Farewell to indigo carmine
With a nationwide shortage of this marker dye, what are the options, and cautions, for obstetricians and gynecologists?
Option to test patency of the fallopian tubes (chromopertubation)
Methylene blue. If methylene blue is used via a cannula in the uterine cavity to test the patency of the fallopian tubes, I recommend diluting 10 mg methylene blue in 150 mL normal saline and using the dilute solution to test tubal patency.
It is unlikely that this process will lead to sufficient methylene blue absorption to cause a serotonin syndrome. Therefore, this technique can be used in patients taking SSRIs, SNRIs and MAOIs. However, if intrauterine injection of the dilute dye solution results in extravasation of the dye into the pelvic veins, a significant amount of dye can enter the circulation.11 There are case reports of anaphylaxis following intrauterine injection of methylene blue to test tubal patency.12,13
Options to diagnose PROM and to use for twin amniocentesis
None. Most experts recommend against the intra-amniotic injection of methylene blue to diagnose PROM or in twin amniocentesis procedures. Methylene blue injected into the intra-amniotic fluid during amniocentesis in multiple gestations has been reported to cause fetal bowel obstruction or atresia.14,15 Fetal death also has been reported.16 Decades ago, indocyanine green, which is FDA approved to determine cardiac output, liver blood flow, and hepatic function, was reported to be useful to mark one sac of a twin gestation during amniocentesis.17 With modern ultrasonography technology, the need to rely on a dye to mark a sac of a twin has decreased significantly.
Our only option is to cope—effectively as possible Over decades, the medical community develops patterns of patient care that are critically dependent on the availability of key pharmaceuticals and devices. When a pharmaceutical or device suddenly becomes unavailable, it can disrupt important patterns of patient care. Imagine the impact on obstetrics practice if oxytocin became unavailable due to manufacturing shortages. Likely, both market forces and government regulation are the root cause of the shortfalls. Preventing the adverse consequences of the sudden loss of key pharmaceuticals and devices is an important priority to ensure optimal care of our patients.
Share your thoughts on this article! Send your Letter to the Editor to rbarbieri@frontlinemedcom.com. Please include your name and the city and state in which you practice.
