. One hundred and sixty patients, who were ASA 1 or 2, 45-65 years of age, and scheduled for elective gastrointestinal surgery under combined general/epidural anesthesia, were allocated randomly to receive the sevoflurane maintenance regimen (group S, n = 80) or sevoflurane/propofol regimen (group SP, n = 80). After induction, anesthesia was maintained with sevoflurane in group S and sevoflurane with propofol (1.2 μg/ml target plasma concentration) in group SP. Bispectral index (BIS) values were maintained within 40-60 during the maintenance. Time to extubation, incidence of serious coughing and agitation, and other recovery characteristics were evaluated during emergence. The time to awakening and extubation in group SP were 7.2 ± 2 min and 8.0 ± 1.8 min, respectively, which were shorter than those results in group S (12.3 ± 1.5 and 12.8 ± 1.6 min, respectively) (P < 0.05). The incidence of serious coughing and agitation in SP (30% and 25%) was lower than that of group S (68% and 53%) (P < 0.05). BIS value, pain score, requirements of analgesics and antiemetics in the PACU, and length of stay in the PACU were similar in the two groups. Compared to sevoflurane maintenance, coadministration of propofol and sevoflurane provides faster awakening and extubation with a low incidence of emergence coughing and agitation.

The effect of intracuff alkalinized 2% lidocaine on emergence coughing, sore throat, and hoarseness in smokers

We evaluated whether endotracheal tube (ETT) intracuff alkalinized lidocaine was superior to saline in blunting emergence coughing, postoperative sore throat, and hoarseness in smokers. In our prospective, double-blind trial, we enrolled 50 smoking patients undergoing surgery under general anesthesia including nitrous oxide (N2O). Patients were randomly allocated to receive either ETT intracuff 2% lidocaine plus 8.4% sodium bicarbonate (L group), or ETT intracuff 0.9% saline (S group). The ETT cuff was inflated to achieve a cuff pressure that prevented air leak during positive pressure ventilation. Incidence of emergence coughing, sore throat, and hoarseness were analyzed. The volume of inflation solution, the intracuff pressure, the duration of anesthesia, the time elapsed to extubation after discontinuation of anesthesia, and the volume of the inflation solution and the air withdrawn from the ETT cuff were also recorded. Intracuff alkalinized 2% lidocaine was superior to saline in blunting emergence coughing (p < 0.001). The incidence of sore throat was significantly lower in the L group at the post-anesthesia care unit (PACU) (p = 0.02). However, at 24 hours after extubation, sore throat incidence was similar in both groups (p = 0.07). Incidence of hoarseness was similar in both groups. Intracuff pressure in the saline group increased with time while the intracuff pressure in the lidocaine group remained constant. The present study demonstrated that the intracuff alkalinized 2% lidocaine was superior to saline in decreasing the incidence of emergence coughing and sore throat during the postoperative period in smokers.

The effect of intracuff alkalinized 2% lidocaine on emergence coughing, sore throat, and hoarseness in smokers

The effect of intracuff alkalinized 2% lidocaine on emergence coughing, sore throat, and hoarseness in smokers

The effect of intracuff alkalinized 2% lidocaine on emergence coughing, sore throat, and hoarseness in smokers

The effect of intracuff alkalinized 2% lidocaine on emergence coughing, sore throat, and hoarseness in smokers

Dose‐dependent attenuation by fentanyl on cough during emergence from general anesthesia

Although fentanyl suppresses tracheal tube-induced cough during anesthetic recovery, it has not been proven if its antitussive effect is dose dependent and complication free. The purpose of this study is to evaluate the relationship between fentanyl doses and cough suppression during emergence from sevoflurane anesthesia. Sixty patients undergoing thyroidectomy were randomly allocated to one of four groups (F0, F1, F1.5, and F2) according to the fentanyl dose (0 mcg/kg, 1 mcg/kg, 1.5 mcg/kg, or 2 mcg/kg). Fentanyl was administered immediately after sevoflurane discontinuation. Coughing was assessed throughout the periextubation period. The relationship between fentanyl dose and incidence of cough was analyzed using Cochran-Armitage trend test. Incidence of more than 30% elevation of mean arterial pressure (MAP) and heart rate (HR), awakening time, extubation time, and respiratory rate after extubation were recorded and compared using Mantel-Haenszel chi-square test and one-way analysis of variance. Fentanyl suppressed emergence cough in a dose-related manner (P = 0.002), and the ED(50) and ED(90) were 1.1 mcg/kg and 2.1 mcg/kg, respectively. The higher dose of fentanyl further reduced the number of patient with MAP and HR elevation (P = 0.003 and 0.005, respectively). Awakening time (8.4 ± 1.9 min) in F2 was comparable with that in F1 and F1.5. Respiratory rate (9 ± 2 bpm) and extubation time (11.9 ± 1.8 min) in F2 were only different from those in F0 (13 ± 3 bpm and 10.4 ± 1.1 min, respectively). Fentanyl suppressed cough in a dose-related manner during recovery from general sevoflurane anesthesia, and 2 mcg/kg may be considered as a proper dose.

The clinical effective dose of alfentanil for suppressing cough during emergence from desflurane anesthesia

BackgroundThe administration of short-acting opioids before emergence is useful for preventing emergence cough induced by an endotracheal tube. This study examined the clinically effective dose of alfentanil for suppressing cough during emergence from desflurane anesthesia.MethodsTwenty-nine adult patients undergoing elective oral surgery were enrolled in this study. During emergence from anesthesia, the patients received alfentanil diluted in 10 ml normal saline when the end-tidal vol% of desflurane decreased to 3%. The initial alfentanil dose was 16 µg/kg. The alfentanil dose for consecutive patients, determined by Dixon's up-and-down method, increased or decreased by 2 µg/kg according to a previous patient's result.ResultsThe 50% effective dose (ED50) of alfentanil for suppressing cough during emergence from desflurane anaesthesia was 9.3 ± 1.5 µg/kg according to Dixon's up-and-down method. Isotonic regression revealed an ED50 and ED95 (95% confidence interval) of alfentanil 10.0 µg/kg (6.8-13.2 µg/kg) and 14.0 µg/kg (7.7-19.4 µg/kg), respectively.ConclusionsThe ED95 of alfentanil for suppressing emergence cough was 14.0 µg/kg. A single bolus administration of alfentanil during emergence from anesthesia was useful for suppressing emergence cough.

Cough During Emergence from Isoflurane Anesthesia

We evaluated the effects of smoking history and albuterol treatment on the amplitude and frequency of cough during emergence from anesthesia.Before induction of anesthesia, 68 patients were randomized to receive two puffs of a placebo or two puffs of albuterol via a metered dose inhaler. Anesthesia was then induced with thiopental, fentanyl, and succinylcholine. The patients' tracheas were intubated with an 8.0 mm-endotracheal tube, and isoflurane administration was initiated. At the end of surgery, isoflurane was discontinued, and the pressure in the endotracheal tube cuff was monitored via the pilot balloon while the end-tidal isoflurane concentration was recorded. Of the 68 patients, 52 coughed before responding to command, but the incidence did not differ between smokers and non-smokers (33 of 43 vs 19 of 25), nor did it differ between albuterol-treated and untreated patients. There was no difference in the frequency or amplitude of coughs between smokers and nonsmokers, nor did albuterol affect either variable. The mean end-tidal concentration at which cough first occurred was 0.30% +/- 0.02%, and only 5% of patients coughed at values >0.6%. We conclude that 1) cough is frequent during emergence; 2) smoking does not affect emergence cough; 3) albuterol treatment does not affect emergence cough; and 4) patients are unlikely to cough at end-tidal values of isoflurane >0.6%. Implications: Most patients cough as they awaken from general anesthesia given via an endotracheal tube. In our study population, cough was frequent but generally did not occur until the end-tidal concentration of isoflurane was <0.6%. Smokers were no more likely to cough than nonsmokers, and the beta-adrenergic agonist albuterol did not prevent cough. (Anesth Analg 1998;87:1170-4)