Anaesthesia
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Clinical Trial
The effect of a cervical collar on the seal pressure of the LMA Supreme™: a prospective, crossover trial.
For personnel inexperienced in airway management, supraglottic airway devices may be the first choice in an emergency. Changing head position is known to reduce the seal pressure of a laryngeal mask airway. The aim of this study was to investigate whether the use of a cervical collar improves the stability of airways secured with the LMA Supreme™ (The Laryngeal Mask Company Limited, Mahé, Seychelles). ⋯ With a cervical collar in place, the seal pressure increased to 28 (22.8-30 [17-30]) cmH(2) O (p<0.001). In the neutral head position, the seal pressure was 22 (17.6-24.5 [12-30]) cmH(2) O without and 27 (22-30 [12-30]) cmH(2) O with a cervical collar in place (p<0.001). We found that a cervical collar stabilises the airway with an LMA Supreme in place and we recommend this combination for (pre-hospital) emergency cases.
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We performed an evaluation of non-Luer spinal devices supplied by four manufacturers or suppliers: Polymedic; Pajunk; Sarstedt; and Smiths. For each supplier, 100 evaluations were performed using a 25-G 90-mm spinal needle, 3-ml syringe, 5-ml syringe and filter needle; for comparison, 100 evaluations were performed with our standard Luer equipment. The non-Luer devices were associated with more qualitative problems compared with the Luer devices, for example, poor feel of dural puncture (9-32% vs 10%, respectively), poor observation of cerebrospinal fluid in the hub (3-27% vs 0%), and connection problem of the syringe to the spinal needle (7-33% vs 0%). ⋯ Specific concerns included poor feel of tissue planes and observation of cerebrospinal fluid (Polymedic), difficulty with connection of the syringe to the spinal needle and trocar removal (Pajunk), poor feel of tissue planes and needle flexibility (Sarstedt) and difficulty with connection of the syringe to the spinal needle (Smiths). We could not demonstrate a short-term learning curve for the new devices. Decisions on purchasing and implementation of the new non-Luer equipment will have to acknowledge that clinicians may have greater technical problems and reduced satisfaction compared with the current equipment.
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We prospectively evaluated the CEL-100 videolaryngoscope(TM) for insertion of double-lumen tracheal tubes in 48 consecutive patients who had been found to have an unanticipated Cormack and Lehane grade 3 (n=43) and grade 4 (n=5) laryngeal view and in whom two attempts at tracheal intubation using the Macintosh laryngoscope had failed. When the CEL-100 was subsequently employed, the glottic view improved in 45 (94%) patients. ⋯ This occurred on the first attempt in 27 (56%) patients, 14 (29%) on the second and two (4%) on the third. We conclude that the CEL-100 videolaryngoscope is an effective device in this context, and we therefore propose that this device can be used in circumstances when double-lumen tube insertion proves difficult.
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We investigated whether genetic variations of the beta-2 adrenergic receptor (ADRB2) modulate the haemodynamic response following spinal anaesthesia for caesarean delivery. We focused on the effects of haplotypes formed by combinations of the Arg16Gly and Gln27Glu polymorphisms. Clinical data from 143 healthy parturients were collected. ⋯ Both groups presented similar baseline characteristics. Comparatively, patients homozygous for the ArgGln haplotype presented consistently higher blood pressure levels throughout the evaluation period (p=0.001 for systolic arterial pressure variation from baseline). In conclusion, our results demonstrate that haplotype variations of the the ADRB2 modulate the haemodynamic response following spinal anaesthesia for caesarean delivery.
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We conducted a study to assess pharmacokinetics of high-dose tranexamic acid for 24 h after administration of the drug in patients undergoing cardiac surgery with cardiopulmonary bypass. High-dose tranexamic acid involved a bolus of 30 mg.kg(-1) infused over 15 min followed by a 16 mg.kg(-1) .h(-1) infusion until chest closure with a 2 mg.kg(-1) load within the pump prime. ⋯ Mean plasma tranexamic acid concentrations during the intra-operative period and in the first 6 postoperative hours were consistently higher than the suggested threshold to achieve 100% inhibition and 80% inhibition of tissue plasminogen activator. With recent studies implicating high-dose tranexamic acid as a possible aetiology of postoperative seizures following cardiac surgery, the minimum effective yet safe dose of tranexamic acid in high-risk cardiac surgery needs to be refined.