During the two year study period between August, 2005 and July, 2007, 326 sickle cell related admissions were screened in the hematology unit, with an average of 18.1 ±5.6 admissions each month. These admissions represented 160 patients; 30% had three or more repeat admissions. Among the 160 patients, 68 (42.8%) patients were admitted for reasons other than acute painful episodes, 28 (17.6%) patients had acute painful episode, but did not have PCA morphine at time of screening and recruitment, 14 (8,8%) were excluded for various reasons (such as, developmental delay, communication disorder, behavioral problems, disruptive behavior, cognitive dysfunction, neurological impairments, patient not appropriate for randomization, parent noncompliant or not appropriate for consenting procedures, patient on legal custody and parent/legal guardian not known), 8 (5.0%) were weaned from pain medications and were planned to be discharged within 24 hours, 4 (2.5%) were eligible, but enrolled in a concurrent study, 2 (1.3%) did not have parents available for consent, 16 (10.1%) refused. A total of 15 patients were randomized in the PCA morphine regimens; two of them (1 from regimen C; the other from regimen A) had withdrawn early. The 13 patients who completed the study were randomly assigned to Regimen A (n=5), B (n=5), and C (n=5).
Baseline characteristics of patients in regimen A (n=5), B (n=5), and C (n=3) were not significantly different (N=13; mean age 13.7 years; eight males; five females; ).
The Hemoglobin phenotype was predominantly HgbSS (n=9). Onset of pain was 1.7 to 3.4 days prior to admission. Lowest mean pain intensity ratings in the Emergency Department (ED) prior to admission ranged from 5.0 to 7.7, with the highest pain intensity ratings from 7.3 to 9.5 on 0 to 10 numerical ratings scales (NRS). Patients received 0.08 to 0.10 mg/kg/dose, which were lower or within the lower range of the recommended morphine dose of 0.1 to 0.2 mg/kg/dose (12
). Patients in regimen B had an overall mean shorter length of stay (); however this was not statistically significant (p > 0.05).
The worst pain intensity ratings in Regimen B decreased significantly during the course of hospitalization (see ). The worst pain intensity rating was 9.5 on day 1 and 5.5 on day 5, p=0.01 for Regimen B. The worst pain intensity ratings for patients on regimen A (9.8 to 9.0, p > 0.05) and regimen C (9.6 to 7.5, p>0.05) did not change significantly during hospitalization (see ). The least pain intensity ratings of patients in regimen C were lower than patients in either regimen A or B (see ). The difference in trends between the worst and least pain intensify ratings across the hospital days was widest in regimen C when compared to either Regimen A or B (see ).
Pain intensity ratings (A), Number of body areas (B) and number of quality word descriptors (C) Day 1 to Day 5 of hospitalization.
Comparison of worst and least pain ratings for regimen A, B, C.
The most frequent areas marked for pain by patients in regimen A were the right upper arm (75%), right abdomen (50%), left thigh and knees (50%), right back chest (50%), and lower back (50%). The most frequent areas marked by patients in Regimen B were chest (83%), right knee (50%), and left thigh and knees (50%). Patients in regimen C marked the chest (66.7%), right upper arm (66.7%), right abdomen (66.7%), and lower back (66.7%).
The number of areas marked on the body outline diagram remained constant throughout hospitalization for regimen C (12.3 to 15.5 areas). The number of areas marked decreased for patients in regimen A (10.2 to 1.5) and B (8.8 to 1.5). Worst pain intensity ratings remained at moderate levels (see ) throughout hospitalization; however, the number of body areas marked with pain decreased for regimen A and B, but not for regimen C (see ).
The number of words to describe the quality of pain remained similar throughout hospitalization from 30.2 on day 1 to 11.0 on day 5 (p > 0.05) for patients on regimen A (see ). The most frequent words were sensory quality (3.7 to 7.5), and fewer affective (1.75 to 2.5), evaluative (2.2 to 2.7), or temporal words (1.7 to 2.5). The number of words to describe the quality of pain decreased from 11.7 to 3.0 for patients on regimen B (see ). The most frequent words were also sensory quality (3.6 to 6.0) and fewer affective (0.8 to 1.3), evaluative (1.7 to 2.2 ), or temporal words (1.8 to 2.6). For patients in regimen C, the number of words remained similar throughout hospitalization, and slightly increased from 13.0 on day 1 to 19.2 on day 5 (p>0.05). The number of sensory (6.3 to 10.0), affective (2.3 to 3.0), evaluative (2.3 to 4.0), and temporal quality words (2.0 to 3.0) were slightly higher, but not significantly different (p>0.05) from the patients in regimen A and B.
The words that were selected by 75% of patients in regimen A to describe the quality of pain were hurting, sharp, pressure, awful, annoying and continuous. The majority of patients (66.7%) in regimen B selected aching, hurting, like a sharp knife, shooting, dizzy, annoying, and uncomfortable. The majority of patients in regimen C (66.7%) selected similar words. In addition, the majority of patients (66.7%) in regimen C also selected other words such as throbbing, tight, sore, like a pinch, stinging, shocking, and pounding from the sensory words; crying and sickening from the affective words; and never goes away, steady, and always from the temporal words.
Daily Morphine Consumption
The amount of morphine that was administered per day was not significantly different (p>0.05) among the three regimens (see A). Patients in regimen A were administered on the average from 59.4 mg on day 1 to 33.8 mg on day 5. This amount was equivalent to 1.2 mg/kg/day on day 1 to 1.1 mg/kg/day on day 5. The largest amount was administered on day 3 (77.3 mg/day or 1,4 mg/kg/day). Patients in regimen B had consistently decreased in the amount of morphine that was administered during hospitalization from 73.5 mg/day on day 1 to 23.5 mg/day on day 5 (equivalent to 1.1 on day 1 to 0.3 mg/kg/day on day 5). Patients in regimen C were administered on the average 55.7 mg (or 1.1 mg/kg/day) on day I and continued to have a slightly higher amount administered on day 4 (117.9 mg/day or 2.4 mg/kg/day) and day 5 (77.3 mg/day or 1.6 mg/kg/day).
Amount of morphine in mg/kg/day (A) and perceived amount of relief [0 to 10 NRS] from medications (B).
Ketorolac (administered 15 to 30 mg every 6 hours) was the only other medication that all patients received for pain. A few patients had diphenhydramine (25 to 50 mg) for itching, and odansetron (8 mg prn) or promethazine (12 mg prn) for nausea/vomiting.
The amount of pain relief did not change significantly (p > 0.05) during hospitalization (). The mean amount of pain relief (from 0 = no relief to 10 = complete relief) for each day of hospitalization was higher for regimen C (6.0 ± 2.0 to 6.5 ±2.1), when compared with Regimen A (4.6 ±2.5 to 5.7 ± 2.1) or B (4.6 ± 2.7 to 6.6 ± 1.9); however, this was not statistically significant.
Few patients were reporting side effects, mostly drowsiness, dizziness, itching, nausea, and vomiting. Two of five patients from regimen A and three of five patients from regimen B reported drowsiness prior to enrollment. Three patients on regimen A and two patients on regimen B also reported itching on day of enrollment. Two patients had nausea from regimen A and one each from regimen B and C had both nausea and vomiting. No one had low blood pressure, heart rate, or respiratory rate. One patient in regimen B had difficulty stooling, which was reported prior to enrollment