Different small-dose remifentanil blunting the cardiovascular response to laryngoscopy and intubation in children: a randomized double-blind comparison

Pharmacological agents for reducing the haemodynamic response to tracheal intubation in paediatric patients: a systematic review

The primary aim of this review was to assess the effect of pharmacological agents administered to attenuate the haemodynamic response to tracheal intubation in paediatric patients up to 16 years of age undergoing elective surgery. Secondary aims were to identify adverse effects related to these agents, and the agents' roles in decreasing arrhythmias. A systematic search was conducted for articles listed in PubMed, CINAHL or the Cochrane database between January 1980 and June 2014. We included randomised controlled trials where the stated aim of the study included observing the effects of pharmacological agents on the haemodynamic response to tracheal intubation. The outcome measures were changes in mean, systolic and diastolic blood pressure and heart rate, adverse effects of drugs and arrhythmias. Sixteen publications with a total of 1408 children (ages two to 15 years) were identified. These studies varied in methodology and quality. Opioids were the commonest agents used and appeared to obtund the response in a dose-related manner. Fentanyl 2 µg/kg, remifentanil 1 µg/kg, sufentanil 0.1 and 0.2 µg/kg and alfentanil 25 µg/kg blunted the haemodynamic response. Remifentanil 3 µg/kg and sufentanil 0.3 µg/kg were the most effective in obliterating the response but led to hypotension in unstimulated patients. Opioid-related side-effects and arrhythmias were observed in few patients. We recommend that when required, the safe and effective doses identified in this review be used to obtund the haemodynamic response to intubation in paediatric patients, with close observation for the uncommon but recognised side-effects.

The median effective effect-site concentration of remifentanil for minimizing the cardiovascular changes to endotracheal intubation during desflurane anesthesia in pediatric patients

Background

Desflurane has the most rapid onset and offset of action among the volatile anesthetic agents used for general anesthesia, but it can cause airway reactivity, tachycardia, and hypertension during induction, especially in pediatric patients. This study was designed to determine a median effective effect-site concentration (EC₅₀) of remifentanil to prevent the cardiovascular changes due to tracheal intubation during the 1 minimum alveolar concentration (MAC) desflurane inhalation, which was required to prevent movement in response to a noxious stimulus in 50% of subjects, in pediatric patients.

Methods

Twenty-four pediatric patients between the ages 5-15 years were enrolled in this study. We injected thiopental intravenously, at the same time remifentanil was infused by Target Controlled Infusion (TCI) device. When the target effect-site concentration (Ce) of remifentanil reached a preset level, desflurane was administrated through the facial mask. Then, we assessed the signs of desflurane related airway reactivity and cardiovascular changes for 2 min. The up-and-down criteria was a 20% change in systolic blood pressure (SBP) and a heart rate (HR) between just prior to intubation and 1 min after intubation. The EC₅₀ of remifentanil was calculated from 8 independent pairs using Dixon's up-and-down method.

Results

We studied 24 pediatric patients in range of 1-5 ng/ml of the Ce of remifentanil. No patient showed airway reactivity during the study. The EC₅₀ of remifentanil to suppress the hemodynamic changes after tracheal intubation during desflurane anesthesia was calculated as 3.4 ± 0.9 ng/ml.

Conclusions

In pediatric anesthesia, the EC₅₀ of remifentanil to minimize the cardiovascular changes due to tracheal intubation during 1 MAC desflurane anesthesia was 3.4 ± 0.9 ng/ml.

Dose of remifentanil for minimizing the cardiovascular changes to tracheal intubation in pediatric patients

Background

The purpose of this study was to investigate a dosage of remifentanil for attenuating cardiovascular changes during anesthetic induction in pediatric anesthesia.

Methods

We examined the effect of remifentanil on the cardiovascular responses to intubation in 90 children ASA 1 patients, aged 4-15 years, randomly allocated to receive 1.0 ug/kg remifentanil as a bolus (R 1), or 1.5 ug/kg remifentanil (R 1.5), or 2.0 ug/kg remifentanil (R 2). Before induction, IV midazolam 0.05 mg/kg was given for sedation. After glycoppylorate 5 ug/kg, thiopental 4.0 mg/kg was injected within 10 seconds and followed by remifentanil. Following check the unconsciousness, patients were received rocuronium 0.6 mg/kg and tracheal intubation were performed 90s later, and anesthesia was maintained with 2% sevoflurane in air/oxygen. Systolic arterial pressure (SAP), mean arterial pressure (MAP) and heart rate (HR) were measured at before induction of anesthesia (B), before, just after and at 1, and 3 minutes after tracheal intubation.

Results

SAP and HR were increased than B values in the three groups just after intubation (P < 0.05). The percentage increases of SAP and HR were 30% and 30% of B values, respectively, in R 1; 19% and 24% in R 1.5; 10% and 22% in R 2. There were significant differences between R 2 group and other two groups in SAP and HR (P < 0.05).

Conclusions

In pediatric anesthesia, a bolus injection of 2 ug/kg remifentanil (R 2) was a dosage to attenuate the cardiovascular responses after intubation in pediatric patients.

Bolus dose remifentanil and sufentanil blunting cardiovascular intubation responses in children: a randomized, double-blind comparison

BACKGROUND AND OBJECTIVE

The present randomized controlled study was designed to compare the efficacy of remifentanil 2 microg kg(-1) and sufentanil 0.2 microg kg(-1) by bolus injection on the cardiovascular response to intubation in healthy children.

METHODS

One hundred and five children, ASA 1-2 and scheduled for elective plastic surgery under general anaesthesia, were randomly divided into one of two study groups to receive the following treatments in a double-blind manner: remifentanil 2 microg kg(-1) (group R) and sufentanil 0.2 microg kg(-1) (group S). Blood pressure and heart rate (HR) were recorded before anaesthesia induction (baseline values), immediately before intubation (postinduction values), at intubation and every minute for 5 min after intubation. The percentage changes in systolic blood pressure (SBP) and HR relative to baseline values were calculated. The incidences of SBP and HR percentage changes of more than 30% of baseline values during the observation were recorded.

RESULTS

As compared with baseline values, blood pressure and HR at intubation and their maximum values during the observation increased significantly in group S, but decreased significantly in group R. Blood pressure and HR at intubation and their maximum values during the observation were significantly different between the groups. There were significant differences between the groups in the percentage changes of SBP and HR relative to baseline values and their maximum percentage changes during the observation. The incidences of SBP and HR percentage increases of more than 30% of baseline values were not significantly different between the groups, but the incidences of SBP and HR percentage decreases of more than 30% of baseline values were significantly higher in group R than in group S.

CONCLUSION

In combination with propofol for anaesthesia induction in children, sufentanil 0.2 microg kg(-1) by bolus injection fails to depress the cardiovascular intubation response. Remifentanil 2 microg kg(-1) by bolus injection can completely abolish the cardiovascular intubation response, but causes more adverse cardiovascular depression.