Perioperative Care of Patients at High Risk for Stroke During or After Non-cardiac, Non-neurological Surgery: 2020 Guidelines From the Society for Neuroscience in Anesthesiology and Critical Care.

Perioperative stroke is associated with considerable morbidity and mortality. Stroke recognition and diagnosis are challenging perioperatively, and surgical patients receive therapeutic interventions less frequently compared with stroke patients in the outpatient setting. These updated guidelines from the Society for Neuroscience in Anesthesiology and Critical Care provide evidence-based recommendations regarding perioperative care of patients at high risk for stroke. Recommended areas for future investigation are also proposed.

Timing and Risk Factors Associated With Postoperative Stroke in Vascular Surgery Patients Using Time-Varying Coefficients From a Cox Model.

BACKGROUND: Mechanisms of postoperative stroke are poorly understood, particularly for strokes occurring after uneventful emergence from anesthesia. We sought to create a model to study retrospectively the timing and associations for stroke in a high-risk surgery population. METHODS: Using a large prospective database containing detailed information on the occurrence and timing of stroke, we identified patients undergoing procedures involving the distal vascular (DV) and the cerebral vascular (CV) to assess the association between perioperative factors and stroke. We used separate Cox regressions with time-varying coefficients, one for each cohort, to assess the association between baseline factors and the timing of postoperative stroke within the DV and CV cohorts. Using time-varying coefficients allows hazard ratios to vary over time rather than assuming that the hazard ratio remains constant with time. Propensity score matching was used to compare the timing of stroke between DV and CV groups. RESULTS: Among the 80,185 patients with qualifying procedures, there were 711 strokes (0.9%) in the first 30 days after surgery. Stroke incidence was lower for DV patients (0.5%, 306/57,553; P < .001) than CV (1.8%, 405/21,940) and the majority of strokes in the DV group were delayed, occurring between postoperative (POD) days 2 and 30 (236/306, 77%). Among the 711 patients who had a stroke, the proportion of strokes that occurred on day 0 was 8% (n = 24 of 306 strokes) in the DV group compared to 35% in the CV group (n = 140 of 405 strokes). Factors associated with stroke on POD 1 for both groups were preoperative mechanical ventilation and emergent procedures. Acute renal failure and female sex were highly associated with delayed stroke (POD 2-30). Perioperative blood transfusion was associated with an increased hazard of delayed stroke in the DV group and a hazard ratio that increased with time in the CV group. CONCLUSIONS: After adjusting for confounding, stroke was more common and occurred earlier in the CV group. Factors associated with delayed postoperative stroke include acute renal failure, emergent procedures, female sex, preoperative mechanical ventilation, and perioperative transfusion.

Perioperative care of patients at high risk for stroke during or after non-cardiac, non-neurologic surgery: consensus statement from the Society for Neuroscience in Anesthesiology and Critical Care*.

Perioperative stroke can be a catastrophic outcome for surgical patients and is associated with increased morbidity and mortality. This consensus statement from the Society for Neuroscience in Anesthesiology and Critical Care provides evidence-based recommendations and opinions regarding the preoperative, intraoperative, and postoperative care of patients at high risk for the complication.

Incidence, predictors, and outcomes of perioperative stroke in noncarotid major vascular surgery.

BACKGROUND: Perioperative stroke is a potentially catastrophic complication of surgery. Patients undergoing vascular surgery suffer from systemic atherosclerosis and are expected to be at increased risk for this complication. We studied the incidence, predictors, and outcomes of perioperative stroke after noncarotid major vascular surgery using the American College of Surgeons National Quality Improvement Program database. METHODS: Forty-seven thousand seven hundred fifty patients undergoing noncarotid vascular surgery from 2005 to 2009 at nonVeterans Administration hospitals were identified from the American College of Surgeons National Quality Improvement Program database. An analysis of patients undergoing elective lower extremity amputation, lower extremity revascularization, or open aortic procedures was performed to determine the incidence, independent predictors, and 30-day mortality of perioperative stroke. RESULTS: The overall incidence of perioperative stroke within 30 days of surgery (n=37,927) was 0.6%. Multivariate analysis revealed that each 1-year increase in age [odds ratio 1.02, 95% confidence interval (CI) (1.01 to 1.04)], cardiac history [1.42, (1.07 to 1.87)], female sex [1.47, (1.12 to 1.93)], history of cerebrovascular disease [1.72, (1.29 to 2.29)], and acute renal failure or dialysis dependence [2.03, (1.39 to 2.97)] were independent predictors of stroke. Only 15% (95% CI, 11%-20%) of strokes occurred on postoperative day 0 or 1. Perioperative stroke was associated with a 3-fold increase in 30-day all-cause mortality [3.36, (1.77 to 6.36)] and an increased median surgical length of stay from 6 (95% CI, 2 to 28) to 13 (95% CI, 3 to 43) days (P<0.001, WMWodds 2.5, 95% CI, 2.0 to 3.2) in a matched-cohort assessment. CONCLUSION: Perioperative stroke is an important source of morbidity and mortality, as reflected by significant increases in median surgical length of stay and all-cause 30-day mortality. The independent predictors of stroke that we have identified in this population are not readily modifiable and the majority of strokes occurred after postoperative day 1. Additional studies are required to identify potentially modifiable intraoperative or postoperative risk factors of perioperative stroke.

Cerebral perfusion pressure below 60 mm Hg is common in the intraoperative setting.

BACKGROUND: Maintaining adequate cerebral perfusion pressure (CPP) is of clinical concern in patients with neurological injury. Although there are extensive data on CPP in the ICU setting, there has been little quantitative study of CPP in the intraoperative setting. METHODS: We retrospectively analyzed the electronic intraoperative records of neurosurgical and trauma patients with concurrent intracranial and arterial pressure monitoring devices in continuous use for ≥45 minutes to calculate CPP (=mean arterial pressure-intracranial pressure). We assessed the total minutes and frequency of 5-minute epochs, during which the median CPP was <60 mm Hg, and the associated risk factors. RESULTS: A total of 155 trauma and neurosurgical patients were studied. In the neurosurgery cohort (n=88), 74% had at least one 5-minute epoch during which the median CPP was <60 mm Hg and the median total minutes of CPP<60 mm Hg was 39 [interquartile range (67), length of surgery 274 (300) min]. In the trauma cohort (n=67), 82% had at least one 5-minute epoch of <60 mm Hg, and the median total minutes CPP of <60 mm Hg was 35 [(59), length of surgery 159 (160) min]. For the entire cohort (n=155), patients with CPP<60 mm Hg were found to have higher intracranial pressure compared with patients with CPP≥60 mm Hg (P<0.001). Unlike the neurosurgical cohort, trauma patients with CPP<60 mm Hg had a greater frequency of episodes of mean arterial pressure <70 mm Hg (P=0.001). CONCLUSIONS: CPP<60 mm Hg is common in the intraoperative setting of a tertiary medical center in 2 different surgical populations with intracranial pathology. Prospective studies of intraoperative CPP and neurological outcomes are warranted.

Fatal case of intracerebral hemorrhage during gamma knife treatment for metastases.

This case report presents a patient suffering acute fatal intracranial-intratumoral hemorrhage during a gamma knife treatment session. Acute hemorrhage during a radiosurgery session is extremely rare and a plausible cause for this case is discussed along with a literature review of previously reported incidents. The patient was a 71-year-old male presenting with three large intracranial lesions and an underlying primary renal cell carcinoma malignancy. Because of a severe kyphotic deformity resulting from ankylosing spondylitis, the patient was placed in a moderate Trendelenburg position to allow his head to fit into the gamma knife unit during the radiosurgery session. The two left-sided lesions were to be treated with 20 Gy to the 50% isodose line, and the right-sided lesion with 16 Gy to the 40% isodose line. Anesthesia was available throughout the treatment session to aid with pain control. The gamma knife treatment was aborted because the patient suffered a generalized seizure while in the unit. Immediate head CT of the patient revealed large acute hemorrhages into all three intracranial masses. This proved to be a fatal complication. It is likely that this positioning contributed to the hemorrhage. The clinical history of this patient is provided as well as a review of the literature on acute intracranial hemorrhage associated with radiosurgical therapy.