Association Between Pre-Operative Anxiety and Post- Spinal Hypotension in Women Undergoing Elective Caesarean Section: A Cross-Sectional Study.

PRIMARY PURPOSE

1.To assess the level of preoperative anxiety in patients scheduled for elective Caesarean delivery.

2.To identify the association between pre-operative anxiety and blood pressure changes during spinal anaesthesia for elective Caesarean delivery.

STUDY HYPOTHESIS

Hypotension after spinal anaesthesia is primarily  due  to  the  suppression  of  sympathetic outflow. Patients with a higher baseline sympathetic drive were seen to  have a profound fall in  blood pressure after spinal anaesthesia. Therefore it can be  rationalized  that  patients  with  higher  pre- operative anxiety may have a markedly significant post-spinal hypotension.

PROCEDURE

After obtaining approval from the Department Postgraduate Research Monitoring Committee  (PGRMC),  Institutional  Ethics  Committee,  this  study  will  be registered in Clinical Trials Registry-India (CTRI). Written informed consent will be obtained from patients after explaining the whole procedure, before the start of the study.

One day before or on the day of surgery, the pre-operative anxiety of the patient is assessed using four standard direct psychological measures of anxiety:

1)  State-Trait Anxiety Inventory (STAI)

2)  Visual Analogue Scale For Anxiety Mood (VAS)

Indirect physical measure of anxiety using Salivary Amylase will also be done. Salivary sample will be collected using a hand-held monitor called Cocorometer from Nipro, Osaka, Japan. This device has a main monitor and test-strips which are sufficient to collect saliva. Saliva will be collected from the sublingual area in about 30 seconds using the test-strips.

The  baseline  blood  pressure  will  be  recorded  on  arrival  of  the  patient  to  the operating theatre. A 18G/20G intravenous line is secured and 500 ml of Ringer’s Lactate  is  given  as  pre-load/co  load  before  the  administration  of  spinal anaesthesia. Spinal anaesthesia will be administered in the left lateral position, at the level of L4–L5 or L5–S1 intervertebral space using 1.8 to 2ml (depending on the height of the patient) of 0.5% hyperbaric bupivacaine. After administration the patient is immediately placed in supine position with a wedge under the right hip. Surgery will be allowed to begin when the sensory level of block is at least T4 level bilaterally.Maternal blood pressure will be measured during the intra-operative period using Non-invasive Blood Pressure (NIBP) monitor. All measurements will be made in the supine position with left uterine displacement using wedge at right hip. Blood pressure will be measured at baseline, immediately before spinal anaesthesia, and every  minute  after  spinal  anaesthesia  until  delivery  and  every  5  mins  until completion of surgery.

Systolic Blood Pressure (SBP) below 100 mm Hg will be treated with a fluid bolus of 250–500 ml. SBP below 90 mm Hg will be treated with I.V. vasopressors (mephentermine/phenylephrine) depending on maternal heart rate.