Anaesthesia and intensive care
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Anaesth Intensive Care · May 2008
Randomized Controlled Trial Comparative StudyComparison of potency of ephedrine and mephentermine for prevention of post-spinal hypotension in caesarean section.
The dosages and potency of intravenous mephentermine for prevention of post-spinal hypotension are not available in English literature. This study was designed to determine the minimum effective dose (ED50) of mephentermine and to compare its potency with that of ephedrine for prevention of post-spinal hypotension in parturients undergoing caesarean section. Dixon's up-down method of sequential allocation was used for vasopressor doses. ⋯ For mephentermine, the up-down method was abandoned due to the success of the minimum dose possible but the ED50 appeared to be less than 5 mg. In conclusion, the minimum effective dose of mephentermine is much less than that of ephedrine for prevention of post-spinal hypotension. Another trial with a lower starting dose and smaller dose interval of mephentermine is required to determine the potency ratio of mephentermine and ephedrine.
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Anaesth Intensive Care · May 2008
Randomized Controlled Trial Comparative StudyHaemodynamic and Bispectral index response to insertion of the Streamlined Liner of the Pharynx Airway (SLIPA): comparison with the laryngeal mask airway.
The newly developed supralaryngeal airway Streamlined Liner of the Pharynx Airway (SLIPA) has been compared successfully to the LMA, but the haemodynamic response to its insertion has not been evaluated in a randomised study. We compared haemodynamic and Bispectral index (BIS) responses to insertion of the SLIPA with classic LMA after standardising the anaesthetic technique using BIS to monitor and control the anaesthetic depth. One hundred patients were randomised to receive either a classic LMA or SLIPA following induction with fentanyl and propofol titrated to a target BIS of 40 and compared heart rate, mean arterial pressure and BIS responses to insertion. ⋯ BIS increased significantly (P<0.05) at one, two, three, four and five minutes following insertion of both the devices, but there was no significant difference between the groups. There was a significantly higher (P=0.001) incidence of blood on the device with the SLIPA (20/50 vs. 6/50 with LMA). Thus, insertion of SLIPA causes significantly higher blood-pressure response but similar BIS response compared to the LMA.
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Anaesth Intensive Care · May 2008
Randomized Controlled Trial Comparative StudyComparison of the laryngeal mask (LMA) and laryngeal tube (LT) with the perilaryngeal airway (cobraPLA) in brief paediatric surgical procedures.
We compared the laryngeal mask airway (LMA) and the laryngeal tube (LT) with the perilaryngeal airway (CobraPLA, PLA) in anaesthetised, paralysed children having brief surgical procedures. After obtaining informed consent, 90 paediatric ASA Status 1 and 2 patients awaiting short surgical procedures were randomised to have their airways managed with an LMA, LT or PLA. Anaesthesia was induced with sevoflurane (2.5 to 4%) and muscle paralysis with mivacurium (0.2 mg/kg intravenously). ⋯ The number and type of airway interventions to achieve an effective airway were comparable. When the airways were removed, positive blood traces were noted on 20% of the LMAs, 20% of the PLAs and 10% of the LTs. Haemodynamic, ventilation and oxygenation variables throughout the surgery were similar with LMA, LT and PLA and there were no significant differences in insertion time or signs or symptoms of mucosal trauma when these devices were used in paralysed children.
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Anaesth Intensive Care · May 2008
Randomized Controlled Trial Comparative StudyIntra-ocular pressure changes associated with intubation with the intubating laryngeal mask airway compared with conventional laryngoscopy.
This open, prospective, randomised study was designed to evaluate the changes in intra-ocular pressure and haemodynamics after tracheal intubation using either the intubating laryngeal mask airway (ILMA) or direct laryngoscopy. Sixty adult patients, ASA physical status 1 or 2 with normal intra-ocular pressure were randomly allocated to one of the two techniques. Anaesthesia was induced with propofol followed by rocuronium. ⋯ Mucosal trauma was more frequent with the ILMA (eight of 30) compared with the laryngoscopy group (three of 30) (P<0.01). The postoperative complications were comparable. In terms of minimising increases in intra-ocular pressure and blood pressure, we conclude that the ILMA has an advantage over direct laryngoscopy for tracheal intubation.