the metablog

Thoughts, news and musings from metajournal.

The importance of non-inferiority and equivalence

Three papers from the first BJA of the new decade highlight the importance of non-inferiority: protective ventilation strategies, dexamethasone for prolonging interscalene blocks, and high inspired oxygen and surgical site infections.

Although none investigated new questions, they all represent studies into areas of ongoing uncertainty. They are each a useful reminder that most perioperative interventions do not significantly improve outcomes, although the majority of these probably do not ever make it to publication.

Lung-protection and atelectasis

Généreux et al. investigated the atelectasis-preventing benefit of a common protective ventilation strategy (PEEP and regular recruitment manoeuvres). Notable not just because there was no difference in atelectasis after extubation, but because the use of ultrasound to measure atelectasis helped to better track the intraoperative and post-extubation changes between the intervention and control groups. [→ article summary]

Read more...

Small Changes & Protection: antihypertensives, cognitive decline and ischaemic preconditioning

Metajournal on Small Changes & Protection: antihypertensives, cognitive decline and ischaemic preconditioning

Three interesting articles that appeared in the past few months, all following a common theme of ‘protection with small changes’. Although only one is itself practice changing, together they challenge us to continue to look to how small practice changes may have significant protective and preventative effects in the lives of our patients.

Antihypertensives evening dosing

Hermida et al. (2019) published impressive results from the massive, 10-year Hygia Project, which randomised almost 20,000 patients to take anti-hypertensive medications at bedtime or awakening.

Not only did patients who took antihypertensives (of any class) in the evenings have better blood pressure control, they also received a 45% reduction in major cardiovascular outcomes, including CVD death, infarct, coronary revascularisation, heart failure and stroke!

Given that many critical care doctors briefly touch on the medications their patients are taking, a simple “you should ask your primary physician about when its best to take your blood pressure tablets” could have a disproportionately large impact on patient health.

Read on for protection with intravenous lidocaine and ischaemic conditioning...

The problem with Electronic Medical Records

Doctors spending too much time using computers and electronic medical records

It is not so much that all Electronic Medical Records are terrible, but rather that it is so close to true that the occasional net-positive EMR roll-out does not move the needle much on its own. The greater challenge is that the reasons why the EMR experience is so poor also make it unlikely that EMRs will get dramatically better in the short-term.

The root of the EMR problem, fundamental to their very nature, ensures that EMRs will get worse before they get better.

I'm yet to be impressed by a hospital-wide monolithic EMR – one that is intuitive to use, enhances safety and reduces clinician workload rather than adding to it. An EMR that offloads administrative burden from healthcare providers, and enhances authentic interactions with patients. Where are the truly efficient EMRs that are true improvements to the paper-based systems they replace?

“Show me an [EMR that] only triples my work and I will kiss [their] feet.” – House of God1

Many EMRs are frustrating and inefficient, though tolerable in a necessary-evil kind of way. Clinicians put up with the many small EMR-inflicted aggravations because of the promises made for improved safety, efficiency and lowered costs. Yet the modern EMRs of today have largely failed to live up to even these low-bar aspirations.2

Read on about failed EMR promises...


  1. Shamelessly stolen and adapted from Samuel Shem's (Stephen Bergman) classic House of God

  2. I use ‘EMR’ (Electronic Medical Record) in the strictest sense here, meaning a system for managing medical records in a hospital or group of hospitals. In North America ‘EMR’ is sometimes used interchangeably with ‘EHR’ (Electronic Health Record) which is more accurately a population-wide record of health, such as Australia’s imperilled My Health Record. In this example the EHR is an aggregator of health summaries, not a hospital medical record. At a medical-practice level, it is more accurate to talk about ‘practice management software’ than EMRs. 

Ketamine, Checklists and Social Media

Metajournal on Ketamine, Checklists and Social Media with ice-cream

As I read articles this week, three very different papers created a nexus of interest and push-back against mildly dogmatic thinking in the critical care specialities. Two challenge existing anaesthesia dogma, while the third highlights the potential for missteps when incorporating new media into our practice and education.

Although critical care specialties like anaesthesia and emergency medicine are often seen from the outside as embracing change and being unafraid of dipping our collective toes into the rivers of progress, there are still many strongly held views that persist even in the face of contrary evidence.

Ketamine and persistent pain

Chumbley, Thompson, Swatman and Urch report in the European Journal of Pain the results of their double-blind, randomised, placebo-controlled trial of a 96-hour perioperative ketamine infusion to reduce persistent post-surgical pain after thoracotomy. Notably they found that this significant-duration ketamine infusion did not reduce post-thoracotomy chronic pain.

This paper is the first quality RCT to follow thoracotomy patients for a year after surgery in the setting of perioperative ketamine. It adds to existing evidence suggesting a lack of effect of ketamine for mitigating persistent surgical pain – even though this has been a popular opinion (hope?) among anaesthetists and pain specialists in the past. The results of the ROCKet trial will provide us with more confidence in answering this question.1

Read on for anaesthesia checklists and FOAMed mistakes...


  1. A collection of related articles can be found here: Does ketamine reduce persistent post-surgical pain? 

Are there any truly universal anaesthesia rules?

It’s not uncommon to hear anaesthesiologists drop verbal markers of universal truths into their clinical utterances: always, every, never. Often it's the most banal practices ("always attach the cannula tegaderm so") that generate our greatest passions.

However there are few, if any, universalisms in anaesthesia. Almost every rule has caveats and exceptions, reflecting the shades-of-grey reality of patient needs and human physiology.

When clinicians decree something is always or never so, they are often confusing truth with convention. Sometimes confusing an absolute with what is instead dogma. A minority reveal the rigidity of their thinking, impeding rather than enhancing the performance of their practice.

Rules are still useful. They are important guardrails, a mental model to keep us on the road of safety unless there is very good reason to cautiously edge onto the gravely shoulder, or even turn down a completely new path. But always with the understanding of the compromise we have intentionally made, reminding us of the cost that may need to be paid.

Universal anaesthesia rules become a problem when we dogmatically extol them without understanding the foundations of why – or use them as a blunt tool to browbeat our colleagues and assistants.

Rules are shortcuts to express the tension between the benefits and risks of different anaesthetic decisions. All difficult airways in specialty exams might require mandatory awake fiberoptic intubation, but in a real world of patient refusals and modern airway toys & techniques, it is a more nuanced decision. In fact, patient refusal might be the closest we get to an absolute rule – but even this is a negotiable area of greys.

As a mental model for normalising risk, rules are an efficient way to communicate our prioritisation of the risk-benefit tension. A tool for education and standard setting, without requiring the immediate overhead of qualifying and rationalising.

First learn the rules. Then master the rules. And only then can you break the rules.

The danger comes when we confuse the mental model – the guardrails – for the reality. Misidentifying a tool to guide perception and practice, as something we mistakenly believe reality can be bent to. When we make this error, reality has a nasty habit of reasserting itself with unsentimental brutality.

I made my mistakes so you don’t have to. Don’t repeat my mistakes. Make your own mistakes. Make better mistakes.

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