Article Notes
- 54% less likely to report headaches
- 64% less likely to report fatigue
- 68% less likely to report muscle pain
- Kuodi, P. et al. Preprint at medRxiv (2022).
- (CH3)3-N-CH2CH2-OCO-CH2CH2-OCO-CH2CH2-N-(CH3)3
- pH 3.5
- Shelf life 3 years at 4°C, though only 'months' at 20°C.
- Dose - ED95 0.5 mg/kg, IV 1.5 mg/kg, IM 2.5-4 mg/kg.
- Absorption - IM, IV.
- Distribution - >0.2 L/kg; crosses placenta slightly but little effect on foetus.
- Protein binding ?
- Onset 30s IV, 2-3 min IM; Offset 3-5 min.
- Metabolism - PChE to succinylmonocholine (5% activity) & choline -> succinic acid & choline.
- tß½ 5 minutes
- Mechanism - binds to alpha subunit of nicotinic ACh receptor, producing persistent depolarisation (phase 1 & phase 2 blocks).
- CNS - ⇡ intra-ocular pressure (4-8 mmHg rise), ⇡ intra-celebral pressure (to 30 mmHg at 2-4 min).
- CVS - arrhythmias (both bradycardia & tachycardia possible), ⇡ systolic blood pressure, (both negative inotropic and chronotropic effects).
- Resp - 'sux apnoea' pharmacogenetic diversity (94% normal, 3.8% heterozyg (10 min duration of effect), <1% homozog (1-2h duration))
- Renal - hyperkalaemia due to K+ release from muscle; beware in neuromuscular conditions, denervation, and extensive burns.
- GIT - ⇡ intragastric pressure, ⇡ secretions, salivation.
- SEs - anaphylaxis, malignant hyperthermia, sux apnoea, muscle pains, masseter spasm.
Surgery should be delayed for at least 7 weeks after COVID, although those with persistent COVID symptoms will still have more than twice the 30-day mortality than those without. (COVID Surg Collaborative 2021)
After recovery from SARS-CoV-2 infection, minor surgery should be delayed 4 weeks and major surgery delayed 8-12 weeks. (Kovoor 2021)
Elective surgery should not be scheduled within 7 weeks of a SARS-CoV-2 infection. (El-Boghdadly 2021)
- Female patients treated by male surgeons more commonly experience post-operative complications and death than when treated by female surgeons. (Wallis 2021)
- Care from male surgeons and/or anaesthesiologists is associated with longer lengths of stay after cardiac surgery. (Sun 2021)
- Female heart-attack patients are less likely to survive when treated by a male physician than a female physician. (Greenwood 2018)
- Treatment from female surgeons is associated with a lower 30 day mortality than the same from male surgeons. (Wallis 2017)
- In-patient care from a female physician is associated with lower 30 day mortality and readmission rate among elderly patients. (Tsugawa 2017)
Early 2020 studies of COVID rapid antigen tests were of low quality and of variable applicability to COVID diagnostic decisions. This situation improved dramatically in 2021 and 2022, and many RATs are now continually validated in existing and emerging variants.
This Cochrane Review was updated in 2021.
Daniel Jolley
Van Decar et al. on the diagnosis and management of intra-operative diabetes insipidus concludes:
For the average adult patient, urine output >125 mL/h is consistent with polyuria. Urinary osmolality and specific gravity should be obtained and levels <300 mOsm/kg and <1.003, respectively, are consistent with hypotonic urine.
It is prudent to rule out other causes of polyuria including hyperglycemia, uremia, or iatrogenic causes including diuretic or mannitol administration.
Serum electrolytes and osmolality should also be obtained, and a high sodium (>146 mmol/L) and plasma osmolality (>300 mOsm/kg) are typically seen with DI.
Treatment should focus on replacement of free water deficit with a balanced salt solution, pharmacotherapy including DDAVP or vasopressin as appropriate, and close monitoring of patient’s fluid and electrolyte status.
Daniel Jolley
3000+ double-Pfizer-vaccinated Israeli subjects, July and November 2021, several months after COVID infection when compared to unvaccinated counterparts:
In fact, prevalence of these long-covid symptoms was no different than among groups not infected with COVID.
Daniel Jolley
Sugammadex is pharmacologically great. A modified γ-cyclodextrin Selective Relaxant Binding Agent that reverses rocuronium muscle relaxation 10-times faster than neostigmine (see: Is sugammadex as good as we think?).
At launch, its biggest obvious disadvantage was simply the new drug's high cost. Now as sugammadex has become more widely used, sugammadex-anaphylaxis has risen as a new, prominent concern.
In Japan, where there was a uniquely rapid take-up of sugammadex, it became one of the commonest causes of anaphylaxis. Oriharia (2020) demonstrated an incidence of sugammadex anaphylaxis in Japan of 1 in 5,000 – a risk that most medically communities would consider too high for routine use of a drug with acceptable alternatives.
Given that in some regions (notably Australia & New Zeleand) rocuronium itself has a high-risk of anaphylaxis, the combination of rocuronium-sugammadex may present a greater risk than even old-school drugs such as suxamethonium.
In other countries, such as the United Kingdom, there has not been quite the same incidence of sugammadex-anaphylaxis. Is this simply because of the lower initial use than in Japan, or are there environmental and phenotypical differences as have been implicated for rocuronium anaphylaxis?
Worryingly, if the Japanese experience is representative, then for some locations the combination of rocuronium-sugammadex may in fact have a higher risk of anaphylaxis than using suxamethonium alone.
The true risk of sugammadex-anaphylaxis is still unclear for many populations. However with the looming expiry of the sugammadex patent in 2023, we will see a rapid increase in its use and subsequently reveal any latent anaphylaxis risk.
Daniel Jolley
Suxamethonium chloride (suxamethonium, succinylcholine or sux) is a depolarising muscle relaxant that produces rapid-onset, short-duration, deep muscle relaxation. First identified in 1906 and used medically in 1951, it is one of the oldest anaesthesia drugs still widely used. Due to its unique properties and low cost, it remains on the World Health Organisation's List of Essential Medicines
A. Physiochemistry
B. Pharmacokinetics
C. Pharmacodynamics
Daniel Jolley
In 2020 the COVID Surg Collaborative demonstrated a shockingly-increased post-operative mortality among patients undergoing surgery during an active COVID infection.
This naturally led to questions regarding timing of elective surgery after COVID-19 recovery.
Although data is scant, the COVID Surg Collaborative again leads the way with a large multicenter study showing increased 30 day mortality even when surgery is delayed 5-6 weeks after COVID infection.
Various guidelines and recommendations exist, but summarising:
Several studies note that these periods are minimum recommended delays, and that patients with persisting symptoms still experience higher 30-day mortality even after delaying seven weeks. El-Boghdadly et al. suggests that this period should be used for functional prehabilitation for these patients.
Daniel Jolley
"...I encourage all patient safety stakeholders to resist an overemphasis on absolute safety, and instead draw on the strengths of both the safety I and safety II approaches. We should be clear about what types of harms can or cannot be prevented and anticipated, work to eliminate those where there is good evidence for preventability by adopting evidence-based practices, improve the ability of everyone responsible for safety to identify risks, conduct better risk analyses to anticipate and reduce unintended harms, measure and celebrate the routine adaptations that prevent harm, and reward organisational learning and improvement." – Thomas, 2020.
Daniel Jolley
File under correlation-is-not-causation-but...
Sometimes even correlations are too significant and important to just be fobbed off by epidemiological cliché. This collection contains articles repeatedly showing association between doctor characteristics, particularly gender, and patient outcome.
Although most recently shown by Wallis in JAMA Surgery (2021), gender-outcome associations are depressingly not new.
The cause of this gender outcome disparity is unclear, and importantly these studies are hypothesis forming, rather than proving. Nonetheless both Wallis (2021) and Greenwood (2018) hint at causes, namely a lack of experience treating female patients for some male doctors, and consequential lesser understanding of gender-disease differences.
The temptation when attempting to understand this is to descend into medical gender essentialism – ironically, probably a contributor to the actual outcome disparities.
A similar doctor-outcome disparity is seen with age. Among physicians, care from older doctors was associated with worse outcomes (Tsugawa 2017), yet for surgeons older age conferred better outcomes (Tsugawa 2018; Satkunasivam 2020). Causes here are possibly a nexus between experience, up-to-date knowledge and work volume – but also, still unclear.
Daniel Jolley
What did they do?
Fascinating big-data study covering 12 years of the 20-most-common surgical procedures in Ontario, Canada. Wallis, Jerath & co. investigated how patient-surgeon sex discordance correlated to a composite for adverse postoperative outcomes. (A deeper investigation of the related Wallis 2017 study).
And they found?
While ~15% of all patients experienced an adverse post-operative outcome, female patients treated by a male surgeon experienced significantly higher odds of a composite of adverse events (OR 1.15 [1.10-1.20]), 30-day complications (OR 1.16 [1.11-1.22]), readmissions (OR 1.11 [1.04-1.19]), and death (OR 1.32 [1.14-1.54]) compared to when treated by female surgeons.
Yet male patients treated by female surgeons experienced either lower odds (death 0.87 [0.78-0.97]) or statistically-similar odds of complications (composite end-point, readmission or post-op complications).
The hot-take
Women once again receive the metaphorical short-end of the medical-stick. Whether societal or elsewhere in the health industry value-chain, long established gender inequity reveals itself in worse surgical outcomes for female patients.
Hang on a sec…
But this cannot just be written off as a consequence of existing social gender inequity, but rather a disquieting causal loop between this as a cause and the result then perpetuating further inequity.
If some part of a surgeon’s ’professional success’ is wrapped-up in the ability to achieve positive outcomes for patients while minimising the adverse, then male surgeons are failing their female patients when compared to either female surgeons, or to the care they provide their male patients.
And yet the same discordance cost is not true for female surgeons.
The take-away
If you are a male surgeon at all interested in successful patient outcomes (surely that’s every surgeon?), then this should make you very, very uncomfortable. At the very least it should make male surgeons stop and consider whether their female colleagues conduct any aspects of their practice differently – particularly when treating female patients.
Daniel Jolley