Effects of oral clonidine premedication on haemodynamic response to laryngoscopy and tracheal intubation: a clinical trial

Determination of the 95% effective dose of remimazolam tosylate in anesthesia induction inhibits endotracheal intubation response in senile patients

Background and Purpose: The prevalence of elderly patients prompts anesthesiologists to determine the optimal dose of medication due to the altered pharmacokinetics and pharmacodynamics of this population. The present study aimed to determine the 95% effective dose (ED₉₅) of remimazolam tosylate in anesthesia induction to inhibit endotracheal intubation-related cardiovascular reaction in frail and non-frail senile patients. Methods: A prospective sequential allocation dose-finding study of remimazolam tosylate was conducted on 80 elderly patients who received general anesthesia between May and June 2022 at the First Affiliated Hospital of Nanchang University. The initial dose was 0.3 mg/kg. The blood pressure and heart rate fluctuations during intubation were either <20% (negative cardiovascular response) or ≥20% (positive cardiovascular response). If positive, the dose of the next patient was increased by 0.02 mg/kg, while if negative, it was reduced by 0.02 mg/kg according to the 95:5 biased coin design (BCD). The ED₉₅ and 95% confidence intervals (CIs) were determined using R-Foundation isotonic regression and bootstrapping methods. Results: The ED₉₅ of remimazolam tosylate to inhibit the response during tracheal intubation was 0.297 mg/kg (95% CI: 0.231-0.451 mg/kg) and 0.331 mg/kg (95% CI: 0.272-0.472 mg/kg) in frail and non-frail senile patients, respectively. Conculation and Implications: The CI of the two groups overlap, and no difference was detected in the ED₉₅ of remimazolam tosylate in inhibiting endotracheal intubation-related cardiovascular response in frail and non-frail senile patients. These results suggested that remimazolam tosylate is an optimal anesthesia inducer for all elderly patients. Clinical Trial Registration: https://www.chictr.org.cn, identifier ChiCTR2200055709.

Hemodynamic response related to the Airway Scope versus the Macintosh laryngoscope: A systematic review and meta-analysis with trial sequential analysis

BACKGROUND

It is important to reduce the hemodynamic response during tracheal intubation. We performed a systematic review and meta-analysis of the Airway Scope and Macintosh laryngoscope to determine whether they reduce the hemodynamic responses of heart rate (HR) and mean blood pressure (MBP) after tracheal intubation under general anesthesia.

METHODS

We performed a comprehensive literature search of electronic databases for clinical trials comparing hemodynamic response to tracheal intubation. The primary aim of our meta-analyst is to determine if the Airway Scope reduces hemodynamic responses (HR and mean MBP) 60 seconds after tracheal intubation compared to the Macintosh laryngoscope. We expressed pooled differences in hemodynamic responses between the 2 devices as weighted mean differences with 95% confidence intervals. We conducted trial sequential analysis. Secondarily, we investigated the ability of the Airway Scope and Macintosh laryngoscope to reduce hemodynamic responses at 120 seconds, 180 seconds, and 300 seconds after tracheal intubation.

RESULTS

We identified clinical trials comparing hemodynamic response via a comprehensive literature search. Of 185 articles found in the search, we selected 8. In comparison to the Macintosh laryngoscope, the Airway Scope significantly reduced HR and MBP at 60 seconds after tracheal intubation (HR; weighted mean difference = -7.29; 95% confidence interval, -10.9 to -3.62; P < .0001; I2 = 57%, MBP; weighted mean difference = -11.5; 95% confidence interval, -20.4 to -2.65; P = .01; I2 = 91%). At the secondary outcome, the Airway Scope significantly reduced the fluctuation of HR after 120 seconds and 180 seconds of tracheal intubation. However, the Airway Scope did not significantly reduce MBP 120 seconds, 180 seconds, and 300 seconds after tracheal intubation. Trial sequential analysis suggested that the total sample size reached the required information size for heart rate.

CONCLUSIONS

Our finding suggested that the Airway Scope attenuated hemodynamic responses at 60 seconds after tracheal intubation in comparison with that of the Macintosh laryngoscope. However, the MBP sample size is small and further research is needed.

Hemodynamic Responses to Tracheal Intubation in Elderly Patients: Intravenous or Spray of Lidocaine versus Fentanyl

Introduction

Laryngoscopy and tracheal intubation are known to increase sympathetic activity that may be detrimental to patients with preexisting ischaemic or hypertensive heart disease.

Aim

The aim of this study was to compare of intravenous and oropharyngeal spray of lidocaine and high dose of fentanyl on systolic and diastolic blood pressures and heart rate of patients over 65 years during tracheal intubation.

Material and Methods

In this clinical trial, 160 patients over 65 yrs who were randomly divided into five groups of 32 patients. For group one lidocaine spray 10%, group two intravenous lidocaine 1.5 mg/kg, group three lidocaine spray along with intravenous lidocaine 0.75 mg/kg, and for group four fentanyl 5μg/kg were administered and group five patients were controls which were given 1 mg of midazolam along with 2 μg/kg fentanyl. Systolic and diastolic blood pressures and heart rate were measured before and after anesthesia and intubation. ANOVA, Scheffe's and Repeated measure tests were used for data comparison and P<0.05 was considered significant.

Results

No significant difference was detected in terms of gender among the understudy groups. The mean (SD) age of patients in all groups were 69 ±3.5 yrs. (65-80 yrs.) and there is no significant difference was detected between the mean age and other basic variables of under study groups (P<0.328). Study results showed that the kind of surgery hasn't different between groups. The table showed that no difference between male and female. No significant difference was observed between groups with different sizes of tracheal tube in terms of systolic and diastolic blood pressures and heart rate. No significant difference was detected in terms of systolic and diastolic blood pressures and heart rate among groups prior to the induction of anesthesia.

Conclusion

All methods were effective for efficient blood pressure control during laryngoscopy and tracheal intubation.

Oral Clonidine vs Oral Pregabalin Premedication to Attenuate Pressor Response to Direct Laryngoscopy in Patients Undergoing Laparoscopic Cholecystectomy: A Randomized Double Blind Study

INTRODUCTION

Direct laryngoscopy and tracheal intubation has adverse effects like tachycardia, hypertension, myocardial ischemia and cerebral haemorrhage. There are several studies on various pharmacological agents to attenuate this response.

AIM

This study was designed to compare efficacy and safety of oral clonidine and oral pregabalin premedication to attenuate stress response in patients undergoing laparoscopic cholecystectomy.

MATERIALS AND METHODS

Total 80 patients of ASA grade I and II, aged between 20-60 years of both sexes scheduled for elective laparoscopic cholecystectomy were included in the study. All the patients were randomized into two groups. Group A received oral clonidine 0.3mg and group B received oral pregabalin 150mg, 60 minutes before surgery. Anaesthesia technique was standardized. Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), mean arterial pressure (MAP) and heart rate were recorded preoperatively, after premedication, immediately after intubation, then at 1 min, 3 min, 5 min, 10 min and 15 min after intubation. Level of sedation, postoperative pain scores and any adverse effects were also noted and compared.

RESULTS

Oral clonidine 0.3mg as well as oral pregabalin 150mg were effective in blunting haemodynamic stress response to laryngoscopy and tracheal intubation. Clonidine was found to be better than pregabalin in lowering of systolic blood pressure, diastolic blood pressure, mean arterial pressure and heart rate changes associated with laryngoscopy. We also found that bradycardia was common with both the drugs, more so in clonidine group. Post-operative analgesia was better in pregabalin group as compared to clonidine group. Both the drugs cause sedation, but it was more with the use of pregabalin.

CONCLUSION

Both the drugs can be used as an effective premedicant to attenuate the sympathetic response to laryngoscopy and tracheal intubation without much side effects and the added advantage of intraoperative and postoperative analgesia.

Comparison of effects of intravenous clonidine and dexmedetomidine for blunting pressor response during laryngoscopy and tracheal intubation: A randomized control study

Context:

Laryngoscopy and endotracheal intubation activates the sympathetic nervous system, causing tachycardia and hypertension. Dexmedetomidine has an affinity for alpha₂ receptors 8 times greater than that of clonidine. It diminishes norepinephrine release and inhibits sympathetic activity leading to decreased heart rate (HR) and blood pressure.

Aims:

The aim was to compare the effect of intravenous (IV) infusion of dexmedetomidine and clonidine on the pressor response among patients undergoing tracheal intubation in elective surgeries under general anesthesia.

Settings and Design:

A prospective, randomized control study.

Subjects and Methods:

Seventy-five adult patients of age 18-55 years in American Society of Anesthesiologists physical status I and II were included in this study. Patients were allocated randomly into Group P, Group D and Group C of 25 patients each. In the operation theatre, clonidine (3 μg/kg) or dexmedetomidine (0.5 μg/kg) or placebo (0.9% normal saline) diluted in 100 ml NaCl 0.9% were infused over a period of 10 min.

Statistical Analysis Used:

Statistical analysis was done using Statistical Package for Social Sciences version 15.0. Chi-square test, ANOVA, Student's t-test, and Paired t-test were used.

Results:

As compared to Group P, the mean systolic blood pressure in Group D and Group C were significantly lower (<0.01) after intubation and all the subsequent intervals. After infusion and after the induction interval, the maximum value was observed in Group D while minimum mean value was observed in Group C. As compared to Group P, the mean arterial pressure in Group D was significantly higher at after infusion and after induction intervals but significantly lower after intubation and subsequent intervals. However, in Group C, the mean value was significantly lower as compared to Group P at all-time intervals except after infusion and after induction intervals. As compared to Group P, the mean HR in Group D was significantly higher at after infusion and after induction intervals. However at all the subsequent intervals, Group D was significantly lower as compared to Group P.

Conclusion:

It was found that attenuating response to hemodynamic changes were observed with dexmedetomidine and clonidine IV infusion. The early onset of dexmedetomidine makes it a promising choice. Hence premedication with IV infusion of dexmedetomidine can safely be recommended for attenuation of hemodynamic response to endotracheal intubation.

Comparison of fentanyl and clonidine for attenuation of the haemodynamic response to laryngocopy and endotracheal intubation

INTRODUCTION

Laryngoscopy and tracheal intubation after the induction of anaesthesia, are nearly always associated with sympathetic hyperactivity. To 'blunt' this pressor response, various methods have been tried, but very few studies have been done to assess the effects of fentanyl orI.V. clonidine on the haemodynamic response during laryngoscopy and tracheal intubation. The purpose of this study was to compare these agents, to find the drug which was best suited for this purpose and the most favourable time for its administration.

METHODS

This was a prospective study which involved 3 groups of patients. The patients in group-1 (control) were given normal saline and the groups 2 and 3 were given i.v. fentanyl and clonidine respectively. Each group had 50 patients who presented for elective, non-cardiovascular surgeries. All the patients were ASA-1 or ASA-II and were operated in PESIMSR, Kuppam.

RESULTS

The heart rate rise was 48.07% in the control group, whereas it was significantly lower in the fentanyl (II) 27.75% and the clonidine groups (III) 12.57% (p<0.001). In the control group, the systolic blood pressure increased maximally after 5 minutes (42.62%) i.e., immediately after the laryngoscopy and the intubation. It decreased gradually over 10 minutes (17.39%). With the administration of fentanyl, the maximum increase as compared to the preinduction value was 9.91%, but it was only 7.38% in the clonidine group. Both, when they were compared with the control, showed a significant suppression (P<.001), with clonidine showing better results. The maximum increase in the diastolic blood pressure was 30.12% in the control group (P<.001) at 5 min and it was 18.22%, and 6.15% in the fentanyl and the clonidine groups respectively, with clonidine faring better again (P<.001).

INTERPRETATION AND CONCLUSION

Clonidine showed better attenuation of the sympathetic response, which is statistically highly significant and it remained so till the end of 10 minutes. Intravenous clonidine 2;g/kg which is administered 5 minutes before the laryngoscopy can be recommended to attenuate the sympathetic response to the laryngoscopy and the intubation.

Attenuation of the pressor response to tracheal intubation in severe preeclampsia: relative efficacies of nitroglycerine infusion, sublingual nifedipine, and intravenous hydralazine

Background:

The pressor response to laryngoscopy is known to be exaggerated in patients with severe preeclampsia.

Objectives:

The aim of the present study was to compare the efficacies of continuous intravenous (IV) infusion of nitroglycerine, IV hydralazine, or sublingual nifedipine in modifying cardiovascular responses to endotracheal intubation, in women with severe preeclampsia undergoing cesarean delivery under general anesthesia.

Patients and Methods:

A total of 120 patients undergoing cesarean delivery were randomly divided into 3 groups, each receiving one of the following drugs before intubation: 5 µg/min nitroglycerine administered by continuous IV infusion (Group NTG, n = 40); a 10-mg capsule of nifedipine deposited sublingually (Group NIF, n = 40); or 5–10 mg hydralazine intravenously (Group H, n = 40). Heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP) were simultaneously recorded in the mother at pre-induction, pre-intubation, and at 1, 3, 5, and 10 min after intubation.

Results:

In contrast to those in group NIF and group H, the patients in group NTG showed no significant increases in HR, SAP, DAP, or MAP after intubation, compared to baseline. The incidence of hypotension was significantly greater in group NIF than in group H or group NTG [15 (37. 5%) vs. 8 (20%) vs. 5 (12. 5%) respectively, P = 0. 025].

Conclusions:

In patients with severe preeclampsia undergoing cesarean delivery, a continuous IV infusion of nitroglycerine was able to attenuate the cardiovascular response to intubation to a greater extent than the use of sublingual nifedipine or IV hydralazine, without significant adverse effects on the newborn.