Adverse Effect
Conditions
Keywords
Phenylephrine, Postspinal anesthesia hypotension, Preeclampsia, Cesarean section, Dose-finding
Brief summary
The purpose of this study is to investigate the suitable infusion dose of phenylephrine for prophylaxis against postspinal anesthesia hypotension in parturients with preeclampsia undergoing cesarean section.
Detailed description
Preeclampsia, which affects 5% to 7% of parturients, is a significant cause of maternal and neonatal morbidity and mortality. Because of constricted myometrial spiral arteries with exaggerated vasomotor responsiveness, though blood pressure in parturients with preeclampsia are apparently higher than healthy parturients, placental hypoperfusion is more common. Spinal anesthesia is still the preferred mode of anesthesia in parturients with preeclampsia for cesarean section. In preeclampsia parturients, spinal anesthesia improve intervillous blood flow (provided that hypotension is avoided) which contribute to increase placental perfusion. Even so, 17-26% parturients with preeclampsia experienced postspinal anesthesia hypotension due to the extensive sympathetic block that occurred with spinal anesthesia. Practical guidelines for obstetric anesthesia from the American Society of Anesthesiologists and an international consensus statement on the management of hypotension with vasopressors indicate either IV ephedrine or phenylephrine may be used to correct hypotension. But the suitable infusion dose of phenylephrine in parturients with preeclampsia is still unknown. The purpose of this study is to investigate the suitable infusion dose of phenylephrine for prophylaxis against post-spinal anesthesia hypotension in parturients with preeclampsia undergoing cesarean section.
Interventions
DRUGNormal saline
Normal saline infusion simultaneous with subarachnoid block
DRUGPhenylephrine
Different infusion dose of phenylephrine simultaneous with subarachnoid block
Sponsors
General Hospital of Ningxia Medical University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
No
Inclusion criteria
* 18-45 years * Primipara or multipara * Singleton pregnancy ≥32 weeks * American Society of Anesthesiologists physical status classification II to III * Scheduled for cesarean section under spinal anesthesia
Exclusion criteria
* Baseline blood pressure ≥180 mmHg * Body height \< 150 cm * Body weight \> 100 kg or body mass index (BMI) ≥ 40 kg/m2 * Eclampsia or chronic hypertension * Hemoglobin \< 7g/dl * Fetal distress, or known fetal developmental anomaly
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The incidence of post-spinal anesthesia hypotension | 1-15 minutes after spinal anesthesia | Systolic blood pressure (SBP) \< 80% of the baseline |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Overall stability of heart rate control versus baseline | 1-15 minutes after spinal anesthesia | Evaluated by performance error (PE) |
| The incidence of severe post-spinal anesthesia hypotension | 1-15 minutes after spinal anesthesia | Systolic blood pressure (SBP) \< 60% of the baseline |
| The incidence of nausea and vomiting | 1-15 minutes after spinal anesthesia | Presence of nausea and vomiting in patients after spinal anesthesia |
| The incidence of bradycardia | 1-15 minutes after spinal anesthesia | Heart rate \< 60 beats/min |
| Overall stability of systolic blood pressure control versus baseline | 1-15 minutes after spinal anesthesia | Evaluated by performance error (PE) |
| pH | Immediately after delivery | From umbilical arterial blood gases. |
| Partial pressure of oxygen | Immediately after delivery | From umbilical arterial blood gases. |
| Base excess | Immediately after delivery | From umbilical arterial blood gases. |
| APGAR score | 1 min after delivery | A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration |
| The incidence of hypertension. | 1-15 minutes after spinal anesthesia | Systolic blood pressure (SBP) \>120% of the baseline. |
Contacts
Primary ContactXinli Ni, Dr.
Backup ContactYi Chen, M.D.
Outcome results
None listed