Comparison of hypotension incidence between remimazolam and propofol in patients with hypertension undergoing neurosurgery: prospective, randomized, single-blind trial.

BACKGROUND: Remimazolam, a newer benzodiazepine that targets the GABAA receptor, is thought to allow more stable blood pressure management during anesthesia induction. In contrast, propofol is associated with vasodilatory effects and an increased risk of hypotension, particularly in patients with comorbidities. This study aimed to identify medications that can maintain stable vital signs throughout the induction phase. METHODS: We conducted a single-center, two-group, randomized controlled trial to investigate and compare the incidence of hypotension between remimazolam- and propofol-based total intravenous anesthesia (TIVA). We selected patients aged between 19 and 75 years scheduled for neurosurgery under general anesthesia, who were classified as American Society of Anesthesiologists Physical Status I-III and had a history of hypertension. RESULTS: We included 94 patients in the final analysis. The incidence of hypotension was higher in the propofol group (91.3%) than in the remimazolam group (85.4%; P = 0.057). There was no significant difference in the incidence of hypotension among the various antihypertensive medications despite the majority of patients being on multiple medications. In comparison with the propofol group, the remimazolam group demonstrated a higher heart rate immediately after intubation. CONCLUSIONS: Our study indicated that the hypotension incidence of remimazolam-based TIVA was comparable to that of propofol-based TIVA throughout the induction phase of EEG-guided anesthesia. Both remimazolam and propofol may be equally suitable for general anesthesia in patients undergoing neurosurgery. TRIAL REGISTRATION: Clinicaltrials.gov (NCT05164146).

A systematic review and meta-analysis comparing the efficacy and safety of ciprofol (HSK3486) versus propofol for anesthetic induction and non-ICU sedation.

Background: Ciprofol (HSK3486) is a novel intravenous anesthetic agent that bears structural similarity to propofol and displays favorable pharmacodynamic characteristics such as rapid onset and offset. The meta-analysis aimed at comparing the efficacy and safety of ciprofol versus propofol in clinical practice. Methods: Medline, EMBASE, Google Scholar, Cochrane Library were searched from inception to April 2023. The primary outcome was success rate of sedation/anesthetic induction and differences in sedation/induction time. The secondary outcomes included risks of hemodynamic instability, respiratory complications, and pain on injection, as well as recovery profiles, satisfaction score, and top-up dose requirement. Results: Twelve RCTs (sedation: n = 6, anesthetic induction, n = 6, all conducted in China) involving 1,793 patients (age: 34-58 years) published from 2021 to 2023 were analyzed. Pooled results revealed no differences in success rate [risk ratio (RR) = 1, 95% confidence interval (CI): 0.99 to 1.01, I2 = 0%, 1,106 patients, p = 1] and time required for successful anesthetic induction/sedation [mean difference (MD) = 7.95 s, 95% CI: -1.09 to 16.99, I2 = 97%, 1,594 patients, p = 0.08]. The risks of top-up dose requirement (RR = 0.94, p = 0.48), cardiopulmonary complications [i.e., bradycardia (RR = 0.94, p = 0.67), tachycardia (RR = 0.83, p = 0.68), hypertension (RR = 1.28, p = 0.2), hypoxemia/pulmonary depression (RR = 0.78, p = 0.24)], and postoperative nausea/vomiting (RR = 0.85, p = 0.72), as well as discharge time (MD = 1.39 min, p = 0.14) and satisfaction score (standardized MD = 0.23, p = 0.16) did not differ significantly between the two groups. However, the ciprofol group had lower risks of hypotension (RR = 0.85, p = 0.02) and pain on injection (RR = 0.17, p < 0.00001) than the propofol group. The time to full alertness was statistically shorter in the propofol group (i.e., 0.66 min), but without clinical significance. Conclusion: Our results demonstrated similar efficacy between ciprofol and propofol for sedation and anesthetic induction, while ciprofol was associated with lower risks of hypotension and pain on injection. Future studies are warranted to evaluate the efficacy and safety of ciprofol in pediatric or the elderly populations. Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/), identifier (CRD42023421278).

Effects of remimazolam combined with sufentanil on hemodynamics during anesthetic induction in elderly patients with mild hypertension undergoing orthopedic surgery of the lower limbs: a randomized controlled trial.

BACKGROUND: This randomized controlled trial was performed to observe the effect of remimazolam with sufentanil on hemodynamics during anesthetic induction in elderly patients with mild hypertension undergoing orthopedic surgery of the lower limbs. METHODS: Sixty elderly patients were randomly assigned to undergo general anesthesia with intravenous injection of either remimazolam besylate (25 mg/vial, batch number 10T11011; Yichang Humanwell Pharmaceutical Co., Ltd., Yichang, China) at 0.2 mg/kg (Group R, n = 30) or propofol at 1.5 mg/kg (Group P, n = 30). Both injections were completed within 15 to 20 s. If the bispectral index value did not reach 40 to 60, then 0.05 mg/kg of remimazolam was added in Group P and 1 mg/kg of propofol was added in Group R. When the BIS value reached 40 to 60, sufentanil was administered at 0.3 to 0.5 µg/kg and cisatracurium was administered at 0.15 to 0.2 mg/kg in both groups. Three minutes later, tracheal intubation and controlled ventilation were performed to maintain the end-tidal carbon dioxide partial pressure at 4.5 to 5.0 kPa. The mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), continuous cardiac index (CI), systemic vascular resistance (SVR), and pulse oxygen saturation were recorded before induction (T0), when the eyelash reflex disappeared (T1), immediately after endotracheal intubation (T2), 1 min after endotracheal intubation (T3), and 5 min after endotracheal intubation (T4). The disappearance time of the eyelash reflex, injection pain, hypotension, bradycardia, hiccupping, nausea and vomiting, and other adverse events were observed. RESULTS: The MAP, HR, CO, and CI at T1, T2, T3, and T4 were significantly higher in Group R than P, while SVR was significantly lower in Group R than P (P < 0.05). In Group P, the MAP, HR, CO, and CI were significantly lower and the SVR was significantly higher at T1, T2, T3, and T4 than at T0 (P < 0.05). Adverse events occurred in 8 (20%) patients in Group R and 22 (73%) in Group P. The total incidence of adverse events was significantly lower in Group R than P (P < 0 0.001). CONCLUSION: Remimazolam combined with sufentanil for general anesthesia induction has the advantages of small hemodynamic fluctuations, stable circulation, and few adverse reactions, making it suitable for elderly patients with mild hypertension. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2300069224, 10/03/2023).

Comparison of preoxygenation efficiency measured by the oxygen reserve index between high-flow nasal oxygenation and facemask ventilation: a randomised controlled trial.

BACKGROUND: High-flow nasal oxygenation and the oxygen reserve index (ORI), which is a non-invasive and innovative modality that reflects the arterial oxygen content, are used in general anaesthesia. This study compares the preoxygenation efficiency (measured by the ORI) of high-flow nasal oxygenation and facemask ventilation during the induction process. METHODS: This single-centre, two-group, randomised controlled trial included 197 patients aged ≥ 20 years who underwent orotracheal intubation for general anaesthesia for elective surgery. The patients were randomly allocated to receive preoxygenation via facemask ventilation or high-flow nasal oxygenation. The ORI was measured and compared between both groups. RESULTS: The ORI increased during preoxygenation in all patients. At 1 min of preoxygenation, the ORI was significantly higher in the high-flow nasal oxygenation group (0.34 ± 0.33) than in the facemask ventilation group (0.21 ± 0.28; P = 0.003). The highest ORI was not significantly different between the two groups (0.68 ± 0.25 in the high-flow nasal oxygenation group vs. 0.70 ± 0.28 in the facemask ventilation group; P = 0.505). CONCLUSIONS: High-flow nasal oxygenation results in an oxygenation status similar to that provided by facemask ventilation during the induction process of general anaesthesia; therefore, high-flow nasal oxygenation is a feasible preoxygenation method. TRIAL REGISTRATION: Clinicaltrials.gov (NCT04291339).

Efficacy and safety of remimazolam for non-obese patients during anesthetic induction in cardiac surgery: study protocol for a multicenter randomized trial.

BACKGROUND: Valvular heart disease remains common in both developed and developing countries, and it requires timely surgical treatment when necessary. However, the stability of hemodynamics during anesthesia induction in patients undergoing valve replacement surgery is difficult to maintain due to their impaired cardiac function. Remimazolam, a novel and ultrashort-acting intravenous sedative-hypnotic, may be beneficial to stable hemodynamics, but the evidence is limited. Therefore, this study aims to evaluate the effect of remimazolam induction on hemodynamics compared with midazolam and etomidate in patients undergoing valve replacement surgery. METHODS: This is a prospective, multicenter randomized controlled trial (RCT). Three hundred and sixty-three non-obese adult patients aged 45 to 80 years old undergoing valve surgery with cardiopulmonary bypass will be randomly allocated to receive remimazolam tosilate, midazolam, or etomidate during anesthetic induction. The primary outcome is the incidence of hypotension within 20 min after the administration of investigated drugs. The hypotension is defined as systolic blood pressure (SBP) < 90 mmHg or a 30% reduction in SBP from baseline or the application of vasoactive drugs. Secondary outcomes include incidence of successful sedation, time to successful sedation, incidence of delirium and postoperative low cardiac output syndrome within 7 days after surgery, hospital mortality, mechanical ventilation time, ICU length of stay, and hospital length of stay. DISCUSSION: To our knowledge, this is the first prospective RCT to investigate the efficacy and safety of remimazolam induction in adult cardiac surgery compared with midazolam and etomidate. This study will provide important information on the application of remimazolam in cardiac surgery in the future. TRIAL REGISTRATION: Chinese Clinical Trial Registry chictr.org.cn ChiCTR2100050122. Registered on August 16, 2021.

Impacto de un programa de educación estructurado sobre el nivel de ansiedad preoperatoria de pacientes pediátricos y de sus padres / Impact of a structured education program on preoperative anxiety level in pediatric patients and their parents

Introducción: los pacientes pediátricos y sus padres sienten ansiedad antes de una cirugía, síntoma que afecta la inducción anestésica, el dolor y el comportamiento postoperatorio. El objetivo fue evaluar el efecto de la educación preoperatoria estructurada en el nivel de ansiedad de niños sometidos a cirugía electiva y de sus padres. Métodos: estudio prospectivo, aleatorio, doble ciego, en niños de 2-12 años, ASA I-II. Los participantes fueron aleatorizados en grupo control (información habitual) y grupo experimental (información estructurada). Se registraron variables demográficas, nivel de ansiedad en unidad preoperatoria y en pabellón en niños y padres; se evaluó el comportamiento de los niños durante la inducción anestésica. Análisis estadístico: t-test, x2; valores expresados en media y desviación estándar; significancia p ≤ 0,05. Resultados: se reclutaron 34 pacientes, 18 en grupo control y 16 en grupo experimental. Los valores ansiedad en niños pre-pabellón fueron 37,7 ± 21,4 en grupo control y 31,9 ± 11,5 en grupo experimental (p= 0,35); durante pre-inducción fue 43,2 ± 25,3 y 36 ± 15,5 respectivamente (p= 0,33). Los niveles de ansiedad en padres pre-pabellón fueron 42,5 ± 15,5 para grupo control y 37,6 ± 6,9 en grupo experimental (p= 0,25), y al retirarse del pabellón fueron de 45,1 ± 16,6 y 43,9 ± 9,8 respectivamente (p= 0,82). No hubo diferencias en el comportamiento durante la inducción anestésica entre ambos grupos (p= 0,24). Conclusiones: no fue posible demostrar efectos de información estructurada en niveles de ansiedad en niños que van a ser operados y en sus padres.

Introduction: Pediatric patients and their parents experience anxiety before surgery, a symptom that affects anesthetic induction, pain and postoperative behavior. The objective was to evaluate the effect of structured preoperative education on the anxiety level in children undergoing elective surgery and their parents. Methods: A prospective, randomized, double-blind study in children aged 2-12 years, ASA I-II. Patients were randomized into a control group (usual preoperative information) and an experimental group (structured information). Demographic variables, anxiety level in the preoperative unit and in operating room in children and parents were recorded; the behavior of children during anesthetic induction was evaluated. Statistical analysis: t-test, x2; values expressed as mean and standard deviation; significance p ≤ 0.05. Results: 34 patients were recruited, 18 in the control group and 16 in the experimental group. The anxiety levels in children in preoperative unit were 37.7 ± 21 and 31.9 ± 11.5.4 in control and experimental group, respectively (p = 0.35), and in operating room were 43.2 ± 25.3 and 36 ± 15.5 respectively (p = 0.33). Parental anxiety levels in preoperative unit were 42.5 ± 15.5 in control group and 37.6 ± 6.9 in experimental group (p = 0.25), and when they leaving operating room were 45.1 ± 16.6 and 43.9 ± 9.8 respectively (p = 0.82). There were no differences in the behavior during anesthetic induction between both groups (p = 0.24). Conclusions: It was not possible to demonstrate effects of structured information on anxiety levels in children undergoing surgery and in their parents.

Pulmonary edema in a pediatric cancer patient after anesthetic induction.

Negative pressure pulmonary edema (NPPE) in the context of anesthesia is a rare condition, although pediatric patients are at higher risk. This case stands out for the severe respiratory clinic that quickly developed in a child with a cancer history whose radiological and clinical presentation suggested multiple differential diagnoses, including tumor recurrence with metastasis or pulmonary tuberculosis. NPPE is a well-described, but a probably underrecognized clinical syndrome, that occurs after intense inspiratory effort against an obstructed airway. In clinical practice, when unexplained pulmonary edema takes place, NPPE should be considered in the differential diagnosis. NPPE usually has a favorable prognosis but pediatricians, radiologists, and anesthesiologists should be aware of this complication.

Etomidate versus ketamine for emergency endotracheal intubation: a randomized clinical trial.

PURPOSE: Etomidate and ketamine are hemodynamically stable induction agents often used to sedate critically ill patients during emergency endotracheal intubation. In 2015, quality improvement data from our hospital suggested a survival benefit at Day 7 from avoidance of etomidate in critically ill patients during emergency intubation. In this clinical trial, we hypothesized that randomization to ketamine instead of etomidate would be associated with Day 7 survival after emergency endotracheal intubation. METHODS: A prospective, randomized, open-label, parallel assignment, single-center clinical trial performed by an anesthesiology-based Airway Team under emergent circumstances at one high-volume medical center in the United States. 801 critically ill patients requiring emergency intubation were randomly assigned 1:1 by computer-generated, pre-randomized sealed envelopes to receive etomidate (0.2-0.3 mg/kg, n = 400) or ketamine (1-2 mg/kg, n = 401) for sedation prior to intubation. The pre-specified primary endpoint of the trial was Day 7 survival. Secondary endpoints included Day 28 survival. RESULTS: Of the 801 enrolled patients, 396 were analyzed in the etomidate arm, and 395 in the ketamine arm. Day 7 survival was significantly lower in the etomidate arm than in the ketamine arm (77.3% versus 85.1%, difference - 7.8, 95% confidence interval - 13, - 2.4, p = 0.005). Day 28 survival rates for the two groups were not significantly different (etomidate 64.1%, ketamine 66.8%, difference - 2.7, 95% confidence interval - 9.3, 3.9, p = 0.294). CONCLUSION: While the primary outcome of Day 7 survival was greater in patients randomized to ketamine, there was no significant difference in survival by Day 28.

Comparison of different scales for the evaluation of anxiety and compliance with anesthetic induction in children undergoing scheduled major outpatient surgery.

INTRODUCTION: Anxiety in children triggered by a scheduled surgical intervention is a major issue due to its frequency and consequences. Preoperative anxiety is associated with increased patient fear and agitation on anesthetic induction. The aim of this study is to compare three preoperative anxiety scales for children undergoing elective outpatient surgery, and to correlate each of these tools with the degree of patient compliance on induction, as assessed by the Induction Compliance Checklist (ICC). METHODS: An observational prospective study was performed on a cohort of children with ages between 2 and 16 years old, scheduled for outpatient surgery. Anxiety was assessed upon arrival to the hospital (M0), during transfer to the surgical unit (M1), and in the operating room during anesthetic induction (M2). Anxiety in the parents (measured with the State-Trait Anxiety Inventory, STAI) and in the children (measured with the Spence Anxiety Scale-Pediatric, SCAS-P, the State-Trait Anxiety Inventory Children, STAIC, and Modified Yale Preoperative Anxiety Scale, m-YPAS) was assessed. Compliance with anesthetic induction was assessed with ICC. RESULTS: The study included 76 patients (72.4% male, median age 7.9 years). Anxiety scores (m-YPAS) increased as the moment of surgery approached, being greater at the entrance to the surgical unit (M0 = 26.1 ± 9.5; M1 = 31.8 ± 18.1; M2 = 33.5 ± 21.1). A strong correlation was found between ICC scale and m-YPAS at M1 (0.738) and M2 timepoints (0.794), but not with the rest of scales at M0. CONCLUSIONS: Standard anxiety assessment scales do not predict the quality of anesthetic induction. m-YPAS scale can detect increasing anxiety in children as they approach the surgical procedure and this correlates strongly with a worse anesthetic induction, defined by higher score on ICC scale.

Remimazolam for induction of anesthesia in elderly patients with severe aortic stenosis: a prospective, observational pilot study.

BACKGROUND: Remimazolam, a novel benzodiazepine, has been reported to cause less hypotension than propofol during induction of anesthesia. Therefore, remimazolam might be a valuable option in elderly patients with severe aortic stenosis who are considered to be the most vulnerable to hemodynamic instability. We aimed to evaluate the feasibility and hemodynamic effects of remimazolam as an induction agent in elderly patients with severe aortic stenosis. METHODS: This prospective, open-label, single-arm, observational pilot study was conducted in a university hospital between November 2020 and April 2021. We included 20 patients aged 65 years or older scheduled for transcatheter or surgical aortic valve replacement for severe aortic stenosis under general anesthesia. Patients were administered intravenous remimazolam infusion at 6 mg/kg/h combined with 0.25 µg/kg/min of remifentanil infusion. The primary outcome was the vasopressor dosage between the induction of anesthesia and the completion of tracheal intubation. The secondary outcomes included hemodynamic changes, bispectral index changes, and the time from the start of remimazolam infusion to loss of consciousness. We also recorded awareness during anesthesia induction and serious adverse events related to death, life-threatening events, prolonged hospitalizations, and disability due to permanent damage. RESULTS: Twenty patients aged 84 [79-86] (median [interquartile range]) with American Society of Anesthesiologists physical status 4 were analyzed. Ephedrine 0 [0-4] mg and phenylephrine 0.1 [0-0.1] mg were administered to 14/20 patients (3 doses in 1 patient, 2 doses in 4 patients, and one dose in 9 patients). Loss of consciousness was achieved at 80 [69-86] s after the remimazolam infusion was started. The mean arterial pressure decreased gradually after loss of consciousness but recovered immediately after tracheal intubation. The bispectral index values gradually decreased and reached < 60 at 120 s after loss of consciousness. Neither awareness during induction of anesthesia nor serious adverse events, such as severe bradycardia (< 40 bpm), life-threatening arrhythmia, myocardial ischemia, or anaphylactic reactions were observed. CONCLUSIONS: Remimazolam could be used as an induction agent with timely bolus vasopressors in elderly patients with severe aortic stenosis. TRIAL REGISTRATION: UMIN Clinical Trials Registry, identifier UMIN000042318 .

Variation in propofol induction doses administered to surgical patients over age 65.

BACKGROUND/OBJECTIVES: Advanced age is associated with increased susceptibility to acute adverse effects of propofol. The present study aimed to describe patterns of propofol dosing for induction of general anesthesia before endotracheal intubation in a nationwide sample of older adults presenting for surgery. DESIGN: Retrospective observational study using the Multicenter Perioperative Outcomes Group data set. SETTING: Thirty-six institutions across the United States. PARTICIPANTS: A total of 350,766 patients aged over 65 years who received propofol for general anesthetic induction and endotracheal intubation between 2014 and 2018. INTERVENTION: None. MEASUREMENTS: Total induction bolus dose of propofol administered. RESULTS: The mean (SD) weight-adjusted propofol dose was 1.7 (0.6) mg/kg. The mean prevalent propofol induction dose exceeded the upper bound of what has been described as the typical geriatric dose requirement across every age category examined. The percent of patients receiving propofol induction doses above the described typical geriatric range was 64.8% (95% CI 64.6-65.0), varying from 73.8% among patients aged 65-69 to 45.8% among patients aged 80 and older. CONCLUSION: The present study of a large multicenter cohort demonstrates that prevalent propofol dosing commonly falls above the published typically required dose range for patients aged ≥65 in nationwide anesthetic practice. Widespread variability in induction dose administration remains incompletely explained by known patient variables. The nature and clinical consequences of these unexplained dosing decisions remain important topics for further study. Observed discordance between expected and actual induction dosing raises the question of whether there should be reconsideration of widespread provider practice or, alternatively, whether what is published as the typical propofol induction dose range should be revisited.

Comparison of the anesthetic effects between 5 mg/kg of alfaxalone and 10 mg/kg of propofol administered intravenously in cats.

To compare the anesthetic effects after intravenous administration of alfaxalone or propofol without premedication, either alfaxalone (5 mg/kg) or propofol (10 mg/kg) was administered intravenously over 120 sec in 6 cats. Each cat received the alternate treatment at least a 7-day interval. Anesthetic effects (tolerance of intubation, behavior changes and neurodepressive score) and physiological parameters were evaluated. Both treatments produced a rapid loss of consciousness, no apnea, and physiological parameters were maintained within clinically acceptable ranges apart from transient hypoxemia. The degree of hypoxemia was greater after the propofol treatment compared with the alfaxalone treatment. During the recovery period, more adverse events (ataxia, muscular tremors) were observed after the alfaxalone treatment compared with the propofol treatment.

Anesthetic Induction With Etomidate in Cardiac Surgical Patients: A PRISMA-Compliant Systematic Review and Meta-Analysis.

OBJECTIVE: This meta-analysis aimed to systematically review the effects of etomidate (ETM) during anesthetic induction on patients undergoing cardiac surgery. DESIGN: Systematic review and meta-analysis. SETTING: Operating room. PARTICIPANTS: Patients undergoing cardiac surgery. INTERVENTIONS: ETM or control drugs. MEASUREMENTS AND MAIN RESULTS: PubMed, Cochrane Library, OVID, and EMBASE were searched through August 31, 2020. Primary outcomes included hemodynamic profiles and stress responses. Secondary outcomes included morbidity, mortality, and postoperative recovery. For continuous/dichotomous variables, treatment effects were calculated as weighted mean difference (WMD)/odds ratio (OR) and 95% confidence interval (CI). A database search yielded 18 randomized controlled trials including 1,241 patients. The present meta-analysis demonstrated that ETM-anesthetized patients had lower heart rates (WMD, -3.31; 95% CI -5.43 to -1.19; p = 0.002), higher blood pressures (systolic blood pressure: WMD, 12.02; 95% CI 6.24 to 17.80; p < 0.0001; diastolic blood pressure: WMD, 5.23; 95% CI 2.39 to 8.08; p = 0.0003; mean arterial pressure (MAP): WMD, 8.64; 95% CI 5.85 to 11.43; p < 0.00001), less requirement for vasopressor (OR, 0.26; 95% CI 0.15 to 0.44; p < 0.00001), and more nitroglycerin usage (OR, 14.89; 95% CI 4.92 to 45.08; p < 0.00001) during anesthetic induction. Current meta-analysis also demonstrated that single-dose ETM lowered cortisol levels transiently and did not have a significant effect on endogenous norepinephrine and epinephrine levels and was not associated with increased postoperative inotrope and/or vasopressor requirement. Additionally, the meta-analysis suggested that ETM anesthesia was associated with neither increased mortality nor morbidity, except a higher incidence of transient adrenal insufficiency in ETM recipients. CONCLUSION: The present meta-analysis suggested that single-dose ETM during anesthetic induction could be associated with more stable hemodynamics, transient and reversible lower cortisol levels, and a higher adrenal insufficiency incidence, but not worse outcomes in cardiac surgical patients.

The Effect of a Small Priming Dose of Sufentanil on Sufentanil-Induced Cough.

PURPOSE: The aim of this study was to investigate the effect of a small priming dose of sufentanil on sufentanil-induced cough during induction of anesthesia. DESIGN: Randomized controlled trial. METHODS: Adult patients (N = 220) aged 18 to 65 years undergoing general anesthesia were randomized into two groups (n = 110), a total dose of sufentanil 0.4 mcg/kg was used during induction of anesthesia. Group P (intervention) received a bolus of 5 mcg of sufentanil 1 minute before a bolus of the remaining larger dose of sufentanil, whereas group C (comparison) received an equal volume of normal saline 1 minute before a bolus of the total dose of sufentanil. The incidence and severity of cough were noted for 1 minute after each injection of sufentanil or normal saline. FINDINGS: The incidence of cough in group P was significantly lower than group C (6.4% vs 21.8%, P < .001). The severity of cough in group P was significantly decreased compared with group C (P < .001). In group P, three patients (2.7%, P = .247) coughed after the priming sufentanil injection. CONCLUSIONS: A priming dose of 5 mcg of sufentanil 1 minute before a larger dose of sufentanil injection could effectively alleviate sufentanil-induced cough, the small priming dose of sufentanil could also elicit cough with a low incidence.

Effect of Tramadol Pretreatment on Sufentanil-Induced Cough.

PURPOSE: To investigate the effect of tramadol pretreatment on the incidence and severity of sufentanil-induced cough. DESIGN: Randomized controlled trial. METHODS: Adults of both genders (N = 304; 18 to 65 years old, American Society of Anesthesiologists physical status I to II), scheduled for elective surgery, were randomized into two groups (n = 152): intravenous administration of tramadol 1 mg/kg (group T) or normal saline (group C). Then sufentanil bolus 0.3 mcg/kg was administered intravenously in 5 seconds. The incidence and severity of cough were observed for 1 minute. Mean arterial pressure, heart rate, nausea, vomiting, and truncal rigidity during induction were also recorded. FINDINGS: Patient characteristics were similar between the two groups. The incidence of cough was significantly lower in group T when compared with group C (7.9% vs 18.4%, P < .05); there were nine patients coughing severely in group C, whereas no severe cough occurred in group T (P < .05). The mean arterial pressure, heart rate, and incidences of other side effects were comparable between the two groups. CONCLUSIONS: Pretreatment of intravenous tramadol 1 mg/kg could be a clinically effective intervention for attenuating sufentanil-induced cough.

Nutritional ketosis delays the onset of isoflurane induced anesthesia.

BACKGROUND: Ketogenic diet (KD) and exogenous ketone supplements can evoke sustained ketosis, which may modulate sleep and sleep-like effects. However, no studies have been published examining the effect of ketosis on the onset of general isoflurane induced anesthesia. Therefore, we investigated the effect of the KD and different exogenous ketogenic supplements on the onset of akinesia induced by inhalation of isoflurane. METHODS: We used a high fat, medium protein and low carbohydrate diet (KD) chronically (10 weeks) in the glucose transporter 1 (GLUT1) deficiency (G1D) syndrome mice model and sub-chronically (7 days) in Sprague-Dawley (SPD) rats. To investigate the effect of exogenous ketone supplements on anesthetic induction we also provided either 1) a standard rodent chow diet (SD) mixed with 20% ketone salt supplement (KS), or 2) SD mixed with 20% ketone ester supplement (KE; 1,3 butanediol-acetoacetate diester) to G1D mice for 10 weeks. Additionally, SPD rats and Wistar Albino Glaxo Rijswijk (WAG/Rij) rats were fed the SD, which was supplemented by oral gavage of KS or KE for 7 days (SPD rats: 5 g/kg body weight/day; WAG/Rij rats: 2.5 g/kg body weight/day). After these treatments (10 weeks for the mice, and 7 days for the rats) isoflurane (3%) was administered in an anesthesia chamber, and the time until anesthetic induction (time to immobility) was measured. Blood ketone levels were measured after anesthetic induction and correlation was calculated for blood beta-hydroxybutyrate (ßHB) and anesthesia latency. RESULTS: Both KD and exogenous ketone supplementation increased blood ketone levels and delayed the onset of isoflurane-induced immobility in all investigated rodent models, showing positive correlation between the two measurements. These results demonstrate that elevated blood ketone levels by either KD or exogenous ketones delayed the onset of isoflurane-induced anesthesia in these animal models. CONCLUSIONS: These findings suggest that ketone levels might affect surgical anesthetic needs, or could potentially decrease or delay effects of other narcotic gases.

Desaturation times between dogs preoxygenated via face mask or flow-by technique before induction of anesthesia.

OBJECTIVE: To compare time to desaturation after induction of anesthesia following administration of oxygen via face mask or flow-by for 3 minutes. STUDY DESIGN: Randomized crossover study. ANIMALS: A group of six healthy adult dogs weighing 15.0 ± 3.4 kg. METHODS: Dogs were anesthetized twice separated by 14 days. Intramuscular administration of dexmedetomidine (4 µg kg-1), acepromazine (0.01 mg kg-1) and butorphanol (0.2 mg kg-1) provided sedation for percutaneous insertion of a catheter into the tracheal lumen. The tip was advanced to the thoracic inlet and position confirmed using fluoroscopy. Using a sample aspiration rate 200 mL minute-1, inspired (FIO2) and end-tidal oxygen (Fe'O2) were measured. Oxygen (100 mL kg-1 minute-1) was delivered into a circle delivery system and administered to the dog for 3 minutes via face mask or flow-by from the circle Y-piece 2.5 cm from the nares. Then, propofol was administered to induce anesthesia and apnea. A pulse oximeter (lingual probe) measured hemoglobin saturation (SpO2). At SpO2 90% (desaturation point), an endotracheal tube was inserted to allow administration of oxygen and artificial ventilation. Arterial blood and data were collected at baseline (before oxygen administration), 5 seconds after induction of anesthesia, and every 30 seconds until the desaturation point was reached. Data were analyzed using an unpaired and paired t test with (p < 0.05). RESULTS: FIO2, Fe'O2 and PaO2 (mean ± standard deviation) were significantly higher after mask preoxygenation [89.7 ± 5.5%, 83.0 ± 7.6% and 394 ± 112 mmHg (52.4 ± 14.9 kPa)] compared with flow-by [30.0 ± 5.4%, 22.7 ± 3.8% and 133 ± 22 mmHg (17.7 ± 2.9 kPa)], respectively. Time to desaturation was significantly longer after mask treatment compared with flow-by (187 ± 67 versus 66 ± 17 seconds). CONCLUSIONS AND CLINICAL RELEVANCE: Mask preoxygenation provided longer time to desaturation compared with the flow-by technique tested.

Corrected QT interval prolongation during anesthetic induction for laryngeal mask airway insertion with or without cisatracurium.

Objective This study was performed to observe the occurrence of corrected QT (QTc) interval prolongation during anesthetic induction for laryngeal mask airway insertion and the effects of cisatracurium administration on the QTc interval. Methods Eighty-eight patients were assigned to two groups: the cisatracurium administration group (n = 45) and non-cisatracurium administration group (n = 43). The QTc interval was continuously recorded by a 12-lead Holter electrocardiogram beginning in the hospital ward and continuing until after anesthetic induction. Results In the cisatracurium administration group, the QTc interval significantly increased from 417.9 ± 27.9 to 451.6 ± 32.5 ms after arrival in the operating room and significantly decreased to 432.4 ± 32.5 ms after a 15-minute rest; it significantly increased to 459.7 ± 23.8 ms again after propofol and fentanyl injection. However, the QTc interval decreased after cisatracurium injection. In the non-cisatracurium administration group, the QTc interval initially showed changes similar to those in the cisatracurium group until fentanyl and propofol were injected. Conclusions The QTc interval was significantly prolonged on arrival in the operating room and after propofol and fentanyl injection. The QTc interval did not significantly change by laryngeal mask airway insertion regardless of the administration of cisatracurium.

Predictors of Pre-operative Anxiety in Indian Children.

OBJECTIVE: To identify the predictors of pre-operative anxiety in school-going children in India. METHODS: A prospective observational study was done at a tertiary care teaching hospital. Children aged 7-12 y scheduled for elective surgery and their parents were enrolled. Pre-operative anxiety in children and parents was assessed using STAI-C and STAI-P questionnaires respectively. The child's anxiety in pre-op room, at the time of parental separation and induction of anesthesia were assessed using m-YPAS scale. Possible predictors of anxiety under 'individual', 'social' and 'healthcare' domains were analyzed using logistic regression. The quality of mask induction of anesthesia was assessed using Induction Compliance Checklist. RESULTS: Sixty children completed the study successfully. Receiver operating characteristic (ROC) curve indicted mYPAS score ≥ 30 (observed score) to identify children with high anxiety as identified by STAI-C ≥37 (self-reported score). The incidence of high anxiety escalated from pre-operative time (48%) to the time of parental separation (72%) and increased further at anesthetic induction (95%). Parental anxiety (p = 0.03) and socioeconomic background (p = 0.03) were significant predictors of the child's pre-operative anxiety. The presence of >4 people at induction (p = 0.002), but not pre-operative anxiety, was found significantly more in children with poor quality of mask induction. CONCLUSIONS: The incidence of peri-operative anxiety in Indian children is significant. Parental anxiety and socioeconomic background were found significant predictors of high pre-operative anxiety in our set-up.

Flavored Anesthetic Masks for Inhalational Induction in Children.

OBJECTIVES: To evaluate the clinical efficacy of masking the odor of inhalational agents using fruit flavors on the anxiety behavior and compliance of children for inhalational induction. METHODS: A prospective randomized double blind, placebo controlled study was conducted on 60 unpremedicated children in the age group of 4-12 y. Thirty children received anesthetic masks smeared with a flavor of child's choice while the other 30 children were induced using masks without flavor. Anxiety was assessed using modified Yale Pre-operative Anxiety Scale (mYPAS) in the pre-op room and during inhalational induction. Mask acceptance was graded by Induction Compliance Checklist (ICC). The cost-effectiveness of flavored anesthetic masks was compared to that of commercially available pre-scented masks. RESULTS: The baseline anxiety in the two groups was comparable. The number of children demonstrating high levels of anxiety at anesthetic induction was similar in flavored and non-flavored mask groups (p 0.45). The compliance to mask induction was also equally good (p 0.99). The authors found significant difference in the cost of flavored mask (INR 56.45 per mask) as compared to commercially available pre-scented masks (INR 660 per mask). CONCLUSIONS: The authors observed a placebo effect that reduced the pre-op anxiety in the control group which probably made the quality of induction equivalent with flavored and non-flavored masks. Therefore, using a flavored anesthetic mask is cost-effective than using a commercially available pre-scented mask.