METHODS
We designed a protocol as a quality improvement initiative for introduction of LDKI for refractory or chronic pain (Supporting information) in 2014 for our pediatric and young adult hematology and oncology patients at UCSF Benioff Children’s Hospital Oakland. Protocol development occurred with involvement of the pain anesthesiologist, palliative care team, hematology/oncology, nursing and pharmacy to provide LDKI at a dose of 1-10 mcg/kg/min (0.06-0.6 mg/kg/h), with patients generally being prescribed 1-5 mcg/kg/min unless with chronic refractory pain or at end of life (Supplemental material). We subsequently obtained institutional review board (IRB) approval to retrospectively review our initial experience from protocol initiation in March 2014 through October 2017, when IRB approval was obtained for hematology/oncology patients through age 21 years prescribed LDKI. Patients were included during their first admission with LDKI. There were no exclusion criteria.
For these patients, their primary diagnosis and reason for admission were recorded in addition to all concomitant scheduled and as-needed medications (opioid and non-opioid) with a focus on use on benzodiazepines for LDKI side effects. Cumulative daily (24 hour) opioid doses were converted to morphine equivalents. Vital signs and pain scores from up to five days before and after initiation of LDKI were recorded and averaged in 24-hour increments. The day of initiation of LDKI was designated day 0 and compared with the day prior to LDKI initiation as well as day 1 and 2 after LDKI initiation to determine if there was a significant daily decrease in opioid utilization, pain scores or heart rate. Given the inter-patient variability and the fact that most all patients with sickle cell disease (SCD) were initiated on LDKI at time of admission, these patients were compared with prior admissions for a vaso-occlusive event (VOE), with a maximum of three admissions recorded within one year prior to the admission in which they received LDKI. These admissions were reviewed to determine if there was a significant decrease in pain scores, opioid utilization or hospital length of stay in the LDKI admission as compared with the prior admissions. Daily physician and nursing progress notes were reviewed for subjective descriptions of each patient’s pain and any reported side effects to ketamine. Given the small sample size, data were compared using medians and Mann Whitney U testing. Friedman test for repeated measures was utilized when there were repeated days with the same number of data points.