Article Notes
- Does peri-operative intravenous dexamethasone reduce pain and opioid consumption after caesarean delivery? YES
- Are the effects statistically significant? YES
- Are the effects clinically significant? Possibly, though pain scores are only modestly improved and the reduction in opioid use is only small.
- Are the findings applicable to my patient population? Possibly, though the majority of studies were performed in Middle East, Asian & South Asian hospitals, and with diverse post-operative analgesic regimes.
- Is peri-operative dexamethasone safe? Probably, though few studies were adequately powered to identify less-common potential side effects, such as infection or delayed wound healing.
- Quality of evidence is low to modest. Notably, the primary outcome for most studies was PONV reduction, not post-operative pain.
- Should this evidence result in routine practice change? Probably not at this stage. IV dexamethasone may however be an appropriate intervention in select patient groups.
- Semi-rigid cup type (3M 1860 or 1860S): 65% FT pass.
- Duckbill type: (BSN ProShield or Halyard Fluidshield): 59% FT pass.
- Flat-fold cup type: (BYD Care DE2322): 32% FT pass.
Low: Under 50 years with mild illness resolving within 7 days.
Intermediate: prolonged symptoms (>7d); persistent SOB or chest pain; pre-existing comorbidities; elite/endurance athletes.
- Consider ECG & baseline pathology, including troponin.
High: hospitalised with COVID; SOB or chest pain at rest; cardiac abnormalities.
- Multi-disciplinary team to advise & monitor return to exercise.
- Begin after 10 days of rest and when 7 days symptom-free.
- Begin with 15 minutes of light activity, with gradual increase guided by lack of fatigue with activity.
- 🚩Red flag symptoms: chest pain, palpitations, severe dyspnoea. STOP & medical review.
The pressure to practice truly patient-focused, evidence-based medicine weighs on every anaesthetist and anaesthesiologist. Yet as the volume of evidence has grown, so has the expectation to always provide the highest quality care.
There is a trap of unknown knowns: evidence known in the greater medical-knowledge body but that we are naively ignorant of.
Bastardising William Gibson (1993), we risk that the evidence:
“…is already here – it's just not very evenly distributed.”
The greatest challenge for evidence-based anaesthesia continues to be the translation of research findings into actual practice change. The key to this is the intersection between quality, personal relevance, general significance, and credibility. But how can we achieve this?
Carlisle investigated the distribution of independent variables between study groups in Fujii's fraudulent research:
"The published distributions of 28/33 variables (85%) were inconsistent with the expected distributions, such that the likelihood of their occurring ranged from 1 in 25 to less than 1 in 1 000 000 000 000 000 000 000 000 000 000 000 (1 in 1033), equivalent to p values of 0.04 to < 1 × 10-33 , respectively."
This editorial from authors working in elite sport, exercise medicine and sports cardiology, contextualises the best current advice on returning to exercise after COVID infection, specifically acknowledging the Omicron variant and its potential differences.
"...with over 6 million cases recorded in Australia & NZ in the first 4 months of 2022, and few reports of serious adverse outcomes with exercise, the approach to return to exercise has become more pragmatic."
The author's experience has been that most vaccinated elite athletes achieve pre-morbid fitness levels after COVID recovery by day 7-14. Recreational athletes are recommended to pursue a more conservative course, but nonetheless they suggest:
"...a quick return to moderate exercise with a more cautious return to higher intensity exercise."
For those with no or minimal symptoms, the authors describe a graduated approach of exercise return over 6 days (days 1-3, 50% intensity for 15-30 min, then days 4-6, 75% intensity for 30 min), culminating in return to normal activity on day 7 if the graduation is well tolerated.
Elite athletes with close medical and training supervision may be able to undertake an accelerated progression of training intensity.
The full-text article includes a useful decision flowchart.
Excellent audit data from a major Australian teaching hospital reporting on the fit test results of their tested 2,161 healthcare workers across four different N95/P2 mask designs.
Why is this important?
Many healthcare workers and significantly, the general public, do not have access to formal Fit Testing (requires expertise, facilities & equipment). We also know that as face shape varies among individuals, so does the effectiveness of protection for different mask types – this is particularly significant for women who have more difficulty in finding suitably-fitting N95 respirators. (Notably 73% of Fit Tested staff in this study were women.)
The results of this study may allow individuals to make educated choices on suitable masks even when they do not have access to Fit Testing, as well as guiding institutional mask purchases.
What did they find?
Three-panel flat-fold N95 masks performed best (3M Aura 9320A+) both for fit test (96% pass) and wearer comfort and usability.
The other three tested designs were not as performant:
Jewson, McNamara & Fitzpatrick describe a roadmap for return to activity after COVID infection, developed by the Australasian College of Sport and Exercise Physicians.
They consider three risk categories:
Graded return to physical activity
Return to exercise flowchart:
Early in the COVID pandemic, diagnostic testing relied entirely on precise-but-expensive PCR testing. Late in 2020 the Lateral Flow Testing techniques, already widely used for home-pregnancy tests and similar, were developed for SARS-CoV-2 antigens, leading to COVID-19 Rapid Antigen Tests (RATs).
While cheap, scalable and able to give a result in 10-15 minutes, they were initially seen mostly as a supplement to PCR testing, with less accuracy. Although true that RATs have lower sensitivity than SARS-CoV-2 PCR – most licensed-RATs have sensitivity 80-95% – today this is both less important, and possibly even a strength of RATs over PCR.
Early in the pandemic the role of testing has primarily about diagnosis, in those either symptomatic or pre-symptomatic. Viral presence was practically assumed to be synonymous with contagion. Today with over half a billion cumulative COVID cases worldwide and counting, along with access to effective vaccines and antivirals, it is often more useful to know whether an individual is infectious or not at a discrete moment in time.
Growing research over the last 12 months shows that adequately-sensitive RATs are effective at identifying infectious individuals, even if the high-sensitivity of PCR testing identifies viral particles in those who are infected but otherwise non-infectious (either pre-infectious, or post-infectious with ongoing viral shedding).
PCR positive results with cycle thresholds (ie. number of thermal cycles of RNA replication required before fluorescence is detected) above 25-30 have good correlation with being non-infectious (ie. unable to culture virus). Adequately approved & validated RATs (by FDA, TGA, MHRA, etc.) have very high sensitivity at CT less than this 25-30 range, depending on the study and specific manufacturer.
The bottom line...
An adequately-validated RAT, when correctly performed, is likely a sensitive indictor of individual infectiousness at that specific moment in time. The reliability of a negative RAT will be improved if using the same manufacturer and technique as a RAT previously positive test, and more so if there are several subsequent negative RATs.