Agreement of somatic and renal near-infrared spectroscopy with reference blood samples during a controlled hypoxia sequence: a healthy volunteer study.

PURPOSE: O3® Regional Oximetry (Masimo Corporation, California, USA) is validated for cerebral oximetry. We aimed to assess agreement of somatic and renal near-infrared spectroscopy with reference blood samples. METHODS: O3 sensors were placed bilaterally on the quadriceps and flank of 26 healthy volunteers. A stepped, controlled hypoxia sequence was performed by adding a mixture of nitrogen and room air to the breathing circuit. O3-derived oxygen saturation values were obtained at baseline and at six decremental saturation levels (5% steps). Blood samples (radial artery, iliac vein (somatic reference) and renal vein) were obtained at each step. Reference values were calculated as: 0.7 × venous saturation + 0.3 × arterial saturation. The agreement between O3-derived values with blood reference values was assessed by calculating root-mean-square error accuracy and Bland-Altman plots. RESULTS: The root-mean-square error accuracy was 6.0% between quadriceps oxygen saturation and somatic reference values. The mean bias was 0.8%, with limits of agreement from -7.7 to 9.3%. These were 5.1% and 0.6% (-8.3 to 9.5%) for flank oxygen saturation and somatic reference values, respectively, and 7.7% and -4.9% (-15.0 to 5.2%) for flank oxygen saturation and renal reference values. The kidney depth was 3.1 ± 0.9 cm below the skin. CONCLUSION: O3 regional oximetry can be used on the quadriceps and flank to monitor somatic saturation, yet has a saturation-level dependent bias. O3-derived values obtained at the flank underestimated renal reference values. Additionally, it is unlikely that the flank sensors did directly measure renal tissue. TRIAL REGISTRATION: Clinicaltrials.gov (NCT04584788): registered October 6th, 2020.

Pain, impaired functioning, poor satisfaction and diminished health status eight years following perilunate (fracture) dislocations.

Purpose: Perilunate (fracture) dislocations are rare injuries and diminished functional outcomes are reported. However, Patient Reported Outcomes (PROs) following these injuries are rarely described. The aim of this study was to investigate the long-term impact of perilunate (fracture) dislocations using a range of measures, including pain, function, and quality of life.Materials and Methods: This cross-sectional study was conducted from January 2016 until March 2016. Eleven patients who had suffered from perilunate (fracture) dislocations between August 1996 and January 2014 were matched on age and gender with 22 healthy controls. Functional outcome included range of motion and grip strength measurements. The Patient Reported Outcomes included: Patient Reported Wrist Evaluation, Disability of Arm, Shoulder and Hand questionnaire, Michigan Hand Questionnaire and the Short Form-36.Results: The 11 patients that were included (9 males) had a median age at injury of 38 years (IQR 33; 54) and median follow up of 97 months (IQR 84-193). Flexion/extension (mean difference -60°, 95% CI -76, -43, p < 0.001) and ulnar/radial deviation (mean difference -28°, 95% CI -38, -18, p < 0.001) were significantly diminished in patients following perilunate (fracture) dislocations. Grip strength was not affected. The patients experienced significantly more pain as assessed on all pain subscales. Physical functioning was significantly worse in the group with perilunate (fracture) dislocations as assessed on all function subscales, except the PRWE function score and the subscale physical functioning of the Short Form-36. Satisfaction as measured with the Michigan Hand Questionnaire satisfaction subscale (mean difference -36, 95% CI -57, -16, p = 0.002) was also reported poorer. No difference was found regarding work participation.Conclusions: A perilunate (fracture) dislocation has a significant impact on everyday life, as patients experience diminished range of motion, pain, diminished physical functioning, diminished satisfaction and report lower general health status than healthy controls. However, no consequences for work participation were found in this study. Level of evidence 3.Implications for rehabilitationFlexion/extension and ulnar/radial deviation remains limited following perilunate (fracture) dislocations.Grip strength is not diminished in patients with perilunate (fracture) dislocations.Pain, restrictions in physical functioning, diminished satisfaction and lower general health status are likely to be present following perilunate (fracture) dislocations.If conservative treatment including pain medication and rehabilitation strategies do not relief pain following perilunate (fracture) dislocations, surgical treatment options such as wrist denervation or arthrodesis should be considered.