Daily Anesthesiology Research Analysis
Two high-quality randomized trials and a translational device study reshape perioperative hemodynamic management. Aggressive mean arterial pressure augmentation showed no benefit in acute spinal cord injury or major abdominal surgery, while targeted epidural spinal cord stimulation restored blood pressure stability after spinal cord injury and improved quality of life.
Summary
Two high-quality randomized trials and a translational device study reshape perioperative hemodynamic management. Aggressive mean arterial pressure augmentation showed no benefit in acute spinal cord injury or major abdominal surgery, while targeted epidural spinal cord stimulation restored blood pressure stability after spinal cord injury and improved quality of life.
Research Themes
- Perioperative hemodynamic targets and outcomes
- Neurostimulation for autonomic dysfunction after spinal cord injury
- Evidence-based blood pressure management in high-risk surgery
Selected Articles
1. An implantable system to restore hemodynamic stability after spinal cord injury.
This translational study introduces a purpose-built epidural spinal cord stimulation system that targets the last three thoracic segments to regulate blood pressure after SCI. In 14 participants, the system rapidly stabilized blood pressure, reduced chronic hypotensive complications, eliminated the need for conservative measures, and improved quality of life and daily function.
Impact: Provides first-in-human evidence that targeted thoracic EES can safely regulate blood pressure after SCI with meaningful functional benefits, defining an anatomical target and a path to pivotal trials.
Clinical Implications: For refractory hypotensive complications after SCI, targeted thoracic (last three segments) epidural stimulation may become a therapeutic option, potentially replacing or reducing conservative pharmacologic measures and improving quality of life.
Key Findings
- In 1,479 participants, chronic hypotensive complications after SCI impose a substantial clinical burden and are poorly controlled by conservative care.
- A purpose-built epidural stimulation system targeting the last three thoracic segments elicited immediate pressor responses and stabilized blood pressure.
- In 14 treated participants, the system reduced hypotensive complication severity, eliminated the need for conservative treatments, and improved quality of life and daily activities.
- Head-to-head testing showed thoracic (not lumbosacral) stimulation is required for safe and effective blood pressure regulation.
Methodological Strengths
- Translational design integrating large-scale epidemiology with first-in-human interventional testing
- Within-participant head-to-head mapping of stimulation targets defining precise thoracic segmental specificity
Limitations
- Small interventional cohort (n=14) without randomization or blinded comparator
- Duration of follow-up and long-term safety not specified in the abstract; generalizability requires larger trials
Future Directions: Conduct pivotal randomized or controlled device trials to confirm efficacy and safety, optimize stimulation parameters, and assess durability, patient selection, and integration with rehabilitation.
A spinal cord injury (SCI) causes immediate and sustained hemodynamic instability that threatens neurological recovery and impacts quality of life. Here we establish the clinical burden of chronic hypotensive complications due to SCI in 1,479 participants and expose the ineffective treatment of these complications with conservative measures. To address this clinical burden, we developed a purpose-built implantable system based on biomimetic epidural electrical stimulation (EES) of the spinal cord that immediately triggered robust pressor responses. The system durably reduced the severity of hypotensive complications in people with SCI, removed the necessity for conservative treatments, improved quality of life and enabled superior engagement in activities of daily living. Central to the development of this therapy was the head-to-head demonstration in the same participants that EES must target the last three thoracic segments, and not the lumbosacral segments, to achieve the safe and effective regulation of blood pressure in people with SCI. These findings in 14 participants establish the path to designing a pivotal device trial that will evaluate the safety and efficacy of EES to treat the underappreciated, treatment-resistant hypotensive complications due to SCI.
2. Early Blood Pressure Targets in Acute Spinal Cord Injury: A Randomized Clinical Trial.
In this multicenter RCT of 92 acute SCI patients, targeting augmented MAP (>85–90 mm Hg) for 7 days did not improve 6-month ASIA motor or sensory recovery compared with conventional MAP targets (>65–70 mm Hg). Augmented MAP increased organ dysfunction scores, respiratory complications, and duration of mechanical ventilation without mortality benefit.
Impact: Challenges a widely adopted practice of aggressive MAP augmentation in acute SCI by showing no neurologic benefit and increased complications.
Clinical Implications: Routine aggressive MAP augmentation after acute SCI should be reconsidered; conventional targets (≥65–70 mm Hg) may suffice for many patients, and clinicians should weigh risks of organ dysfunction and respiratory complications when using vasopressors.
Key Findings
- No significant differences in 6-month ASIA upper or lower extremity motor score changes between augmented and conventional MAP targets.
- Augmented MAP increased non-cardiovascular SOFA scores at days 3 and 6, prolonged mechanical ventilation, and raised respiratory complication rates.
- No mortality difference was observed between groups.
- Trial underpowered but provides the first randomized evidence questioning MAP augmentation practice after acute SCI.
Methodological Strengths
- Multicenter randomized design with protocolized MAP targets
- Clinically meaningful neurologic endpoints (ASIA scores) and comprehensive safety outcomes
Limitations
- Underpowered with substantial attrition (few survivors completed 6-month follow-up)
- Inability to blind hemodynamic targets; potential confounding by vasopressor choice and injury heterogeneity
Future Directions: Identify subgroups who may benefit from higher MAP (e.g., specific injury levels or perfusion phenotypes), elucidate mechanisms of harm, and conduct adequately powered RCTs.
IMPORTANCE: Early blood pressure management is central to neurologic resuscitation of spinal cord injury; however, the role of augmented blood pressure is unclear. OBJECTIVE: To compare the efficacy and safety of augmented vs conventional blood pressure on 6-month neurologic outcomes after acute spinal cord injury. DESIGN, SETTING, AND PARTICIPANTS: This multicenter randomized clinical trial took place from October 3, 2017, to July 26, 2023, and assessed patients 18 years or older with spinal cord injury followed up for 6 months at 13 large US trauma centers. INTERVENTIONS: Patients were equally randomized to augmented (>85-90 mm Hg) or conventional (>65-70 mm Hg) mean arterial pressure for 7 days or until intensive care unit discharge. MAIN OUTCOMES AND MEASURES: Primary end points were change in motor and sensory American Spinal Injury Association Impairment Scale scores from baseline to 6 months. Safety end points included organ dysfunction and complications. RESULTS: The trial randomized 92 patients (mean [SD] age, 53.78 [18.74] years; 76 [83%] male). At 6 months, 38 patients had completed follow-up and 15 had died. Among survivors, there were no mean (SD) differences in change from baseline in upper extremity motor scores (34.95 [3.25] vs 32.95 [3.65]; difference, 2.48; 95% CI, -5.93 to 10.90; P = .55), lower extremity motor scores (18.53 [4.62] vs 19.95 [4.59]; difference, -4.56; 95% CI, -16.11 to 7.03; P = .43), or total sensory scores (108.47 [12.49] vs 130.89 [14.87]; difference, -32.00; 95% CI, -65.40 to 1.40; P = .06) comparing the augmented and conventional groups. The augmented group had higher mean (SD) modified Sequential Organ Failure Assessment scores (excluding cardiovascular components) at day 3 (1.65 [1.79] vs 0.80 [1.10]; difference, 0.85; 95% CI, 0.23-1.47; P = .008) and day 6 (1.55 [1.82] vs 0.80 [1.35]; difference, 0.74; 95% CI, 0.05-1.44; P = .04), longer mechanical ventilatory support (9.44 [15.27] vs 3.78 [8.42] days; difference, 5.67 days; 95% CI, 0.48-10.85 days; P = .03), and more respiratory complications (36 [78%] vs 18 [39%]; risk difference, 40%; 95% CI, 22%-58%; P < .001) than the conventional group. No differences in mortality or other secondary outcomes were observed. CONCLUSIONS: Although underpowered, this randomized clinical trial of patients with spinal cord injury did not demonstrate better neurologic recovery comparing early augmented and conventional blood pressure and calls this practice into question. Further study is needed to identify groups who may benefit from augmenting blood pressure and determine potential harm mechanisms. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02878850.
3. Intensive vs Conventional Intraoperative Blood Pressure Management on Cardiovascular Events After Major Abdominal Surgery: The BP-CARES Randomized Trial.
In 1,477 high-risk adults undergoing major abdominal surgery, targeting intraoperative MAP ≥80 mm Hg reduced hypotension exposure but did not lower the 30-day composite of cardiovascular events compared with a conventional target (≥65 mm Hg or ≥60% baseline). Findings support conventional thresholds for many patients.
Impact: Provides large randomized evidence that higher intraoperative MAP targets do not translate into fewer cardiovascular events despite reducing hypotension exposure.
Clinical Implications: Conventional MAP targets (≥65 mm Hg or ≥60% of baseline) appear sufficient for many high-risk abdominal surgery patients; individualized targets should balance hypotension avoidance with vasopressor-related risks.
Key Findings
- Randomized 1,477 adults to intensive (MAP ≥80 mm Hg) vs conventional (MAP ≥65 mm Hg or ≥60% baseline) intraoperative targets.
- Intensive strategy reduced hypotension exposure (e.g., median duration of MAP <65 mm Hg: 1 vs 8 minutes) but did not reduce 30-day cardiovascular complications (14.5% vs 13.6%; RR 1.07; P=0.61).
- Supports conventional MAP thresholds for perioperative care in major abdominal surgery.
Methodological Strengths
- Investigator-initiated multicenter RCT with large sample and mITT analysis
- Clinically relevant composite cardiovascular endpoint with standardized MAP protocols
Limitations
- Conducted at three sites in China, which may limit generalizability to other settings
- Open-label hemodynamic management; potential confounding from anesthetic/vasopressor choices
Future Directions: Define patient subgroups that may benefit from individualized higher targets (e.g., severe coronary disease, chronic hypertension) and integrate continuous perfusion metrics to refine thresholds.
BACKGROUND: Intraoperative hypotension is associated with cardiovascular complications after major noncardiac surgery, but randomized trials assessing whether intensive blood pressure management during surgery can reduce these complications have shown inconsistent results. OBJECTIVES: The purpose of this study was to determine whether intensive intraoperative blood pressure management reduces the incidence of a composite of cardiovascular complications within 30 days after major abdominal surgery. METHODS: In this investigator-initiated parallel-group trial, patients at 3 Chinese sites were randomly assigned (1:1) to intensive blood pressure management targeting intraoperative MAP ≥80 mm Hg (intensive strategy group) or conventional management targeting intraoperative MAP ≥ the higher of 65 mm Hg or 60% of preoperative baseline pressure (conventional strategy group). We included patients aged ≥45 years who had known cardiovascular disease or cardiovascular risk factors and were scheduled for inpatient abdominal surgery expected to last at least 2 hours. The primary outcome was a composite of myocardial injury or infarction, new-onset clinically important arrhythmias, acute heart failure, stroke, cardiac arrest, and all-cause death within 30 days of surgery. RESULTS: Between June 30, 2020, and September 23, 2022, 1,500 patients were enrolled, of whom 1,477 were included in the modified intention-to-treat population (739 in the intensive strategy group and 738 in the conventional strategy group). Patients assigned to intensive intraoperative blood pressure management experienced a lower burden of hypotension exposure, as assessed by several measures. For example, the median cumulative duration of MAP <65 mm Hg was 1 minute (Q1-Q3: 0-7 minutes) in the intensive strategy group, compared with 8 minutes (Q1-Q3: 0-20 minutes) in the conventional strategy group. The primary composite outcome occurred in 107 of 739 patients (14.5%) in the intensive strategy group and 100 of 738 patients (13.6%) in the conventional strategy group (relative risk: 1.07; 95% CI: 0.83-1.38; P = 0.61). CONCLUSIONS: In high-risk patients having major abdominal inpatient surgery, intensive intraoperative blood pressure management targeting a mean arterial pressure ≥80 mm Hg did not reduce the incidence of cardiovascular events compared with the conventional target of ≥65 mm Hg and 60% of the preoperative baseline.