The first 24 h: opioid administration in people with spinal cord injury and neurologic recovery.

STUDY DESIGN: Retrospective chart review. OBJECTIVES: The objective of this study was to characterize opioid administration in people with acute SCI and examine the association between opioid dose and (1) changes in motor/functional scores from hospital to rehabilitation discharge, and (2) pain, depression, and quality of life (QOL) scores 1-year post injury. SETTING: Spinal Cord Injury Model System (SCIMS) inpatient acute rehabilitation facility. METHODS: Patients included in the SCIMS from 2008 to 2011 were linked to the National Trauma Registry and the electronic medical record. Three opioid dose groups (low, medium, and high) were defined based on the total morphine equivalence in milligrams at 24 h. The associations between opioid dose groups and functional/motor outcomes were assessed, as well as 1-year follow-up pain and QOL surveys. RESULTS: In all, 85/180 patients had complete medication records. By 24 h, all patients had received opioids. Patients receiving higher amounts of opioids had higher pain scores 1 year later compared with medium- and low-dose groups (pain levels 5.5 vs. 4 vs. 1, respectively, p = 0.018). There was also an 8× greater risk of depression 1 year later in the high-dose group compared with the low-dose group (OR: 8.1, 95% CI: 1.2-53.7). In analyses of motor scores, we did not find a significant interaction between opioid dose and duration of injury. CONCLUSIONS: These preliminary findings suggest that higher doses of opioids administered within 24 h of injury are associated with increased pain in the chronic phase of people with SCI.

Increment Threshold Functions in Retinopathy of Prematurity.

PURPOSE: To assess scotopic background adaptation in subjects with a history of preterm birth and retinopathy of prematurity (ROP). Retinopathy of prematurity is known to have long-term effects on rod photoreceptor and rod mediated postreceptor retinal function. METHODS: Rod-mediated thresholds for detection of 3° diameter, 50 ms stimuli presented 20° from fixation were measured using a spatial forced choice method in 36 subjects (aged 9-17 years) with a history of preterm birth and 11 age similar term-born subjects. Thresholds were measured first in the dark-adapted condition and then in the presence of 6 steady background lights (-2.8 to +2.0 log scot td). A model of the increment threshold function was fit to each subject's thresholds to estimate the dark-adapted threshold (TDA) and the Eigengrau (A0, the background that elevates threshold 0.3 log unit above TDA). RESULTS: In subjects with a history of severe ROP, both TDA and A0 were significantly elevated relative to those in former preterms who never had ROP and term-born control subjects. Subjects who had mild ROP had normal TDA but elevated A0. Neither TDA nor A0 differed significantly between former preterms who never had ROP and term-born controls. CONCLUSIONS: The results suggest that in severe ROP, threshold is affected at a preadaptation site, possibly the rod outer segment. In mild ROP, changes in the Eigengrau may reflect increased intrinsic noise in the photoreceptor or postreceptor circuitry or both.

Extrafoveal Cone Packing in Eyes With a History of Retinopathy of Prematurity.

PURPOSE: To study the density and packing geometry of the extrafoveal cone photoreceptors in eyes with a history of retinopathy of prematurity (ROP). We used a multimodal combination of adaptive optics (AO) scanning light ophthalmoscopy (SLO) and optical coherence tomography (OCT). METHODS: Cones were identified in subjects (aged 14-26 years) with a history of ROP that was either severe and treated by laser ablation of avascular peripheral retina (TROP; n = 5) or mild and spontaneously resolved, untreated (UROP; n = 5), and in term-born controls (CT; n = 8). The AO-SLO images were obtained at temporal eccentricities 4.5°, 9°, 13.5°, and 18° using both confocal and offset apertures with simultaneous, colocal OCT images. Effects of group, eccentricity, and aperture were evaluated and the modalities compared. RESULTS: In the SLO images, cone density was lower and the packing pattern less regular in TROP, relative to CT and UROP retinae. Although SLO image quality appeared lower in TROP, root mean square (RMS) wavefront error did not differ among the groups. In TROP eyes, cone discrimination was easier in offset aperture images. There was no evidence of cone loss in the TROP OCT images. CONCLUSIONS: Low cone density in TROP confocal SLO images may have resulted from lower image quality. Since AO correction in these eyes was equivalent to that of the control group, and OCT imaging showed no significant cone loss, the optical properties of the inner retina or properties of the cones themselves are likely altered in a way that affects photoreceptor imaging.

Temporal summation in children with a history of retinopathy of prematurity.

PURPOSE: To assess temporal summation in children with a history of retinopathy of prematurity (ROP) by determining the critical duration (tCRIT) for complete temporal summation under rod-mediated conditions. From prior ERG studies, it is known that the kinetics of activation of phototransduction are prolonged in the ROP rod photoreceptor. METHODS: Dark-adapted thresholds for detecting 10° diameter stimuli with durations from 10 to 640 ms were measured. A two-alternative, spatial, forced-choice psychophysical procedure was used. The tCRIT for complete summation was estimated in former preterm subjects with a history of severe ROP (n = 7), mild ROP (n = 23), and no ROP (n = 15). The subjects ranged in age from 10.4 to 17.6 (median 15.6) years. Age-similar term-born control subjects (n = 5) were also tested. RESULTS: Critical duration was significantly longer in subjects with a history of ROP than in subjects who never had ROP or who were born at term. Mean tCRIT in the mild ROP group [127.5 (SD = 19.9) ms] and severe group [147.6 (SD = 18.9) ms] did not differ significantly, but both were significantly longer than in former preterms who never had ROP [101.1 (SD = 16.5) ms] and in term-born controls [101.0 (SD = 19.5) ms]. CONCLUSIONS: In ROP subjects, tCRIT is significantly prolonged. This is likely due to abnormal kinetics in the rod outer segment.