Article Notes
Why is this important?
In-hospital cardiac arrest (IHCA) training is an important component of both foundational and continuing medical education. Nonetheless patient survival after IHCA continues to vary across institutions, making it a priority for improvement.
What did they do?
Josey and team set out to identify whether greater hospital use of in-situ AHCI drills (‘in-situ mock codes’ - ISMC) was associated with improved IHCA survival. They measured both hospital-level simulation participation and IHCA discharge survival rates across 26 hospitals in their US multi-state non-profit health system.
And they found?
Hospitals with more active in-hospital cardiac arrest simulation training also had better IHCA survival (43% vs 32%, OR 0.62), even after adjusting for case-mix and acuity.
It is reasonable to conclude that better in-hospital code training leads to better basic & advanced life support and thus better IHCA survival – suggested, for example, by their observation of shorter time to defibrillation during arrest drills among high participation hospitals.
In fact they extraopated that each additional 1.1 drill/100 beds/year equated with one extra life saved. Interestingly the benefit of ISMC held up for large and medium-sized hospitals, but not small hospitals (=< 25 beds).
Be smart
Whether these results represent a direct casual effect of simulation training to improve survival, or an indirect effect of hospital safety culture on both simulation participation and patient survival, it is nonetheless an important result.
Plus a great example of studying a meaningful outcome (survival to discharge) instead of surrogate markers often employed in resuscitation and simulation research.
Why is this relevant?
Anaesthetists and anesthesiologists have long worried about the recall of labouring women when presented with risk-benefit discussions prior to epidural analgesia or receiving anaesthesia for cesarean section.
This UK survey of over 900 women across 28 Greater London hospitals explored recall of this antenatal and intrapartum information, along with maternal satisfaction.
What did they find?
There was very little recall of receiving either thorough labour analgesia information (9%) or anaesthesia for CS (12%) provided during the antenatal period.
During the interpartum period, fewer than two-thirds (62%) recalled receiving thorough information during labour before insertion, and less than one-third (28%) before Caesarean section anaesthesia.
13% of women did not recall receiving any information before epidural insertion.
These are concerning findings in a modern era where patient autonomy and informed consent are prioritised, and more so where informed decision making may contribute to a positive birth experience.
Interestingly, verbal information appeared best recalled (OR 5.9 to 20.7 across different categories), although this is counter to past studies showing superiority of written information.
Be clear
Because the 28 hospitals contributing to the survey had large practice differences in how antenatal anaesthetic information was provided, it is difficult to determine whether the provision of information or recall itself is the problem.
Take-home...
Regardless of the cause, a large proportion of pregnant women did not recall being adequately informed before epidural analgesia or caesarean anaesthesia. This needs to be improved.
Why is this interesting?
Lidocaine/lignocaine has been increasingly used intra- and perioperatively as an analgesic adjunct, with further research suggesting a potential neuroprotective effect. Cognitive decline is a common problem following cardiac surgery (40-50%), with lidocaine potentially offering a simple and safe intervention to reduce this complication. Past studies have showed conflicting results.
What did they do?
This Duke University team randomized 478 cardiac surgery patients across multiple centres to lidocaine intraoperatively (1 mg/kg bolus then decreasing infusions across 2.9 / 1.5 / 0.6 mg/kg/h over 48 hours) or blinded control. Cognitive function was assessed at 6 weeks and 1 year.
They found...
No difference in cognitive deficit between lidocaine infusion and saline control at either 6 weeks or 1 year.
Be smart
Intravenous lidocaine infusion remains relatively safe, practical and is still likely a useful analgesic adjunct. Similar to magnesium, which has been shown to be neuroprotective in premature infants but not adult cardiac patients, the problem for lidocaine may well be context rather than physiological benefit itself.
Relevance?
Although anti-hypertension therapies are the domain of primary care physicians, because of their widespread use they are common medications for hospital patients. Previous studies have shown that nocturnal anti-hypertensive dosing improves BP control, although have not addressed major cardiac outcomes.
This 10-year, large, multicenter RCT demonstrates benefit of evening medication dosing that has implications perioperatively.
The study...
The Hygia Project randomised 19,084 patients (x̄=61y 56%♂ 34%♀) to take their anti-hypertensive medications (≥1) either at bed-time or on awakening. Patients were followed for a median 6.3 years, routinely using 48h ambulatory BP monitoring at each follow-up review.
They found that...
Patients taking anti-hypertensives in the evening experienced better BP control and 45% lower rates of major cardiovascular outcomes, including CVD death, infarct, coronary revascularisation, heart failure and stroke.
Interestingly the progressive decline in sleeping SBP during the study was the strongest predictor of cardiovascular risk, stronger than traditional risk markers such as age, gender, DM, CKD, cholesterol or even smoking!
Practice changing?
This is a significant finding from a large, high-quality study. It confirms the benefits of nocturnal dosing, also likely (though unconfirmed) to have intraoperative and perioperative benefits compared with morning dosing.
Why the fuss?
Acute renal injury is a common post-operative complication among high-risk patients and after major surgery, particularly cardiac and major vascular surgery, as is relevant to this study. The clinical relevance of ischaemic preconditioning continues to be controversial.
Even mild post-operative acute kidney injury (AKI) is associated with a wide range of poor perioperative outcomes, and current interventions have struggled to reduce such risk.
What is remote ischaemic preconditioning (RIPC)?
In an effort to protect an at-risk end organ from ischaemia (eg. heart, brain, kidneys), RIPC cyclically induces ischaemia in a remote site (typically an arm using an NIBP cuff). This activates physiological protective mechanisms against hypoxia and reperfusion injury in the target organ. It is cheap, easy and safe.
RIPC as a technique is based upon Murray’s 1986 observations of dog LAD arteries.
Although remote ischaemic (pre)conditioning has been demonstrated in animal models, human studies have been contradictory.
What was done...
This Shanghai research team randomised 130 patients undergoing open aortic arch replacement to receive either remote ischaemic preconditioning (4x 5-min-up 5-min-down) or sham preconditioning.
They found...
Fewer patients demonstrated renal injury at 7 days in the treatment group (55% vs 74%, ARR 95% CI 2-35%), in addition to shortening mechanical ventilation duration (18 vs 25 hours).
Practice changing? No
Although this study has shown a marked reduction in AKI in a uniquely very-high-risk group, as a sole small single-centered study it can barely be applied to the actual study population, let alone generalised to other high-risk groups.
Even when AKI in the control group was a massive 74%, the confidence interval for absolute risk reduction (2-35%) is so wide as to cast doubt on the credibility of this result.
Go deeper:
Meybohm (NEJM 2015), Hausenloy (NEJM 2015), and Menting (Cochrane 2017) failed to show any significant renoprotective effect from RIC in other high-risk groups.