Article Text

Should premedication be used for semi-urgent or elective intubation in neonates?
Free
1. E Byrne,
2. R MacKinnon
1. St Mary’s Hospital, Manchester, UK; ralph.mackinnon{at}cmmc.nhs.uk

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A neonate on the intensive care unit requires semi-urgent intubation. As the procedure is being carried out, the medical student notices that the neonate is struggling, prolonging the procedure, and appears to be in distress. The medical student asks why no medication was given before the neonate was intubated as this is the procedure in adults and children.

## Structured clinical question

In neonates undergoing semi-urgent intubation [patients] should premedication [intervention] be used to facilitate easier intubation with less physiological stress [outcome]?

## Search strategy and outcome

Medline: 1966 to present.

Embase: 1980 to 2005 week 27.

Cinahl: 1982 to June week 4 2005.

Using the ovid interface.

{exp Infant, newborn or neonat$.mp.} AND {exp premedication or premed$.mp. or exp analgesia or analges$.mp. or exp hypnotics and sedatives or sedat$.mp. or exp anesthesia or anaesth$.mp. or exp. Muscle relaxants, central or muscle relax$ or exp fentanyl or fentanyl.mp. or exp morphine or morphine.mp. or exp thiopental or thiopental.mp. or exp atropine or atropine.mp. or exp succinylcholine or succinylcholine.mp. or exp pancuronium or pancuronium.mp. or exp halothane or halothane.mp. or exp alfentanil or alfentanil.mp. or suxamethonium.mp. or sevoflurane.mp.} AND {exp endotracheal intubation or endotracheal intubation.mp. or exp intubation or intubat\$.mp.}. Limit to English language and Newborn infant (birth to 1 month).

Medline search found 459 papers, of which 12 were relevant and of a sufficient quality to be included in the paper.

Embase search found a further one paper.

Cinahl found no further papers.

Two further relevant papers were found by searching through the references from the papers found.

All three databases were searched again combining the above search strategy with [AND {exp pain or pain.mp.}]. No further papers were identified.

See table 4.

Table 4

Premedication for semi-urgent intubation

## Commentary

Intubation is a potentially painful and distressing procedure. It is suggested that such physiological distress may increase neonatal morbidity. Premedication for intubation with potent opiates or anaesthetic agents and muscle relaxants is the routine for children and infants. Premedication is not common practice for the intubation of neonates; Whyte et al in 1998 revealed that only 14% of the UK’s neonatal units had a written policy for premedication for semi-urgent or elective intubation. Only 37% of the neonatal units surveyed routinely used sedation prior to intubation, and those that did used drug doses that varied by factors up to 200.16 Premedication is more commonly used for term rather than preterm neonates.16–18

Recent research and debate has focused on whether premedication of the neonate for a routine semi-urgent intubation (that is, when intravenous access is available and difficult intubation is not expected) may be safer and a more effective method than awake intubation.

From the available evidence it is clear that awake intubation is associated with a significantly higher intracranial pressure,5,8,10–13 higher blood pressure,3,7,11 and more variable heart rate2,3,5,12 than premedicated intubation. In addition, the increased time taken to intubate2–4,6,7 and the greater number of attempts associated with awake intubation2,4,6 may compound these factors and lead to increased morbidity. Studies using thiopentone show significantly lower intracranial pressure, significantly more stable heart rate, and lower blood pressure; fewer attempts to intubate are needed and the time taken to intubate is shorter in neonates premedicated with thiopentone than in control neonates.3–5,10 Studies using opiates show a significantly lower blood pressure and shorter duration of hypoxia during intubation, and shorter length of time taken to intubate with a potent opiate than in control neonates.6,7 They also show that morphine and pethidine are not the drugs of choice.1,6 This is likely to be due to their variable pharmacokinetics and pharmacodynamics in neonates.16 Muscle relaxant studies show a significantly lower intracranial pressure, improved cerebral perfusion pressure, less heart rate variability, and a shorter time needed to intubate in neonates premedicated with a muscle relaxant than in control neonates.7,8,12,13 Chest wall rigidity was reported in three of seven neonates given fentanyl without a muscle relaxant in one randomised controlled trial,7 and in four neonates in one cohort study, resolving with suxamethonium in three cases and self limiting in the other.14 No other studies reported this adverse event when an opiate is used with a muscle relaxant.

Current evidence suggests that for routine semi-urgent intubation of neonates, the use of premedication is a more effective technique, with less potentially harmful physiological fluctuations, than traditional awake intubation.

### CLINICAL BOTTOM LINE

• Routine premedication for semi-urgent or elective intubation in neonates produces more optimal intubation conditions (fewer attempts and shorter times) and less potentially harmful physiological fluctuations and pain. (Grade B)

• A potent opiate (fentanyl or alfentanil) or thiopentone with a muscle relaxant is the intubating drug combination of choice. (Grade B)

• More clinical trials are required to determine the optimal premedication strategy.

## Footnotes

• Edited by Bob Phillips