Low-dose sufentanil as a supplement to halothane/N2O anaesthesia in infants and children

Different small-dose sufentanil blunting cardiovascular responses to laryngoscopy and intubation in children: a randomized, double-blind comparison

BACKGROUND

Sufentanil is a potent opioid analgesic frequently used in clinical anaesthesia. This prospective, randomized, double-blind study was designed to assess the efficacy of different small-dose sufentanil attenuating the cardiovascular intubation response in healthy children, aiming at determining the optimal dose of sufentanil for this purpose.

METHODS

A total of 165 children aged 3-9 yr were randomized to one of four groups to receive the following in a double-blind manner: normal saline (Group 1), sufentanil 0.1 microg kg(-1) (Group 2), sufentanil 0.2 microg kg(-1) (Group 3), and sufentanil 0.3 microg kg(-1) (Group 4). Anaesthesia was induced with propofol 2.5 mg kg(-1) and vecuronium 0.1 mg kg(-1). Non-invasive blood pressure (BP) and heart rate (HR) were recorded before induction of anaesthesia (baseline value), at immediately before intubation (post-induction values), at intubation, and at 1 min intervals for 5 min after intubation. The per cent changes of systolic blood pressure (SBP) and HR during the observation were calculated.

RESULTS

Except for Group 4, tracheal intubation caused significant increases in BP and HR in Groups 1, 2, and 3 compared with baseline values. BP and HR at intubation and their maximum values during the observation were significantly different among the four groups. The maximum per cent increases of SBP and HR during the observation were 20 and 28% of baseline values, respectively, in Group 2, 13 and 13% in Group 3, and 0 and 4% in Group 4 compared with 24 and 37% in Group 1. Except for the Group 3 vs Group 4 comparison, the incidences of SBP and HR per cent increases >30% of baseline values were also significantly different among the four groups.

CONCLUSIONS

In combination with propofol for induction of anaesthesia in children, the bolus administration of sufentanil can produce a dose-related attenuation of the cardiovascular intubation response and sufentanil 0.3 microg kg(-1) can completely abolish the cardiovascular intubation response.

A comparison between pre-operative carprofen and a long-acting sufentanil formulation for analgesia after ovariohysterectomy in dogs

OBJECTIVE

To assess the analgesic efficacy and adverse effects of a novel, long-acting sufentanil preparation in dogs undergoing ovariohysterectomy (OHE).

STUDY DESIGN

Blinded, positively controlled, randomized field trial with four parallel treatment groups.

ANIMALS

Eighty client owned dogs undergoing elective OHE randomly allocated into four treatment groups (each n = 20).

MATERIALS AND METHODS

Three groups received intramuscular (IM) sufentanil (at 10, 15 and 25 microg kg(-1), respectively) and the control group received subcutaneous (SC) carprofen 4 mg kg(-1) SC plus acepromazine 0.05 mg kg(-1) IM as pre-anaesthetic medication. OHE was performed under thiopental/halothane anaesthesia. Visual Analogue Scale (VAS) scores for pain and sedation were awarded and mechanical nociceptive thresholds were measured at the wound and hock before surgery and up to 24 hours after tracheal extubation. Serum cortisol was measured before surgery, during surgery and up to 24 hours after tracheal extubation. Animals with inadequate post-operative analgesia were given rescue medication.

RESULTS

In the carprofen group, VAS pain scores were significantly higher, wound tenderness was greater and requirement for rescue analgesia was more than in the sufentanil-treated groups. Sufentanil produced dose dependent analgesia and sedation. All treatment groups showed similar patterns of change for cortisol concentrations. Use of the sufentanil preparation was associated with a relatively high incidence of adverse events.

CONCLUSIONS

The long-acting preparation of sufentanil provided excellent post-operative analgesia that was significantly better than that provided by carprofen. However, use of this formulation, in the anaesthetic technique used in the study, resulted in a relatively high incidence of adverse effects.

CLINICAL RELEVANCE

Full mu (MOP) opioid agonists provide significantly better post-operative analgesia than nonsteroidal anti-inflammatory drugs after moderately painful surgery. However, the widely recognized adverse effects of opioids may preclude the use of these agents.

A systematic review of trial methodology, using the placebo groups of randomized controlled trials in paediatric postoperative pain

Trial methodology was evaluated in paediatric analgesic studies. Databases were searched for randomised, placebo controlled studies of systemic paracetamol, NSAIDs and opioids administered for acute postoperative pain in children. Eighty-three studies met the inclusion criteria and 40 were included for the analysis. Analgesics were administered for established postoperative pain in two studies only. In all other studies they were administered in a prophylactic manner. As study design and sensitivity are particularly demanding in studies using pre-emptive dosing of analgesics, the placebo groups were analysed for issues of study sensitivity. Postoperative pain outcomes included pain scores in 34, rescue analgesia in 36, time to first rescue analgesia in 15, pain on activity in eight, number of patients with pain in six, pain relief in three, global efficacy rating in two and analgesic consumption via PCA in four studies. Twenty of 36 studies reported criteria for rescue analgesia that varied from 20 to 77% of the maximum pain intensity. Need of rescue analgesia showed more often differences between study groups than time to first rescue analgesia or pain intensity. Rescue analgesia was administered to 21-100% of the patients in the placebo groups where no other analgesics were given perioperatively. Most patients in the placebo groups had pain that was greater than 30% of the maximum. In conclusion, analysis of the methodology showed several aspects of trial design that can be improved in future studies. Placebo control groups can be used in paediatric analgesic studies to demonstrate internal sensitivity.

Unexpected "gas" casualties in Moscow: a medical toxicology perspective

In October 2002, the Russian military used a mysterious "gas" to incapacitate Chechen rebels at a Moscow theater. Despite increased interest in the potential use of lethal chemical weapons in recent years, the medical community has paid little attention to the development of incapacitating, calmative, and "less than lethal" technologies. In this analysis, we review the events surrounding the use of a calmative "gas" during the Russian military action and discuss what is currently known about fentanyl derivatives, their aerosolization, and the rationale for their use as incapacitating agents. Collectively, the available evidence strongly suggests that a combination of a potent aerosolized fentanyl derivative, such as carfentanil, and an inhalational anesthetic, such as halothane, was used. The paper also assesses potential errors leading to the loss of a substantial number of hostages. Several lessons can be learned from this surprising and novel use of an incapacitating gas.

Total intravenous anesthesia for infants and children undergoing correction of tetralogy of Fallot: sufentanil versus sufentanil-flunitrazepam technique

The effects of two total intravenous anesthetic techniques were compared in 20 infants and children undergoing primary correction of tetralogy of Fallot (TOF). All patients (mean body weight, 11.4 +/- 4.2 kg; range, 6 to 20 kg; mean age, 32 +/- 21 months, range, 7 to 85 months) were premedicated with atropine, 0.02, mg/kg, morphine, 0.2, mg/kg, and flunitrazepam, 0.04 mg/kg, intramuscularly, 1 hour preoperatively. Anesthesia was induced with 1 microgram/kg of sufentanil (S) and pancuronium, 0.1 mg/kg, intravenously. Patients were ventilated with 100% oxygen. Hemodynamic parameters, heart rate (HR), systolic (SBP), diastolic (DBP) and mean arterial blood pressure (MAP), central venous pressure (CVP), and peripheral arterial blood oxygen saturation (SaO2) were recorded. Plasma concentrations of S, epinephrine (E), norepinephrine (NE), and blood gases were determined. To obtain a further depth of anesthesia, 10 patients (SM group) received 4 micrograms/kg of S and 10 patients (SF group) received 4 micrograms/kg of S in combination with flunitrazepam, 40 micrograms/kg, in a randomized manner. Measurements were made before and after induction of anesthesia, before and after anesthetic loading, 2 minutes after sternotomy, 15 minutes after initiation of extracorporeal circulation (ECC), and at sternal closure. Peak values for plasma S concentrations of 3.14 +/- 1.13 (SM group) and 3.45 +/- 97 ng/mL (SF group) were found before sternotomy. Following intubation HR, SBP, DBP, and MAP remained close to values measured before induction, but SaO2 increased significantly (P less than 0.01) in all patients. HR, SBP, and MAP decreased during anesthetic loading in both groups. Hemodynamics and plasma E and NE remained essentially unchanged after sternotomy in the SF group.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics of sufentanil in normal children

The pharmacokinetic variables of sufentanil were studied in 20 healthy children between two and eight years of age. The plasma concentrations of sufentanil were measured for up to 480 min after administration of a bolus of sufentanil, 1-3 micrograms.kg-1. The distribution half-life (t1/2 alpha) was 5.2 +/- 2.2 (mean +/- SD) min and the elimination half life (t1/2 beta) was 97.0 +/- 42.0 min. The volume of distribution at steady state (Vdss) was 2.9 +/- 0.6 L.kg-1 and the clearance was 30.5 +/- 8.8 ml.kg-1.min-1. The Vdss was one and a half times greater than that reported in adults when expressed as a function of body weight but similar to that of adults when expressed as a function of body surface area. According to our results, the clearance of sufentanil in normal children between two and eight years of age is twice as rapid as that described in adults and adolescents. A greater clearance of sufentanil in children suggests that they would require relatively greater maintenance doses than adults.