Jugular venous vasopressin increases during carotid endarterectomy after cerebral reperfusion

Peri-Procedural Management of Hemodynamic Instability in Patients Undergoing Carotid Revascularization

Acute perioperative changes in arterial pressure occur frequently, particularly in patients with cardiovascular disease or those receiving vasoactive medications, or in relation to certain cardiovascular surgical procedures. Hemodynamic Instability (HI) are common in patients undergoing carotid revascularization because of unique patho-physiological and surgical factors. The operation, by necessity, disrupts the afferent pathway of the baroreflex, which can lead to postendarterectomy HI. Poor arterial pressure control is associated with increased morbidity and mortality after carotid revascularization, but good control of arterial pressure is often difficult to achieve in practice. The incidence, implications, and etiology of HI associated with carotid surgery are reviewed, and some recommendations made for its management. Close monitoring and titration of therapy are probably the most important considerations rather than specific choice of agents.

A rare case of neurological dysfunction due to severe hyponatremia after carotid artery endarterectomy: A review of the clinical approach to hyponatremia

Development of severe hyponatremia after carotid endarterectomy procedure is rare. Several pathophysiological mechanisms related to the carotid endarterectomy procedure may infer an increased risk of developing this complication in specific populations.

Hyponatremia accompanying volatile hypertension caused by baroreflex failure after neck surgery: case report and literature review

: The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the most common cause of euvolemic hyponatremia, and many disorders have been associated with it. Baroreflex failure is a rare disorder characterized by extreme blood pressure (BP) fluctuations, most frequently caused by neck or head trauma and irradiation. We report a case of a 48-year-old patient referred to our department for asymptomatic hyponatremia and volatile hypertension. His past medical history included nasopharyngeal carcinoma treated with surgery and bilateral neck radiation. Following the diagnostic algorithm for hyponatremia, the diagnosis of SIADH was made. Ambulatory BP monitoring revealed highly variable BP; extensive autonomic nervous system function testing suggested baroreflex-cardiovagal failure. We propose the hypothesis that not only labile hypertension because of baroreflex failure but also hyponatremia can develop as a late consequence of neck trauma and irradiation.

Inappropriate Secretion of Antidiuretic Hormone: A Rare Complication after Carotid Endarterectomy

The syndrome of inadequate secretion of the antidiuretic hormone (SIADH) is a very rare complication after carotid endarterectomy, characterized by hyponatremia, decrease of serum osmolarity as well as an increase in urinary osmolarity. We report the case of an 80-year-old woman who developed, 24 hours after the surgery, a picture of drowsiness and lethargy without neurological focality. The diagnosis of SIADH was suspected. We conclude that is important to have in mind this clinical entity in the differential diagnosis of non-focal neurological deficit after carotid endarterectomy.

Comparison of Catecholamine Hormone Release in Patients Undergoing Carotid Artery Stenting or Carotid Endarterectomy

PURPOSE

To investigate the pattern of catecholamine response in patients undergoing carotid endarterectomy (CEA) or carotid artery stenting (CAS).

METHODS

Adrenaline, noradrenaline, and renin levels were measured at 5 time points in 12 patients undergoing 13 CEAs (1 bilateral) and 13 patients undergoing unilateral CAS. Arterial blood samples were taken at the following time points: (1) after induction in CEA patients or 5 minutes following first contrast injection in CAS patients, (2) 5 minutes following ICA clamp release in surgical patients or deflation of the balloon in the CAS cohort, (3) 60 minutes following ICA clamp release in surgical patients or deflation of the balloon in the CAS cohort, and (4) 24 hours following the procedure. Intraoperative blood pressure and heart rate were recorded using radial arterial monitoring. Changes in adrenaline, noradrenaline, and renin levels are expressed as ratios versus baseline.

RESULTS

Patterns of adrenaline and noradrenaline release were significantly different in patients undergoing CAS and CEA, with much higher and more variable surges of adrenaline and noradrenaline occurring in CEA patients. Adrenaline and noradrenaline levels increased significantly over baseline following carotid artery clamping in patients undergoing CEA (noradrenaline ratio before clamping: 1.54+/-1.25, 24 hours after unclamping: 8.38+/-16.35 [p<0.001]; adrenaline ratio before clamping: 1.12+/-0.49, 60 minutes after unclamping: 17.59+/-19.14 [p<0.001]). Conversely, in patients undergoing CAS, catecholamine levels remained unchanged (noradrenaline ratio before dilation: 0.96+/-0.23, 24 hours after the procedure: 0.92+/-0.32 [p=NS]; adrenaline ratio before dilation: 0.83+/-0.33, 60 minutes after balloon deflation: 0.56+/-0.32 [p=NS]).

CONCLUSIONS

CAS is associated with a significantly less marked catecholamine response than CEA, which may reflect down-regulation of the sympathetic nervous system in response to carotid sinus stimulation during carotid angioplasty.

Unruptured intracranial aneurysms in patients with transient cerebral ischemic episodes. Optional managements and literature review

Clinical experience about the management of patients with an unruptured intracranial aneurysm (UIA) presenting transient cerebral ischemic attacks (TIAs) is usually restricted to a few case reports. Some authors assume tha it is safe to perform an endarterectomy without acutely increasing the risk of aneurysm rupture while others reported a post-operative aneurysmal bleeding even for aneurysms smaller than 10 mm between some days and several months after endarterectomy. The aim of this paper is to analyse the factors involved in the particular ischemic episodes, the examination methods to be employed, and the optional management for each individual case on a literature review and own experience-based data.

Temporary hypotension following endarterectomy for severe carotid stenosis: should we treat it?

In patients with severe carotid stenosis, the author has observed that temporary low blood pressure often occurs in the postoperative period. The hypotension typically develops 2 to 4 hours following operation, is asymptomatic, and resolves within 12-24 hours. In recent years treatment has consisted of simple observation, avoiding the use of vasopressors. Other reports of hemodynamic instability following carotid endarterectomy emphasize high blood pressure. The author rarely observes postoperative hypertension in his practice and has wondered if technical factors explain the difference. A consecutive series of primary carotid endarterectomies recently performed by the author was prospectively studied to determine the incidence of postoperative hypotension. Forty-nine of 180 consecutive patients (27%) developed hypotension below 90 mm Hg systolic (range 65-90). All had severe stenosis as an indication for operation. Only 1 patient required treatment for symptoms related to the low blood pressure. Simple observation of the remaining 48 patients with postoperative hypotension did not result in complications nor delay discharge. Data management, selection of patients, surgical technique, and results are discussed. Temporary postoperative hypotension in patients with severe carotid stenosis is common and appears to be benign. The author speculates that this phenomenon may protect ischemic brain tissue from sudden hyperperfusion, and as such should not be treated with vasopressor medication unless symptoms are present.

Hemodynamic benefits of regional anesthesia for carotid endarterectomy

OBJECTIVE

The objective of this study was to define differences in perioperative hemodynamics and associated outcomes in patients who undergo carotid endarterectomy (CEA) with regional and general anesthesia.

METHODS

All the patients who underwent CEA during a 25-month period were reviewed, with a comparison of those who underwent operation with cervical block anesthesia (CB) with those who underwent operation with general anesthetic (GA). Baseline intraoperative and postoperative blood pressure and heart rate were recorded, and deviation from initial values was calculated. The administration of vasoactive medications was assessed. Operative time, intensive care unit admission, postoperative length of stay, and cardiac/neurologic morbidity were recorded.

RESULTS

From October 16, 1998, to December 1, 2000, 550 nonemergent CEAs were performed in 527 patients (226 with CB and 324 with GA). The patients in both groups were similar in age, presentation, and associated comorbidities. Although baseline blood pressure and heart rates were similar in both groups, those patients who underwent operation with GA had significantly greater intraoperative and postoperative hemodynamic variability and received more vasoactive medications during surgery (87% versus 51%; P <.001) and in the recovery room (36% versus 21%; P =.0009). Major postoperative blood pressure derangements were more common in the GA group (18% versus 10%; P <.05). Patients who underwent operation with GA more frequently needed intensive care unit admission (16% versus 7%; P =.01) and had more frequent delays in discharge (20% versus 11%; P =.008; postoperative length of stay, 2.1 versus 1.6 days; P =.01). Although no difference was seen in neurologic morbidity rates between groups (combined major stroke/death rate, 1.8%), the major cardiac morbidity rate was noted to be lower in the CB group (1% versus 4%; P =.05). The total in-room time was shorter in the CB group (108 versus 122 minutes; P <.001).

CONCLUSION

CEA performed with CB is associated with significantly less perioperative hemodynamic instability than with GA. This results in fewer major adverse cardiac events. Ultimately, decreased critical care resource use is realized as is a shortened length of stay.

Postoperative blood pressure changes associated with cervical block versus general anesthesia following carotid endarterectomy

The purpose of this report was to determine if cervical block anesthesia (CBA) was associated with fewer hypertensive and hypotensive episodes and decreased need for ICU monitoring following carotid endarterectomy, compared with general anesthesia (GA). A retrospective review of carotid endarterectomies performed using GA (n = 118) versus CBA (n = 116) was carried out and perioperative blood pressure changes and morbidity and mortality rates were analyzed. With increasing emphasis in today's health care market concerning cost containment without sacrificing safety, our results suggest that CBA should be considered preferable to GA for patients undergoing carotid endarterectomy. Fewer significant postoperative hemodynamic changes occurred and costly intensive care monitoring may be avoided.

Hemodynamic instability after carotid endarterectomy: risk factors and associations with operative complications

OBJECTIVE

To examine the incidences of hypertension, hypotension, and bradycardia after carotid endarterectomy (CEA) and to identify any hemodynamic variables predictive of postoperative stroke, death, or cardiac complications.

METHODS

Retrospective population-based cohort study of 291 consecutive patients undergoing CEA using hospital chart review. Hemodynamic data collected from time of arrival in the recovery room until the end of the 1st postoperative day. Primary and secondary outcome events were stroke or death within 30 days of surgery and any postoperative cardiac complication (angina, congestive heart failure, dysrhythmia, or myocardial infarction), respectively.

RESULTS

The incidences of postoperative hypertension (systolic blood pressure > 220 mm Hg), hypotension (systolic blood pressure < 90 mm Hg), and bradycardia (pulse < 60 beats/min) were 9% (26 of 290 cases), 12% (36 of 290 cases), and 55% (159 of 290 cases), respectively. The stroke or death rate was 5.2% (15 of 291 cases). Postoperative hypertension was associated significantly with stroke or death (P = 0.04) and by a statistical trend with cardiac complications (P = 0.07). Independent preoperative risk factors for postoperative hypertension by multivariate analysis included angiographic intracranial carotid stenosis greater than 50%, cardiac dysrhythmia, preoperative systolic blood pressure greater than 160 mm Hg, neurological instability, and renal insufficiency. Postoperative hypotension and bradycardia did not correlate with primary or secondary outcomes.

CONCLUSION

Hemodynamic instability was commonly observed after CEA, but only postoperative hypertension was associated with stroke or death and, possibly, with cardiac complications. Patients undergoing CEA, especially those at risk for postoperative hypertension, may be monitored best in settings suited to the expeditious management of neurological and cardiovascular emergencies.