Wednesday, 26 March 2014

Consensus Guidelines for the Management of Postoperative Nausea and Vomiting. anesthesia-analgesia. January 2014 • Volume 118 • Number 1

Since the 2004 NEJM article investigating PONV, there have been several guidelines for the evaluation, prophylaxis, and management of PONV.  This current article takes a more detailed re-evaluation of the subject, taking into consideration additional/newer studies and newer classes of anti-emetics.
The overall recommendations provide an improved and modified risk-scoring system and a few new directions in recommendations for specific pharmacologic therapy.

The utilization of antiemetics is (likely) one of the most common pharmacologic therapies given consistently across our perioperative patient population.  Considering the significant proportion of our patient population, we would be remiss to not familiarize ourselves with these new guidelines. MD

De Vasconcellos K & Sneyd JR. Nitrous oxide: are we still in equipoise? A qualitative review of current controversies. BJA (2013), 111(6): 877-85.

This review article looks at the current position of nitrous oxide in anaesthetic practice, The article compare its relative advantages and disadvantages – the classically known ones which we are all aware of from our primary exams such as diffusion hypoxia, expansion of gas-fille spaces, postoperative nausea and vomiting to more recent concerns with neurotoxicity, wound complications and adverse cardiovascular outcomes. The authors also review recent suggested beneficial effects on the central nervous system, cardiovascular system, reduction of awareness with recall and pain (both acute and chronic) and argue that although nitrous oxide has fallen out of favour in the practice of many anaesthetists, we should re-consider current evidence and any new data (eg. ENIGMA-II) and consider nitrous oxide an option. GK

Myocardial Injury after Noncardiac Surgery. A Large, International, Prospective Cohort Study Establishing Diagnostic Criteria, Characteristics, Predictors, and 30-day Outcomes. Anesthesiology, V 120 • No 3. March 2014

This large study showed that myocardial injury after non-cardiac surgery is an independent predictor of 30-day mortality. Myocardial injury (diagnosed by a troponin T peak of 0.03 ng/ml) is relatively common (8% of patients) and mainly occurs in the first 2 days after surgery. 1 in 10 of these patients will die in the next 30 days. This can be easily missed since most patients do not have any ischemic symptoms and do not fit the diagnostic criteria for myocardial infarction. Patients who had a troponin rise from nonischemic etiology such as pulmonary embolism or sepsis were excluded. It is estimated that worldwide around 8 million patients per year may suffer from perioperative myocardial injury.

Preoperative cardiac evaluation and management of patients undergoing elective non cardiac surgery. MJA 199 (10) , 18 November 2013.

Perioperative cardiac complications occur commonly in patients having non-cardiac surgery, resulting in 30-day mortality rates between 15-20%. It has been found that some adverse events are a result of inadequate or incorrect preoperative assessment. This article looks at some of the evidence surrounding the preoperative evaluation and management of cardiac risk in patients undergoing elective non-cardiac surgery.

Thursday, 7 November 2013

Identification of doctors at risk of recurrent complaints: a national study of healthcare complaints in Australia Bismark MM, Spittal MJ, Gurrin LC, et al. BMJ Qual Saf 2013;22: 532–540.

Can we identify doctors who are at risk of having formal complaints made against them? This Australian study suggests that there are risk factors that can be identified, mainly on the basis of how many complaints you have received before. Over an 11 year period 18,907 formal complaints were made against doctors in Australia. 3% of doctors account for 49% of complaints, and 1% account for 25%, showing that a few doctors are at risk of serial complaints.
Luckily for us, whilst 47% of complaints are against GPs and 14% against surgeons, only 4% are against anaesthetists.
Most complaints relate to treatment, diagnosis and medications, but importantly nearly 25% relate to communication (15% to attitude or manner, 6% to information given and 3% to consent).
79% of complaints are against male doctors.
In terms of recurrence, if more than 2 complaints have been made, there is a 57% chance of a further complaint within 2 years, rising to 79% for 5 complaints, and a 97% chance of a new complaint within a year for someone who has had 10 or more previous complaints.
Across the board we are most at risk of having a formal complaint made against us within 6 months of a previous complaint.
by SW

Risk of Major Adverse Cardiac Events Following Noncardiac Surgery in Patients with Coronary Stents. JAMA October 2013

This article looks at the risk factors for adverse cardiac events in patients who have had a coronary stent within 2 years prior to undergoing non-cardiac surgery. Its findings question the current guideline recommendation of delaying elective non-cardiac surgery for 1 year after drug eluting stent placement and 6 weeks after bare metal stent placement. Over 25,000 operations occurring 6 weeks or more after stent placement were included in this study. The investigators found that the 3 most important risks for a Major Adverse Cardiac Event (MACE) occurring in these patients are emergency surgery, history of myocardial infarction in the last 6 months and advanced cardiac disease. Stent type and timing of surgery after 6 months did not seem to be significantly associated with increased MACE, nor did cessation of anti-platelet therapy. Well designed studies are needed on this subject to help guide management of these patients.

Asymptomatic Aortic Stenosis in the Elderly. A Clinical Review. JAMA October 2013

Aortic stenosis is the most common form of valvular heart disease. So how should we approach the patient who presents to preadmission with severe aortic stenosis? If they are asymptomatic and have a normal left ventricular ejection fraction then it is unlikely they will require a valve replacement. An exercise test will be useful in those with uncertain symptomatology. This is an informative review on the subject.

Tuesday, 5 November 2013

Neuroaxial block, death and serious cardiovascular morbidity in the POISE trial. BJA Sept 2013

This post hoc analysis of the POISE trial has discovered an association between epidural combined with GA (versus GA alone) and increased risk of adverse cardiovascular outcomes in patients at high risk of cardiovascular morbidity. The most notable increased risk was shown with thoracic epidurals. Rather than change practice, this article highlights the need for more studies to help guide the patient population that will benefit most from a neuraxial block and those who we may actually harm. An accompanying editorial discusses the limitation of the methodology of propensity-score matching used in the analysis.

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.

Sunday, 25 August 2013

From Mindless to Mindful Practice – Cognitive Bias and Clinical Decision Making

Our brains tend to process and manage information either "intuitively" or "analytically". Intuitive thinking is fast, is based on experience and common sense, and is usually right, while analytical thinking is slow, thorough and ensures that we use all our available deductive powers and resources and don't miss things. Analytical thinking (eg thorough use of algorithms, checklists etc) usually results in fewer mistakes or oversights, but is time consuming and simply not practical when dealing with the many decisions required in our daily activities. The problem in medicine is that intuitive thinking (something many experienced clinicians are often proud of) accounts for most of the major clinical mistakes. How then do we balance our use of both thought processes to deal efficiently with the many clinical problems we face every day without exposing patients to unnecessary risks by mentally "cutting corners"? This editorial looks at this question and has enough in it to give us all reason to think about it.


A Rude Awakening – The Perioperative Sleep Apnea Epidemic

The perioperative sleep apnoea epidemic has probably not been the "rude awakening" suggested in the title of this article for any anaesthetist working in Western Sydney any time this century. Just knowing about the problem, however, doesn't automatically mean we can fix it. This opinion piece highlights the increasingly common dilemma facing anaesthetists and surgeons and while it doesn't provide all the answers it does put out an important call for protocols that heighten awareness of the problem and make best use of the resources available to fix it. Westmead is looking at such protocols as well as contributing to the much needed research in this area. Worth a read.


Risk of venous thromboembolism associated with peripherally inserted central catheters

PICC lines are commonly used and often have advantages over central lines, but their thrombotic complications have perhaps been under appreciated until now. This metanalysis shows that they have a slightly higher incidence of DVT than central lines, and a subsection of observational work quantifies this risk and identifies the patient groups at highest risk. It comes with a useful editorial for those that don't want to read all the fine print, but it's worth thinking about the next time you're weighing up the pros and cons of a PICCline over a central line.