This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Which anesthetic modality is to be avoided in sickle cell disease? 
Select and explain. 
A. General Anesthesia, B. Brachial Plexus Block, C. Intravenous Regional Anesthesia, D. Spinal Anesthesia
C: Intravenous Regional Anesthesia
Answer: C: Intravenous Regional Anesthesia 
Explanation: 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.