ABG 40: Hypotension Prevention After Spinal Placement for Elective Cesarean Section

MEASURE DESCRIPTION:
Percentage of patients, who present for elective Caesarean section under spinal anesthesia who have phenylephrine infusions started prophylactically to prevent hypotension.

NQS DOMAIN:
Patient Safety

MEASURE TYPE:
Process

HIGH PRIORITY STATUS:
Yes

HIGH PRIORITY TYPE:
Patient Safety

INVERSE MEASURE:
No

RISK ADJUSTED:
No

INSTRUCTIONS:
This measure is to be reported each time a patient undergoes spinal anesthesia for elective Caesarean section during the reporting period. Phenylephrine IV infusion is to be started prophylactically in all eligible patients. It is anticipated that qualified anesthesia providers and eligible clinicians who provide denominator-eligible services will submit this measure.

Measure Reporting via the Qualified Clinical Data Registry

Patient demographics and CPT codes are used to identify patients who are included in the measure denominator. G-codes and Registry Codes are used to capture the numerator.

DENOMINATOR: 
Patients who have elective Caesarean section and undergo spinal anesthesia.

  • Denominator Criteria (Eligible Cases):

    All patients who undergo spinal anesthesia electively

    AND

    Patient encounter during the reporting period (CPT): 

    59510, 59514, 59515

    AND

    ASA CPT:

    01961, 01968

  • Denominator Exclusions:

    ASA Physical Status = E

  • Denominator Exception:

    Contraindication to use of phenylephrine infusion (e.g. bradycardia, compromised cardiac function, pre-eclampsia, etc.)  (ABG Measure Response Code 1083)

NUMERATOR:
Patients who have a phenylephrine infusion started for prophylactic treatment of hypotension.

Numerator Note: Infusion may be started immediately prior to or immediately after placement of spinal.

Numerator Note: Dosing of infusion left to discretion of provider (recommended starting at 50 μg min-1).

  • Numerator Options:

    Performance Met: Phenylephrine infusion started prophylactically (ABG Measure Response Code 1081)

    OR

    Performance Not Met: Phenylephrine infusion NOT started prophylactically (ABG Measure Response Code 1082)

    OR

    Denominator Exception: Contraindication to use of phenylephrine infusion (e.g. bradycardia, compromised cardiac function, pre-eclampsia, etc.) (ABG Measure Response Code 1083)

RELEVANT FIELDS:

  • ASA Physical Status

  • ASA CPT code

  • C-Section Performed

  • Primary Anesthesia Type

  • Phenylephrine given

RATIONALE:

Spinal hypotension is common in women who receive spinal anesthesia for Caesarean delivery, with an incidence of up to 71%. Spinal hypotension can occur precipitously and, if severe, can result in important perinatal adverse outcomes, such as maternal nausea and vomiting, fetal acidosis and may be an important contributory factor for maternal death related to regional anesthesia. Mothers with pre-delivery hypovolemia may be at risk of cardiovascular collapse because the sympathetic blockade may severely decrease venous return. As a consequence, prevention of spinal hypotension has been a key research area within the field of obstetric anesthesia.

To prevent spinal hypotension, a number of approaches have been investigated, notably fluid loading, vasopressors, or both. Despite early enthusiasm, the efficacy of fluid loading for preventing spinal hypotension has been called into question. In contrast, the use of vasopressors has gained increasing prominence as the primary technique for the prevention and treatment of spinal hypotension during Caesarean delivery.

There is accumulating evidence that phenylephrine delivered as an infusion is the most effective method for preventing maternal hypotension and intraoperative nausea or vomiting. In a recent meta-analysis that assessed the harm and benefit of prophylactic phenylephrine infusions, phenylephrine was associated with a reduced risk of pre-delivery hypotension (RR 1⁄4 0.36; 95% CI 1⁄4 0.18–0.73) and nausea and vomiting (R 1⁄4 0.39; 95% CI 1⁄4 0.17–0.91) compared with placebo.25 Furthermore, the use of an ‘on–off’ phenylephrine infusion (commenced at 100mg min21) in combination with crystalloid co-hydration has been shown to nearly eliminate the likelihood of spinal hypotension.

REPORTING CODES: