Influence of Outer-Sphere Anions on the Photoluminescence from Samarium(II) Crown Complexes.

Three samarium(II) crown ether complexes, [Sm(15-crown-5)2]I2 (1), [Sm(15-crown-5)2]I2·CH3CN (2), and [Sm(benzo-15-crown-5)2]I2 (3), have been prepared via the reaction of SmI2 with the corresponding crown ether in either THF or acetonitrile in good to moderate yields. The compounds have been characterized by single crystal X-ray diffraction and a variety of spectroscopic techniques. In all cases, the Sm(II) centers are sandwiched between two crown ether molecules and are bound by the five etheric oxygen atoms from each crown ether to yield 10-coordinate environments. Despite the higher symmetry crystal class of 1 (R3c), the samarium center resides on a general position, whereas in 2 and 3 (both in P21/c) the metal centers lie upon inversion centers. Moreover, the complexes in 2 and 3 are approximated well by D5d symmetry. The molecule in 1, however, is distorted from idealized D5d symmetry, and the crown ethers are more puckered than observed in 2 and 3. All three complexes luminesce in the NIR at low temperatures. However, the nature of the luminescence differs between the three compounds. 1 exhibits broadband photoluminescence at 20 °C but at low temperatures transitions to narrow peaks. 2 only exhibits nonradiative decay at 20 °C and at low temperatures retains a mixture of broadband and fine transitions. Finally, 3 displays broadband luminescence regardless of temperature. Spin-orbit (SO) CASSCF calculations reveal that the outer-sphere iodide anions influence whether broadband luminescence from 5d → 4f or fine 4f → 4f transitions occur through the alteration of symmetry around the metal centers and the nature of the excited states as a function of temperature.

Methadone and a Clinical Pathway in Adolescent Idiopathic Scoliosis Surgery: A Historically Controlled Study.

STUDY DESIGN: Historically controlled clinical trial. OBJECTIVES: Patients presenting for correction of adolescent idiopathic scoliosis (AIS) by posterior spinal fusion may benefit from structured clinical pathways. We studied the effects of implementing a published clinical pathway for the perioperative care of patients with AIS that required intraoperative use of methadone at our institution. METHODS: We performed a historically controlled clinical trial of patients undergoing posterior spinal fusion for AIS by comparing a retrospectively collected control group of 25 patients with a prospective experimental group of 14 patients receiving methadone, gabapentin, propofol, and remifentanil as part of a new clinical pathway. RESULTS: Use of the pathway decreased average pain scores evaluated by the Numeric Rating Scale in the 24 hours following surgery (4.8 [4-6] to 3.4 [2-4], P = .03 [-2.6 to -0.2; t = -2.3]) and postoperative opioid consumption by 76% (41 [29-51] mg to 10 [4-17] mg, P < .001 [-45 to -15; Welch's t = 4.9]) during the same period. Improved analgesia and reduced reliance on opioids facilitated other postoperative elements of the clinical pathway and shortened the average hospital length of stay by 1 day (4 [3-6] days to 3 [3-5] days, P = .001 [-2 to -1; U = 67, Z = -3.3]). CONCLUSIONS: Multimodal analgesia and a clinical pathway add value in the perioperative care of patients undergoing posterior spinal fusion for AIS by improving analgesia and shortening hospitalization. The prospective arm of the trial was registered at clinicaltrials.gov under NCT02481570.

Radiographic, Pulmonary, and Clinical Outcomes With Halo Gravity Traction.

STUDY DESIGN: Single-center retrospective chart review. OBJECTIVES AND SUMMARY: Halo gravity traction (HGT) is a safe and effective intervention to improve spinal deformity prior to corrective instrumentation. Our study aimed to report on a large series of patients undergoing HGT, demonstrate the correlation between thoracic height achieved and pulmonary function, and evaluate the efficacy of nutritional assessment and intervention while in HGT for these often malnourished or nutritionally compromised patients. METHODS: 107 patients underwent HGT for severe spinal deformity. Major coronal and sagittal Cobb angles, T1-T12 ht, and T1-S1 ht were collected pre-HGT, during HGT, postoperation, and 2 years postoperation. Pulmonary function tests (PFTs) recorded forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1). Nutritional interventions such as formal nutrition consult, resulting nutritional supplementation, or interventions were recorded. RESULTS: Patients were in HGT for mean of 82.1 days and mean maximum percentage body weight in traction was 49.5%. Mean major coronal Cobb angle prior to HGT was 92.6°, improving to 65.8° in maximal traction and to 47° after surgical intervention. Traction accounted for 78% of T1-T12 height and 79% of T1-S1 length gains from pre- to postoperation. We showed a positive correlation between gain in T1-T12 height and percentage predicted changes in FVC and FEV1. Weight Z score for the entire cohort of patients improved from -2.8 pretraction to -2.4 in traction and then to -2.3 postoperative. CONCLUSIONS: Our study again demonstrated that HGT achieves radiographic improvement safely and effectively in severe spinal deformity. We demonstrated a positive correlation between improvement in PFTs and increase in thoracic height seen with HGT. Additionally, improvement in weight Z score was seen in the entire population and the most at risk patients for malnutrition, results that have not been shown before. LEVEL OF EVIDENCE: Level IV.