Regional Anaesthesia for Carotid Endarterectomy
Regional Anaesthesia for Carotid Endarterectomy
Good communication at all times is important for patient reassurance and cooperation. The patient is positioned in a 'deck-chair' position with the head on a soft head-ring, extended (if tolerated), and rotated contralaterally. Patient comfort is vital to allow them to tolerate 2–3 h in this position. Other potential comfort measures include: the use of a non-heated mattress, padding and support under all pressure areas, a pillow placed under the patient's knees, ensuring the patient's bladder is emptied before the operation, and keeping surgical drapes off the patient's face. Clear plastic drapes may be used to reduce the sensation of claustrophobia. Blood loss is rarely a problem, so fluids should be kept to a minimum to avoid the need to void intraoperatively. Water (e.g. from a 20 ml water for injection ampoule) may be administered to 'wet the lips' during the operation. Avoid allowing the patient to drink, however, as the combination of lying supine, the possibility of recurrent laryngeal nerve block, and residual sedation effects make accidental aspiration of water possible, resulting in choking, coughing, hypertension, and potential venous bleeding.
Oxygen is administered via a Hudson facemask continuously throughout the operation. Perioperative monitoring should be placed before sedation and performance of the regional block. Respiratory monitoring consists of pulse oximetry, respiratory rate by thoracic impedance measurement, end-tidal respiratory gases sampled within the Hudson mask, and arterial blood gas analysis as required. Cardiac monitoring consists of electrocardiography (II and V5) and invasive and non-invasive arterial pressure monitoring. ST segment analysis may be useful.
Arterial pressure should be recorded in both arms and the higher value used for invasive monitoring as there may be significant discrepancies between the arms of vascular patients. However, some clinicians choose to use the contralateral side to the operation for the arterial line due to the risk of intraoperative subclavian artery occlusion and thus loss of the arterial waveform. In patients with poor cardiac function or cardiac ischaemia, more invasive haemodynamic monitoring may be considered.
Intraoperative Management
Good communication at all times is important for patient reassurance and cooperation. The patient is positioned in a 'deck-chair' position with the head on a soft head-ring, extended (if tolerated), and rotated contralaterally. Patient comfort is vital to allow them to tolerate 2–3 h in this position. Other potential comfort measures include: the use of a non-heated mattress, padding and support under all pressure areas, a pillow placed under the patient's knees, ensuring the patient's bladder is emptied before the operation, and keeping surgical drapes off the patient's face. Clear plastic drapes may be used to reduce the sensation of claustrophobia. Blood loss is rarely a problem, so fluids should be kept to a minimum to avoid the need to void intraoperatively. Water (e.g. from a 20 ml water for injection ampoule) may be administered to 'wet the lips' during the operation. Avoid allowing the patient to drink, however, as the combination of lying supine, the possibility of recurrent laryngeal nerve block, and residual sedation effects make accidental aspiration of water possible, resulting in choking, coughing, hypertension, and potential venous bleeding.
Oxygen is administered via a Hudson facemask continuously throughout the operation. Perioperative monitoring should be placed before sedation and performance of the regional block. Respiratory monitoring consists of pulse oximetry, respiratory rate by thoracic impedance measurement, end-tidal respiratory gases sampled within the Hudson mask, and arterial blood gas analysis as required. Cardiac monitoring consists of electrocardiography (II and V5) and invasive and non-invasive arterial pressure monitoring. ST segment analysis may be useful.
Arterial pressure should be recorded in both arms and the higher value used for invasive monitoring as there may be significant discrepancies between the arms of vascular patients. However, some clinicians choose to use the contralateral side to the operation for the arterial line due to the risk of intraoperative subclavian artery occlusion and thus loss of the arterial waveform. In patients with poor cardiac function or cardiac ischaemia, more invasive haemodynamic monitoring may be considered.
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