Weekly Anesthesiology Research Analysis
This week’s anesthesiology literature delivered several practice‑influencing RCTs and mechanistic studies: high‑field neuroimaging delineated drug‑specific effects of sedatives on memory and pain networks; perioperative inhaled nitric oxide reduced AKI and improved 6‑month renal function after cardiac surgery in CKD patients; and an operative hemodynamics RCT (PRESSURE) questioned routine CVP‑lowering during minimally invasive liver resection by showing no blood‑loss benefit and more instability
Summary
This week’s anesthesiology literature delivered several practice‑influencing RCTs and mechanistic studies: high‑field neuroimaging delineated drug‑specific effects of sedatives on memory and pain networks; perioperative inhaled nitric oxide reduced AKI and improved 6‑month renal function after cardiac surgery in CKD patients; and an operative hemodynamics RCT (PRESSURE) questioned routine CVP‑lowering during minimally invasive liver resection by showing no blood‑loss benefit and more instability. Methodological and meta‑research (oxygen strategy, nutrition, data conversions) and several airway and monitoring trials (videolaryngoscopy in obesity, remimazolam vs propofol respiration) together point toward more personalized, physiology‑driven perioperative care.
Selected Articles
1. Effects of Sedative Doses of Propofol, Dexmedetomidine, and Fentanyl on Memory and Pain in Healthy Young Adults: A Randomized, Controlled, Single-blind Crossover Study Using Functional Magnetic Resonance Imaging at 7 Tesla.
In a randomized, placebo‑controlled single‑blind crossover study (n=92) using 7T fMRI and concurrent painful stimulation, propofol produced the strongest impairment of next‑day recollection and reduced hippocampal/amygdala encoding activation while attenuating pain‑related insula/ACC responses. Dexmedetomidine preserved recollection and showed limited hippocampal disruption; fentanyl produced distinct effects on somatosensory and limbic activations. The study maps drug‑specific network effects relevant to intraoperative amnesia and analgesia strategies.
Impact: Mechanistic, high‑resolution neuroimaging provides empirical mapping of how common sedatives differentially affect memory encoding and pain networks, informing sedative selection when amnesia versus preserved cognition is desired.
Clinical Implications: Consider sedative choice based on desired cognitive and analgesic profiles: propofol may be preferable when robust amnesia is desired, dexmedetomidine when preserving memory is important, and fentanyl when specific nociceptive network modulation is targeted; translate findings cautiously to older/surgical populations.
Key Findings
- Propofol reduced next‑day recollection (d') and decreased hippocampus/amygdala activation during encoding.
- Dexmedetomidine preserved recollection and had limited hippocampal disruption.
- Fentanyl altered somatosensory and limbic pain/memory activations in a distinct pattern from propofol and dexmedetomidine.
2. Perioperative Nitric Oxide Conditioning Reduces Acute Kidney Injury in Cardiac Surgery Patients with Chronic Kidney Disease (the DEFENDER Trial): A Randomized Controlled Trial.
In a randomized trial of 136 CKD patients undergoing cardiac surgery with cardiopulmonary bypass, perioperative inhaled nitric oxide (80 ppm intraoperatively and for 6 h postoperatively) reduced AKI incidence at 7 days (23.5% vs 39.7%; RR 0.59) and improved 6‑month GFR, with fewer postoperative pneumonias and acceptable safety monitoring (methemoglobin/NO2).
Impact: A pragmatic pharmacologic intraoperative strategy demonstrating both early (AKI) and longer‑term (GFR) renal benefits in a high‑risk surgical population; immediately actionable where NO delivery capability exists.
Clinical Implications: Consider perioperative inhaled NO (protocolized delivery and monitoring) for CKD patients undergoing CPB to reduce AKI risk and preserve renal function, while ensuring methemoglobin/NO2 surveillance and multidisciplinary implementation.
Key Findings
- AKI incidence reduced from 39.7% (control) to 23.5% (NO); RR 0.59 (95% CI 0.35–0.99).
- 6‑month GFR higher in NO group and postoperative pneumonia less frequent with NO.
- No safety signal for methemoglobinemia, NO2 toxicity, bleeding, or transfusion differences.
3. Reduction of Central Venous Pressure in Elective Robotic and Laparoscopic Liver Resection: The PRESSURE Trial-A Randomized Clinical Study.
The PRESSURE randomized double‑blind trial (n=112) found that deliberate CVP reduction during minimally invasive liver resection did not reduce total intraoperative blood loss but increased intraoperative hemodynamic instability. Ninety‑day mortality and overall morbidity were similar between groups, suggesting routine aggressive CVP lowering in MILR may be unnecessary and potentially harmful.
Impact: Challenges a long‑standing intraoperative practice (CVP lowering for blood‑loss control in hepatectomy) with high‑quality randomized evidence, directly affecting anesthetic fluid and hemodynamic management protocols.
Clinical Implications: Avoid routine aggressive CVP‑lowering strategies during minimally invasive liver resections; prioritize hemodynamic stability and consider alternative blood‑sparing techniques that do not compromise circulation.
Key Findings
- No significant difference in total intraoperative blood loss with CVP reduction (280 mL vs 360 mL; P=0.30).
- CVP reduction increased intraoperative hemodynamic instability (30% vs 12%; P=0.03).
- 90‑day mortality and overall morbidity were similar between groups.