Near‐infrared spectroscopy changes during hypothermic circulatory arrest with retrograde cerebral perfusion

Abstract

SummaryWe report on the changes in cerebral near-infrared spectroscopy during grafting of a thoraco-abdominal aneurysm. A 58-year-old man presented with a complex dissecting aortic aneurysm. Repair of the aneurysm was performed under hypothermic circulatory arrest with retrograde cerebral perfusion. Cerebral near-infrared spectroscopy monitoring revealed a reduction in the values recorded for total haemoglobin, oxygenated haemoglobin and cytochrome aa3 along with an increase in deoxygenated haemoglobin during circulatory arrest. When retrograde cerebral perfusion was commenced the signals representing total haemoglobin, oxygenated haemoglobin and cytochrome aa3 were all restored to near baseline values. Deoxygenated haemoglobin, however, remained elevated. These changes support the hypothesis that some cerebral perfusion occurs during retrograde cerebral perfusion. Keywords ... Correspondence to: Dr T. H. Clutton-BrockNear-infrared spectroscopy (NIRS) is a technique that is used for measuring the absorption of near-infrared light by chromophores (i.e. haem-containing species). Total haemoglobin, its constituent oxygenated and deoxygenated forms and cytochrome aa3, which is the terminal enzyme in the mitochondrial respiratory chain, all absorb infrared light and can be quantified by NIRS [1][2][3]. The attraction of NIRS is in its potential to yield noninvasive information on both organ blood flow and cellular activity. We report on the NIRS changes which occurred when monitoring cerebral activity during hypothermic circulatory arrest with retrograde cerebral perfusion. Case historyA 58-year-old man was admitted for emergency graft repair of an ascending and descending thoraco-abdominal aneurysm. He presented with acute severe chest pain and had recently had a mild right-sided stroke. Chest X-ray revealed a wide mediastinum and subsequent computerised axial tomography and echocardiography confirmed a complex aortic dissection originating from just above the aortic valve and extending to just above the renal arteries. There was minimal evidence of aortic regurgitation and left ventricular function was reported to be good.The patient was premedicated with temazepam, ranitidine and metaclopromide and anaesthesia was induced with fentanyl and etomidate followed by pancuronium. The patient's trachea was intubated and anaesthesia was maintained with intravenous infusions of propofol (5 356ᮊ 1997 Blackwell Science Ltd of total haemoglobin (THb), oxygenated haemoglobin (O 2 Hb), deoxygenated haemoglobin (HHb) and cytochrome aa3 (Cyt) activity. The data from the monitor were collected via the serial port of a notebook personal computer using Critikon data logger software.After a left posterolateral thoracotomy the patient was established on cardiopulmonary bypass (CPB) with bicaval venous lines and a right femoral arterial line (Fig. 1a). Interposition grafting of the ascending aorta, including the arch of the aorta, was performed using hypothermic circulatory arrest and retrograde cerebral perfusion. To achieve this, t...

Jugular bulb oximetry during cardiac surgery

“…From these studies [9,79], S j o 2 can be considered as a good monitor for safe management of the cerebrum during aortic arch replacement. In addition, near-infrared spectroscopy has been used to monitor regional cerebral oxygenation in adults undergoing aortic arch surgery [29], and in children undergoing hypothermic circulatory arrest [80].…”

Retrograde cerebral perfusion: clinical and experimental aspects

“…The rSO 2 rapidly falls with the start of HCA but using RCP, the fall appears less rapid. 51,52 This is further evidence that RCP is actually perfusing the brain. The normal human brain weighs about 1400 g and contains approximately 75 ml of blood, but only 10-20 ml is arterial.…”

Near infrared spectroscopy monitoring during pediatric aortic coarctation repair

“…There is good evidence that monitoring rSO 2 provides a real‐time continuous assessment of regional oxygenation of a variety of tissue beds. Rigg et al (10) demonstrated changes in regional cerebral oxygenation associated with retrograde cerebral perfusion on cardiopulmonary bypass. Others have shown that changes in rSO 2 track changes in perfusion of the liver, calf muscles during aerobic exercise, gluteal muscle and visceral perfusion during abdominal aortic surgery (11–13).…”