Effective analgesia in arthroscopic shoulder surgery is a major concern and is essential for
all aspects of the patient's recovery. Multimodal pain management is recommended for early
postoperative pain control. Regional anesthesia is preferred in shoulder surgery as an
effective means of providing anesthesia and postoperative analgesia. Commonly used techniques
for shoulder surgery include interscalene brachial plexus (ISB) blocks, continuous ISB (CISB)
blocks, suprascapular nerve blocks (SSB), supraclavicular nerve blocks (SCB), local
infiltration (LI), and ISB with adjuvants.Interscalene brachial plexus (ISB) block is
considered the analgesic technique of choice for shoulder surgery. Shoulder block which is
combination of suprascapular nerve block and axillary nerve block has been recently proposed
as an alternative anesthetic and postoperative analgesic modality in this patient population.
These two nerve blocks cause the loss of the sensory innervation of the shoulder. Shoulder
block is advantageous to the interscalene brachial plexus block since it does not lead to
respiratory dysfunction due to phrenic nerve palsy or other serious complications.The
pericapsular nerve group (PENG) block may be safely applied for both partial anesthesia and
analgesia in selected shoulder surgery cases. It did not cause motor block or pulmonary
complications, nor result in muscle laxity, blocking only the shoulder and the upper third of
the humerus. PENG block has been studied extensively in hip surgeries but its place in
shoulder surgeries is not yet clear. Therefore, this study will be conducted to compare
efficacy of ultrasound guided shoulder block with PENG block for postoperative analgesia in
patients undergoing arthroscopic shoulder surgeries.
The aim of this study:
assess the quality of pain relief in patients who will undergo arthroscopic shoulder
surgeries receiving either shoulder block versus PENG block comparing and evaluating the
differences between the two techniques.
Sample Size Calculation:
Sample size was calculated using Power Analysis and Sample Size software program (PASS)
version 11.0.4 for windows (2011) with time to first analgesic request as the primary
outcome. Using the results published by Pani et al 2019 with the mean time to first analgesic
request in shoulder block group was (5.9 ± 1.2 hours) Using a two-sided two-sample
unequal-variance t-test, sample size of 40 patients is needed to achieve 90% power to detect
20 % difference in time to first analgesic request. Using a two-sided hypothesis test with a
significance level of 0.05. A 10% drop out is considered, so a total of 46 patients will be
enrolled (23 in each group) in this study.
Methods:
The study will be conducted in Mansoura university hospital on Forty six patients who will be
scheduled for arthroscopic shoulder surgery under general anesthesia. They will be randomly
assigned to two equal groups (PENG group and shoulder block group) according to
computer-generated table of random numbers using the permuted block randomization method. The
group allocation will be concealed in sequentially numbered, sealed opaque envelopes which
will be opened only after obtaining the written informed consent. A written informed consent
will be obtained from all study subjects after ensuring confidentiality. The study protocol
will be explained to all patients after enrollment into the study along with VAS after
enrollment into the study. Basic demographic characters including age, sex, and weight will
be recorded. In both groups, The PENG and shoulder block procedures will be performed in the
preoperative regional room under strict aseptic conditions using 30 ml 0.25% bupivacaine.
Statistical Methods:
The collected data will be coded, processed, and analyzed using SPSS(Statistical Package for
the Social Sciences) program (version 22) for Windows. Normality of numerical data
distribution will be tested by Shapiro-Wilk test. Continuous data of normal distribution will
be presented as mean ± SD(standard deviation) and compared with the unpaired student's t
test. Non-normally distributed data will be presented as median (range) and compared with the
Mann-Whitney U test. Repeated measures ANOVA will be used for comparisons within the same
group. Categorical data will be presented as number (percentage) and compared with the
Chi-square test. All data will be considered statistically significant if P value is ≤ 0.05.