Interscalene Block and Dysfunction Diaphragmatic (NUMEROBIS)

Interscalene Block and Dysfunction Diaphragmatic: Effect of Low Volume of Ropivacaine 0,1%. A Randomised, Controlled Trial

The study seeks to show that interscalene injection of a small volume (<8ml) of ropivacaine at a low concentration (0.1%) reduces the frequency of hemi-diaphragmatic paresis compared to low volume injection at the standard concentration (0.5%) in patients undergoing arthroscopic shoulder surgery with ISB.

It's a prospective monocentric randomized controlled clinical trial in 2 parallel groups in double blind. the study concerns patients undergoing arthroscopic shoulder surgery with ISB. The study seeks to show that interscalene injection of a small volume (<8ml) of ropivacaine at a low concentration (0.1%) reduces the frequency of hemi-diaphragmatic paresis compared to low volume injection at the standard concentration (0.5%) in patients undergoing arthroscopic shoulder surgery with ISB. Randomization in one of the two arms: Experimental group: <8ml ropivacaine 0.1%. Control group: <8mL of ropivacaine 0.5%. Evaluation of diaphragmatic stroke by ultrasound and ventilatory function by spirometry and snip test before performing the ISB, then after installation of the ISB. Performing the surgical procedure under general anesthesia assessment of postoperative analgesia and patient satisfaction during the following 48 hours.

interscalene block, shoulder surgery, local anesthesic, respiratory function, diaphragmatic dysfunction, echography, locoregional anesthesia

Interscalene block for arthroscopic shoulder surgery with small volume of low concentration (0.1%) of ropivacaine

Interscalene block for arthroscopic shoulder surgery with small volume of standard concentration (0.5%) of ropivacaine

Hemi diaphragmatic paresis is evaluated by quantifying the homolateral diaphragmatic stroke at interscalene block (ISB) by ultrasound analysis (measured in centimeter), during slow and deep inspiration. Diaphragmatic hemiparesis is defined as a decrease (at post-ISB time vs. pre-ISB time) of more than 25% of the diaphragmatic stroke during this slow and deep inspiration.

Hemi-diaphragmatic paralysis refers to the absence of diaphragmatic movement (or paradoxical movement) in ultrasound during rest ventilation and slow, deep inhalation.

Duration of effective analgesia (defined as the period up to the first EVA > 3 (excluding PACU Consumption of morphine in PACU and analgesics within the first 24 hours.

Presence of a respiratory impairment detected by spirometry (Spiro-USB® device) and presence of a diaphragmatic impairment detected by snip test, (micro-RPM®). Ventilation impairment will be considered present if there is a decrease of at least 25% in vital capacity between the pre and post ISB. Diaphragmatic damage is defined as a decrease of at least 25% in the Snip-test values between the pre and post ISB.

Evaluation of patient satisfaction by questionnaire at the patient's bedside or by telephone call within 24h-48h postoperatively. It is assessed on a numerical scale from 0 to 10 (0 being the lowest satisfaction value and 10 the highest value)

Evaluation of contralateral diaphragmatic compensation (diaphragmatic stroke in ultrasound, comparison of post-ISB time vs. pre-ISB time, expressed in %).

Inclusion Criteria: orthopedic surgery compatible with interscalene block french speaking Patient who signed consent to participate in the study Exclusion Criteria: Pregnant woman ASA score > 3 Severe chronic respiratory insufficiency COPD >3 or 4 of Gold score coagulation trouble Allergic to medication involved in the study Breastfeeding women