Percentage of cases with systolic blood pressure <90mmHg for less than or equal to 5 (cumulative) minutes.

Neuraxial anesthesia is widely used for cesarean delivery and is associated with lower mortality and morbidity when compared to general anesthesia.^5,8,10 Though overall morbidity is lower, neuraxial anesthesia can lead to maternal hypotension which has been cited as a common maternal complication during cesarean delivery.^5-11 Hypotension can cause fetal acidosis and maternal nausea and vomiting.^2,10,12 Prolonged hypotension can result in organ ischemia, uteroplacental hypoperfusion, loss of consciousness, and cardiovascular collapse.^2,8 Techniques currently used to prevent hypotension related to spinal placement include intravenous fluid prehydration, vasopressor infusions, and less commonly physical methods such as leg elevation and compression stockings.^2,5,8,10,11 

In a Cochrane review of 126 studies including 9565 patients, 94 of the studies defined hypotension as a maternal systolic blood pressure below 80% of baseline recording, absolute value of less than 90 or 100 mmHg, or some combination thereof.² Patients experiencing severe preeclampsia may be at lower risk of hypotension (but higher risk of other complications)  as compared to healthy parturients.¹ Nonetheless, hypotension and low placental perfusion remain a risk for the preeclamptic patient undergoing neuraxial anesthesia, necessitating the same level of vigilance as for non pre-eclamptic patients.^3,7

Neuraxial placement to Neonate Delivery

Cesarean Delivery cases where neuraxial anesthesia was used.

• Cesarean Delivery cases determined by Obstetric Anesthesia Type value codes: 1, 2, and 7
• Neuraxial anesthesia determined by Anesthesia Technique Neuraxial value codes > 0.

• Abnormal uterine or vaginal bleeding, unspecified (ICD-10: N93.9).
• Cesarean delivery patients undergoing general anesthesia (determined using Anesthesia Technique: General value codes >0)
• Cesarean hysterectomy (determined by Obstetric Anesthesia value code: 4 and 8)
• Emergency cesarean delivery with diagnosis of placental abruption (ICD-10: O45*).
• Hemorrhage from placenta previa, antepartum condition or complication (ICD-10: 641.13).
• Hemorrhage from placenta previa, delivered, with or without mention of antepartum condition (ICD-10: 641.11).
• Labor Epidurals (Obstetric Anesthesia value code: 3)
• Newborn affected by intrauterine blood loss from ruptured cord (ICD-10: P50.1).
• Placenta previa with hemorrhage, third trimester (ICD-10: O44.13).
• Rupture of uterus (spontaneous) before onset of labor (ICD-10: O71.0).

ICD-10 Codes associated with the case and documented from 7 days before to 30 days after the case are considered.

SBP <90mmHg for less than or equal to 5 minutes during the time period of spinal placement to delivery.

Measure Start Time: 

1. For scheduled cesarean delivery cases (as determined by the Obstetric Anesthesia Type phenotype): Will use Neuraxial Start Time phenotype.
   1. If Neuraxial Start Time is earlier than Anesthesia Start, will use Anesthesia Start phenotype.
2. For labor epidural cases that are converted to cesarean delivery and are documented as a single case (as determined by the Obstetric Anesthesia Type phenotype): Will use the Cesarean Delivery Start Time for Conversion Cases phenotype.
3. For labor epidural cases that are converted to cesarean delivery and documented as two separate cases (as determined by the Obstetric Anesthesia Type phenotype): Will use the Cesarean Delivery Start Time for Conversion Cases phenotype.

Measure End Time (limited to concepts between anesthesia start and anesthesia end): 

1. Delivery of Neonate 2 (Concept ID: 50189). If not available 
2. Delivery of Neonate (Concept ID: 50358), If not available, 
3. Oxytocin (Concept ID: 10343) Administration Start Time (bolus or infusion). If not available,
4. Obstetrics - Uterine Incision (Concept ID: 50357). If not available,
5. AACD Anesthesia End Date/Time (Concept ID: 50009)

• Multiple blood pressures: Instances where there are two blood pressure monitoring methods, the higher MAP will be used to determine measure compliance.
• Artifact: Artifact readings will be identified and removed from final measurement calculation. Artifact processing: if systolic and diastolic blood pressures are present, the values must be at least 5 mmHg apart; otherwise, the values will be excluded. MAP values less than 10 are excluded.
• Each incidence of hypotension will count for a max of 5 minutes or until ‘Measure End’ (whichever is sooner) if there is a gap in blood pressure measurement.
• Oxytocin administration start time only considers the earliest oxytocin dose or infusion documented within the measure time period.

*This measure will include valid MPOG cases defined by the Is Valid Case MPOG phenotype.

Not applicable

Departmental only measure - not available for provider feedback emails.

1. Aya AGM, Mangin R, Vialles N, Ferrer J-M, Robert C, Ripart J, La Coussaye J-E de: Patients with severe preeclampsia experience less hypotension during spinal anesthesia for elective cesarean delivery than healthy parturients: a prospective cohort comparison. Anesth Analg 2003; 97:867–72
2. Chooi C, Cox JJ, Lumb RS, Middleton P, Chemali M, Emmett RS, Simmons SW, Cyna AM: Techniques for preventing hypotension during spinal anaesthesia for caesarean section. Cochrane Database Syst Rev 2017; 8:CD002251
3. Dyer RA, Piercy JL, Reed AR, Lombard CJ, Schoeman LK, James MF: Hemodynamic changes associated with spinal anesthesia for cesarean delivery in severe preeclampsia. Anesthesiology 2008; 108:802–11
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8. Macarthur A, Riley ET: Obstetric anesthesia controversies: vasopressor choice for postspinal hypotension during cesarean delivery. Int Anesthesiol Clin 2007; 45:115–32
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10. McDonnell NJ, Paech MJ, Muchatuta NA, Hillyard S, Nathan EA: A randomised double-blind trial of phenylephrine and metaraminol infusions for prevention of hypotension during spinal and combined spinal-epidural anaesthesia for elective caesarean section. Anaesthesia 2017; 72:609–17
11. Ngan Kee WD, Khaw KS, Ng FF: Prevention of Hypotension during Spinal Anesthesia for Cesarean DeliveryAn Effective Technique Using Combination Phenylephrine Infusion and Crystalloid Cohydration. Anesthesiology 2005; 103:744–50
12. Reynolds F, Seed PT: Anaesthesia for Caesarean section and neonatal acid-base status: a meta-analysis. Anaesthesia 2005; 60:636–53