Monday, 30 September 2013

Residual paralysis - helpful refresher article

Residual paralysis: a real problem or did we invent a new disease? Canadian journal of Anesthesia  July 2013.
Since Neuromuscular blockade reversal is so topical at Westmead currently, we have included this continuing professional development article from the CJA. This article discusses the physiological effects of residual neuromuscular blockade and estimates the extent of the problem. Surveys show the majority of anaesthetist underestimate the incidence of residual paralysis. The correct interpretation of neuromuscular monitoring and pitfalls to be avoided are discussed. The article points out the ceiling effect of neostigmine, which may occur at or near clinically used doses. Furthermore they recommend at least 4 twitches prior to reversal to obtain a TOF ratio of > 0.9 at 10-15 minutes. This is a good refresher article for the next departmental discussion on Sugammadex.

What we don't know about Tranexamic acid ...

Trauma and Tranexamic acid – Editorial . MJA Sept 2013

The CRASH-2 (Clinical Randomisation of an Antifibrinolytic Significant haemorrhage 2) is a landmark study that has changed our practice when dealing with trauma patients. This editorial discusses the gaps in our knowledge with  regards to tranexamic acid  and trauma patients . To address some unknowns  about this topic, a new study PATCH- Trauma ( Pre-hospital Anti- fibrinolytics for traumatic coagulopathy and Haemorrhage study) funded by the NHMRC will start recruiting soon from trauma centres throughout Australia and New Zealand. Westmead will certainly be involved!

Can we decrease Gram positive surgical site infections ?

Effectiveness of a bundled intervention of decolonization and prophylaxis to decrease Gram positive surgical site infections after cardiac or orthopedic surgery: systematic review and meta-analysis . BMJ 2013;346:f2743 doi: 10.1136/bmj.f2743 (Published 13 June 2013)
This is a systematic review and meta-analysis assessing the effectiveness of a bundle of nasal decolonisation and glyopeptide prophylaxis in preventing surgical site infections (SSI) in adults undergoing cardiac and orthopaedic surgery (predominantly joint replacement). This is an important area to study, as surgical site infections (SSI) significantly increase hospital length of stay, mortality and costs.

This MA looked at 39 trials (RCTs, quasi-RCTs, and retrospective cohort studies) in which a bundled intervention was employed, or one of the two strategies was used alone.
They found that nasal decolonization alone decreased the rates of S aureus SSIs (RR 0.41, 0.3 – 0.55), but there was high heterogeneity. When looking at RCTs alone this was not significant (0.63, 0.36 – 1.13).
 Glycopeptide prophylaxis protected against MRSA SSI (0.4, 0.2 – 0.8), but not all Gram positive bacteria (0.7, 0.47 – 1.04).
 Bundle intervention including both approaches found a significant reduction in the risk of SSI caused by all gram positive bacteria (0.41, 0.3 – 0.56). Importantly however, none of these were RCTs.
 So, this MA suggests the use of nasal decolonization in conjunction with glycoprotein prophylaxis may help reduce the incidence of S aureus SSI. However, there are significant limitations with this MA, particularly the poor quality of the studies included. Whilst attempts were made to mitigate this issue, there remains the need for a well conducted, adequately powered RCT in this area.

Article worth looking at ...

Safety and efficacy of Intravenous iron therapy in reducing requirement for allogenic blood transfusion : systematic review and meta-analysis of randomized clinical trials . BMJ  August 2013

The use of intravenous iron to treat anaemia and hence reduce the need for blood transfusions is becoming more popular. It is now recommended by the National Blood Authority in their Patient Blood Management Guidelines as a part of preoperative haemoglobin optimisation.
This meta-analysis looks at over 10 000 patients who were involved in randomized controlled trials of intravenous iron compared with either no iron or oral iron. They found that intravenous iron increases the haemoglobin concentration (standardized mean difference 6.5g/L, 5.1 – 7.9) and reduces the need for blood transfusions (risk ratio 0.74, 0.62 – 0.88). They also found however that the risk of infection was increased (RR 1.33, 1.1-1.64).
So, IV iron is good to reduce the need for transfusion but may result in more infections. We need a well powered RCT looking at the end points of infection, morbidity and mortality to work out the role of iron transfusion as a therapy to reduce the need for tranfusions.