Mark Giles, DNP, CRNA is a 2016 graduate of Quinnipiac University, Hamden, Connecticut, post master's program. He is a staff CRNA at Yale New haven Hospital, New Haven, Connecticut, and an adjunct faculty member at Quinnipiac University.
General Anesthesia versus Conscious Sedation for treatment of acute ischemic stroke with Intra-arterial mechanical thrombectomy: A Case Report
Abstract: Patients with acute ischemic stroke are treated with several standard-operating principles. The primary goal is to lyse the clot via intravenous fibrinolysis or intra-arterial method to re-establish blood flow in the blocked territory. Current protocols states intra-venous tissue plasminogen activator (IV TPA) should be given within 4.5 hours of stroke onset. Early revascularization has been associated with improved prognosis, and several techniques allow for mechanical removal of the thrombus. Several retrospective studies have noted differences in outcomes in patients receiving general anesthesia versus conscious sedation. Anesthesia providersí awareness of these differences is imperative for better patient outcomes.
Key Words: intra-arterial thrombectomy, general anesthesia, conscious sedation, patient outcomes, acute ischemic stroke.
Patients presenting with acute ischemic stroke (AIS) must be treated sooner rather than later if we want to see good functional outcomes. The ischemic stroke can be medically treated by lysing the clot via intravenous fibrinolysis or removal of the clot through an intra-arterial method to re-establish blood flow to the blocked vessel. The management of AIS has evolved over the last decade using IV TPA, however, a significant number of patients have failed this treatment or have a contraindication for its use. Intra-arterial mechanical thrombectomy was developed to endovascularly remove larger clots thus improving revascularization. Initially, these procedures were performed under general anesthesia, but recent publications
of conscious sedation anesthesia have shown improved clinical outcomes. Treatment factors such as hypotension and hypertension (systolic blood pressure less than 140 mmHg or greater than 180 mmHg), as well as keeping the patient very still during the procedure have influenced the controversy of the anesthesia technique. Neuroradiologists in favor of general anesthesia site the benefits of patient immobility, potential neuroprotection from inhaled anesthetics, control of blood pressure, and better mapping of images. Those in favor of conscious sedation site the benefits of monitoring the patientsí neurologic status during the procedure, as well as the early alert of an intracranial bleed. Davis et al (2012) found the association between general anesthesia (GA) and poor outcomes to be high, with 15% of GA patients having a probability of good outcomes compared with 60% in conscious sedation (CS). Several other retrospective and meta-analysis studies have concluded CS to be associated with lower mortality, improved functional outcome, decreased respiratory issues, and better revascularization compared to GA. A task force for the Society for neuroscience in Anesthesiology and Critical Care (SNACC) published a paper on this subject stating, ďthe choice of anesthetic technique and pharmacological agents should be individualized based on clinical characteristics of each patientĒ. When patients present who are uncooperative, agitated, or cannot protect their own airway, GA is the preferable choice. The posterior circulation stroke victim usually presents in this fashion. Anterior circulation stroke victims usually present with an intact airway, and are cooperative which makes CS feasible, but the anesthesia provider must always be prepared to convert to GA if necessary.
A 47-year-old man presented to a local hospital emergency room complaining of severe headache and left sided weakness. His wife around 10:40am picked up the patient from work. During the drive home, he developed an acute onset of left sided weakness and a severe headache. He was driven to the hospital. On admission, he stated a headache x 3 days, which was bitemporal but now, feels the pain behind his eyes. Vital signs in the emergency department were: B/P 128/84, pulse 90, RR 16, temp. 97.0, SpO2 97% on room air. His medical history included Helicobacter Pylori (H. pylori) infection, migraines, motor vehicle accident, stab wound to the neck in 7/15, former smoker (quit 11/22/15), former cocaine abuse (quit 10 years ago). A CT scan was performed which showed right middle cerebral artery (MCA) territory hypo density, CTA with filling defect in right M2 (M2 extending anteriorly on the insula, also known as the insular segment). His National Institutes of Health Stroke Scale (NIHSS) score was 14 on a scale of 0-42. TPA was given at 11:41am and he was then transferred to a local university hospital, which functions as a stroke code center. On arrival to the university hospital his NIHSS score was 9.
Upon arrival, a MRI was performed which showed a clot in the M1 (also known as the sphenoidal segment), M2 bifurcation. A stroke code was called and the patient was taken to Interventional Radiology (IR). Patient was seen and examined by anesthesia. A review of the systems yielded an awake, alert, and oriented to person, place, and time. He was noted to have left sided weakness in his hand and leg. All other physical examinations were within normal limits. He was
classified as an ASA class 3. The anesthesia care plan was for conscious sedation with general anesthesia as a backup. The emergency department performed blood typing and screening. A discussion with the neuro radiologist and the anesthesia team was performed stating to keep the patients SBP between 140-180.
The patient was transferred to the operating table. A 16-gauge IV catheter was already in place in the left ante cube, a right lateral arm 20-gauge IV, and an 18-gauge IV was placed in the right hand. The patientís hands were secured with wrist restraints, and his head was taped to the bed. The procedure was explained to the patient who verbalized understanding. During the two and half hour procedure, he received a total of 200mcg of fentanyl, versed 2mg, labetolol 15mg, zofran 4mg, lactated ringers solution 600ml, and nasal cannula 02 at 3L. During the entire procedure, a second neuro radiologist was present who performed neuro checks every 10-15 minutes. The patientís hemodynamic status was stable with blood pressures ranging from 138/76- 190/99. During the brief period of his SBP being greater than 180, labetolol was given. During the last 10 minutes of the procedure the patient became agitated and wanted to move. Staff members were able to talk to him and he calmed down. A 1cm clot was removed from the distal M1, M2 bifurcation at 18:45. The time to recanalization was 8 hours. At the end of the case the neuro radiologist did a thorough exam, which continued to show left sided weakness. The patient was transferred to the neuro intensive care unit (NICU).
The hospital course was unremarkable and the patient was discharged to home on 1/22/16 with out patient physical therapy and occupational therapy. A 24-hour post tPA CT of the head showed no hemorrhagic transformation, and a repeat MRI/MRA of the brain showed evolution of his previous stroke. At discharge patient was noted to have left pronator drift, and was unable to perform left fine finger movements. On 2/8/16 patient was discharged from PT and OT with complete resolution of all deficits.
The therapeutic reference for acute ischemic stroke is intravenous thrombolysis with tPA within 4.5 hours of stroke onset according to the National Stroke Association. When the occluded artery is large or proximal tPA may not always work and recanalization is highly correlated with the patientís prognosis. Endovascular techniques have been developed to mechanically remove the clot, thus restoring blood flow. Intra-arterial thrombectomy (IAT) have been performed under general anesthesia as well as conscious sedation with varying degrees of results. A 36 patient study by Soize, et al. 2013 showed mechanical thrombectomy while under CS (86.1%) is associated with a high percent of good functional outcomes at 3 months. There are a number of potential complications that may occur during this procedure. The most serious and feared is symptomatic intra-cerebral hemorrhage. Others are vessel perforation, arterial dissection, and issues with the groin access site. There is a paucity of literature directly looking at the various products on the market that is used for the procedure. A retrospective study of 190 patients by John et al. 2014 showed GA being associated with poorer outcomes and higher mortality in patients undergoing IAT. Many of the studies identified limitations to their findings such as patient level of conscious at presentation, retrospective, selection bias, and the particular device used to remove the clot.
In this case, the patientís initial presentation of awake, alert and the ability to protect his own airway made him an ideal candidate for CS. The activation of the stroke code and staff members working quickly to stabilize the patient are key factors in getting the patient to IR for clot removal. The importance of communication between the neuro radiologist and the anesthesia team played a critical role in a favorable outcome for this patient. Anesthesia providers will always have a major place in stroke code therapy by choosing the most appropriate and least harmful anesthesia to patients with acute stroke treated by mechanical thrombectomy. Further studies comparing general anesthesia versus conscious sedation on patient outcomes would be useful.
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Soize, S., Kadziolka, K., Estrade, L., Serre, I., Bakchine, S., & Pierot, L. (2013). Mechanical thrombectomy in acute stroke: Prospective pilot trial of the solitaire FR device while under conscious sedation. AJNR.American Journal of Neuroradiology, 34(2), 360-365. doi:10.3174/ajnr.A3200 [doi]