BACKGROUND AND PURPOSE:

• Yao et al. (AJOG MFM, 2021) developed a pregnancy-specific early warning score to identify patients with positive SARS-CoV-2 infection at risk for clinical deterioration and requiring advanced respiratory support (ARS) based on initial clinical characteristics

METHODS:

• Retrospective cohort study
• Participants
  • Pregnant patients with SARS-CoV-2 infection (April 2020 to December 2020)
• Study design
  • Prediction model derived from 50 patients with SARS-CoV-2 infection
  • The authors compared initial clinical characteristics between patients who required ARS and patients who were asymptomatic or had mild symptoms
  • Risk factors for ARS requirement used to create the Obstetric Warning Score (OWS)
  • OWS validated against a separate 30 patient test cohort
  • Receiver operator curve (ROC) was generated to evaluate OWSS against
    • The Early Warning Score (EWS)
    • The National Early Warning Score 2 (NEWS2)
    • The Maternal Early Warning Criteria (MEWC)

RESULTS:

• 50 patients training cohort | 30 patients validation cohort
• Women who required ARS were more likely to present with
  • Dyspnea (p < 0.001)
    • Required ARS: 100%
    • Asymptomatic and mild: 33.3%
  • Higher heart rate (p < 0.001)
    • Required ARS: 113.4 bpm
    • Asymptomatic and mild: 93 bpm
  • Higher respiratory rate (p < 0.001)
    • Required ARS: 23.5 bpm
    • Asymptomatic and mild: 17.7 bpm
  • Higher temperature (p = 0.004)
    • Required ARS: 99.1 °F
    • Asymptomatic and mild: 98.3 °F
  • Higher levels of C-Reactive Protein (CRP; p < 0.001)
    • Required ARS: 7.4 mg/dL
    • Asymptomatic and mild: 2.4 mg/dL
  • Chest x-ray findings consistent with pneumonia
    • Required ARS: 88.2% of patients
    • Asymptomatic and mild: 20.0% of patients
• Total points ≥3 used to predict high risk for clinical deterioration
  • 1 point each for the following: HR > 100 bpm | Temperature > 99.0 °F | CRP >2.0 mg/dL | Respiratory rate ≥20 and <24 bpm | Complaints of dyspnea | Positive chest x-ray for pneumonia
  • 2 points: Respiratory rate >24 bpm
• Area under the curve for OWS was 0.97 compared to
  • EWS: 0.72
  • NEWS2: 0.92
  • MEWC: 0.85
• An OWS score ≥3 was predictive of ARS requirement with
  • Sensitivity: 100%
  • Specificity: 64%
  • Positive predictive value: 36%

CONCLUSION:

• The OWS score was able to identify pregnant patients with SARS-CoV-2 infection who are most at risk of requiring advance respiratory care
• The authors state

It is our hope that the OWS prediction model can help to appropriately direct resources for pregnant patients and reduce the burden COVID-19 has placed on the healthcare system

Learn More – Primary Sources:

Initial clinical characteristics of gravid SARS-CoV-2 positive patients and the risk of progression to severe COVID-19 disease

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