Ultrasonography of the axillary vein to predict fall in blood pressure after spinal anesthesia.

Not yet recruiting

• Conditions: Medical and Surgical, (2) ICD-10 Condition: R688||Other general symptoms and signs,

• Registration Number: CTRI/2021/03/032093
• Lead Sponsor: Dr Aishwarya V

Brief Summary

**Introduction andNeed for study**

Spinal Anaesthesia is a frequently employedanaesthesia technique in clinical practice. It is usually preferred for infra umbilicalsurgeries. However, most commonly noted complication following spinalanaesthesia is Post spinal anaesthesia hypotension (PSAH). PSAH occurs as aresult of sympathetic blockade causing vasodilation of the arterioles,eventually leading to hypo perfusion and ischemia of vital organs. Pre-operativevolume may differ depending upon the physical status, comorbidities, fasting,that make the patients susceptible to intra operative hypotension. Timelyintervention is needed to prevent hypotension following spinal anaesthesiathereby reducing morbidity and mortality among the patients.

Several measures such as intra vascular volumepreload or prophylactic vasopressors has been used to prevent intra operativehypotension. But, these measures pose a danger of volume overload, especiallyin patients with a pre-existingcardiac or renal pathology.

Severalassessments have been tried to predict hypotension such as heart ratevariability, perfusion index and passive leg raise test with equivocal results.[1]

Ultrasonographyis emerging as an useful tool in daily clinical practice. Ultrasonography ofInferior vena cava (IVC) during spontaneous respiration helps to assess thevolume status in a patient[2]. Measuring the collapsibility index ofIVC is found to be definitive, easy, low cost and non- invasive,  yet it has its own limitations in patientswith upper abdominal tenderness, guarding of the abdomen, abdominal distensionor in bronchial asthma or any respiratory illness.

Axillary vein/Subclavian vein is foundto be an appropriate alternative for IVC to assess the volume status.[3]

Axillary/Subclavianvein is located near the surface of the skin but is subject to less externalcompression by the probe compared with the internal jugular or femoral veinsand is easily assessed in most patients by using a linear probe.

The goal of this study is to predicthypotension in patients receiving spinal anaesthesia by assessing thecollapsibility index of infraclavicular axillary vein during spontaneousrespiration and deep inspiration.

**REVIEW OFLITERATURE**

Choiet al. studied the preoperative diameter and collapsibility index of the subclavianvein (SCV) or infraclavicular axillary vein to predict the occurrence ofhypotension after induction of general anaesthesia in patients scheduled forlaparoscopic cholecystectomy. A total of 77 patients were recruited in thisstudy and 19 patients among them developed hypotension of 34.1± 6.6 mm Hg. They were noted to have a higher collapsibility indexof SCV during spontaneous breathing (P=0.009) and a higher collapsibility indexof SCV during deep inspiration (P=0.002). This study concluded that thecollapsibility index of the SCV during deep inspiration was a significantpredictor of occurrence of intraoperative hypotension and percentage fall inMAP after general anaesthesia induction.[4]

Salama et al. evaluated the efficacy of IVCcollapsibility index (IVCCI) and IVC to aorta diameter (IVC: Ao) index,measured pre-operatively for predicting post spinal anaesthesia hypotension. Atotal of 100 patients were enrolled in the study of which 45 patients developedPSAH and it was inferred that pre-operative IVCCI and IVC: Ao  index are good predictors of occurrence ofPSAH, with IVC: Ao being a better predictor of PSAH.[5]

Cerutiet al. evaluated the need for ultrasonography of IVC (IVCUS) guided volumeoptimization to prevent post-spinal hypotension. A prospective, randomised,cohort study, 160 patients scheduled for surgery under spinal anaesthesia werecategorised into IVCUS group and Control group (group C) where there was noultrasonography assessment made. The relative risk reduction of hypotensionbetween the groups was 35% and the need for vasoactive drugs in the IVCUS groupwas relatively lower compared to the control group and the total amount offluid administered was significantly higher in the IVCUS group compared to thecontrol group. Here, IVC collapsibility was correlated with the amount of fluidadministered. They also concluded that IVCUS is an effective method to preventpost spinal anaesthesia hypotension by administration of fluid through IVC viaultrasonography guidance before spinal anaesthesia.[2]

Zhanget al. studied the need for inferior vena caval ultrasonography beforeinduction of General anaesthesia to predict hypotension. A total of 104patients were recruited, but only 90 patients were analysed as the IVC scanningwas unsuccessful in those 14 patients and mean blood pressure, maximum IVCdiameter and collapsibility index were noted preoperatively obtained from the90 patients included in the study. This study inferred that pre-operativeultrasonography was indeed a reliable predictor of hypotension after inductionof general anaesthesia where the collapsibility index more than 43% wasconsidered as threshold.[6]

Kentet al. conducted a prospective study regarding the interchangeability of IVCcollapsibility index and SVC collapsibility index to assess intravascularvolume status in surgical intensive care patients where 34 patientsparticipated in the study. They underwent serial, paired assessment of IVC-CIand SVC-CI using portable ultrasound devices. It was concluded that SCVcollapsibility index was a reasonable adjunct to IVCCI in surgical intensivecare unit patients and the correlation between the two techniques is acceptableand overall measurement bias is noted to be low.[3]

**OBJECTIVE OF THE STUDY:**

Determination of collapsibility index ofthe infraclavicular axillary vein during spontaneous respiration and deepinspiration to predict hypotension post spinal anaesthesia.

**MATERIAL ANDMETHODS:**

**Source of data:**

In this study, patients of either genderaged between 18 and 65 years, undergoing elective surgeries requiring spinalanaesthesia at M S Ramaiah Medical College and Hospital will be enrolled aftertaking a written informed consent.

**DURATION OF STUDY:**

March 2021-October 2022.

20 months.

**METHOD OFCOLLECTION OF DATA:**

**Sample size**: 286 patients

The study by Kent et al. (184:561 -566) has shownthat IVC CI and SCV/AV CI has acceptable correlation. In the study by Salama etal. (36:297- 302) the incidence of PSAH was 45%. Based on  this findings with a absolute power of 5 anddesired confidence level of 95%, it is estimated that 286 patients need to berecruited for this study.

**TYPE OF STUDY**: Prospective observational study

**Inclusion criteria:**

Patients undergoingelective surgery under spinal anaesthesia.

Aged above 18 -65 yearsof either sex.

ASA Physical StatusI and II.

**Exclusion criteria:**

Anycontraindications for spinal anaesthesia.

BMI>30kg/m2.

Pregnant women

Emergency surgeries

Autonomicneuropathy

**Methodology:**

Patientsfulfilling the inclusion criteria will be taken up for the study after writteninformed consent.

Inthe pre operative room, all patients will be lying supine, breathingspontaneously for at least 5 minutes before examination, followed by ultrasonographyof the infraclavicular axillary vein using the Venue 40 (GE electronics)instrument and a linear high frequency ultrasound probe by an experiencedanaesthesiologist. The axillary vein, beginning at the lower margin of theteres major as a continuation of Brachial vein and continues its courseproximally until it terminates at the lateral margin of the first rib to becomethe subclavian vein. The infraclavicular axillary vein lies in thedeltopectoral groove, deep to the pectoralis minor muscle. The probe is placedin the sagittal plane over the middle third of the clavicle and traced laterallyto visualise the vein.

Thepatients will be instructed to breathe normally at rest (spontaneous respiration)and then to inspire as deeply as possible and expire naturally (deepinspiration).The diameter of the infraclavicular axillary vein duringspontaneous respiration (dAVmin) and deep respiration (dAVmax) will be recordedin M mode. The collapsibility index of the infraclavicular axillary vein willbe given by (dAVmax - dAVmin)/dAVmax \*100.

Noprior fluid loading will be done. Baseline vitals such as heart rate, bloodpressure, and oxygen saturation will be noted during ultrasound study.

Thepatient will then be transported to the operating theatre and vitals will benoted just prior to administration of spinal anaesthesia with the patient lyingsupine. Spinal anaesthesia will be performed with the subject in sittingposition at L3-L4 intervertebral space with 25G Quincke needle and 3 ml of Inj.Bupivacaine 0.5% heavy will be administered. Patient will be immediately put insupine position and heart rate, blood pressure and oxygen saturation will bemonitored every minute for the first ten minutes following which the vitalswill be measured every five minutes till the end of the surgery. There will beneither any change in the position of the patient nor any surgical interventionin the first ten minutes. The Anaesthetist who will be performing thesubarachnoid block and monitoring the intraoperative vitals will be blinded tothe ultrasonographic measurement of subclavian diameter and collapsibilityindex. The level of spinal blockade, intra operative blood loss and volume offluid administered will be noted and assessed.

Crystalloids fluidswill be infused at a rate of 10ml/kg body weight/hour after spinal anaesthesia.

Inthis study, intraoperative hypotension is defined as an absolute value of SBPless than 90mm Hg or decrease in systolic blood pressure of more than 20% ofthe baseline or an absolute value of MAP less than 60mm Hg. Patients will thenbe divided into two groups depending on whether they develop PSAH or not.

Any episodes of hypotension will be treated withfluid bolus of 200ml and if hypotension persists, bolus doses of IV of Inj. Ephedrine6mg will be given. Inj. Atropine 0.6mgIV will be given for bradycardia (HR<50bpm).

Thecorrelation between preoperative collapsibility index of infraclavicular veinand developing hypotension will be assessed in this study.

**Statistical Analysis:**

Descriptive statistics will be employed to describethe continuous variables such as age, height, weight, Body mass index (BMI),etc. Percentages will be employed to describe categorical variables such asgender, ASA physical status, development of hypotension, presence ofcomorbidities, etc. Differences in the quantitative variables between the twogroups such as those who developed hypotension and who did not develophypotension will be tested for statistical significance by ‘Student t test’. Incase the data does not follow normal distribution, non-parametric tests ofsignificance will be employed. To test for differences in percentages betweenthose who developed hypotension versus those not developing hypotension will betested for statistical significance by Chi-square test of significance will beemployed. To find out the independent predictors for development ofhypotension, multivariate logistic regression analysis will be employed.

Sensitivity, specificity, positive and negativelikelihood values will be estimated at different level of percentage deepinspiration. To predict the patients who are likely to develop hypotensionversus not developing, receiver operating curve (ROC) drawn to estimate the cutoff levels of deep inspiration.

 **References**

 1. Duggappa DR, Lokesh M, Dixit A, RinitaPaul, RS Raghavendra Rao, P Prabha. Perfusion index as a predictor ofhypotension following spinal anaesthesia in lower segment caesarean section. Indian J Anaesth 2017; 61:649 -654.

 2.  Ceruti S,Anselmi L, Minotti B, D Franceschini, J Aguirre, A Borgeat, et al*.* Prevention of arterialhypotension after spinal anaesthesia using vena cava ultrasound to guide fluidmanagement. Br J Anaesth 2018; 120:101 -108.

 3.   Kent A, Bahner DP,Boulger CT, Daniel SE, Eric JA, David CE*,* et al.Sonographic evaluationof intravascular volume status in the surgical intensive care unit: aprospective comparison of subclavian vein and inferior vena cava collapsibilityindex. J Surg Res 2013; 184:561 -566.

 4.ChoiMH, Chae JS, Lee HJ, Woo JH. Pre-anaesthesia ultrasonography of thesubclavian vein/infraclavicular axillary vein for predicting hypotension afterinducing general anaesthesia: a prospective observational study. Eur JAnaesthesiol*.*2020; 37:474 -48.

 5.SalamaER, Elkashlan M. Pre-operativeultrasonographic evaluation of inferior vena cava collapsibility index andcaval aorta index as new predictors for hypotension, after spinal anaesthesia:a prospective observational study. Eur J Anaesthesiol 2019; 36:297 -302.

 6.Zhang J, Critchley LA. Inferior venacava ultrasonography before general anaesthesia can predict hypotension afterinduction. Anaesthesiology 2016; 124:580 -589.

Detailed Description

Not available

Study Timeline

• Study Start: 2021-03-17
• Last Update Posted: 2021-03-17

Recruitment & Eligibility

• Status: Not Yet Recruiting
• Sex: All
• Target Recruitment: 286

Inclusion Criteria

• Patients undergoing elective surgery under spinal anaesthesia.
• Aged above 18 -65 years of either sex.
• ASA Physical Status I and II.

Exclusion Criteria

• Any contraindications for spinal anaesthesia.
• Pregnant women Emergency surgeries Autonomic neuropathy.

Study & Design

• Study Type: Interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Determination of correlation between collapsibility index of the infraclavicular axillary vein and hypotension post spinal anaesthesia.	Non invasive Blood pressure readings at 0 minutes, 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, followed by every 5 minutes until the end of surgery.

Trial Locations

Locations (1)

M S Ramaiah Medical College and Hospital; 🇮🇳 Bangalore, KARNATAKA, India

M S Ramaiah Medical College and Hospital

🇮🇳Bangalore, KARNATAKA, India

Dr Vinayak P S

Principal investigator

9900859460

drvinayak_ps@yahoo.co.in