Continuous Intercostal Nerve Blockade for Traumatic Rib Fractures

Prime "Rib" Time: Randomized Control Trial Evaluating the Use of Continuous Intercostal Nerve Blockade for Traumatic Rib Fractures

Rib fractures are common injuries in accident patients and can be associated with significant pain during recovery. If poorly controlled, pain from splinting due to rib fractures can result in difficulty in breathing leading to incomplete expansion of lung, and even the need to put a patient on a ventilator to help them breathe. Therefore, pain control is critical in managing patients with rib fractures. To date, many studies have shown the effectiveness of continuous intercostal nerve blockade (a slow release of pain medications at the site of injury that prevents the transmission of pain signals). This approach has never been studied in a randomized fashion in rib fracture patients, and has never been compared to patient-controlled narcotic pain medication, commonly used at many hospitals. The purpose of this study is to evaluate the effectiveness of the placement of an elastomeric infusion pump (a small, external, wearable balloon used to deliver medication over time) attached to a continuous infusion catheter or "soaker" catheter (a tube which releases the pain medication through tiny holes in it, right at the site of injury) to deliver local anesthetic medication to reduce pain caused by two or more rib fractures.

Treatment of rib fractures using an elastomeric infusion pump (a small, external, wearable balloon used to deliver medication over time) containing pain medication and a continuous infusion catheter or "soaker" catheter (a tube which releases the pain medication through tiny holes in it, right at the site of injury) placed in the extrathoracic paraspinous space (a site in the back that is near the broken ribs) to create a continuous intercostal nerve block is relatively novel. Truitt and colleagues have published two studies evaluating the effectiveness of this approach. A pilot study on 30 patients was published in 2010 showing that placement of these catheters was a safe, viable and effective procedure, and resulted in decreased pain scores in rib fracture patients. A second study included 102 patients studied prospectively (from the time of admission to the hospital) comparing epidural anesthesia (an injection of anesthetic into the spine) with local catheter delivery in a non-randomized fashion in 2011. This approach is beginning to be more widely used, but has never been studied in a randomized fashion, and has never been compared to patient-controlled analgesia (PCA, delivery of a pain medication by the push of a button), commonly used at many hospitals. We hypothesize that accident patients with two or more rib fractures who receive pain control through the continuous infusion system will achieve improved pain control in a dose-dependent fashion, improved lung function, and therefore, will require less narcotic pain medication, achieve discharge criteria earlier and have a shorter hospital length of stay in comparison to patients treated with PCA alone.

Procedure: Standard of care - Intravenous Patient Controlled Anesthesia (PCA) 0.1 mg hydromorphone hydrochloride, every 6 minutes. Boluses of 0.1 mg IV hydromorphone for uncontrolled pain up to a maximum of 2.5 mg/hr.

Standard PCA infusion 0.1 mg hydromorphone hydrochloride, every 6 minutes. Bolus 0.1 mg hydromorphone for uncontrolled pain up to a maximum of 2.5 mg/hr. Infusion catheter placement. Bupivacaine 0.25% 4 ml/hr total for dual chamber catheter.

Standard PCA infusion 0.1 mg hydromorphone hydrochloride, every 6 minutes. Bolus 0.1 mg hydromorphone for uncontrolled pain up to a maximum of 2.5 mg/hr. Infusion catheter placement. Bupivacaine 0.5% 4 ml/hr total for dual chamber catheter.

Quantity of systemic narcotic used (hydromorphone hydrochloride, Dilaudid) averaged per day over the length of hospital stay, in mg/24 hours.

Determine the impact of catheter-infused medications on maximal inspiratory lung volume measured by incentive spirometer (IS) as a change from baseline at 24, 48, 72 hours and at 3 days post catheter placement or at discharge (or PCA placement in comparator group). Endpoint will be the time to improvement of vital capacity to greater than 1.4 liters (or 15 mL/kg).

Determine the impact of catheter-infused medications on self-reported pain intensity reported as a change from baseline (admission) at 24, 48, 72 hours and at 3 days post catheter placement or at discharge (or PCA placement in comparator group) on a 0-10 point Likert scale, with 0=no pain, and 10= the worst pain ever. Response will be defined as time to a decrease of at least two points on the scale.

Collection of complications observed at any point during the hospital admission that included randomization, including pneumothorax, hemothorax, acute respiratory distress syndrome, pneumonia, empyema, need for tracheostomy, need for mechanical ventilation, length of time on mechanical ventilation, and an assessment of the degree of association of each event with the catheter insertion procedure or with underlying trauma. Each of these outcomes will be scored as yes/no.

All cause death, death associated with infusion catheter, within 30 days from date of randomization. This outcome will be scored as yes/no and cause of death will be collected.

Integer days of admission to the surgical intensive care unit. For patients not requiring admission to surgical intensive care, patient is not analyzed. Usual range is 3-5 days.

Inclusion Criteria: Admission to trauma service at Beaumont Hospital, Royal Oak, Michigan Two or more rib fractures in an anatomic pattern feasible for nerve blockade (unilateral or bilateral) Age greater than or equal to 18 years Ability to comprehend and endorse an informed consent Exclusion Criteria: Patients who are pregnant or breastfeeding Patients intubated before placement of continuous infusion catheter Any significant concomitant injuries potentially confounding for evaluation of the effectiveness of analgesia (eg., traumatic brain injury) History of an allergic reaction to local anesthetic Use of other regional anesthetics before evaluation (epidural or paravertebral nerve blockade) International Normalized Ratio (INR) > 2.0 Inability to obtain informed consent