The Latest In Critical Care: July 9, 2025
DNR training, early warning systems, NIV after cardiac surgery, ischemic preconditioning, O2 in trauma
In the News
CDC's Healthcare Infection Control Practices Advisory Committee (HICPAC) may be getting DOGE’d.
—from MedPage Today
Residents can be trained to obtain DNR orders more often (Swiss ones, anyway)
At six teaching hospitals in Switzerland, residents who were randomized to additional teaching and use of checklists and decision aids (vs. no extra training) had a significantly higher rate of obtaining DNR status in their patients (50% vs. 37%). Patients were more confident in their code status decisions when counseled by the up-trained residents, and also scored higher on an assessment of their knowledge about resuscitation.
The high rates of DNR obtained in the study highlight the large cultural differences between Switzerland and the U.S., where as few as 7% of ICU patients have a DNR order. If you’re interested in learning more about their teaching process, the corresponding author is Dr. Sabina Hunziker (sabina.hunziker@usb.ch).
—Becker et al, NEJM Evidence April 2025
Patients flagged as deteriorating by nurses+AI have better outcomes
Columbia U. implemented an early warning system, called COmmunicating Narrative Concerns Entered by RNs (CONCERN), which integrates nursing assessments with a machine learning algorithm to update estimated patient risk for deterioration on an hourly basis. As they rolled it out in a cluster-randomized fashion at 74 units in two health systems, the patients flagged by the system had much lower risk of death, ICU transfer, or sepsis.
—Rosetti et al, Nature Medicine, April 2025
Perioperative positive pressure ventilation to reduce respiratory failure after cardiac surgery
Among 216 patients undergoing cardiac surgery at a single center in France, those randomized to noninvasive ventilation before and after surgery had lower rates of cardiorespiratory failure (predefined or adjudicated) or respiratory failure at one month. However, there was no difference in intubation rates.
Similarly, among 407 patients with postoperative respiratory failure after cardiac surgery, those randomized to CPAP had lower rates of intubation in the first 48 hours, but no difference in intubation rates at 28 days.
—Pasero et al, European J of Anesthesiology,June 2025
Ischemic preconditioning or nitric oxide to prevent AKI after cardiac surgery
A preoperative controlled ischemic insult to a remote tissue bed can prime the kidneys to tolerate the reperfusion injury after cardiac bypass better, multiple small studies suggest.
The ischemic challenge has most commonly been performed by compressing an arm or a leg with a blood pressure cuff for a long period of time. We reviewed that literature here:
Does squeezing an arm really hard improve outcomes after cardiac surgery?
Cardiopulmonary bypass (CPB) for cardiac surgery induces ischemic injury throughout the body, but especially in the kidneys. Acute kidney injury occurs in up to a third of patients undergoing CPB.
Another strategy to pretreat with nitric oxide, theoretically promoting vasodilation and protecting endothelium.
In the DEFENDER randomized trial of 136 patients with chronic kidney disease undergoing elective cardiac surgery with bypass, those treated with 80 ppm nitric oxide during and after surgery had a 24% incidence of AKI, compared to 40% not receiving NO. Improvement in creatinine clearance persisted after six months of follow-up.
A 2022 RCT by some of the same authors had similar positive results, as did a 2022 RCT.
Remote ischemic preconditioning was shown not to reduce rates of MI or improve other measured outcomes in the PRINCE trial.
—Kamenshchikov et al, Anesthesiology 2025
Targeting normoxemia in trauma patients (SAVE O2 trial)
Among 12,487 trauma patients at 8 U.S. centers randomized to either targeted SpO2 90-96% (normoxemia) or usual care, hyperoxemia was reduced without apparent harm.
The results are concordant with the large (and enlarging) signal that targeting low-normal oxygenation is the rational course for most critically ill patients.
Is higher or lower oxygenation better in critical illness? Let's settle this (Review)
This post is long with multiple forest plots and tables. If you’re reading this in an email, click the title to view it on pulmccm.org or in the Substack app for a better experience. —Ed.
Very large multicenter trials are underway to identify any subgroup of patients that might benefit from higher oxygen targets.
UK-ROX, recently reported, found no difference in mortality between conservative and liberal oxygen strategies.
—Douin et al, JAMA Network Open 2025
Physiology Flashback:
ICU Physiology in 1000 Words: Airway Pressure Release Ventilation – Part 1
Jon-Emile S. Kenny MD [@heart_lung]
