Tuesday, March 8, 2011


Department of Pediatric Dentistry
Resident’s Name:Murphy Program: Lutheran Medical Center - Providence

Article title:Perioperative Management of the Glucose-6-Phosphate Dehydrogenase Deficient Patient: A Review of Literature
Author(s): Cpt Ali Elyassi, DDS, and Maj Henry H. Rowshan, DDS
Journal: American Dental Society of Anesthesiology
Year. Volume (number). Page #’s: 2008. pg 86-90
Major topic: G6PD
Main Purpose: Literature review discussing disease background, pathophysiology and clinical implications for the g6pd pt.
Overview of method of research: Lit review search using PubMed, The Cochrane Library, Web of Science, OMIM, and Google using the keywords g6pd, anesthesia, analgesia, anxiolysis, management, favism, hemolytic anemia, benzos, codeine/codeine derivatives, ketamine, barbiturates, propofol, opiods, fentanyl, and inhalation anesthetics. 23 papers and 1 website were used to compile the review.

Findings:
g6pd deficiency is the most common enzymatic disorder of red blood cells, affecting 400 million people. The highest prevalence of g6pd is reported in Africa, southern Europe, Middle East, Southeast Asia, and the Pacific Islands. The g6pd enzyme catalyzes the first step in the pentose phosphate pathway, leading to antioxidants that protect cells against oxidative damage. A pt. W/ g6pd def lacks the ability to protect red blood cells against oxidative stresses from certain drugs, metabolic conditions, infections, and ingestion of fava beans. G6pdd is known to provide protection against malaria, specifically the most deadly form. Areas endemic to malaria usually have more people w/ g6pdd, possible due to evolutionary advantage.

The World Health Org has classified g6pdd variants in the following ways.

Class I: Severely deficient, chronic hemolytic anemia
Class II:1-10% residual activity
Class III:10-60% residual activity
Class IV:60-150% normal activity
Class V:>150% increased activity

Class IV and V are of no clinical significance.

A number of drugs can precipitate hemolysis in g6pdd patients. The drugs interact with hemoglobin and oxygen, leading to intracellular formation of hydrogen peroxide and other oxidizing radicals. This cause accumulation of enzyme def. Cells, leading to loss of function and cell death. Benzos, codeine and it’s derivatives, propofol, fentanyl, and ketamine have all shown to be safe with g6pdd patients. Hemolytics crisis induced by inhalational general anesthetic agents is still being studied. Some authors relate g6pd to malignant hyperthermia.

Drugs such as benzocaine, lidocaine, articaine, prilocaine, and silver nitrate should be avoided in g6pdd patients because they can induce methemoglobinemia.

Infections is the most common factor leading to hemolysis in a g6pdd patient. In general, hemolysis is seen 1-3 days after contact with the triggering factor It is self limiting, but in rare cases it may necessitate blood transfusion. Signs and symptoms include

- cyanosis
-headache
-fatigue
-tachycardia
-dyspnea
-lehtargy
-lumbar/substernal pain
-abdominal pain
-splenomegaly
-hemoglobinura
-scleral icterus
-jaundic
-blood in urine
After the triggering factor is removed, hemoglobin concentrations begin to recover 8-10 days later.
General anesthesia can mask the immediate signs of hemoylsis, making it difficult to indentify the hemolytic crisis. A simple post op phone call to check on the patient could be vitally important to the patient’s health.

Key points/Summary:
-The most important management strategy is to prevent hemolysis by avoiding oxidative stressors.
-Any suggested of having g6pdd should be screened
-Patients with g6pdd should be informed of risks along with signs and symptoms of an acute hemolytic crisis
-Clinicians need to be able to identify both laboratory and clinical signs of hemolysis
-If an acute hemolytic crisis is identified, the patient needs to be admitted immediately for observation and care.

Assessment of Article: Excellent, thorough, no nonsense review of g6pdd.

Here is a great website about g6pdd, discussing what it is, and importantly for us, what drugs to avoid.

http://www.g6pd.org/favism/english/index.mvc?pgid=myhome

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