Hypotension
Conditions
Keywords
hypotension, spinal anesthesia, cesarean section, phenylephrine, ephedrine, closed-loop system, continuous non-invasive monitor
Brief summary
Hypotension occurs commonly during spinal anesthesia for caesarean section with maternal and fetal adverse effects. The investigators developed a double-vasopressor automated system incorporating continuous non-invasive arterial pressure monitoring (CNAP, CNSystems, Austria).
Detailed description
Hypotension occurs commonly during spinal anesthesia for cesarean section with maternal and fetal adverse effects. The investigators developed a double-vasopressor automated system incorporating continuous non-invasive arterial pressure (CNAP, CNSystems, Austria) monitoring feeding hemodynamic data to a laptop computer, which triggers syringe pumps to deliver phenylephrine 50mcg or ephedrine 4mg (if heart rate\<60 beats.min-1) every 30 seconds when systolic blood pressure fell to below 90% of baseline. A randomised controlled trial was done to compare with manual bolus technique. With the manual bolus technique, phenylephrine 100mcg or ephedrine 8mg (if heart rate\<60 beats.min-1) was given every 60 seconds by the attending anesthesiologist when systolic blood pressure was below 90% of baseline as measured by conventional intermittent non-invasive blood pressure monitoring.
Interventions
DEVICEVasopressor automated delivery system
Novel closed-loop system incorporating: 1. Continuous non-invasive arterial pressure (CNAP) monitor that measured and recorded hemodynamic data in real time. 2. Controller algorithm loaded onto a laptop computer that monitored the hemodynamic data from CNAP and determined if vasopressors should be administered. 3. Two syringe pumps loaded with phenylephrine and ephedrine that was activated by the controller algorithm.
DRUGPhenylephrine
Phenylephrine is a vasopressor drug that was administered when the participant's systolic blood pressure fell below 90% of baseline systolic blood pressure, with heart rate of at least 60bpm.
DRUGEphedrine
Ephedrine is a vasopressor drug that was administered when the participant's systolic blood pressure fell below 90% of baseline systolic blood pressure, with heart rate of less than 60bpm.
DEVICEManual vasopressor delivery system
Manual dosing system consisting: 1. Non-invasive intermittent blood pressure monitor that measured and recorded blood pressure at 1-minute intervals. 2. Attending anesthesiologist that noted the blood pressure readings and manually administered phenylephrine or ephedrine according to the algorithm.
Sponsors
KK Women's and Children's Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Investigator)
Eligibility
Sex/Gender
FEMALE
Age
21 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* age 21-45 years old, * weight 40-90 kg, * height 145-170 cm
Exclusion criteria
* contraindications to spinal anaesthesia, * allergy to drugs used in the study, and * those with uncontrolled medical conditions such as hypertension, diabetes mellitus, and cardiovascular disease
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Hypotension | 1 day | Incidence of systolic blood pressure less than 80% of baseline systolic blood pressure |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Hypertension | 1 day | Incidence of systolic blood pressure more than 120% of baseline systolic blood pressure |
| Nausea and vomiting | 1 day | Incidence of nausea and vomiting during cesarean section |
Contacts
PRINCIPAL_INVESTIGATORBan Leong Sng, FANZCA
KK Women's and Children's Hospital
Outcome results
None listed