Remifentanil and the tunnelling phase of paediatric ventriculoperitoneal shunt insertion. A double-blind, randomised, prospective study

Fetal, Preterm, and Term Neonate Exposure to Remifentanil: A Systematic Review of Efficacy and Safety

BACKGROUND

Owing to its pharmacodynamic properties, especially the rapid onset and short duration of its action, the use of remifentanil in obstetric anesthesia, as well as in neonatology, might be increasingly used.

OBJECTIVE

We conducted a systematic review to assess the efficacy and safety of remifentanil in preterm and term neonates. Outcomes of interest were neonatal adaptation after fetal exposure; neonatal pain, distress, and discomfort control during invasive procedures; and the occurrence of hemodynamic effects or respiratory depression induced by remifentanil infusion.

METHODS

Given the different contexts of use, we have organized this work into three parts: (A) use of remifentanil for labor or cesarean section, with exposure of the fetus before birth, (B) brief use for neonatal procedural analgesia, and (C) prolonged use for sedation/analgesia of neonates. The bibliographic search was conducted based on keywords using electronic medical databases (DATABASE, Cochrane Library, PubMed, and EMBASE) from 1 January 2000 until 31 December 2022.

RESULTS

Twenty-two articles were included (10 in part A, 5 in part B and 7 in part C). Prospective, controlled, randomized, blinded, and intention-to-treat trials were retained. Neonates were well adapted after exposure to remifentanil in the fetal period. Pain, stress, and discomfort were controlled during a brief or prolonged invasive procedure when remifentanil was used for sedation/analgesia. The physiological parameters were stable and the procedures were straightforward. Chest wall rigidity appeared to be a common side effect, but this can be managed by slow and continuous infusion and by using the minimum effective dose.

CONCLUSIONS

Remifentanil appears to be effective and safe in the short term in preterm and full-term neonates. However, its safety is compromised by the risk of chest wall rigidity. It should be used in appropriate neonatal units and in the presence of physicians able to monitor its side effects. Long-term outcomes have not been evaluated, to our knowledge.

Opioids for procedural pain in neonates

BACKGROUND

Neonates might be exposed to numerous painful procedures due to diagnostic reasons, therapeutic interventions, or surgical procedures. Options for pain management include opioids, non-pharmacological interventions, and other drugs. Morphine, fentanyl, and remifentanil are the opioids most often used in neonates. However, negative impact of opioids on the structure and function of the developing brain has been reported.

OBJECTIVES

To evaluate the benefits and harms of opioids in term or preterm neonates exposed to procedural pain, compared to placebo or no drug, non-pharmacological intervention, other analgesics or sedatives, other opioids, or the same opioid administered by a different route.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was December 2021.

SELECTION CRITERIA

We included randomized controlled trials conducted in preterm and term infants of a postmenstrual age (PMA) up to 46 weeks and 0 days exposed to procedural pain where opioids were compared to 1) placebo or no drug; 2) non-pharmacological intervention; 3) other analgesics or sedatives; 4) other opioids; or 5) the same opioid administered by a different route.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were pain assessed with validated methods and any harms. We used a fixed-effect model with risk ratio (RR) for dichotomous data and mean difference (MD) for continuous data, and their confidence intervals (CI). We used GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We included 13 independent studies (enrolling 823 newborn infants): seven studies compared opioids to no treatment or placebo (the main comparison in this review), two studies to oral sweet solution or non-pharmacological intervention, and five studies (of which two were part of the same study) to other analgesics and sedatives. All studies were performed in a hospital setting. Opioids compared to placebo or no drug Compared to placebo, opioids probably reduce pain score assessed with the Premature Infant Pain Profile (PIPP)/PIPP-Revised (PIPP-R) scale during the procedure (MD -2.58, 95% CI -3.12 to -2.03; 199 participants, 3 studies; moderate-certainty evidence); may reduce Neonatal Infant Pain Scale (NIPS) during the procedure (MD -1.97, 95% CI -2.46 to -1.48; 102 participants, 2 studies; low-certainty evidence); and may result in little to no difference in pain score assessed with the Douleur Aiguë du Nouveau-né (DAN) scale one to two hours after the procedure (MD -0.20, 95% CI -2.21 to 1.81; 42 participants, 1 study; low-certainty evidence). The evidence is very uncertain about the effect of opioids on pain score assessed with the PIPP/PIPP-R scale up to 30 minutes after the procedure (MD 0.14, 95% CI -0.17 to 0.45; 123 participants, 2 studies; very low-certainty evidence) or one to two hours after the procedure (MD -0.83, 95% CI -2.42 to 0.75; 54 participants, 2 studies; very low-certainty evidence). The evidence is very uncertain about the effect of opioids on episodes of bradycardia (RR 3.19, 95% CI 0.14 to 72.69; 172 participants, 3 studies; very low-certainty evidence). Opioids may result in an increase in episodes of apnea compared to placebo (RR 3.15, 95% CI 1.08 to 9.16; 199 participants, 3 studies; low-certainty evidence): with one study reporting a concerning increase in severe apnea (RR 7.44, 95% CI 0.42 to 132.95; 31 participants, 1 study; very low-certainty). The evidence is very uncertain about the effect of opioids on episodes of hypotension (RR not estimable, risk difference 0.00, 95% CI -0.06 to 0.06; 88 participants, 2 studies; very low-certainty evidence). No studies reported parent satisfaction with care provided in the neonatal intensive care unit (NICU). Opioids compared to non-pharmacological intervention The evidence is very uncertain about the effect of opioids on pain score assessed with the Crying Requires oxygen Increased vital signs Expression Sleep (CRIES) scale during the procedure when compared to facilitated tucking (MD -4.62, 95% CI -6.38 to -2.86; 100 participants, 1 study; very low-certainty evidence) or sensorial stimulation (MD 0.32, 95% CI -1.13 to 1.77; 100 participants, 1 study; very low-certainty evidence). The other main outcomes were not reported. Opioids compared to other analgesics or sedatives The evidence is very uncertain about the effect of opioids on pain score assessed with the PIPP/PIPP-R during the procedure (MD -0.29, 95% CI -1.58 to 1.01; 124 participants, 2 studies; very low-certainty evidence); up to 30 minutes after the procedure (MD -1.10, 95% CI -2.82 to 0.62; 12 participants, 1 study; very low-certainty evidence); and one to two hours after the procedure (MD -0.17, 95% CI -2.22 to 1.88; 12 participants, 1 study; very low-certainty evidence). No studies reported any harms. The evidence is very uncertain about the effect of opioids on episodes of apnea during (RR 3.27, 95% CI 0.85 to 12.58; 124 participants, 2 studies; very low-certainty evidence) and after the procedure (RR 2.71, 95% CI 0.11 to 64.96; 124 participants, 2 studies; very low-certainty evidence) and on hypotension (RR 1.34, 95% CI 0.32 to 5.59; 204 participants, 3 studies; very low-certainty evidence). The other main outcomes were not reported. We identified no studies comparing different opioids (e.g. morphine versus fentanyl) or different routes for administration of the same opioid (e.g. morphine enterally versus morphine intravenously).

AUTHORS' CONCLUSIONS

Compared to placebo, opioids probably reduce pain score assessed with PIPP/PIPP-R scale during the procedure; may reduce NIPS during the procedure; and may result in little to no difference in DAN one to two hours after the procedure. The evidence is very uncertain about the effect of opioids on pain assessed with other pain scores or at different time points. The evidence is very uncertain about the effect of opioids on episodes of bradycardia, hypotension or severe apnea. Opioids may result in an increase in episodes of apnea. No studies reported parent satisfaction with care provided in the NICU. The evidence is very uncertain about the effect of opioids on any outcome when compared to non-pharmacological interventions or to other analgesics. We identified no studies comparing opioids to other opioids or comparing different routes of administration of the same opioid.

Opioids for procedural pain in neonates

BACKGROUND

Neonates might be exposed to numerous painful procedures due to diagnostic reasons, therapeutic interventions, or surgical procedures. Options for pain management include opioids, non-pharmacological interventions, and other drugs. Morphine, fentanyl, and remifentanil are the opioids most often used in neonates. However, negative impact of opioids on the structure and function of the developing brain has been reported.

OBJECTIVES

To evaluate the benefits and harms of opioids in term or preterm neonates exposed to procedural pain, compared to placebo or no drug, non-pharmacological intervention, other analgesics or sedatives, other opioids, or the same opioid administered by a different route.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was December 2021.

SELECTION CRITERIA

We included randomized controlled trials conducted in preterm and term infants of a postmenstrual age (PMA) up to 46 weeks and 0 days exposed to procedural pain where opioids were compared to 1) placebo or no drug; 2) non-pharmacological intervention; 3) other analgesics or sedatives; 4) other opioids; or 5) the same opioid administered by a different route.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were pain assessed with validated methods and any harms. We used a fixed-effect model with risk ratio (RR) for dichotomous data and mean difference (MD) for continuous data, and their confidence intervals (CI). We used GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We included 13 independent studies (enrolling 823 newborn infants): seven studies compared opioids to no treatment or placebo (the main comparison in this review), two studies to oral sweet solution or non-pharmacological intervention, and five studies (of which two were part of the same study) to other analgesics and sedatives. All studies were performed in a hospital setting. Opioids compared to placebo or no drug Compared to placebo, opioids probably reduce pain score assessed with the Premature Infant Pain Profile (PIPP)/PIPP-Revised (PIPP-R) scale during the procedure (MD -2.58, 95% CI -3.12 to -2.03; 199 participants, 3 studies; moderate-certainty evidence); may reduce Neonatal Infant Pain Scale (NIPS) during the procedure (MD -1.97, 95% CI -2.46 to -1.48; 102 participants, 2 studies; low-certainty evidence); and may result in little to no difference in pain score assessed with the Douleur Aiguë du Nouveau-né (DAN) scale one to two hours after the procedure (MD -0.20, 95% CI -2.21 to 1.81; 42 participants, 1 study; low-certainty evidence). The evidence is very uncertain about the effect of opioids on pain score assessed with the PIPP/PIPP-R scale up to 30 minutes after the procedure (MD 0.14, 95% CI -0.17 to 0.45; 123 participants, 2 studies; very low-certainty evidence) or one to two hours after the procedure (MD -0.83, 95% CI -2.42 to 0.75; 54 participants, 2 studies; very low-certainty evidence). No studies reported any harms. The evidence is very uncertain about the effect of opioids on episodes of bradycardia (RR 3.19, 95% CI 0.14 to 72.69; 172 participants, 3 studies; very low-certainty evidence). Opioids may result in an increase in episodes of apnea compared to placebo (RR 3.15, 95% CI 1.08 to 9.16; 199 participants, 3 studies; low-certainty evidence). The evidence is very uncertain about the effect of opioids on episodes of hypotension (RR not estimable, risk difference 0.00, 95% CI -0.06 to 0.06; 88 participants, 2 studies; very low-certainty evidence). No studies reported parent satisfaction with care provided in the neonatal intensive care unit (NICU). Opioids compared to non-pharmacological intervention The evidence is very uncertain about the effect of opioids on pain score assessed with the Crying Requires oxygen Increased vital signs Expression Sleep (CRIES) scale during the procedure when compared to facilitated tucking (MD -4.62, 95% CI -6.38 to -2.86; 100 participants, 1 study; very low-certainty evidence) or sensorial stimulation (MD 0.32, 95% CI -1.13 to 1.77; 100 participants, 1 study; very low-certainty evidence). The other main outcomes were not reported. Opioids compared to other analgesics or sedatives The evidence is very uncertain about the effect of opioids on pain score assessed with the PIPP/PIPP-R during the procedure (MD -0.29, 95% CI -1.58 to 1.01; 124 participants, 2 studies; very low-certainty evidence); up to 30 minutes after the procedure (MD -1.10, 95% CI -2.82 to 0.62; 12 participants, 1 study; very low-certainty evidence); and one to two hours after the procedure (MD -0.17, 95% CI -2.22 to 1.88; 12 participants, 1 study; very low-certainty evidence). No studies reported any harms. The evidence is very uncertain about the effect of opioids on episodes of apnea during (RR 3.27, 95% CI 0.85 to 12.58; 124 participants, 2 studies; very low-certainty evidence) and after the procedure (RR 2.71, 95% CI 0.11 to 64.96; 124 participants, 2 studies; very low-certainty evidence) and on hypotension (RR 1.34, 95% CI 0.32 to 5.59; 204 participants, 3 studies; very low-certainty evidence). The other main outcomes were not reported. We identified no studies comparing different opioids (e.g. morphine versus fentanyl) or different routes for administration of the same opioid (e.g. morphine enterally versus morphine intravenously).

AUTHORS' CONCLUSIONS

Compared to placebo, opioids probably reduce pain score assessed with PIPP/PIPP-R scale during the procedure; may reduce NIPS during the procedure; and may result in little to no difference in DAN one to two hours after the procedure. The evidence is very uncertain about the effect of opioids on pain assessed with other pain scores or at different time points. No studies reported if any harms occurred. The evidence is very uncertain about the effect of opioids on episodes of bradycardia or hypotension. Opioids may result in an increase in episodes of apnea. No studies reported parent satisfaction with care provided in the NICU. The evidence is very uncertain about the effect of opioids on any outcome when compared to non-pharmacological interventions or to other analgesics. We identified no studies comparing opioids to other opioids or comparing different routes of administration of the same opioid.

Remifentanil patient-controlled analgesia for labor - monitoring of newborn heart rate, blood pressure and oxygen saturation during the first 24 hours after delivery

INTRODUCTION

There is no available information about the effects of remifentanil labor analgesia on newborns' vital signs in the first hours after delivery. The aim of the study was to assess changes in the heart rate, blood pressure and oxygen saturation during the first 24 h of neonatal life after using remifentanil patient-controlled analgesia (PCA) for labor analgesia.

MATERIAL AND METHODS

Forty-four full-term neonates, 23 from intravenous PCA remifentanil labor anesthesia 0.2 µg/kg, repeated not more frequently than every 2 min, and 21 born to mothers without any pharmacological forms of analgesia, were studied. Heart rate, oxygen saturation, and systolic (SBP) and diastolic blood pressure (DBP) were monitored using a Nellcor Oxi Max monitor N5500 (Tyco Healthcare), and recorded at 1 h, 6 h, 12 h and 24 h.

RESULTS

No significant differences in heart rate (p = 0.54; p = 0.26; p = 0.60; p = 0.83), oxygen saturation (p = 0.21; p = 0.27; p = 0.61; p = 0.9) and DBP (p = 0.98; p = 0.31; p = 0.83; p = 0.58) between the groups at 1 h, 6 h, 12 h and 24 h. Newborns from the remifentanil group had lower SBP at 1 h of life (59 mm Hg vs. 68.5 mm Hg) but the difference was just on the borderline of statistical significance (p > 0.06). There were no significant differences in SBP between the groups at 6 h (p = 0.65), 12 h (p = 0.11), and 24 h (p = 0.89) of life.

CONCLUSIONS

Remifentanil PCA analgesia during labor does not significantly modify the oxygen saturation, heart rate and blood pressure in infants during the first day of their life. Therefore, further studies are needed to explain the observed trend for arterial hypotension in the first hour of life in infants born to mothers treated with remifentanil.

Remifentanil in neonatal intensive care and anaesthesia practice

Remifentanil is a relatively new ultrashort action synthetic opioid. Studies on the use of remifentanil in neonatology have emerged demonstrating its effectiveness and safety in neonates. The present study describes the use of remifentanil in both full-term and premature newborns, highlighting the theoretical benefits for this population in terms of both neonatal intensive care and anaesthesia. A Medline search was undertaken of all reviews and reports about the use of remifentanil in neonates published between 1996 and 2009 using MeSH search terms 'remifentanil', 'analgesia', 'anaesthesia', 'newborn' and 'neonate'. The review points that remifentanil has been used with advantages in newborns including preterm neonates and even for foetal anaesthesia. It proved to be a good option to attenuate the hemodynamic/endocrine markers of stress related to surgery. Owing to its unique pharmacokinetic profile, shorter extubation times can be achieved what makes the drug also a good option for short duration invasive procedures in NICUs (InSurE). A concern on its use is that the hemodynamic response (hypotension) may become significant when the drug is associated to other drugs like sevoflurane.

CONCLUSION

Remifentanil seems to be an effective and safely used opioid for neonatal intensive care and anaesthesia practice.

Experience with remifentanil in neonates and infants

Remifentanil is a relatively new synthetic opioid, which is not licensed worldwide for neonates and infants. Because of its unique pharmacokinetic properties with a short recovery profile, it could be the ideal opioid for neonates and infants, who are especially sensitive to respiratory depression by opioids. Therefore, we conducted a MEDLINE search on all articles dealing with the use of remifentanil in this important subgroup of patients. Most experience with remifentanil in neonates and infants is as maintenance anaesthesia during surgery. In approximately 300 neonates and infants, remifentanil proved to be an effective and safely used opioid for this indication. However, very limited data exist on remifentanil for analgesia and sedation of mechanically ventilated paediatric intensive care patients. Further research with remifentanil in neonates and infants should focus on this group of patients because remifentanil, with its very short context-sensitive half-life, could result in shorter extubation times compared with commonly used opioids such as morphine or fentanyl.

Intracranial pressure and haemodynamic changes during the tunnelling phase of ventriculoperitoneal shunt insertion

BACKGROUND AND OBJECTIVE

The tunnelling phase of ventriculoperitoneal shunt insertion is the most painful part but patients are often given inadequate opioid analgesic for fear of post operative delayed recovery and/or respiratory depression. This may result in an increase in intracranial pressure.

METHODS

Twenty adults scheduled to undergo ventriculoperitoneal shunt insertion were administered standard anaesthesia. Monitoring included heart rate, electrocardiogram, end-tidal carbon dioxide, invasive blood pressure, and oxygen saturation. Intracranial pressure was monitored by placing the ventricular end of shunt catheter in the dilated lateral ventricle. Five minutes before tunnelling, fentanyl 1 microg kg(-1) was administered. Mean arterial pressure, heart rate and intracranial pressure were recorded during tunnelling and subsequently at 1-min interval for 5 min. Data were analysed using t-test and repeated measured test.

RESULTS

Tunnelling caused significant increase in mean arterial pressure (from 81.4 +/- 11.0 to 110.9 +/- 15.3 mmHg, P < 0.05), intracranial pressure (from 21.4 +/- 8.1 to 29.2 +/- 12.5 mmHg, P < 0.05) and heart rate (from 74.4 +/- 13.8 to 94.1 +/- 17.8 beats min(-1), P < 0.05). Whereas, the increase in haemodynamic parameters persisted for 3 min post-tunnelling, elevated intracranial pressure lasted for 2 min.

CONCLUSION

Tunnelling significantly increases intracranial pressure and blood pressure despite prior fentanyl administration. This may be deleterious in the presence of intracranial pathology.

Remifentanil for sedation and analgesia in a preterm neonate with respiratory distress syndrome

We present the efficacy and safety of the use of remifentanil for intubation, sedation and analgesia in a preterm infant during mechanical ventilation for respiratory distress syndrome. A 34-week-old baby, born by cesarean delivery that developed respiratory distress, required intubation and ventilatory support. For intubation, the baby was given midazolam (0.2 mg.kg(-1)) and remifentanil (1 microg.kg(-1)). The intubation conditions were assessed and classified as excellent. The remifentanil infusion was started at dose 0.75 microg.kg(-1).min(-1) and the dose adjustments were made depending on the neonatal infant pain scale (NIPS), hemodynamic and respiratory changes or the presence of spontaneous movements. Pulse oximetry, respiratory rate, ECG and invasive blood pressure were continuously monitored. He was given surfactant within 2.5 h of life after which ventilator parameters could be progressively decreased. Three hours later, the remifentanil infusion was decreased to 0.5 microg.kg(-1).min(-1), and he remained sedated (NIPS < 2). Six hour after surfactant administration, blood gases and chest X ray were normal. The remifentanil infusion was then discontinued and 30 min later the baby was awake and extubated with success. There were no side effects after intubation or during the continuous infusion. The profile of remifentanil allowing a rapid recovery, the absence of side effects and a good level of sedation and analgesia support the choice of this opioid for sedation in the NICU.

[Anesthetic management of pediatric cleft lip and cleft palate repair]

We have developed a modern strategy for the anesthetic management of pediatric cleft lip and cleft palate repair using anesthetic drugs such as sevoflurane, desflurane, acetaminophen, remifentanil, and pirtitramide together with new techniques. It provides best conditions for the surgeon and maximum safety for the pediatric patient. A team of pediatricians, neonatologists, pediatric surgeons, and pediatric anesthetists have tackled the problem of management of children with craniofacial abnormalities such as cleft lip and cleft palate. The best and safest anesthetic techniques are outlined and the most frequent complications are discussed, e.g. management of the difficult airway, the airway in patients with complex craniofacial abnormalities, fiberoptic endotracheal intubation through a laryngeal mask, intraoperative dislocation of the endotracheal tube, postoperative airway obstruction and perioperative bleeding.

Remifentanil update: clinical science and utility

The anilidopiperidine opioid remifentanil has pharmacodynamic properties similar to all opioids; however, its pharmacokinetic characteristics are unique. Favourable pharmacokinetic properties, minimally altered by extremes of age or renal or hepatic dysfunction, enable easy titration and rapid dissipation of clinical effect of this agent, even after prolonged infusion. Remifentanil is metabolised by esterases that are widespread throughout the plasma, red blood cells, and interstitial tissues, whereas other anilidopiperidine opioids (e.g. fentanyl, alfentanil and sufentanil) depend upon hepatic biotransformation and renal excretion for elimination. Consequently, remifentanil is cleared considerably more rapidly than other anilidopiperidine opioids. In addition, its pKa (the pH at which the drug is 50% ionised) is less than physiological pH; thus, remifentanil circulates primarily in the non-ionised moiety, which quickly penetrates the lipid blood-brain barrier and rapidly equilibrates across the plasma/effect site interface. By virtue of these distinctive pharmacokinetic properties, the context-sensitive half-time (i.e. the time required for the drug's plasma concentration to decrease by 50% after cessation of an infusion) of remifentanil remains consistently short (3.2 minutes), even following an infusion of long duration (> or =8 hours). Remifentanil, a clinically versatile opioid, is useful for intravenous analgesia and sedation in spontaneously breathing patients undergoing painful procedures. Profound analgesia may be achieved with minimal effect on cognitive function. Remifentanil may also provide sedation and analgesia during placement of regional anaesthetic blocks, and in conjunction with topical anaesthesia and airway nerve blocks, it may be useful for blunting reflex responses and facilitating 'awake' fibreoptic intubation. Compared with fentanyl and alfentanil in a day-surgery setting, remifentanil supplementation of general anaesthesia may improve intraoperative haemodynamic control. Both emergence time and the incidence of respiratory depression during post-anaesthetic recovery may be reduced. However, outcomes such as home discharge time, post-emergence adverse effect profile, and patient and provider satisfaction are not significantly improved, and the incidence of intraoperative hypotension and bradycardia is greater. In addition, drug acquisition costs for remifentanil are higher and clinicians may need extra time to familiarise themselves with the drug's unique pharmacokinetics.Ironically, the quick dissipation of opioid analgesic effect following remifentanil discontinuation may be a significant clinical disadvantage. Unless little or no postoperative pain is anticipated, the clinician may wish to treat prospectively using local or regional anaesthesia, non-opioid analgesics, or longer-acting opioid analgesics.

The Use of Ultra-Short-Acting Opioids in Paediatric Anaesthesia

Remifentanil is a synthetic opioid that was developed in the early 1990s and introduced into clinical use in 1996. It is a methyl ester and is metabolised by nonspecific tissue and plasma esterases. Consequently, it is a drug that undergoes rapid elimination and has a reported terminal elimination half-life of between 10 and 35 minutes. Because there is no drug accumulation, the context-sensitive half-time remains constant; thus the pharmacokinetics of the drug do not change regardless of the duration of infusion. The organ-independent elimination of remifentanil, coupled with the fact that its clearance is greater in infants and neonates compared with older age groups, make its pharmacokinetic profile different from any other opioid. In addition, its unique metabolism confers predictability in its clinical use. Like other opioid mu receptor agonists, remifentanil provides dose-dependent analgesia, while the adverse effects of this drug, e.g. respiratory depression, are also thought to be dose related. The incidence of nausea and vomiting appear similar to other opioids. Its rapid and consistent metabolism regardless of duration of infusion has made remifentanil an attractive analgesic/anaesthetic option for paediatric care providers.

Remifentanil: an update

PURPOSE OF REVIEW

Remifentanil has now reached maturity, as reflected by the increasing number of clinical papers relating to its use. Its position among anaesthetic drugs is now better understood, and this review will attempt to place it in the context of current clinical practice.

RECENT FINDINGS AND SUMMARY

Propofol reduces the initial distribution of remifentanil, leading to higher concentrations during induction. Propofol and remifentanil administered together at sedative doses display a major synergistic interaction on the respiratory drive. Remifentanil accelerates the penetration of sevoflurane to its site of effect. The risk of intraoperative awareness seems to be low when remifentanil is associated to very low concentrations of hypnotic drugs, but this field warrants further investigation. Acute tolerance to opioids and its prevention remain controversial.

SUMMARY

Remifentanil is the opioid of choice for tracheal intubation without muscle relaxants. It provides an alternative to regional anaesthesia in labour pain control. Target-controlled infusion may further improve the administration of remifentanil.