Low-Concentration Norepinephrine Infusion for Major Surgery: A Safety and Feasibility Pilot Randomized Controlled Trial.

BACKGROUND: Prevention of hypotension during the intra- and postoperative period is an important goal. Peripheral administration of low-concentration norepinephrine may be a safe and effective strategy to reduce the risk of hypotension. METHODS: We conducted a 2-center, randomized pilot feasibility trial, with a target of 60 adult patients undergoing major noncardiac surgery. We randomized patients to receive a peripheral low-concentration (10 µg/mL) norepinephrine or placebo (saline 0.9%) infusion. The study drug infusion was titrated to achieve a minimum systolic blood pressure target, preselected within 10% of baseline value and within the range limit 100 to 120 mm Hg during surgery and for up to 4 or 24 hours postoperatively. RESULTS: We achieved a high consent rate (84%), successful study drug administration throughout surgery (98% of patients) and absence of unblinding. There were no important study drug-related adverse events. The average intraoperative systolic blood pressure was 120 ± 12.6 mm Hg in the norepinephrine group and 115 ± 14.9 mm Hg in the placebo group. The mean difference between the intraoperative systolic blood pressure achieved less the preselected minimum systolic blood pressure target was 10.0 ± 12.7 mm Hg in the norepinephrine group and 2.9 ± 14.7 mm Hg in the placebo group; difference in means, 7.1 (95% confidence interval, 0.2-14.0) mm Hg. CONCLUSIONS: A future large trial evaluating the effectiveness and safety of peripheral administration of low-concentration norepinephrine during the perioperative period is feasible, and likely to achieve a minimum systolic blood pressure threshold.

Novel Preoxygenation Technique to Deliver High-Flow Oxygen in a Patient With Facial Trauma: A Case Report.

This case demonstrates a novel preoxygenation technique in a patient with difficult access to the airway after a traumatic facial injury. To find a solution, a fusion of oxygenation equipment was trialed by altering and combining a tracheostomy mask and the tubing of an Optiflow circuit from which the nasal cannula component had been removed. This novel combination delivered high-flow humidified oxygen (60 L/min) orally, avoided further facial injury, and was well tolerated by the patient. Effective preoxygenation was confirmed by arterial gas measurements. This study supports the use of this novel Optiflow-tracheostomy mask fusion device in appropriately selected cases.

Association of the phosphodiesterase 4D (PDE4D) gene and cardioembolic stroke in an Australian cohort.

BACKGROUND: Large-scale epidemiological studies support an important role for susceptibility genes in the pathogenesis of ischemic stroke, with phosphodiesterase 4D identified as the first gene predisposing to ischemic stroke. Several single nucleotide polymorphisms within the phosphodiesterase 4D gene have been implicated in the pathogenesis of stroke. Aim Undertake a multivariate analysis of six single nucleotide polymorphisms within the phosphodiesterase 4D gene in a previously defined Australian stroke cohort, to determine whether these single nucleotide polymorphisms have an association with ischemic stroke. METHODS: This case-control study was performed using an existing genetic database of 180 ischemic stroke patients and 301 community controls, evaluated previously for cerebrovascular risk factors (hypertension, hypercholesterolemia, diabetes, paroxysmal atrial fibrillation, smoking and history of stroke in a first-degree relative). Based on previously reported associations with large vessel disease, ischemic stroke, cardioembolic stroke or a mixture of these, six single nucleotide polymorphisms in the phosphodiesterase 4D gene were selected for study, these being single nucleotide polymorphisms 13, 19, rs152312, 45, 83 and 87, based on previously utilized DeCODE nomenclature. Single nucleotide polymorphisms were genotyped using a sequence-specific polymerase chain reaction method and gel electrophoresis. Logistic regression was undertaken to determine the relevance of each polymorphism to stroke. Further analysis was undertaken to determine the risk of stroke following stratification for stroke sub-type and etiology. RESULTS: Significant odds ratios were found to be associated with cardioembolic strokes in two single nucleotide polymorphisms: rs152312 and SNP 45 (P < 0 · 05). CONCLUSIONS: Our findings demonstrated an association between cardioembolic stroke and phosphodiesterase 4D single nucleotide polymorphisms rs152312 and 45. No significant association was found for the other four single nucleotide polymorphisms investigated within the phosphodiesterase 4D gene. We propose that the results from this Australian population support the concept that a large prospective international study is required to investigate the role of phosphodiesterase 4D in the cardiogenic cause of ischemic stroke.