Glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency) is an enzymopathy of red blood cells in humans . It is an X-linked, hereditary genetic defect, prevalent in up to 400 million people worldwide mainly in about 10% of African-Americans as well as to a lower frequency in the Mediterranean people [15,18]. It is known that G6PD-deficient cells protect against the malaria parasite Plasmodium falciparum in women by means of slowest parasite growing in these cells or earlier phagocytosis by macrophages [9,10,41,46]. G6PD is an enzyme necessary for the production of antioxidants, which protect red blood cells from oxidative stressors . In case of G6PD deficiency, red blood cells can be damaged by oxidative stresses from certain drugs, metabolic conditions (diabetic ketoacidosis, metabolic acidosis), infections [5,28,44], hypothermia, lawsone (Henna), ingestion of fava beans or stress related to surgical interventions, resulting in haemolysis [17,18].
The severity of disease is determined by the magnitude of enzyme deficiency: Class I variants have severe enzyme deficiency with chronic non-spherocytic haemolytic anaemia (<10% residual enzyme activity), class II variants also have severe enzyme deficiency (<10% residual enzyme activity) but with intermittent acute haemolysis, class III variants have moderate enzyme deficiency (10-60% residual enzyme activity) with intermittent acute haemolysis. Class IV and V variants are of no clinical significance - class IV has no enzyme deficiency and class V has increased enzyme activity . However, severity is more pronounced in G6PD deficient white patients (acute renal failure) than in the black population (selflimitation) [10,11]. Haemolysis is influenced by the type of mutation causing disease, genetic make-up and gender of the individual, age of erythrocytes, the type and dose of offending drug  and the number of other present risk factors, for example infections .
The main anaesthetic concern in the treatment of patients with G6PD deficiency is the choice of drugs using for anaesthetic management, and postoperative pain therapy since exposure to oxidative drugs can lead to haemolytic crisis in these patients.