Premium
A 3:1 volume admixture of 1% propofol and 2.5% thiopentone reduces pain on induction in paediatric anaesthesia
Author(s) -
Pollard R.C.,
Makky S.,
Mcfadzean J.,
Ainsworth L.,
Goobie S.M.,
Montgomery C.J.
Publication year - 2002
Publication title -
pediatric anesthesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.704
H-Index - 82
eISSN - 1460-9592
pISSN - 1155-5645
DOI - 10.1046/j.1460-9592.2002.10271_25.x
Subject(s) - propofol , medicine , anesthesia , incidence (geometry) , general anaesthesia , acute pain , surgery , physics , optics
The incidence of pain on injection with 1% propofol in adult and paediatric patients ranges from 50 to 100% (1). In paediatric practice, the addition of lignocaine 1 mg·kg −1 to propofol reduces the incidence of pain. The incidence of pain with this technique in a pilot study in our institution was 20%. Thiopentone mixed with propofol may also reduce injection pain (2). The purpose of this study was to evaluate the incidence of pain on injection during intravenous induction using a 3:1 volume admixture of 1% propofol and 2.5% thiopentone (P/T) compared to a 10:1 volume admixture of 1% propofol and 2% lignocaine (P/L). Methods After ethics committee approval and informed written parental consent, 127 children, aged 1–10 years and weighing < 40 kg were randomised into two groups; group P/L received 5 mg·kg −1 of 1% propofol and 1 mg·kg −1 of lignocaine, group P/T received 3 mg·kg −1 of 1% propofol and 3 mg·kg −1 of 2.5% thiopentone in a standardised fashion. Any subject who was not calm and cooperative immediately prior to induction after establishment of intravenous access was excluded from further study. A single, blinded observer scored pain behavior defined as any one of. a motor response of the arm, a verbal complaint of pain, cry and/or one of three standardised facial expressions of pain. Results The incidence of pain on injection was higher in the P/L group where 34% subjects experienced pain compared with 14% in the P/T group (χ 2 = 7.5, P = 0.006). Motor response was the most frequent pain response in the P/L group (68%). Discussion The hemodynamic effects, immediate in‐hospital or late recovery profile and incidence of postoperative nausea and vomiting of these admixtures were not evaluated in this study. Our clinical impression is that using either the P/L or P/T combination allowed rapid IV induction, and therefore rapid ventilation and LMA insertion without obvious hypotension. The P/T admixture may be less painful to inject simply because propofol is diluted. The optimum ratio of dilution of propofol with thiopentone may not be 3:1 and requires a dose‐finding study evaluating in detail the efficacy and side effects of other ratios of admixtures. Conclusion The use of a 3:1 volume admixture of 1% propofol and 2.5% thiopentone compared to a 10:1 volume admixture of 1% propofol and 2% lignocaine reduces pain on injection at induction of anaesthesia in paediatric patients from 34% to 14%, and is a practical solution for pain on injection in pediatric patients.