One should be aware that spinal anesthesia can sometimes lead to major blocks, with paralysis of intercostal muscles and the diaphragm, especially in pregnant women.
Caution should be exercised in patients with degree II and III AV block since local anesthetics can lower the conduction capacity of myocardium. Elderly patients and patients with severe hepatic disease, severely impaired renal function or in generally reduced general condition also require special attention. Patients treated with class III anti-arrhythmic drug (e.g. Amiodarone) should be closely observed and ECG monitoring should be considered,
Like all local anesthetic drugs, bupivacaine can cause acute central nervous and cardiovascular toxic effects in cases of use leading to high concentrations in the blood.
There is increased risk of extensive or total spinal blockade in elderly patients and patients in late stages of pregnancy. The dose should there be reduced for these patients Spinal anesthesia can lead to a fall in blood pressure and bradycardia.
The risk can be reduced by means of intravenous administration of crystalloid or colloid solution. A fall in blood pressure should be treated immediately, for example with ephedrine 5- 10 mg intravenously, repeated as required.
Neurological disorders, such as multiple sclerosis, hemiplegia, paraplegia and neuromuscular disturbances are not thought to be adversely affected by spinal anaesthesia, but caution should be exercised.