Anaesthesia
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Randomized Controlled Trial Comparative Study
A randomised crossover simulation study comparing the impact of chemical, biological, radiological or nuclear substance personal protection equipment on the performance of advanced life support interventions.
Recent incidents involving chemical, biological, radiological and nuclear substances have stressed the importance of sufficient personal protection equipment for medical first-responders. Modern lightweight, battery-independent, suit ensembles may prove superior to the current protective suit used in the UK. This study compared the powered respiratory protective suit (PRPS ensemble) with a lightweight suit consisting of a SARATOGA® Multipurpose CBRN Protective Coverall Polyprotect 12 in conjunction with the Avon C50 Respirator/Avon CBRNF12CE filter canister and butyl rubber protective gloves (Polyprotect 12 ensemble). ⋯ Total mean (SD) completion time for the five interventions was significantly longer for the PRPS compared with the Polyprotect 12 ensemble (204 (53) s vs. 149 (36) s, respectively; p < 0.0001). Participants rated mobility, noise, heat, vision, dexterity and speech intelligibility significantly better in the Polyprotect 12 ensemble compared with the PRPS ensemble. The combination of a lightweight Polyprotect 12 suit and an Avon C50 air-purifying respirator is preferable to the powered respiratory protective suit during simulated emergency life support, due to a combination of shorter task completion times and improved mobility, communication and dexterity.
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Multicenter Study
Transfusion in critical care - a UK regional audit of current practice.
A consistent message within critical care publications has been that a restrictive transfusion strategy is non-inferior, and possibly superior, to a liberal strategy for stable, non-bleeding critically ill patients. Translation into clinical practice has, however, been slow. Here, we describe the degree of adherence to UK best practice guidelines in a regional network of nine intensive care units within Wessex. ⋯ The reason why recommendations on transfusion triggers have not translated into clinical practice is unclear. With a clear national drive to decrease usage of blood products and clear evidence that a threshold of 70 g.l-1 is non-inferior, it is surprising that a scarce and potentially dangerous resource is still being overused within critical care. Simple solutions such as electronic patient records that force pause for thought before blood transfusion, or prescriptions that only allow administration of a single unit in non-emergency circumstances may help to reduce the incidence of unnecessary blood transfusions.
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The primary goal of this study was to determine the median effective dose (ED50 ) of spinal chloroprocaine for labour analgesia. Thirty-eight parturients requesting neuraxial analgesia were enrolled. ⋯ Effective analgesia was defined as a score ≤ 10 mm within 15 min on a 100-mm visual analogue pain scale. Using the isotonic regression estimator method, the ED50 of chloroprocaine for the spinal component of a combined spinal-epidural for labour was calculated to be median (95%CI) 12.0 (9.3-17.0) mg.
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Observational Study
Effects of acute controlled changes in end-tidal carbon dioxide on the diameter of the optic nerve sheath: a transorbital ultrasonographic study in healthy volunteers.
Transorbital ultrasonographic measurement of the diameter of the optic nerve sheath is a non-invasive, bed-side examination for detecting raised intracranial pressure. However, the ability of the optic nerve sheath diameter to predict acute changes in intracranial pressures remains unknown. The aim of this study was to examine the dynamic changes of the optic nerve sheath diameter in response to mild fluctuations in cerebral blood volume induced by changes in end-tidal carbon dioxide. ⋯ With hypercapnia, there was a significant increase in optic nerve sheath diameter, with a mean (SD) increase from baseline 4.2 (0.7) mm to 4.8 (0.8) mm; p < 0.001. On return to normocapnia, the optic nerve sheath diameter rapidly reverted back to baseline values. This study confirms dynamic changes in the optic nerve sheath diameter with corresponding changes in carbon dioxide, and their reversibly with normocapnia.
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Observational Study
Heart rate variability as a predictor of hypotension following spinal for elective caesarean section: a prospective observational study.
Post-spinal hypotension remains a common and clinically-important problem during caesarean section, and accurate pre-operative prediction of this complication might enhance clinical management. We conducted a prospective, single-centre, observational study of heart rate variability in 102 patients undergoing elective caesarean section in a South African regional hospital. We performed Holter recording for ≥ 5 min in the hour preceding spinal anaesthesia. ⋯ Baseline heart rate (p = 0.20; OR 1.022, 95%CI 0.988-1.057) and BMI (p = 0.60; OR 1.017, 95%CI 0.954-1.085) did not predict hypotension. Heart rate variability analysis is a potentially useful clinical tool for the prediction of hypotension. Future studies should consider a low-frequency/high-frequency ratio threshold of 2.0 for prospective validation.