Sunday, August 23, 2009

blocks the cardiac sympathetic fibers and consequently decreases heart rate, cardiac output and contractility

The CEA (Cervical Epidural Anaesthesia) blocks the cardiac sympathetic fibers and consequently decreases heart rate, cardiac output and contractility. The mean blood pressure is unchanged or decreased, depending on peripheral systemic vascular resistance changes. The baroreflex activity is also partly impaired. Sympathetic blockade also decreases myocardial ischaemia. The cardiovascular changes induced by CEA are also partly due to the systemic effect of the local anaesthetic. The respiratory effects are minimal and depend on the extent of the blockade and the concentration of the local anaesthetic. A moderate restrictive syndrome occurs. Since the phrenic nerves originate from C3 to C5, ventilation may be impaired by CEA. Extension of the block may also impair intercostal muscle function, with a risk of respiratory failure when a CEA is used in patients with compromised respiratory function. The potential specific complications, mainly cardiovascular and respiratory, are the exacerbation of the effects of CEA. Side effects such as bradycardia, hypotension and acute ventilatory failure in relation to respiratory muscle paralysis, may be observed. Close monitoring of haemodynamics, respiratory rate and level blockade is required.
Ann Fr Anesth Reanim. 1993;12(5):483-92.
PMID: 8311355 [PubMed - indexed for MEDLINE