Comparison of ephedrine and ketamine in prevention of injection pain and hypotension due to propofol induction

Lornoxicam use to reduce the pain associated with propofol injection

Aim: To investigate the efficacy of lornoxicam in the prevention of the pain associated with propofol injection.

Material and method: Approval for this study was granted by the ethics committee of our hospital. Using a computer randomisation software, 120 patients undergoing elective surgery were assigned to four equal groups. In Group I (control group), immediately before anaesthesia induction, 10 ml of isotonic 0.9% NaCl solution (placebo) was administered intravenously (IV). In Groups II, III and IV, the same injection contained 2 mg, 4 mg and 8 mg of lornoxicam respectively. A tourniquet was then applied to the forearm for two minutes. Pain evaluation was made using a verbal pain score.

Results: Differences in pain severity scores were statistically significant between Groups I and II, Groups I and III, Groups I and IV and between Groups II and III (p < 0.05). However, no significant difference was determined between Groups III and IV (p = 0.401).

Conclusion: In all groups administered with lornoxicam, there was a significant reduction in the severity of pain associated with propofol injection, in comparison with the control group. Maximum effect is obtained with a dose of 4 mg.

Effect of ondansetron on prevention of post-induction hypotension in elderly patients undergoing general anesthesia: A randomized, double-blind placebo-controlled clinical trial

Background:

Elderly patients are susceptible to post-induction hypotension. Volume loading and vasopressors for prevention of hypotension in elderly patients may increase perioperative cardiovascular risks. Ondansetron by blocking Bezold–Jarisch reflex (BJR) through inhibition of serotonin receptors has been effective in the prevention of post-spinal hypotension, and bradycardia. Bradycardia frequently accompanies post-induction hypotension in elderly patients, which signifies a possible preventing role for ondansetron. No previous study has evaluated the prophylactic effects of ondansetron for the prevention of post-induction hypotension.

Materials and Methods:

In this randomized placebo-controlled clinical trial, ondansetron 4 mg was given intravenously to 65 elderly patients, 20 min before induction of general anesthesia, and the rate of post-induction hypotension defined as 25% or more reduction in mean arterial blood pressure, compared with a placebo groups.

Results:

A total of 114 patients completed the study (58 in ondansetron and 56 in the placebo group). Proportions of post-induction hypotension were 9 (16%) and 25 (45%) in ondansetron and placebo groups, respectively, (P = 0.001). Forty-five patients (40%) developed bradycardia. Rates of bradycardia were not significantly different between two groups.

Conclusions:

The results of this study show the effectiveness of intravenous ondansetron for prevention of post-induction hypotension in elderly patients. The mechanism of this effect largely is unknown. Role of ondansetron for prevention of post-induction hypotension may not fully understandable by its interaction with BJR, as has been shown in post-spinal hypotension.

Efficacy of ephedrine in the prevention of vascular pain associated with different infusion rates of propofol

Context:

Vascular pain is a frequent and hypotension is most important complications of propofol administration.

Aims:

The goal of this study is to evaluate frequency of vascular pain during rapid and slow injection of propofol and also effect of ephedrine for decreasing of vascular pain.

Materials and Methods:

After approval of local ethical committee, 120 patients with American Society of Anesthesiologists status I (ASA I), who were candidates for cataract surgery, were divided randomly into three groups. The first group received 20 mg of lidocaine, and propofol 1% at 1 ml per 5 seconds (slow injection). The second and third groups received propofol at 10 ml per 5 seconds without lidocaine (rapid injection) and also in the third group, 10 mg of ephedrine were injected at first and vascular pain were evaluated with 5-point scale.

Statistical analysis:

Data were analyzed with Statistical Package for the Social Sciences (SPSS) v16, Chi-square test, one-way analysis of variance (ANOVA), Kruskel-Wallis. P <0.05 was considered statistically significant.

Results:

Demographic characteristics of the three groups were similar. The vascular pain was 52.5%, 40%, and 27.5% in first, second, and third group, respectively. The injection pain was more severe in the slow injection (P = 0.025), but was the same between two rapid groups (P = 0.76). Heart rate and blood pressure changes were similar between all groups (P = 0.45 and P = 0.58, respectively).

Conclusion:

Rapid propofol injection induced less vascular pain compared with slow injection, but 10 mg ephedrine was not more effective.

Prophylactic effect of ephedrine to reduce hemodynamic changes associated with anesthesia induction with propofol and remifentanil

BACKGROUND

One of the complications of anesthesia induction with propofol is a substantial decrease in arterial blood pressure and heart rate (HR), which can be intensified by adding remifentanil. This study aimed to assess the prophylactic effects of two doses of ephedrine to control the hypotension and bradycardia caused by anesthesia induced with propofol and remifentanil.

MATERIALS AND METHODS

A total of 150 patients candidate for short-term minor elective orthopedic and ophthalmic surgery under general anesthesia were randomized to three groups receiving normal saline, low dose ephedrine (0.07 mg/kg) or high dose ephedrine (0.15 mg/kg). Anesthesia was induced in all groups with propofol 2.5 mg/kg and remifentanil 3 μg/kg. No neuromuscular blocking agent was used. Patients' hemodynamic status was assessed in the following four steps: Immediately before, 2 min after induction of anesthesia, as well as 1 and 5 min after intubation.

RESULTS

A total of 143 patients consisting of 46 patients in the low dose ephedrine (0.07 mg/kg) group, 49 patients in the high dose ephedrine (0.15 mg/kg) group and 48 controls completed the trial. In all three groups, after induction of anesthesia, significant decreases occurred in the mean systolic, diastolic and mean arterial pressures, as well as in the mean HR. This decline was highest in the control group and lowest in the high dose ephedrine (0.15 mg/kg) group.

CONCLUSION

Our findings suggest that the administration of high dose ephedrine (0.15 mg/kg) may have a significant effect in preventing hypotension and bradycardia after anesthesia induction with propofol and remifentanil.

Prevention of pain with the injection of microemulsion propofol: a comparison of a combination of lidocaine and ketamine with lidocaine or ketamine alone

Background

Aquafol, a microemulsion propofol, causes more severe and frequent pain on injection than propofol. The purpose of this study was to compare a combination of lidocaine and ketamine on aquafol-induced pain with lidocaine or ketamine alone during the induction of anesthesia.

Methods

In this prospective, randomized, double-blinded study, 130 healthy patients who were undergoing elective surgery under general anesthesia were enrolled. The patients received IV lidocaine 40 mg plus ketamine 25 mg (Group LK, n = 43), lidocaine 40 mg (Group L, n = 42), or ketamine 25 mg (Group K, n = 45) with a rubber tourniquet on the forearm 1 min before the injection of microemulsion propofol. The pain score was assessed by a 4-point verbal rating scale (VRS) at 10 seconds after injection of microemulsion propofol 30 mg and during the injection of the remaining total dose.

Results

The incidence and severity of pain was significantly lower in Group LK than Group L or Group K at 10 seconds after the injection of microemulsion propofol 30 mg (P < 0.05). And the incidence and severity of pain was significantly lower in Group LK and Group K than Group L during the injection of the remaining total dose (P < 0.05).

Conclusions

Pretreatment with IV lidocaine 40 mg plus ketamine 25 mg with a rubber tourniquet on the forearm 1 min before the injection of microemulsion propofol is more effective than lidocaine 40 mg or ketamine 25 mg alone in preventing pain from the injection of microemulsion propofol.

Ketamine eliminates propofol pain but does not affect hemodynamics during induction with double-lumen tubes

BACKGROUND AND OBJECTIVE

Propofol injection during induction of anesthesia induces pain. Ketamine has been shown to reduce the injection pain. However, ketamine has unfavorable adverse effects, including increased secretion production and hemodynamic responses, which might induce pulmonary or hemodynamic adverse events, especially in patients undergoing lung surgery who require a double-lumen tube (DLT). The aim of this study was to determine whether ketamine can safely reduce propofol injection pain during induction of anesthesia for lung surgery.

METHODS

Forty-five patients scheduled for elective lung surgery requiring DLT were randomly allocated into three groups. Patients received saline (control), ketamine 0.5 mg kg(-1) (0.5 ketamine), or ketamine 1.0 mg kg(-1) (1.0 ketamine), followed by 5 ml propofol 30 s later. An anesthesiologist blinded to the study group assessed pain score during induction, hemodynamics during DLT placement, and secretion production during anesthetic management.

RESULTS

Pretreatment of 0.5 mg kg(-1) ketamine reduced the incidence and intensity of propofol injection pain, whereas 1.0 mg kg(-1) ketamine completely eliminated the pain. There were no significant differences regarding oxygenation during one-lung ventilation (OLV) and hemodynamics during induction among the three groups, although ketamine increased secretion production.

CONCLUSIONS

One milligram per kilogram of ketamine completely eliminated pain associated with propofol injection without affecting hemodynamics during induction of anesthesia and oxygenation during OLV.

Propofol inhibits phorbol 12, 13-dibutyrate-induced, protein kinase C-mediated contraction of rat aortic smooth muscle

BACKGROUND

Propofol induces dose-dependent vasodilation and hypotension in the clinical situation, and protein kinase C (PKC)-mediated Ca2+ sensitization plays an important role in vascular smooth muscle contraction. This study is designed to examine the effects of propofol on the active phorbol ester (phorbol 12, 13-dibutyrate; PDBu)-induced, PKC-mediated contraction of rat aortic smooth muscle.

METHODS

The PDBu-induced contraction of endothelium-denuded rat aortic rings was measured in the presence or absence of PKC inhibitor, bisindolylmaleimide I, or propofol, using isometric force transducers. The PDBu-induced PKC phosphorylation of endothelium-denuded rat aortic strips was detected in the presence or absence of bisindolylmaleimide I or propofol, using Western blotting.

RESULTS

PDBu, but not the inactive phorbol ester, 4-alpha-phorbol 12-myristate-13-acetate, dose-dependently induced both a slowly developing sustained contraction and PKC phosphorylation of rat aortic smooth muscle, reaching the peak level at the concentration of 10(-6) M. The PDBu (10(-6) M)-induced contraction was dose-dependently inhibited by bisindolylmaleimide I with reductions of 6.8 +/- 1.8% (P > 0.05), 39.8 +/- 8.7% (P < 0.01) and 96.7 +/- 1.4% (P < 0.01) in response to concentrations of 5 x 10(-7) M, 10(-6)x M and 5 x 10(-6) M, respectively, and by propofol with decreases of 5.2 +/- 1. 6% (P > 0.05), 9.4 +/- 1.7% (P < 0.05), 65.3 +/- 9.2% (P < 0.01) and 96.2 +/- 1.6% (P < 0.01) in response to concentrations of 5 x 10(-7) M, 10(-6) M, 5 x 10(-6) M and 10(-5) M, respectively. Both bisindolylmaleimide I and propofol also inhibited the PDBu-induced increase in the density of the phosphorylated PKC bands in a dose-dependent manner, with decreases of 6.3 +/- 2.8% (P > 0.05), 42.9 +/- 3.2% (P < 0.01) and 96.6 +/- 3.4% (P < 0.01) in response to 5 x 10(-7) M, 10(-6) M or 5 x 10(-6) M bisindolylmaleimide I, respectively, and with decreases of 4.2 +/- 2.5% (P > 0.05), 13.5 +/- 1.7% (P < 0.05), 69.5 +/- 3.5% (P < 0.01) and 95.3 +/- 4.3% (P < 0.01) in response to 5 x 10(-7) M, 10(-6) M, 5 x 10(-6) M and 10(-5) M propofol, respectively.

CONCLUSION

Propofol dose-dependently inhibits PDBu-induced, PKC-mediated contraction of rat aortic smooth muscle.

Preventing pain during injection of propofol: effects of a new emulsion with lidocaine addition

BACKGROUND AND OBJECTIVE

Previous studies found that lidocaine addition to propofol long-chain triglyceride was associated with a lower incidence of injection pain than medium-chain triglyceride/long-chain triglyceride formulation, but the incidence was still high (31-40%). Our study investigated whether the incidence of injection pain could be further reduced by the addition of lidocaine (10 mg, 20:1) to propofol medium-chain triglyceride/long-chain triglyceride.

METHODS

In a randomized double-blind controlled trial 464 patients scheduled to undergo regional anaesthesia were assigned to receive one of the following four options: propofol medium-chain triglyceride/long-chain triglyceride + lidocaine, propofol long-chain triglyceride + lidocaine, propofol medium-chain triglyceride/long-chain triglyceride or propofol long-chain triglyceride. Propofol was injected to reach grade 3 of the Observer's Assessment of Alertness/Sedation scale.

RESULTS

Incidence of injection pain was 18% in the propofol medium-chain triglyceride/long-chain triglyceride + lidocaine group, 31% in the propofol long-chain triglyceride + lidocaine group, 47% in the propofol medium-chain triglyceride/long-chain triglyceride group and 60% in the long-chain triglyceride group. Propofol medium-chain triglyceride/long-chain triglyceride + lidocaine was associated with a statistically significant reduced incidence of injection pain compared with propofol long-chain triglyceride +lidocaine (P =0.0249, number needed to treat =7.7).

CONCLUSIONS

Premixing propofol medium-chain triglyceride/long-chain triglyceride with lidocaine is one of the most effective measures currently available to reduce the incidence of injection pain in sedated patients during regional anaesthesia.