Journal of Postgraduate Medicine Medknow Publications and Staff Society of Seth GS Medical College and KEM Hospital, Mumbai, India ISSN: 0022-3859 EISSN: 0972-2823 Vol. 48, Num. 3, 2002, pp. 240-241

Journal of Postgraduate Medicine, Vol. 48, Issue 3, 2002 pp. 240-241

Letter to the Editor

Anaesthetic Management of Clip Ligation of Ruptured Intracranial Aneurysm Associated with Coarctation of Aorta

Sherke R, Yemala R, Srinivas M, Panigrahi M¹

Department of Anaesthesiology and Intensive Care, Department of Neurosurgery¹, Nizam's Institute of Medical Sciences, Hyderabad, India. E-mail: sherke_rl@yahoo.com

Code Number: jp02082

Sir,

Two male patients aged 23 years (patient A) and 42 years (patient B) presented with intracranial hemorrhage with Hunt and Hess grade of IV. In the patient A, coarctation of aorta was suspected due to failure to negotiate the catheter across the thoracic aorta and was confirmed by duplex doppler ultrasonography. In patient B, suspicion of coarctation of aorta on echocardiography was confirmed by aortography. Four-vessel cerebral angiography revealed aneurysm at bifurcation of right middle cerebral artery in patient A and direct puncture carotid angiogram demonstrated basilar artery aneurysm in patient B.

Anaesthetic management was similar in both the cases except for delay of 1 month in patient B which was necessitated by treatment for pulmonary infection subsequent to prolonged ventilatory support. Premedication included fentanyl 1 mg/kg^- and glycopyrolate 0.01 mg/kg^. After pre-oxygenation, induction of anaesthesia was done with thiopentone 5 mg/kg. Tracheal intubation was done after adequate muscle relaxation with Vecuronium 0.1 mg/kg in patient A and tracheostomy was used in patient B. Anaesthesia was maintained with 60% nitrous oxide in oxygen, 0.25%-0.5% isoflurane and vecuronium. Besides routine intra-operative monitoring, invasive blood pressure measurement in radial and dorsalis pedis arteries with estimation of hourly urinary output were undertaken to assess and ensure adequate tissue perfusion beyond the stenosed segment of aorta. These were especially done during controlled hypotension for 20 minutes with continuous nitroglycerine infusion. Mean arterial pressure (MAP) was between 50 and 60 mm Hg in the lower limbs and between 70 and 80 mmHg in the upper limbs. Gradient in MAP between the upper and lower limbs had decreased from 38 mmHg to 11.3 mmHg in patient A and from 36.7 mmHg to 14 mmHg in patient B.

Controlled hypotension endangers the circulation of vital organs distal to coarctation of aorta during management of intracranial aneurysm. Various modalities used to ensure the adequate circulation include invasive and noninvasive blood pressure monitoring in the lower limbs, invasive cardiac function monitoring, spinal somatosensory evoked potential (SSEP) and spinal CSF fluid pressure.^1,2 However, such an extensive, sophisticated and expensive monitoring may not be available at most of the centers in the developing countries. In addition, these provide only minimal advantage over more physiological monitoring such as invasive or noninvasive monitoring of blood pressure in the lower limbs combined with estimation of hourly urinary output. We used this simple monitoring tool based on the fact that the MAP more than 50-60 mm Hg is sufficient to maintain renal autoregulation, and adequate spinal cord circulation and cerebral perfusion.^3,4,5

Maintenance of urinary flow more than 1 ml/min/Kg during the perioperative period while maintaining the MAP in the lower limbs above 50-60 mmHg, should ensure adequate circulation in the kidneys and other vital organs including spinal cord distal to coarctation. MAP in the upper torso is guided by the decrease that can be achieved in the MAP in the lower torso beyond the stenotic segment of aorta. Decrease in the gradient in the MAP between the upper and lower limbs during controlled hypotension allows greater reduction in blood pressure in the upper torso with considerably less reduction in the blood flow to the lower limbs, thus decreasing the risk of ischemia beyond coarctation of aorta.²

Sherke R, Yemala R, Srinivas M, Panigrahi M¹

Department of Anaesthesiology and Intensive Care, Department of Neurosurgery¹, Nizam's Institute of Medical Sciences, Hyderabad, India. E-mail: sherke_rl@yahoo.com

References

1. Orsi P, Rosa G, Liberatori G, Lunardi PP, Ferrante L. Repair of two unruptured intracranial aneurysms in the presence of coarctation of aorta anaesthetic implications and management. J Neurosurg Anesthesiol 1993;5:48-51.
2. Goodie DB, Rigg DL. Controlled hypotension for cerebral aneurysm surgery in the presence of severe aortic coarctation. Br J Anaesth 1991;67:329-31.
3. Hughes RK, Reemtsma K. Correction of coarctation of aorta: Manometric determination of safety during test occlusion. J Thorac Cardiovasc Surg 1971;62:31-3.
4. Dworkin LD, Brenner BM. The Renal Circulation. In: Brenner BM, Rector FC Jr, editors. The Kidney, 4^th ed. Philadelphia: WB Saunders Company; 1991. p. 164-204.
5. Zhang P, Wang B, Wang E, Chen X. Preliminary study on controlled hypotension induced by nimodipine in craniocerebral surgery. Chin Med J 1995;108:420-22.

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