SUMMARY:

The Society for Obstetric Anesthesia and Perinatology (SOAP) commissioned a consensus document on the topic of  neuraxial procedures in the context of thrombocytopenia. The following professional bodies were included: American Society of Regional Anesthesia and Pain Medicine (ASRA), ACOG, SMFM, and the American Society for Hematology (ASH). The panel was convened to address an ongoing issue where obstetric patients with thrombocytopenia are often denied neuraxial anesthesia due to risk of spinal epidural hematoma. However, there are significant maternal and fetal risks associated with general anesthesia during pregnancy.

Definition and Background:

• Thrombocytopenia  in pregnancy
  • Defined during pregnancy as a platelet count <150,000 x 10⁶/L
• Occurs in 7% to 12% of women
• Most common diagnoses include
  • Gestational thrombocytopenia
  • Immune thrombocytopenia
  • Thrombocytopenia associated with hypertensive disease
• Additional causes: Acute fatty liver of pregnancy | Thrombotic thrombocytopenic purpura | Inherited thrombocytopenia | Sepsis-induced thrombocytopenia

Note: For more information on thrombocytopenia in pregnancy including etiologies and management, see ‘Related ObG Topics’ below

Anesthesia Risks

Neuraxial Anesthesia: Thrombocytopenia-Related Spinal Henatoma

• Spinal hematoma is the neuraxial anesthesia complication that is associated with the highest potential morbidity
• Incidence
  • General obstetric population: 1:200,000 to 250,000
  • Incidence based on platelet count
    • 70K to 100K 10⁶/L: 0.2%
    • 50K to 69K 10⁶/L: 3%
    • <50K 10⁶/L: 11% | Most spinal epidural hematomas occur in this range
• Symptoms
  • Lower extremity motor deficit | Back pain | Lower extremities pain and paresthesia | Urinary/bowel dysfunction
  • 95% present symptoms within 48 hours of procedure
• Management
  • Prompt imaging and neurosurgical consultation are critical
  • Treatment: Decompressive laminectomy within 8 hours of symptom onset

Risks Associated with General Anesthesia

• Maternal
  • Severe adverse events related to induction | Failed tracheal intubation | Severe hypertensive response to tracheal intubation | Uterine atony | Inability to provide neuraxial opioids for pain control
• Fetal:
  • Respiratory depression | Apgar < 7 at 5 minutes | Limitation on immediate breastfeeding

Laboratory Considerations

• CBC
  • Absolute platelet count: +/- 3% coefficient of variation
  • Rarely: Low platelet counts due to clumping induced by EDTA | Collect in a tube with other anticoagulant or count manually
• PTT, PT
  • Unless coagulation defect is known or suspected, no utility in predicting bleeding risk in pregnant women with thrombocytopenia
• Thromboelastography (TED) and rotational thromboelastometry (ROTEM)
  • Dynamic point of care tests
  • Evaluate properties of blood clots subjected to rotation
  • Insufficient evidence to recommend routine use to determine safety of neuraxial anesthesia in obstetric patients with thrombocytopenia
• Platelet function analyzer (PFA-100)
  • Evaluates platelet function by stimulating in-vivo platelet plug formation
  • Insufficient evidence to recommend routine use to determine safety of neuraxial anesthesia in obstetric patients with thrombocytopenia

Platelet Transfusion Prior to Neuraxial Procedure

• Risks of platelet transfusion
  • Transfusion reaction | Circulatory overload | Acute lung injury
• Expected increase: 30K to 50K 10⁶/L after a pheresis-derived bag of platelets
  • Less effective in preeclampsia or consumption disorders
• Platelet transfusions are recommended for
  • Life-threatening hemorrhage
  • In preparation for urgent surgery
• Lack of evidence regarding efficacy: A Cochrane review assessed the benefit of platelet transfusion prior to neuraxial anesthesia and concluded that

We found no evidence from RCTs or non‐randomised studies on which to base an assessment of the correct platelet transfusion threshold prior to insertion of a lumbar puncture needle or epidural catheter

RECOMMENDATIONS: 

WITH Known Etiology of Thrombocytopenia (e.g., Gestational Thrombocytopenia, Immune Thrombocytopenia or Hypertensive Disease of Pregnancy)

• Concern for hemostasis disorder or DIC: “Reasonable to avoid neuraxial procedures”
• Platelet count ≥70K 10⁶/L: “Reasonable to proceed with neuraxial procedure”
• Platelets count between 50K and 70K 10⁶/L: “Competing risk/benefits may justify proceeding with neuraxial procedure” | Will be dependent on clinical setting
• Platelets count <50K 10⁶/L: “Reasonable to avoid neuraxial procedure”

WITHOUT Known Etiology of Thrombocytopenia 

• Concern for hemostasis disorder or DIC: “Reasonable to avoid neuraxial procedures”
• Platelet count ≥70K 10⁶/L without history of or current bleeding: “Reasonable to proceed with neuraxial procedure”
• Platelets count <70K 10⁶/L: “Additional (hematologic) work-up may be beneficial prior to proceeding with neuraxial procedure”

Aspirin Therapy in Women with Thrombocytopenia

• There is “insufficient evidence” regarding neuraxial procedures in pregnant and postpartum women with thrombocytopenia who are taking aspirin
• While the 1/2 life of aspirin is only 20 minutes, the lifetime of a platelet can be up to 10 days | However, hemostasis can be achieved with only 20% normal platelet COX activity
• Due to limited data

…clinicians and patients should engage in shared decision-making about the perceived competing risks/benefits of proceeding with or withholding neuraxial anesthesia in cases of severe thrombocytopenia and concurrent aspirin use

Frequency of Lab Testing with Preeclampsia

• Limited evidence for frequency of testing in women with thrombocytopenia and preeclampsia
• However, in the presence of HELLP, the panel recommends that “it may be reasonable to verify platelet count within 6 hours of the planned neuraxial procedure”

Learn More – Primary Sources

The Society for Obstetric Anesthesia and Perinatology Interdisciplinary Consensus Statement on Neuraxial Procedures in Obstetric Patients with Thrombocytopenia

SOAP Thrombocytopenia Consensus Statement FINAL

Cochrane Review: Use of platelet transfusions prior to lumbar punctures or epidural anaesthesia for the prevention of complications in people with thrombocytopenia

Related ObG Topics: