Anterior Suprascapular Nerve Block is an Effective and Diaphragm Protective Approach for Arthroscopic Shoulder Surgery

Anterior Suprascapular Nerve Block is an Effective and Diaphragm Protective Approach for Arthroscopic Shoulder Surgery

Anterior Suprascapular Nerve Block is as Effective as Interscalene Nerve Block and Causes Less Diapragm Paralysis in Arthroscopic Shoulder Surgery

Interscalene block is still the gold standard in shoulder surgery analgesia. The most important side effect is diaphragm paralysis due to the phrenic nerve being affected. It may cause symptomatic dyspnea, especially in patients with limited respiratory capacity. There are studies showing that an effective analgesia, as much as the interscalene block can do, can be provided by blocking the suprascapular nerve in the neck region. The aim of our study is to show that the anterior suprascapular block applied with ultra-low volume (5ml) in shoulder arthroscopy operations is at least as effective as the interscalene block and does not cause diaphragm paralysis.

Interscalene block is still the gold standard in shoulder surgery analgesia. The most important side effect is diaphragm paralysis due to the phrenic nerve being affected. It may cause symptomatic dyspnea, especially in patients with limited respiratory capacity. More distal brachial plexus blocks have been defined to avoid diaphragmatic paralysis . Thus, it is aimed to apply the local anesthetic drug further from the phrenic nerve. With the application of ultrasound, the amount of local anesthetic drug was reduced to less than 20 ml. There are studies showing that an effective analgesia, as much as the interscalene block can do, can be provided by blocking the suprascapular nerve in the neck region. Although it has been shown in a cadaver study that the phrenic nerve can be stained after anterior suprascapular nerve block, the clinical effect is not fully known. The effect of continuous local anesthetic drug administration on respiratory muscles through catheters placed in the peripheral nerve is another matter of concern. The method that will not affect the phrenic nerve at all and at the same time provide an effective analgesia is still under investigation. The aim of our study is to show that the anterior suprascapular block applied with ultra-low volume (5ml) in shoulder arthroscopy operations is at least as effective as the interscalene block and does not cause diaphragm paralysis. One of the questions that our research aims to answer is how the continuous application of local anesthetic drugs affects the diaphragm muscle with the insertion of catheters in both regions.

Diaphragm Paralysis Due to Local Anesthesia, Anterior Suprascapular Nerve Block, Analgesia, Arthroscopic Shoulder Surgery

arthroscopic shoulder surgery, Interscalene nerve block, Anterior suprascapular nerve block, Analgesia, postoperative, Diaphragm paralysis

The patients will be divided into two groups as patients who underwent suprascapular nerve block with the supraclavicular approach and patients who underwent conventional interscalene nerve block. 5 ml of 0.5% Bupivacaine will be injected into both groups. Diaphragmatic movement will be evaluated with ultrasound at the right and left subcostal border with the patients in a semi-sitting position. The reduction in diaphragm motion will be calculated as the difference (in percent) in diaphragm motion measured before and 30 minutes after the block.

patients will be placed in a semi-sitting position with their heads facing the opposite side. Linear ultrasound probe (GE Loqic P9 7-15 MHz) to detect the brachial plexus. At the cervical level 5-6, the posterior brachial plexus will be approached as "in-plane" from the posterior with the needle (Contiplex C, Braun) through the catheter. The nerve structure will be confirmed with stimulation in the upper extremity muscles with a nerve stimulator and 5 ml 0.5% Bupivacaine will be injected.

patients will be placed in a semi-sitting position with their heads facing the opposite side. Linear ultrasound probe (GE Loqic P9 7-15 MHz) will be placed in the suprascapular region in a coronal oblique manner. The omohyoid muscle, under it the suprascapular nerve, the brachial plexus and the subclavian artery will be identified. The suprascapular nerve will be approached from the posterior as "in-plane" with a needle (Contiplex C, Braun) through the catheter. The nerve structure will be confirmed by stimulation in the supraspinous muscle with a nerve stimulator and 5 ml 0.5% Bupivacaine will be injected.

Diaphragmatic movement will be evaluated with ultrasonography and a 5-2 MHz convex transducer will be used. The ultrasound probe is placed between the mid-clavicular line and the anterior axillary line by directing it vertically and slightly cranially. During quiet breathing and deep breathing, diaphragm movement will be measured. The reduction in diaphragm motion will be calculated as the difference (in percent) in diaphragm motion measured before and 30 minutes after the block. Each test will be done 3 times and the values will be averaged. A decrease between 75% and 100% will be defined as complete paresis, a decrease between 25% and 75% as partial paresis, and less than 25% decrease in diaphragmatic movement will be defined as no paresis. In order to investigate the effect of continuous local anesthetic drug administration on diaphragm movement via nerve catheter, the same procedure will be repeated 24 hours after surgery.

Inclusion Criteria: Patients > 18 years old American Society of Anesthesiology (ASA) score of 1-3 Scheduled for elective surgery. Exclusion Criteria: Patients with a condition that prevents peripheral nerve block Coagulopathies Chronic opioid use Stroke Polyneuropathy Cognitive dysfunction Communication difficulties Allergies to drugs used

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