Ultrasound Versus C arm Fluoroscopic Guided Subarachnoid Block In Patients With Predicted Difficulty For Subarachnoid Block Posted for Infraumbilical Surgeries: A Prospective Randomized Controlled Study

Subarachnoid block is routinely accessed blindly by the use of anatomical landmarks in the localization of the subarachnoid space, Performing the subarachnoid block using the landmark technique in patients with difficult spinal anatomy can be challenging and may lead to failed subarachnoid block, post dural puncture headache, spinal hematoma and spinal cord injury Bone  does  not  permit  ultrasound  beam  transmission, thus  casting  a  hypoechoic  shadow  on  the  image, Conversely, passage of the ultrasound beam through the interspinous and interlaminar windows allows visualization of the hyperechoic dura and subarachnoid space and posterior aspect of the vertebral body This appropriate view facilitates identification of the optimal location for proper needle insertion during neuraxial block and estimation of the skin-to-dura distance Fluoroscopy is an imaging modality that employs beam of x rays to pass through body and detect x ray beams through C-arm (Computer assisted radio monitoring), This enables practitioners to visualize accurate intervertebral spaces and needle paths in real time and enables to use both hands for needle manipulation  In this study we will compare the efficacy of Fluoroscopy C-arm guided versus ultrasound guided technique in patients  with  predicted  procedural  difficulty  for sub arachnoid block  posted  for infraumbilical surgeries

RESEARCH QUESTION

Whether ultrasound imaging  and C arm fluoroscopy imaging is better than anatomical landmarks guided subarachnoid block in patients with predicted procedural difficulty posted for infraumbilical surgeries ?

AIM OF STUDY

•To compare the efficacy among c-arm fluoroscopy, ultrasound guided and anatomical landmarks guided subarachnoid block in patients with predicted procedural difficulty posted for infraumbilical surgeries

PRIMARY OBJECTIVES

To compare the success rate

To compare the total procedure time in each technique

To compare the number of insertion attempts in each technique

SECONDARY OBJECTIVES:

To compare the  Haemodynamic Parameters

To compare the Patient satisfaction score

To compare the complications, if any

INCLUSION CRITERIA:

1.    Patients aged between 18-80 years2.    Patients of either sex (Male/Female) 3.    American Society of Anaesthesiologist physical status â…  and â…¡4.    Patients scheduled for infraumbilical surgeries under subarachnoid block with predicted difficulty for subarachnoid block due to BMI ≥ 30kg/m2

EXCLUSION CRITERIA:1.    Patients who refused Subarachnoid Block procedure

2.    Patients receiving thromboprophylaxis

3.    Patients having Allergy to local anaesthetics

4.    Infection at the site of procedure

5.    Obstetric population

6.    Patients with spina bifida

7.    Patients with Aortic stenosis, mitral stenosis, mitral regurgitation

8.    Patients with raised intracranial tension

9.    Patients with inherited and acquired coagulopathies

STUDY METHODOLOGY

We will perform a prospective randomized controlled study on all the patients who will be included in the study after taking institutional ethical committee approval.

Patients will be randomized into 3 groups using computer generated random number table:

Group A (n=20) - Patients undergoing sub arachnoid block under guidance of ultrasonography

Group B (n=20) - Patients undergoing sub arachnoid block under fluoroscopic c arm guidance

Group C (n=20) - Patients undergoing sub arachnoid block using anatomical landmark guided

technique

To achieve adequate expertise, we will perform ultrasound guided subarachnoid block and

c-arm fluoroscopy guided subarachnoid block on 25-25 normal patients who are posted for infraumbilical surgeries respectively before starting the study.

Pre-anaesthetic check-up including detailed history, general examination, systemic examination of cardiovascular, respiratory, central nervous system and for systemic illness will be done. Patients will be explained about concerned procedure, written and informed consent will be taken after explaining the procedure. Patients will be instructed to keep fasting for 6-8 hours on the day before surgery. After shifting the patients to operation theatre heart rate, non-invasive blood pressure, oxygen saturation (spo2), electrocardiogram (ECG) will be monitored. In operation theatre peripheral vascular access will be secured with 18-gauge (G) intravenous cannula in all patients and Ringer Lactate infusion will be started. Patients of all 3 groups will be administered with injection Ondansetron 4 mg iv and Injection ranitidine 50mg iv. Subarachnoid block will be performed by the person who will be involved in the study and all the observations will be recorded by the person who is not involved in the study.

Total procedure time is defined as Time taken to identify the landmark by each technique followed by administration of drug in subarachnoid space. Number of needle insertion attempts is defined as number of any separate skin puncture by a needle. Success rate is defined as successful dural puncture followed by free flow of cerebrospinal fluid.

Patient satisfaction score with the block procedure is rated by patient immediately after completion of subarachnoid block on 5-point Likert scale

(5= very satisfied, 4= satisfied,

3= enough satisfied, 2= dissatisfied, 1= very dissatisfied)

PROCEDUREAll patients will be placed in sitting position under routine monitoring. Under all aseptic precautions, the desired Intervertebral space will be identified by manual palpation of anatomical Landmark. A horizontal imaginary line passing over top of both iliac crests which is known as tuffiers line corresponding to (L4-L5) intervertebral space will be taken as guide to identify the space.

GROUP A

The ultrasound probe will be covered with sterile sleeve and sterile gel applied on the probe.  After positioning probe at the sacrum, the probe will be directed from caudal to cephalad direction to identify the successive intervertebral laminas (L5, L4, L3, and so on). The L4-L5 intervertebral spaces will be identified on this plane and marked on the skin. The distance from skin to intrathecal space will be measured and recorded, following which skin around L4-L5 Intervertebral space will be infiltrated with 2% Lidocaine. A 25G 90mm long Quincke’s spinal needle will be inserted in L4-L5 intervertebral space and needle tip will be advanced under real time ultrasound guidance and the direction of the needle shaft will be adjusted under ultrasound guidance to enter the subarachnoid space. After confirmation of the free flow of cerebrospinal fluid, inj. Bupivacaine 0.5% hyperbaric (0.3mg/kg) will be injected into subarachnoid space.

GROUP B

Skin around L4-L5 intervertebral space will be infiltrated with 2% lidocaine following which fluoroscopy C-arm machine will be positioned over lumbar spine with appropriate

x ray views will be taken. A 25gauge 90mm long Quincke’s spinal needle will be inserted in L4-L5 intervertebral space. Simultaneously real time imaging with fluoroscopy c arm with series of x-ray images of lumbar spine will be done and the shaft of the needle will be adjusted accordingly till free flow of cerebrospinal fluid comes out. Inj. Bupivacaine 0.5% hyperbaric (0.3mg/kg) will be injected into sub arachnoid space.

GROUP C

The skin around L4-L5 Intervertebral space will be infiltrated with 2% lidocaine, following which 25gauge 90mm long Quincke’s spinal needle will be inserted in (L4-L5) intervertebral space. Successful entry of needle into sub arachnoid space will be confirmed by free flow of cerebrospinal fluid from the needle hub, after which inj. Bupivacaine 0.5% hyperbaric (0.3mg/kg) will be injected into sub arachnoid space. All the patients will be immediately placed in supine position after giving subarachnoid block.

Successful spinal anaesthesia will be defined as bilateral T6 block after intrathecal drug administration.

Hemodynamic parameters, heart rate (HR), systolic blood pressure (SBP),

diastolic pressure (DBP), Mean arterial pressure (MAP), respiratory rate (RR),

oxygen saturation (SPO2) will be monitored throughout the surgery.

    Outcome variables:

Total procedure time is defined as time taken to identify the landmarks by each technique upto free flow of cerebrospinal fluid

Number of needle insertion attempts is defined as number of any separate skin puncture by a needle.

Success rate is defined as successful dural puncture followed by free flow of cerebrospinal fluid.

Failure is defined as failure of localization of subarachnoid space with lumbar puncture in three needle insertion attempts

Patient satisfaction score with the block procedure is rated by patient immediately after completion of procedure on

5-point Likert scale (5= very satisfied, 4= satisfied, 3= enough satisfied, 2= dissatisfied, 1= very dissatisfied)