Pulmonary Edema Resolution in Severe Preeclampsia and Eclampsia

Background - Maternal mortality from treatable causes concerning the critical care domain in low- income countries remains strikingly high. Maternal mortality in Sierra Leone is the highest in the world with 1,360 deaths per 100,000 born alive. The burden of obstetric-related critical care morbidity is also extremely high. In high-income countries less than 2% of intensive care unit admissions relate to obstetric illnesses, but these rise to 10% in resource-limited settings. Pre-eclampsia/eclampsia are hypertensive disorders of pregnancy, one of the 3 leading causes of maternal morbidity and mortality worldwide. Respiratory distress and pulmonary oedema are known complications of preeclampsia-eclampsia and their insurgence is a hallmark of severe disease. Pulmonary oedema is reported as a complication in 2.9% of patients with preeclampsia-eclampsia. Pulmonary involvement is associated with worse maternal and perinatal outcomes. Incidence is significantly higher in low income countries, rising to 12% due to poorer prenatal care and access to hospital care, and suboptimal diagnostic and management processes .

Aim - The primary aim is to describe the frequency of lung ultrasound consistent with pulmonary oedema and the timing of resolution after delivery.

Secondary aims include the assessment of the frequency of acute respiratory failure, other LUS findings beyond pulmonary edema, the assessment of oxygenation, the use of respiratory organ support strategies, assessment of cardiac function, and quantification of major direct/ indirect obstetric complications and of perinatal complications.

Hypothesis -

1. A high proportion (>20%) of patients show LUS signs consistent with pulmonary edema before delivery.
2. There is incomplete resolution of both clinical and ultrasound signs after in the 72 hours after delivery.

Setting - Princess Christian Maternity Hospital, Freetown, Sierra Leone Population - Female subjects, hospitalized with severe preeclampsia or eclampsia Methods - Single centre, prospective, cohort study of patients with severe pre-eclampsia and eclampsia. The expected duration of study is 1 year. All patients with suspected severe pre-eclampsia or eclampsia will undergo screening upon admission to HDU and the Eclamptic ward. Eligible patients will undergo a systematic clinical and LUS examination, straight after admission (before delivery). Clinical examination will focus on signs of respiratory, neurologic and cardiac failure. Lung ultrasound will be performed using a Butterfly ultrasound probe (Butterfly, USA). Lung ultrasound will be performed using the validated 12-region method. As heart failure is a common finding in preeclamptic women, echocardiography performed with a cardiac sector probe, will enable real-time assessment of maternal cardiac contractility and cardiac output. The same clinical, LUS and echocardiographic assessment will be repeated between 24 h to 72 h (after delivery). Whenever the pre-delivery timepoint is not feasible due to late arrival, emergency scenario or postpartum onset, the after delivery examination only will be performed.

Primary outcomes

• Frequency of LUS consistent with pulmonary edema [during hospital stay, average of 1 month]: Frequency endpoint: proportion of patients with a LUS positive for pulmonary edema Severity: LUS aeration score
• Timing of resolution after delivery [during hospital stay, average of 1 month]: Categorical: Fraction of patients with improvement or resolution of LUS findings. Numerical: delta LUS score between T1 and T2

Secondary outcomes

• Frequency of acute respiratory failure in patients with Severe Pre eclampsia and in patients with Eclampsia [during hospital stay, average of 1 month]: Proportion of patients with acute respiratory failure
• Frequency of other LUS findings [during hospital stay, average of 1 month]: Proportion of patients with * consolidations * isolated pleural effusion * minor LUS findings
• Frequency of organ support strategies [during hospital stay, average of 1 month]: Fraction of patients that receive oxygen and/or CPAP (Continuous Positive Airway Pressure) and/or mechanical ventilation
• Frequency of patients with abnormal cardiac function [during hospital stay, average of 1 month]: Defined as low cardiac index measured by ultrasound
• Oxygenation assessment [during hospital stay, average of 1 month]: SpO2 (peripheral capillary oxygen saturation) to FiO2 (fraction of inspired oxygen) ratio
• Frequency of Major Direct Obstetric Complications (MDOCs) [during hospital stay, average of 1 month]: Fraction of patients with at least one additional MDOC (antepartum hemorrhage, postpartum hemorrhage, sepsis, uterine rupture, obstructed labour)
• Frequency of Indirect Obstetric complications [during hospital stay, average of 1 month]: Fraction of patients with at least one among stroke, severe malaria, acute kidney injury and cardiac insufficiency.
• Frequency of perinatal complications [during hospital stay, average of 1 month]: Intra uterine fetal death (IUFD), Apgar score, Admission to special care baby unit (SCBU)

Sex: Female

Inclusion Criteria:

\- All patients with severe pre-eclampsia or eclampsia admitted to hospital Princess Christian Maternity Hospital

Exclusion Criteria:

* Patients with chronic hypertensive disorders
* Lung ultrasound not feasible, e.g., due to electricity breakdown, or absence of the trained sonographer or presence of subcutaneous emphysema,

• Study Protocol and Statistical Analysis Plan (PDF, 2023-04-08)

• Luigi Pisani, Principal investigator, Doctors with Africa - CUAMM
• Adeniji Adetunji Oladeni, Principal investigator, University of Sierra Leone Teaching Hospitals Complex, Princess Christian Maternity Hospital