Prostaglandin E1 attenuates the hypertensive response to tracheal extubation

Alleviating Stress Response to Tracheal Extubation in Neurosurgical Patients: A Comparative Study of Two Infusion Doses of Dexmedetomidine

BACKGROUND

Tracheal extubation is almost always associated with increase in sympathoadrenal activity may result in hypertension, tachycardia, and arrhythmias. Attempts have been made to oppose the pressor response by the use of various drugs. Dexmedetomidine decreases norepinephrine which reduces the blood pressure and the heart rate (HR). We hypothesize that the infusion of dexmedetomidine may produce more stable hemodynamics during extubation as compared to boluses.

MATERIALS AND METHODS

Ninety adult patients aged 18-65 years, the American Society of Anesthesiologists Grade I-II undergoing intracranial surgeries for various neurologic problem at All India Institute of Medical Sciences were enrolled in this randomized controlled trial. Primary.

OBJECTIVES

(1) To observe the hemodynamic changes (HR and mean arterial pressure [MAP]) and airway responses during tracheal extubation following two infusion doses of dexmedetomidine.

SECONDARY OBJECTIVES

(1) Time to emergence and time to tracheal extubation, (2) Early postoperative complications such as laryngospasm and bronchospasm, and (3) adverse effects of the study drug. Patients were assigned into three groups - (1) Group D0.2 - 0.2 μg/kg/h diluted to 50 ml, (2) Group D0.4 - 0.4 μg/kg/h diluted to 50 ml and Group P (Placebo) - 0.9% NS 50 ml. The hemodynamics including the HR and MAP were recorded just before the loading dose of the study drug and then were recorded every 5 min till the infusion was stopped at tracheal extubation and every 1 min till 10 min postextubation. In addition, the airway, respiratory and cardiovascular complications along with postoperative nausea and vomiting, shivering, cough grading, Aldrete score, Ramsay sedation scale, and intraoperative awareness were recorded.

STATISTICAL ANALYSIS

Continuous variables such as HR and MAP were analyzed using analysis of variance and categorical variables were analyzed using the Chi-square test.

RESULTS

Patient demographics were comparable between the three groups. There was a significant reduction in HR and MAP just before extubation and up to 10 min post extubation in the D0.2 and D0.4 groups as compared to placebo (P < 0.001) but the difference among the dexmedetomidine groups were not significant. Patients belonging to D0.2 group emerged faster than D0.4 group, however, the results were comparable with placebo group. 73.3% patients of the placebo group had tachycardia and hypertension at emergence as compared to only 3.3% patients in the D0.4 group (P < 0.001). Eighty percentage patients of D0.2 and 100% patients of D0.4 group had a significant reduction in cough as compared to placebo (P < 0.001). No patient in either groups had intraoperative awareness, any respiratory complications, or allergic reactions to the study drug. Modified Aldrete scoring and Ramsay sedation scale were comparable in all the three groups.

CONCLUSION

Dexmedetomidine suppresses cough and hemodynamic responses (HR and MAP) to tracheal extubation significantly without delaying emergence.

Attenuation of circulatory and airway responses to endotracheal extubation in craniotomies for intracerebral space occupying lesions: Dexmedetomidine versus lignocaine

OBJECTIVES

The objective of the study is to compare the effect of dexmedetomidine versus lignocaine in attenuation of circulatory and airway responses during endotracheal extubation in craniotomies for intracerebral space occupying lesions (ICSOL).

MATERIALS AND METHODS

A total of 50 patients of American Society of Anesthesiologists Grade I and II of either sex, aged 18-50 years undergoing craniotomies for non-vascular ICSOL under general anesthesia were divided into two groups according to drug received. Group D (n = 25) received dexmedetomidine (0.5 mcg/kg) whereas group L (n = 25) received lignocaine (1.5 mg/kg). Both the drugs were given 5 min before the extubation over a period of 60 s. Values for heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), were recorded just before (A0) and 1, 3, 5 (A1, A3, A5) min after the study drug administration, at extubation (E) and 1, 3, 5, 10, 15 min after extubation (E1, E3, E5, E10 and E15). Respiratory rate, oxygen saturation and airway responses like coughing, breath-holding, laryngospasm/bronchospasm were recorded only at extubation (E) and 1, 3, 5, 10, 15 min after extubation (E1, E3, E5, E10, E15). Quality of extubation was recorded with four point scale. After extubation all these patients were also observed for sedation by Ramsey sedation score.

RESULTS

Both groups showed a statistically significant increase (D < L) in HR, SBP and DBP during (E) and immediately after extubation (E1) (P < 0.05). Dexmedetomidine (72%) produced a higher degree of sedation (Grade 3) as compare with lignocaine (0%) and with no incidence of coughing or breath holding (P < 0.05).

CONCLUSION

Single dose of dexmedetomidine (0.5 mcg/kg) given 5 min before extubation produced significant attenuation of circulatory and airway responses produced during extubation as compared to Lignocaine (1.5 mg/kg) in ICSOL.

Laryngoscopic techniques to assess vocal cord mobility following thyroid surgery

BACKGROUND

Assessment of vocal cord mobility using Macintosh laryngoscope is frequently performed after extubation following thyroid surgery to rule out laryngeal nerve palsy. This study compared patient comfort and assessment accuracy of post-operative vocal fold mobility with Macintosh laryngoscope and fibreoptic endoscope.

METHODS

One hundred four physically fit patients undergoing thyroid surgery were included for the study. Tele-laryngoscopy was done to rule out pre-existing vocal cord palsy. Direct laryngoscopy (DL) was performed to each patient after extubation, followed by nasal fibreoptic endoscopy (NFE) to assess the vocal cord mobility. Tele-laryngoscopic assessment was repeated after 1 week to compare the DL and NFE findings. Patient reactivity score (PRS) and haemodynamic parameters were recorded with each technique.

RESULTS

Macintosh laryngoscope could pick up 4 (50% sensitivity and 88% specificity) and fibreoptic endoscope 7 (87.9% sensitivity and 98.9% specificity) out of the 8 vocal cord palsies identified by tele-laryngoscopy. Patients had significant discomfort during DL (PRS median 3) when compared with NFE and tele-laryngoscopy (PRS median 2), P<0.05. Grade 1 view of larynx in 92.1% patients during intubation worsened to grade 2 (76.3%) and grade 3 (15.8%) during extubation with DL, and a significant rise in mean arterial pressure and heart rate was observed from the baseline value till 5 min and when compared with NFE (P<0.05).

CONCLUSION

NFE provides accurate assessment of vocal fold mobility with reasonable patient comfort in the immediate post-operative period. Macintosh laryngoscope fails to give optimum visualization and predisposes the patient to significant discomfort and stress.

Neuroanesthesiology review--2006

In this article, we will provide a review of the 2006 literature of interest to those readers who provide perioperative care to patients with neurologic disease. This evaluation of the literature is not intended to be comprehensive, nor were systematic criteria used to include or exclude articles. Instead, the authors attempted to highlight those articles of greatest clinical relevance or those that provided unique insights into the physiology, pharmacology, and pathomechanisms of neurologic function for practicing clinicians and clinician-investigators. This article focuses on intracranial hemorrhage, anesthetic considerations in neurosurgical patients, cerebral hemodynamics, electrophysiologic monitoring, neuroprotection, and traumatic brain injury.

Comparison of Nicardipine Versus Esmolol in Attenuating the Hemodynamic Responses to Anesthesia Emergence and Extubation

OBJECTIVE

The purpose of this study was to compare the effectiveness of intravenous (IV) nicardipine versus esmolol in controlling heart rate (HR) and blood pressure (BP) responses to emergence and extubation.

DESIGN

Prospective, randomized, double blind.

SETTING

University hospital, single institution.

PARTICIPANTS

Twenty-two American Society of Anesthesiologists physical class 1 to 3 adult inpatients scheduled for general anesthesia.

INTERVENTIONS

General endotracheal anesthesia with oxygen/isoflurane and muscle relaxation. At end of surgery, with at least 2 twitches by nerve stimulator and end-tidal isoflurane <0.4%, muscle relaxant reversal was accomplished with neostigmine and glycopyrrolate. Two minutes postreversal, the IV study drug nicardipine, 0.03 mg/kg, or esmolol, 1.5 mg/kg, was administered. HR and BP were measured every minute up to 10 minutes and at minute 15 postreversal.

MEASUREMENTS AND MAIN RESULTS

There were no significant differences between groups in age, weight, gender, American Society of Anesthesiologists physical class or preoperative hemodynamics (HR, BP, mean arterial pressure [MAP]). Compared with nicardipine, 0.03 mg/kg IV, esmolol, 1.5 mg/kg IV, significantly (p < 0.05) attenuated HR more than nicardipine for the 15-minute time period poststudy drug. Compared with esmolol, nicardipine was significantly (p < 0.05) more effective in controlling MAP and systolic BP for the 1- to 3-minute and diastolic BP for the 1- to 2-minute time periods poststudy drug. There were no episodes of hypotension or adverse events.

CONCLUSIONS

Although esmolol, 1.5 mg/kg, IV was more effective than nicardipine, 0.03 mg/kg, IV for attenuating the HR response to extubation, nicardipine was more effective in controlling the BP response.

A comparative study between the effects of 4% endotracheal tube cuff lignocaine and 1.5 mg/kg intravenous lignocaine on coughing and hemodynamics during extubation in neurosurgical patients: a randomized controlled double-blind trial

A prospective, randomized double-blind trial was performed to compare the effects of 4% endotracheal tube cuff lignocaine and 1.5 mg/kg intravenous (IV) lignocaine on coughing and hemodynamics during extubation in patients undergoing elective craniotomies in supine position. Forty-one patients received 4% lignocaine into the endotracheal tube cuff after intubation (ETT group) and 41 patients received IV lignocaine at 1.5 mg/kg before extubation (IV group). Coughing was assessed by a scale of 3 at the time of extubation. Hemodynamic parameters recorded at 1-minute interval after extubation for 5 minutes were compared with the baseline values recorded before skin closure. Results showed that there was no significant difference between the groups in terms of coughing or the hemodynamic response to tracheal extubation. In conclusion, 4% endotracheal tube cuff lignocaine was not superior to 1.5 mg/kg IV lignocaine in attenuating coughing and hemodynamic changes during extubation.

Comparison of nicardipine versus placebo to control hemodynamic responses during emergence and extubation

OBJECTIVE

To compare 2 different doses of intravenous nicardipine versus placebo to control heart rate and blood pressure responses to emergence and extubation.

DESIGN

Prospective, randomized, double-blind, placebo-controlled.

SETTING

University hospital, single-institutional.

PARTICIPANTS

Forty-five American Society of Anesthesiologists (ASA) class I through III adult patients.

INTERVENTIONS

General endotracheal anesthesia was with oxygen and isoflurane and muscle relaxation. At the end of surgery, with at least 2 twitches present by nerve stimulator and end-tidal isoflurane <0.4%, reversal was accomplished with neostigmine and glycopyrrolate. Two minutes post-reversal, the study drug (nicardipine, 0.015 mg/kg; nicardipine, 0.03 mg/kg; or a saline placebo) was given. Heart rate and blood pressure were measured for every minute up to 10 minutes and at 15 minutes postreversal.

MEASUREMENTS AND MAIN RESULTS

There were no significant differences among groups in age, gender, ASA class, weight, or heart rate. The nicardipine groups, 0.015 and 0.03 mg/kg, had lower blood pressure values than the placebo group. There was a significant difference in blood pressure among groups, with greater and more consistent attenuation of blood pressure occurring with the larger nicardipine dose. There were no episodes of hypotension or adverse events.

CONCLUSIONS

Compared with placebo, both nicardipine doses attenuated blood pressure but not heart rate responses during emergence and extubation. Greater blood pressure control occurred with the larger nicardipine dose of 0.03 mg/kg.

Prostaglandin E1 produces spasmolytic effects on histamine-induced bronchoconstriction in dogs

OBJECTIVE

In this study, we evaluated the spasmolytic effect of intravenous prostaglandin (PG) E1 on histamine-induced bronchoconstriction with a direct visualization method using a superfine fiberoptic bronchoscope.

SETTING

A university research laboratory.

SUBJECTS

Mongrel dogs.

INTERVENTIONS

The bronchial cross-sectional area (BCA) of mongrel dogs was measured by a direct visualization method using a superfine fiberoptic bronchoscope. Bronchoconstriction was elicited with histamine (H) infusion: 10 microg/kg iv bolus + 500 microg/kg/h continuous iv. The first protocol (n = 7) was designed to determine the effects of intravenous bolus of PGE1: 0 (saline), 0.01, 0.1, 1.0 and 10 microg/kg on H-induced bronchoconstriction. BCA was assessed before and 30 min after starting the H infusion and 5 min after each dose of intravenous PGE1. The second protocol was designed to determine whether continuous intravenous infusion of PGE1 reverses H-induced bronchoconstriction. In the PG group (n = 6), PGE1 was continuously infused at 0.1 microg/kg/min (20 mL/hr). In the control group (n = 6), saline was administered at a rate of 20 mL/hr iv. BCA was assessed before and 30 min after starting the H-infusion and at 5, 10, 30 and 60 min after commencing the PGE1 or saline infusion. Arterial blood was obtained simultaneously for measurement of plasma concentrations of epinephrine and norepinephrine by gas chromatography mass spectrometry.

MEASUREMENTS AND MAIN RESULTS

In the first protocol, PGE1 produced a dose-dependent increase in the percentage of BCA and 10 microg/kg of PGE1 almost fully reversed the H-induced bronchoconstriction. Plasma catecholamines did not change significantly. In the second protocol, continuous infusion of PGE1 produced a time-dependent reversal of H-induced bronchoconstriction (percentage of BCA increased to 80.0+/-9.0% 60 min after the start of PGE1 infusion), whereas saline infusion did not reverse the bronchoconstriction. Plasma catecholamines did not change significantly in either group.

CONCLUSIONS

Both intravenous bolus and continuous intravenous infusion of PGE1 reversed the H-induced bronchoconstriction. PGE1 may be used safely for patients with the hyperreactive airway and might be useful as a therapeutic agent for these patients.

Combined diltiazem and lidocaine reduces cardiovascular responses to tracheal extubation and anesthesia emergence in hypertensive patients

PURPOSE

Hypertensive patients exhibit exaggerated cardiovascular responses to tracheal extubation. This study was undertaken to compare the efficacy of combined diltiazem and lidocaine with each drug alone in suppressing the hemodynamic changes during tracheal extubation.

METHODS

Sixty hypertensive patients (ASA II), defined as systolic blood pressure > 160 mmHg and/or diastolic blood pressure > 95 mmHg (WHO), undergoing elective orthopedic surgery received, in a randomized, double-blind manner, 0.2 mg x kg(-1) diltiazem, 1.0 mg x kg(-1) lidocaine, or 0.2 mg x kg(-1) diltiazem plus 1.0 mg x kg(-1) lidocaine (n=20 of each) i.v. before tracheal extubation. Changes in heart rate (HR), mean arterial pressure (MAP) and rate-pressure product (RPP) were measured before and after tracheal extubation.

RESULTS

Hemodynamic changes during tracheal extubation were less in patients receiving diltiazem plus lidocaine than in those receiving diltiazem or lidocaine as a sole medicine (RPP; 10322 +/- 1674 (combined) vs 11532 +/- 1802 (diltiazem), 15388 +/- 2050 (lidocaine), mean +/- SD, P < 0.05).

CONCLUSION

Combined diltiazem and lidocaine is more effective prophylaxis than diltiazem or lidocaine alone for attenuating the cardiovascular responses to tracheal extubation and emergence from anesthesia in hypertensive patients.

Calcium channel blockers attenuate cardiovascular responses to tracheal extubation in hypertensive patients

PURPOSE

Hypertensive patients exhibit exaggerated cardiovascular responses to tracheal extubation. This study was undertaken to examine the inhibitory effects of calcium channel blockers, nicardipine and diltiazem, on haemodynamic changes after tracheal extubation.

METHODS

Sixty hypertensive patients (ASA physical status II) undergoing elective orthopaedic (upper and lower extremity) surgery received, in a randomized, double-blind manner, 30 micrograms.kg-1 nicardipine, 0.2 mg.kg-1 diltiazem or saline (as a control) (n = 20 of each) i.v. before tracheal extubation. Changes in heart rate (HR), mean arterial pressure (MAP) and rate-pressure product (RPP) were measured before and after tracheal extubation.

RESULTS

The HR, MAP and RPP increased after tracheal extubation in the control group (P < 0.05). The increases in these haemodynamic variables were attenuated with nicardipine or diltiazem. The inhibitory effects of diltiazem on these cardiovascular responses to tracheal extubation were greater than those of nicardipine (HR; 86 +/- 7 vs 101 +/- 10, RPP; 11,437 +/- 1,575 vs 14,675 +/- 2,874, mean +/- SD, P < 0.05).

CONCLUSION

Compared with nicardipine, administration of diltiazem produced greater attenuating the circulatory responses to tracheal extubation in hypertensive patients.

Prostaglandin E1, lidocaine, and prostaglandin E1-lidocaine combination for attenuating cardiovascular responses to extubation

PURPOSE

Tracheal extubation produces haemodynamic changes that may cause myocardial ischaemia in patients with coronary arterial disease. Intravenous infusion of prostaglandin E1 (PGE1) attenuated the hypertensive response to tracheal extubation but failed to blunt the tachycardia, which was attenuated by intravenous lidocaine. Thus, we investigated whether a combination of PGE1 and lidocaine can overcome the drawbacks of treatment with PGE1 alone.

METHODS

One hundred adult patients (ASA 1) undergoing elective minor surgery were randomly assigned to receive one of four treatments: saline (as a control), 1 mg-kg-1 lidocaine, infusion of 0.1 microgram-1.kg-1.min-1 PGE1, or infusion of 0.1 microgram-1.kg-1.min-1 PGE1 plus injection of 1 mg-1.kg-1 lidocaine. Lidocaine was injected two minutes before tracheal extubation. The PGE1 was infused from completion of surgery until five minutes after tracheal extubation. Anaesthesia was maintained with sevoflurane 1.0%-2.5% and nitrous oxide 60%. Heart rate (HR) and blood pressure (BP) were measured before and after tracheal extubation.

RESULTS

Lidocaine alone and PGE1-lidocaine combination attenuated the increases in BP and HR observed in the control group: PGE1 alone was effective in attenuating hypertensive response but ineffective for tachycardia. The suppressive effect of the PGE1-lidocaine combination on BP increase was superior to that of each drug alone, and the combined effect on HR increase was similar to that of lidocaine alone.

CONCLUSION

The combination of PGE1 infusion and lidocaine is a more effective method of attenuating hypertension and tachycardia associated with tracheal extubation than either drug alone.