BIS monitoring may not reduce the incidence of awareness under general anesthesia.
The incidence of awareness-with-recall under general anesthesia in the United States is 1-2 cases per 1,000 patients.
Note that the reported ’reduction in respiratory failure’ was entirely due to a small difference in post-op ventilation duration in the ICU between the groups. Significant, but perhaps not clinically remarkable.
Perioperative epidural analgesia in high-risk patients undergoing major abdominal surgery improves analgesia but doesnot have other morbidity or mortality benefits.
Intraoperative warming of patients avoids hypothermia, reduces wound infection and shortens hospital stay after colorectal surgery.
Perioperative aspirin use does not reduce mortality or myocardial infraction, but does increase the risk of major bleeding.
This meta-analysis (unsurprisingly) confirms that pre-operative troponin levels are post-operatively associated with both major adverse cardiac events and mortality risk.
This sounds obvious, why should we care?
First, there's a difference between evidence and that vague feeling we call common-sense that a disproportionate number of our clinical decisions are based upon.
Surgical patients are getting older and sicker. We need better tools for risk stratifying patients before surgery to improve perioperative planning. Most importantly (though not exclusively) reliably identifying biomarkers for risk allows closer postoperative surveillance and monitoring – which may alter outcomes.
We already know that troponin I and T are markers of cardiac damage, and unlike brain natriuretic peptide (BNP), troponin assays are readily available in most healthcare settings.
Ok, you convinced me... what did they find?
Analysing 10 studies totally 10,371 patients, they found an association between preoperative troponin elevation and MACE (OR 6.9), and short-term & long-term mortality (OR 4.2 & 2.5). Note though that the confidence intervals were quite wide.
There's always a but... the included studies were all observational in nature, used a variety of troponin assays, and the results were quite heterogenous across the 10. Most importantly, even assuming troponin is an accurate preop risk marker, we don't yet know whether that knowledge will allow us to alter outcomes for these patients.
Plasma fibrinogen measurement is usually a more important target in post-partum hemorrhage than other coagulation lab results.
Collins et al share their insights from 10 years of Cardiff research and pragmatic clinical experience managing postpartum hemorrhage.
Why is this important?
PPH incidence is increasing globally and is still the number one cause of maternal death. Many routine PPH transfusion practices are dogmatic and based upon non-pregnant trauma data. Applicability to PPH is at best questionable.
Of interest they note:
- The utility of fibrinogen measurement as an early indicator of coagulopathy and severe PPH, especially <2 g/L.
- The value of point-of-care testing, such as with ROTEM®.
- The typical maintenance of normal PT & APTT until 4-5 L of blood loss, unlike fibrinogen which was abnormal after ~2 L loss.
- The rarity of needing to replace factors other than fibrinogen even in severe PPH. FFP can usually be safely withheld in moderate-to-severe PPH when POCT is available.
- The value of fibrinogen concentrate over cryoprecipitate, although without value in pre-emptive formulaic treatment.
- The value and practicality of measuring blood loss versus estimation.
The take-away: Plasma fibrinogen is generally a more important target than PT or APTT in most PPH cases. (Placental abruption is an important exception.)
Interesting physiological tidbit... because normal term fibrinogen is 4 g/L and FFP fibrinogen is 2 g/L, undirected FFP transfusion in PPH could theoretically contribute to dilutional hypofibrinogenemia.
An interesting exploration of the surgeon-anesthesiologist relationship, framed in terms of it being the critical dyad of the operating theatre team.
Cooper explores the positives and negatives, the stereotypes that each craftgroup holds of the other, and the ways in which these translate to team performance.
Most significantly, Cooper makes the point that when highly functional this relationship can lead to the highest quality patient care, but at its worst, dysfunction can lead to extreme harm and compromise patient safety.