Blood Pressure and End-tidal Carbon Dioxide Ranges during Aneurysm Occlusion and Neurologic Outcome after an Aneurysmal Subarachnoid Hemorrhage

Abstract

EDITOR’S PERSPECTIVE What We Already Know about This Topic It remains unknown what end-tidal carbon dioxide and mean arterial pressure are optimal for surgical management of patients with an aneurysmal subarachnoid hemorrhage What This Article Tells Us That Is New The investigators retrospectively evaluated 1,099 patients who had endovascular coiling or surgical clipping for subarachnoid hemorrhages There were no clinically important or statistical significant associations between either end-tidal carbon dioxide or mean arterial pressure thresholds and Glasgow Outcome Scale at discharge or three months Other prognostic factors are more important than carbon dioxide and blood pressure, at least within the observed clinical ranges Background Hypocapnia, hypotension, and hypertension during aneurysm occlusion in patients with an aneurysmal subarachnoid hemorrhage may lead to a poor prognosis, but evidence for end-tidal carbon dioxide (ETco2) and mean arterial pressure (MAP) targets is lacking. Within the ranges of standardized treatment, the authors aimed to study the association between hypocapnia (Paco2 < 35 mmHg), hypotension (MAP < 80 mmHg), and hypertension (MAP >100 mmHg) during general anesthesia for aneurysm occlusion and neurologic outcome. Methods This retrospective observational study included patients who underwent early aneurysm occlusion after an aneurysmal subarachnoid hemorrhage under general anesthesia. ETco2 and MAP were summarized per patient as the mean and time-weighted average area under the curve for various absolute (ETco2 < 30, < 35, < 40, < 45 mmHg; and MAP < 60, < 70, < 80, > 90, > 100 mmHg) and relative thresholds (MAP < 70%, < 60%, < 50%). Clinical outcome was assessed with the Glasgow Outcome Scale at discharge and at three months, as primary and secondary outcome measure, respectively. Results Endovascular coiling was performed in 578 patients, and 521 underwent neurosurgical clipping. Of these 1,099 patients, 447 (41%) had a poor neurologic outcome at discharge. None of the ETco2 and MAP ranges found within the current clinical setting were associated with a poor neurologic outcome at discharge, with an adjusted risk ratio for any ETco2 value less than 30 mmHg of 0.95 (95% CI, 0.81 to 1.10; P < 0.496) and an adjusted risk ratio for any MAP less than 60 mmHg of 0.94 (95% CI, 0.78 to 1.14; P < 0.530). These results were not influenced by preoperative neurologic condition, treatment modality and timing of the intervention. Comparable results were obtained for neurologic outcome at three months. Conclusions Within a standardized intraoperative treatment strategy in accordance with current clinical consensus, hypocapnia, hypotension, and hypertension during aneurysm occlusion were not found to be associated with a poor neurologic outcome at discharge in patients with an aneurysmal subarachnoid hemorrhage.

Appropriate Blood Pressure in Cerebral Aneurysm Clipping for Prevention of Delayed Ischemic Neurologic Deficits

“…Regarding ETCO 2 , we found no statistically significant difference between the DNID and non-DNID groups (p > 0.05). Our ETCO 2 result was similar to Akkermans et al [6] that showed no association between ETCO 2 and the development of DNID with an adjusted risk ratio of 0.95 (95% CI 0.81-1.10; p < 0.496) for ETCO 2 less than 30 mmHg. However, the lowest point of ETCO 2 in our study is observed at 27 mmHg that yields a sensitivity of 78.6% and specificity of 35.7%.…”

“…However, recommendations for the target point of appropriate blood pressure during surgery vary [2]. However, in contrast to that mentioned above, a recent retrospective observational study found that hypotension and hypertension during aneurysm occlusion were not associated with a poor neurological outcome in aneurysmal subarachnoid hemorrhage patients [6]; therefore, this issue remains controversial. In addition, hypocapnia is another factor that may induce cerebral vasoconstriction and causing brain ischemia [7].…”

High-normal PaCO2 values might be associated with worse outcome in patients with subarachnoid hemorrhage – a retrospective cohort study

“…Consequently, it is plausible that high-normal P a CO 2 values may have a different effect on outcome than lownormal values. Another recent study focused on endtidal CO 2 values during the coiling or clipping procedure and found no association with clinical outcome [24]. The results of this study imply that P a CO 2 values might have to be studied for a longer period of time and not only for the time of intervention / surgery.…”

Effect of intraoperative intravenous lignocaine infusion on the haemodynamic stability and postoperative recovery following intracranial aneurysm surgery: A case series

“…demonstrate the importance of a standardised intraoperative blood pressure management with regards to the postoperative neurological outcome in their recent retrospective observational study. [ 12 ]…”