Which anesthetic modality is to be avoided in sickle cell disease?
Prevention of conditions that favor suckling is the basis of peri-operative management.

Supplemental oxygen is recommended during and after regional anesthesia/GA.
Circulatory stasis can be prevented with hydration and anticipation of intraoperative blood loss in order to avoid acute hypovolemia
Normothermia is desirable because hyperthermia increases the rate of gel formation, and hypothermia produces vasoconstriction that impairs organ blood flow.
The use of a tourniquet and hence Bier's block (intravenous regional anesthesia) is contraindicated because blood stasis can cause local acidosis, hypoxia with suckling of cells.
Drugs commonly used for anesthesia should not have significant effects on the suckling process.
General Anesthesia
Brachial Plexus Block
Intravenous Regional Anesthesia
Spinal Anesthesia