New research suggests the common clinical practice of elevating blood pressure for patients with acute spinal cord injury may do more harm than good.
The study, published today in the journal JAMA Network Open, involved a multicenter, randomized clinical trial of 92 patients across the country between October 2017 and July 2023. It found no difference in patients' movement or sensory scores after six months but found higher respiratory complications, longer mechanical ventilatory support and worse organ function among patients treated to augment their blood pressure in the hospital.
The study began at Oregon Health & Science University, which is among 13 large surgical centers included in the nationwide study.
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Current clinical guidance for treatment of spinal cord injury in the United States recommends augmenting blood pressure for three to seven days. The clinical guidance stands on the theory that the body's natural ability to auto-regulate blood flow to the spinal cord may be compromised after injury, said co-author Brandon Togioka, M.D., associate professor of anesthesiology and perioperative medicine in the OHSU School of Medicine.
However, the guidance was based on low-quality evidence of neurological improvement and had yet to be studied in a randomized clinical trial.
The study found that elevating blood pressure did not improve clinical outcomes.
"While this study does not support allowing patients to have low blood pressure, it does suggest that aggressively elevating blood pressure may be doing more harm than good," Togioka said.
The study's senior author is Miriam Treggiari, M.D., professor of anesthesiology in the Duke University School of Medicine. She began the project in her previous capacity as vice chair of clinical research in the Department of Anesthesiology and Perioperative Medicine in the OHSU School of Medicine.
"As an ICU physician, I've often questioned whether pushing higher blood pressure was truly helping my patients," Treggiari said. "This study was born out of that clinical concern of side effects while trying to achieve targets that may not reflect meaningful benefit."
The study involved patients 18 and older who were treated for spinal cord injuries; researchers followed them for six months afterward.
Participants were randomized into two groups: One was treated with conventional management of blood pressure, which is maintaining a mean arterial pressure, or MAP, above 65 millimeters of mercury. The other was augmented with medications to maintain a MAP of 85 to 90 millimeters of mercury for seven days, which follows the guidelines issued in 2013 by the American Association of Neurological Surgeons and the Congress of Neurological Surgeons.
Both courses of treatment resulted in no differences in pain outcomes, activities of daily living, mobility, or cardiovascular function after six months.
However, the study did find differences.
The group whose blood pressure was augmented experienced a higher rate of respiratory complications, longer duration of mechanical ventilation in the hospital and worse organ function compared with the group whose blood pressure was managed without augmentation.
Togioka said the results suggest that the body may maintain auto-regulation of blood pressure in spinal cord injuries, and therefore augmentation may not be advisable.
This work was supported by the Office of the Assistant Secretary of Defense for Health Affairs, through the Spinal Cord Research Program under Award No. W81XWH-16-1-0748. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the Department of Defense.
