Patient-Controlled Anxiolysis With Dexmedetomidine (PCA-DEX) for Burn-care Dressing Changes

Study Procedures Dexmedetomidine PCA Protocol: The PCA-DEX dosing algorithm will consist of a loading dose (0.25 mcg/kg) given intravenously over 10 minutes, administered 10 minutes prior to the start of burn wound care, followed by a continuous basal infusion of 0.4 mcg/kg/hr with 6 allowable patient-controlled self-boluses per hour (0.1 mcg/kg) each with a 10-minute lock-out. Drs. Larry Jones and J. Kevin Bailey or their designate will write the PCA-DEX medication orders. Subjects will receive standard opioid therapy (oral oxycodone/acetaminophen 5/325 mg 60 min. prior and IV morphine 4-12 mg or hydromorphone IV 0.5-1.5 mg 5 to 10 min. prior and buccal fentanyl 400 mcg as needed during burn wound care) and can receive bolus supplemental sedative medications (benzodiazepines) as ordered by Drs. Jones or Bailey if needed in the judgment of the burn-care nurse. Subjects will be monitored closely by research personnel during the first burn wound care session from 1 hour prior to 1 hour after completion of burn wound care. Every heart rate and blood pressure recordings will be abstracted from the medical record from 1 hour prior to through 1 hour after completion of the daily burn wound dressing changes for days 1 through 5. Alert adverse events will be reported by research personnel or the patient-care nurse to first the attending physician and then to the safety monitor.

Nurse alert parameters to notify the attending physician and independent safety monitor include: heart rate (HR) < 55 beats per min sustained for > 10 min; systolic BP < 90 mm Hg or >140 mm Hg sustained for >10 minutes; diastolic BP < 50 mm Hg or >90 mm Hg sustained for >10 minutes, respiratory rate < 10 breaths per minute sustained for >10 minutes or oxygen saturation <92% sustained for >10 minutes; or persistent inability to understand rationale for triggering the PCA device despite education and demonstration.

If the study subject has evidence of sustained hemodynamic instability (HR<60 bpm, SBP <90 mmHg or DBP < 50 mmHg) during the daily pre-procedure assessment, the patient will not be eligible to receive study drug on that day. For that day the patient will receive standard of care as appropriate instead of the study intervention. The patient will then be reassessed prior to the subsequent study days to determine eligibility for study drug up through day 5.

Data Collection Measures and Procedures Study entry demographic and descriptive data: Data to be recorded includes: age, gender, race, ethnicity, admission weight, severity of burn injury, burn etiology, total body surface area burned and depth of injury, and all home and hospital medications.

Daily Measures on Protocol. The following will be obtained from enrolled patients each day by a member of the research team.

Overall anxiety and pain. The abbreviated Burn Specific Anxiety and Pain Scale (BSAPS) on day 1, 1 hour prior to the first burn dressing change.

Procedural Anxiety. Anxiety, defined as a state marked by apprehension, agitation, increased motor activity, arousal, and fearful withdrawal will be obtained from subjects. Patients will evaluate current anxiety level 1 hour before and 1 hour after each burn dressing change using a 100-mm Visual Analogue scale-anxiety (VAS-A). Subjects will be asked to rate their current level of anxiety on the VAS-A in response to, "How anxious are you feeling today?" A 100-millimeter vertical line will be anchored on each end by statements 'not anxious at all' to 'the most anxious I have ever been'. The VAS-A will have a vertical orientation, as it is more sensitive and easier for subjects to use, particularly for those with a narrowed visual field or when under stress. Subjects will be asked to mark their current anxiety level on the vertical line. Scores will be derived by the distance in millimeters from the bottom anchor to the mark placed by the subject, yielding interval level data. Reason(s) for not obtaining a daily anxiety assessment will be recorded. The proportion of those assessments completed and reasons for non-completion will be used to inform strategies to minimize missing data for our planned randomized clinical trial.

Procedural Pain. Patients' will evaluate current pain level 1 hour before and 1 hour after each burn dressing change using a 100-mm Visual Analogue Scale-Pain. Patients will be asked to rate their current level of pain on the VAS-P in response to "How much pain are you having right now?" A 100-millimeter vertical line will be anchored on each end by statements of 'no pain at all' to 'the most pain I have ever experienced'. As with the VAS-A, the vertical orientation has been chosen due to increased sensitivity and ease of use for patients.Subjects will be asked to mark their current pain level on the vertical line. Scores will be derived by the distance in millimeters from the bottom anchor to the mark placed by the subject, yielding interval level data. Reason(s) for not obtaining the pain assessments will be recorded. The proportion of those assessments completed and reasons for non-completion will be used to inform strategies to minimize missing data for our planned randomized clinical trial.

Protocol adherence. A checklist will be completed daily to monitor the number of days subjects are able to use the PCA device for up to 5 days. A checklist will also be used to monitor the ability of the burn-nurses to adhere to the PCA protocol per instructions.

Daily adverse event monitoring. Research staff will record and report the presence of hypotension, bradycardia (known adverse effects of dexmedetomidine), and protocol deviations related to drug, pump or both. Heart rate and blood pressure will be abstracted from the medical record. Research team staff or burn-nurses caring for PCA-DEX subjects will alert the attending physician and the safety monitor for HR < 55 bpm sustained for > 10 min; systolic BP < 90 mm Hg or >140 mm Hg sustained for >10 minutes; diastolic BP < 50 mm Hg or >90 mm Hg sustained for >10 minutes, respiratory rate < 10 breaths per minute sustained for >10 minutes or oxygen saturation <92% sustained for >10 minutes during the period 1 hour prior through 1 hour after completion of burn wound dressing change on days 1-5 for any necessary intervention or protocol withdrawal.

Post-PCA-DEX Acceptability Survey. Upon completion of the PCA-DEX protocol, we will query subjects and nurses about their satisfaction with self-administration of medication to manage anxiety, ease of medication administration, and the resulting level of relaxation.