This prospective randomised study has been designed to
evaluate and compare the efficacy of ultrasound guided pericapsular nerve group
block with that of ultrasound guided femoral nerve block for reducing pain
associated with positioning for subarachnoid block in patients undergoing
surgery for hip fracture.
We hypothesise that Ultrasound guided Pericapsular nerve
group block is more efficacious than
ultrasound guided femoral nerve block
for reducing pain associated with positioning for subarachnoid block in patients undergoing surgery for hip fracture.
The study will be conducted on 60 adult patients ( 18-60
years of age) of either sex, ASA grades 1 & 2 scheduled for surgery
for hip fracture under
subarachnoid block.
Patients will be randomly allocated to two groups of 30 each
using
Computer generated random number table in two groups P&F. Allocations will be
concealed in sealed numbered opaque envelopes, where F represents group
receiving femoral nerve block and P represents group receiving PENG block. Once
a patient will consent to enter a trial , an envelope will be opened and the
patient will then be offered the allocated group.
Group P
(N=30) : Patients will receive
ultrasound guided pericapsular nerve group block with 20 ml of 0.5% ropivacaine.
Group F
(N=30): Patients will receive
ultrasound guided femoral nerve block with 20 ml of 0.5% ropivacaine . All the
patients will undergo detailed pre anaesthetic checkup and relevant
investigations.
Patients will be examined one day prior to surgery and
subjected to complete physical as well as systemic examination . All the
patients will be made to fast overnight. The purpose of the
study, advantages and side effects of both the techniques of
the study will be explained to patients and informed written consent will be
obtained.
Preoperatively the patients will be familiarized with visual
analog scale (VAS) pain score and its use in pain assessment.
Upon arrival in the room for block performance, standard
monitoring including heart rate (HR), noninvasive blood pressure (NIBP),
electrocardiography (ECG) and pulse oximetry (SpO2) will be established.
Intravenous line will be secured with 18 G venous cannula. Ringer lactate infusion will be started and a nasal cannula
will provide oxygen (3L/min). No
sedative or analgesic medications will be administered.
Equipment and drugs required for providing general
anaesthesia ,emergency resuscitation, and ultrasound guided nerve blocks will
be kept ready.
Visual Analog Scale (VAS) score will be assessed and noted
using a standard 10 cm VAS with 0 corresponding to no pain and 10 designating
the worst possible pain before the block at rest and at dynamic hip movement of
affected limb (straight leg raise of 15degrees above table) .20
Patients will be administered either of the blocks according
to group allocation.
Heart rate, non invasive blood pressure (systolic ,diastolic,
mean), respiratory rate and SpO2 will be recorded at 5,10 and 20 , 30 minutes
after performing the block procedure and at positioning for subarachnoid block and
monitored continuously while performing the block and during perioperative
period.
Procedure:
For ultrasound guided Pericapsular nerve group block
The regional block will be performed with the patient in the
supine position. Using strict aseptic precautions a curvilinear low-frequency
ultrasound probe (2-5 MHz, M Turbo, SonoSite Inc., USA) will be initially placed
in the transverse plane over the anterior inferior iliac spine and then aligned
with the pubic ramus by rotating the probe counterclockwise approximately 45
degrees. In this view the iliopubic eminence, the iliopsoas muscle and tendon,
the femoral artery and pectineus muscle will be observed. A skin wheal of local
anaesthetic will be made 1 cm away from the lateral edge of the ultrasound
probe. A 22-gauge, 100-mm long echogenic needle will be inserted from lateral
to medial in an in-plane approach to place the tip in the musculofascial plane
between the psoas tendon anteriorly and the pubic ramus posteriorly. Following
negative aspiration, the local anaesthetic solution (20 ml of 0.5% ropivcaine)
will be injected in 5-mL increments while observing for adequate fluid spread
in this plane.13
Procedure:
For ultrasound guided femoral nerve group block
Femoral block will be performed with the patient in the supine position.
Using strict aseptic precautions a linear transverse high frequency probe(8-18
MHz M Turbo Sonosite) will be positioned
over the femoral crease to identify the femoral artery and nerve. If the nerve
is not immediately apparent lateral to the artery, the transducer will be tilted proximally or
distally to highlight the nerve from the iliacus muscle and the more
superficial adipose tissue. In doing so, an effort will be made to identify the
iliacus muscle and its fascia, as well as the fascia lata. Once the femoral
nerve is identified, a skin wheal of local anaesthetic will be made 1 cm away from
the lateral edge of the transducer. The 80mm long , 22 gauge echogenic needle will be
inserted in-plane in a lateral to medial orientation and advanced toward
the femoral nerve after piercing fascia lata and layer of fascia iliaca. After
negative aspiration 20 ml of 0.5% ropivacaine will be injected and spread of
the drug will be noted by displacement of
the femoral nerve.19
After 20 min patient will be moved to operating room. Patient
will be made to sit up for positioning for subarachnoid block 30 minutes after administration
of the analgesic block.
Subarachnoid block will be performed using a median or
paramedian approach at the L3-L4 or L4-L5 interspace using spinal needle.
PENG block and femoral nerve blocks will be given by an anaesthesiologist
who would have performed both the blocks 10 times before starting the study
cases. Observation for various parameters will be done by other
anaesthesiologists blinded to the type of block given.
If the patient reports a VAS score ≥4 during positioning,
procedure will be stopped,intravenous fentanyl 0.5 μg/kg will be given and positioning will be re-attempted after 5
minutes. reduction of VAS to less than 4 by giving intravenous 0.5 μg/kg of inj. fentanyl every 5 minutes repeated
up to maximum of 3 doses..
Primary objective is to compare the analgesia provided
by ultrasound guided pericapsular nerve
group block with that of ultrasound guided femoral nerve block on positioning
for subarachnoid block in patients undergoing surgery for hip fracture using
visual analog scale (VAS) score for
pain.
Secondary objective: Quality of patient’s position for
subarachnoid block , Total amount of fentanyl required during positioning for
subarachnoid block, Time taken for performing subarachnoid block, Patient’s satisfaction
with the nerve block .
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