A Double-Blinded, Randomized, Controlled Trial to Test the Efficacy of Continuous Ultrasound Guided Erector Spinae Block on Lung Function for Rib Fracture Related Pain

Arm 1: The interventional treatment arm group consisting of 30 patients will have an ultrasound guided continuous erector spinae plane (ESP) catheter placed at the midpoint vertebral level of the affected fractured rib. A high linear (or curvilinear probe in morbidly obese patients) frequency transducer will be held in a parasagittal plane at the centre of the pain source. Next, the transverse process at the vertebral level of the middle fractured rib will be identified with the overlying erector spinae muscle. Other important sonoanatomical landmarks are the skin, subcutaneous tissue, trapezius muscle and the rhomboid muscle, which tapers off below the T5/6 region. Under strict aseptic conditions, an E-Catheter plus 20G with stylet and 15mm extended tip / indwelling cannula 18G x 75mm (3") / SonoPlex 21G x 94mm (3 2/3") will be directed from the short edge of the ultrasound probe either in a cranio-caudal direction or caudo-cranial direction depending on logistics and fracture location into the erector spinae plane, which is the fascial plane between the anterior border of the erector spinae muscle that abut the posterior margin of the relevant transverse process. Once contact to bone is established both in a tactile fashion as well as visible on live imaging. A bolus dose of 0.35 mls/kg of 0.5% Ropivacaine will be injected into the plane and the successful endpoint in proper needle positioning will be a lifting off the erector spinae muscle from the transverse process.The continuous erector spinae block will be maintained with strict programmable bolus dosing of 20 mls of 0.2% Ropivaine every 4 hours for 24 hrs. In addition, breakthrough pain will be treated with systemic opioids via patient controlled analgesia (PCA) + regular Paracetamol Arm 2: The control group will have a catheter placed into the exact same method and into the same myofascial compartment as the study group, with the only difference being, that placebo (normal saline) shall be injected into the plane with the exact same volume and under the exact same regime as in the study group. The ESP catheter will be inserted by a dedicated group of anesthesiologists with extensive experience in regional anaesthesia and analgesia single shot and continous catheter techniques " Under strict aseptic conditions, an 18 G indwelling catheter x 75 mm ( with a 21 G x 94 mm SonoPlex cannula) will be directed from the short edge of the ultrasound probe either in a cranio-caudal direction or caudo-cranial direction depending on logistics and fracture location into the erector spinae plane, which is the fascial plane between the anterior border of the erector spinae muscle that abut the posterior margin of the relevant transverse process. A bolus of 0.35 ml/kg of 0.5% Ropivacaine will be injected into the plane and the successful endpoint in proper needle positioning will be a lifting off the erector spinae muscle from the transverse process. The Sonoplex cannula will be removed and an 18 G x 75 mm E- Cath Plus will be inserted via the indwelling cannula at a predefined length (15 mm protruding tip of E-Cath past the indwelling cannula).