Adverse Effect
Conditions
Brief summary
The objective of this study is to investigate the 90% effective dose of phenylephrine infusions for preventing postspinal anesthesia hypotension under intensive and standard treatment in preeclamptic patients during cesarean section
Detailed description
Post-spinal anesthesia hypotension is a frequent complication during spinal anesthesia for cesarean section. The incidence of post-spinal anesthesia hypotension is as high as 62.1-89.7% if prophylactic measures are not taken. The 2016 ASA guidelines for obstetric anesthesia suggest avoiding hypotension following spinal anesthesia in women and emphasize the use of vasopressors, specifically alpha-receptor agonists, as the preferred strategy to prevent and manage post-spinal anesthesia hypotension. The 2018 International Consensus in the United Kingdom and Northern Ireland recommends maintaining maternal systolic blood pressure above 90% of the baseline value following lumbar anesthesia, while avoiding dropping below 80% of the baseline value. Currently, the threshold for maintaining blood pressure above 80% of the baseline value is widely adopted as a standard; however, limited evidence supports the advantage of sustaining maternal blood pressure above 90% of the baseline value. The objective of this study is to investigate the 90% effective dose of phenylephrine infusions for preventing postspinal anesthesia hypotension under intensive and standard treatment in preeclamptic patients during cesarean section.
Interventions
DRUGAlpha-Agonist
An initial infusion dose of prophylactic phenylephrine (0.625 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.125 ug/kg/min of prophylactic phenylephrine according to the responses of previous patients according to the up-down sequential allocation.
An initial infusion dose of prophylactic phenylephrine (0.625 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.125 ug/kg/min of prophylactic phenylephrine according to the responses of previous patients according to the up-down sequential allocation.
Sponsors
General Hospital of Ningxia Medical University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Caregiver)
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 I to III * Scheduled for cesarean section under spinal anesthesia
Exclusion criteria
* Baseline blood pressure ≥160 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 |
|---|---|---|
| ED50 and ED90 | 1-15 minutes after spinal anesthesia | The dose of prophylactic phenylephrine that would be effective in preventing postspinal anesthesia hypotension in 50% (effective dose, ED 50) and 90% (ED90) of patients |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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 bradycardia. | 1-15 minutes after spinal anesthesia | Heart rate \< 60 beats/min. |
| 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 hypertension. | 1-15 minutes after spinal anesthesia | Systolic blood pressure (SBP) \>120% of the baseline. |
| The incidence of post-spinal anesthesia hypotension | 1-15 minutes after spinal anesthesia | Systolic blood pressure (SBP) \< 80% of the baseline |
| Base excess | Immediately after delivery | From umbilical arterial blood gases. |
| Partial pressure of oxygen (PO2) | Immediately after delivery | From umbilical arterial blood gases. |
| APGAR score | 1 min after delivery | A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration; 0(Worst)-10(Best) |
| pH | Immediately after delivery | From umbilical arterial blood gases. |
Contacts
Primary ContactYi Chen, M.D.
Outcome results
None listed