Ann Acad Med Singap
-
Ann Acad Med Singap · Jul 1994
Randomized Controlled Trial Clinical TrialPlacebo effect of eutectic mixture of lidocaine and prilocaine (EMLA) cream in reducing venepuncture pain in children.
A randomized double-blind study was made of 60 children aged 5 to 11 years to assess the efficacy of a eutectic mixture of local anaesthetics (EMLA), lidocaine and prilocaine, and placebo cream in reducing venepuncture pain. The 5% EMLA or placebo cream, approximately 2 grams (2 ml), was applied to the anticipated venepuncture site and covered with an occlusive dressing for a least 60 minutes. The venepuncture of 20-gauge butterfly needle was done after wiping the skin dry and observing for any local reactions. ⋯ The results showed that there were no statistical differences in the subject characteristics and pain scores, between the EMLA and the placebo group. Most children in both groups experienced no pain to mild pain from venepuncture. The possible causes were discussed and it was concluded that the placebo effect of having cream and good doctor-children rapport reduced fear and anxiety, resulting in the reduction of venepuncture pain in children.
-
The development of new preoperative fasting guidelines in paediatrics was reviewed in the light of present knowledge and some recent investigations. Although the proportion of healthy children with the potential risk of aspiration pneumonitis is relatively high (60-75%), the incidence of aspiration is low--1 to 8.6 in 10,000. In healthy children, there is no increase in the risk of aspiration by allowing them to drink clear fluids up to 2-3 hours before anaesthesia when compared with the conventional fasting regimen. ⋯ It is useful to have simple and explicit preoperative fasting instructions for parents to follow, especially in the day case setting. It is essential to note that the laryngeal mask airway (LMA) does not protect the patient's airway against the risk of regurgitation and aspiration of gastric contents in the same way as an endotracheal tube. Hence, constant vigilance is required when LMA is used in children.
-
The anaesthetic machine used by most anaesthetists today closely resembles the anaesthetic machine of the late 1940s, with the addition of a multitude of devices and monitors necessary for the complexity of modern anaesthesia. Although modern anaesthesia boasts of a high level of safety, the ad hoc development of the anaesthetic machine has done little to enhance this safety record. Future improvements in patient safety will at least partially depend on improved ergonomics and human factor engineering in the design and arrangement of the anaesthetic workplace. Some innovative designs are now being seen both commercially and experimentally in which all monitoring is integrated and servo feedback control loops are used to deliver anaesthetic agents to the patient.
-
The mechanism of anaesthesia is still a black box, although many investigators have been concerned about this theme since the 19th century. It is too complex to clarify the mode of anaesthetic action, as a variety of compounds have been adopted as anaesthetics. Hill coefficients calculated from the righting reflex dose-response curve in enflurane, isoflurane sevoflurane and halothane anaesthesia in a certain strain of mice were from 14 to 56. ⋯ It is suspected from Overton's experiment that the action site is not in the core of lipid bilayer but on the surface of membrane. It was demonstrated by 2 methodologies. Two-dimensional nuclear Overhauser effect spectrum in H1-NMR spectra of dipalmitoyl phosphatidylcholine (DPPC) vesicle membrane in the presence of methoxyflurane revealed from the existence of the cross-peak between the methoxy-proton and the choline methyl-proton that methoxyflurane molecule interacted only to the polar head of lipid membrane at lower temperatures.(ABSTRACT TRUNCATED AT 400 WORDS)
-
Ann Acad Med Singap · Jul 1994
Randomized Controlled Trial Comparative Study Clinical TrialSubcutaneous infusion of ketamine and morphine for relief of postoperative pain: a double-blind comparative study.
Low dose ketamine by subcutaneous infusion (0.1 mg.kg-1.h-1) was compared in a double-blind fashion with a similar infusion of morphine (0.03 mg.kg-1.h-1) for postoperative analgesia in 60 ASA-I adults after major abdominal surgery. Pain was assessed using visual analogue scales and sedation was graded on a four-point rank drowsiness score. Cardiovascular and respiratory parameters were also recorded. ⋯ Both tidal and minute volume parameters improved better with ketamine (P < 0.001); patients were more awake and alert as evidenced by the drowsiness score (P < 0.001). Nine out of 30 patients who received morphine required catheterisation for urinary retention (P < 0.05). The study revealed higher analgesic efficacy of a low dose subcutaneous infusion of ketamine with lesser sedation and fewer side effects.