Effects of Sedation on Spinal Anesthesia-induced Maternal Hypotension

Study Overview
=================
Brief Summary
-----------------
Background: This study was designed to investigate the effect of sedation on the occurrence of maternal hypotension in preoperatively anxious parturients undergoing urgent category-1 Cesarean section (C/S) under spinal anesthesia. Methods: After institutional ethics committee approval, prospectively collected data of 1824 parturients undergoing C/S were reviewed. Parturients with high preoperative anxiety scores (visual analogue scale for anxiety (VAS-A)≥70) undergoing C/S under spinal anesthesia with thiopental (Group S=49) and without any other type of sedation (Group NS=53) were included in the analysis. Hemodynamic parameters were documented and maximum systolic arterial pressure (SAP) reductions from the baseline after spinal anesthesia were calculated. Incidences of hypotension (SAP≥30% decrease from baseline or <100 mmHg) and bradycardia (HR<55 beats/min), and related-ephedrine and -atropine requirements were noted. Our primary endpoint was to compare the maximum SAP reductions from the baseline values in Groups S and NS. Secondary endpoints were incidences of hypotension and bradycardia, required ephedrine and atropine doses, newborn Apgar scores at 1st and 5th min.

Detailed Description
-----------------
Background: This study was designed to investigate the effect of thiopental sodium sedation on the occurrence of maternal hypotension in preoperatively anxious parturients undergoing urgent category-1 Cesarean section (C/S) under spinal anesthesia. Methods: After institutional ethics committee approval, prospectively collected data of 1824 parturients undergoing C/S at Van Training and Research Hospital between August 2014 and February 2015 were reviewed. Parturients with high preoperative anxiety scores (visual analogue scale for anxiety (VAS-A)≥70) undergoing C/S under spinal anesthesia with thiopental (Group S=49) and without any other type of sedation (Group NS=53) were included in the analysis. All parturients received SA with hyperbaric bupivacaine 0.5% 2.5 mL. Hemodynamic parameters were documented and maximum systolic arterial pressure (SAP) reductions from the baseline after spinal anesthesia were calculated. Incidences of hypotension (SAP≥30% decrease from baseline or <100 mmHg) and bradycardia (HR<55 beats/min), and related-ephedrine and -atropine requirements were noted. All data were obtained from the surgical database and patient charts. Primary endpoint of our study was to compare the maximum SAP reductions from the baseline values in Groups S and NS. Secondary endpoints were incidences of hypotension and bradycardia, required ephedrine and atropine doses, newborn Apgar scores at 1st and 5th min.

Official Title
-----------------
Effects of Sedation on Spinal Anesthesia-induced Maternal Hypotension in Preoperatively Anxious Parturients Undergoing Urgent Category-1 Cesarean Section: A Historical Cohort Study

Conditions
-----------------
Cesarean Section, Preoperative Anxiety, Spinal Anesthesia, Sedation, Maternal Hypotension

Intervention / Treatment
-----------------
* Drug: Sedation
* Drug: No sedation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Urgent category-1 C/S ASA physical status I-II Aged between 18 and 35 years Term (≥37 weeks) singleton pregnancy BMI <40 kg/m2 Height >150 cm or <180 cm High preoperative anxiety scores (visual analogue scale for anxiety (VAS-A) ≥70) Spinal anesthesia with thiopental sodium sedation Spinal anesthesia without any sedation Exclusion Criteria: Preoperative prehydration Placenta previa Placenta accreta Hypertension Pregnancy-induced hypertension Urgent category ≥2 General anesthesia Spinal anesthesia with sedation other than thiopental sodium

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sedation (S)<br>Parturients who received IV thiopental 2 mg kg-1 and if necessary additional 50 mg immediately after spinal anesthesia until reaching at least Ramsay sedation score of 3 (1: patient anxious, agitated or restless, 6: patient with no response to light glabella tap or loud auditory stimulus.). | Drug: Sedation<br>* Parturients who received IV thiopental 2 mg kg-1 and if necessary additional 50 mg immediately after spinal anesthesia until reaching at least Ramsay sedation score of 3 (1: patient anxious, agitated or restless, 6: patient with no response to light glabella tap or loud auditory stimulus.).<br>* Other names: Thiopental;|
| No sedation (NS)<br>Parturients who did not receive any sedative agent after the spinal anesthesia performance. | Drug: No sedation<br>* Parturients did not receive any type of sedation after spinal anesthesia.<br>* Other names: No drug;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum systolic arterial pressure (SAP) reductions from the baseline values | % SAP reduction after spinal anesthesia | 0-10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of maternal hypotension | Incidence of hypotension during the surgery (decrease in SAP >30% from baseline or an absolute value <100 mmHg) | 0-30 minutes | 
| Incidence of maternal bradycardia | Incidence of bradycardia during the surgery (heart rate (HR) <55 beats min-1) | 0-30 minutes | 
| Ephedrine requirement | Ephedrine 5 mg IV boluses were administered with 2 min intervals until SAP returned to a value of >100 mmHg | 0-30 minutes | 
| Atropine requirement | Bolus of IV 0.5 mg atropine was given if bradycardia (HR <55 beats min-1) occurred | 0-30 minutes | 
| Incidence of maternal nausea | If any during the Cesarean section, recorded | 0-30 minutes | 
| Incidence of maternal vomiting | If any during the Cesarean section, recorded | 0-30 minutes | 
| Newborn Apgar score 1st min | Apgar score at 1st min (0-3: severely depressed, 4-6: moderately depressed, 7-10: excellent condition) | 1st min | 
| Newborn Apgar score 5th min | Apgar score at 5th min (0-3: severely depressed, 4-6: moderately depressed, 7-10: excellent condition) | 5th min |