Validity and reliability of measurement of peripheral oxygen saturation during the 6-Minute Walk Test in patients with systemic sclerosis

Peripheral oxygen saturation (SpO2) using the fingers may have important limitations due to Raynaud's phenomenon and sclerodactyly in patients with systemic sclerosis (SSc). Sensors located at more central body positions may be more accurate as these as less prone to Raynaud attacks. To determine the validity and reliability of the SpO2 measured at the finger, forehead, and earlobe during the 6-Minute Walk Test (6MWT). Eighty two patients with SSc had an arterial line placed while performing the 6MWT. Peripheral oxygen saturation was simultaneously measured by finger, forehead, and earlobe sensors and compared to the arterial oxygen saturation (SaO2) measured before and after the 6MWT. 40 patients repeated the 6MWT one week later to determine re-test reliability. We used Bland-Altman plots to display the agreement between SpO2 and SaO2. The intraclass correlation coefficient for repeated measurement of minimum SpO2 was calculated. The mean difference between SpO2 and SaO2 after the 6MWT was - 3% (SD: ± 5), 0% (SD: ± 2), and 1% (SD: ± 2) for the finger, forehead, and earlobe, respectively. The minimum SpO2 measured at the finger demonstrated the poorest re-test reliability: The ICC (95% CI) showed good agreement using the ear and forehead probe (ICCear = 0.89 [95% CI 0.80; 0.94]; ICCforehead = 0.77 [95% CI 0.60; 0.87]), while a modest reliability was found using the finger probe (ICCfinger = 0.65 95% CI [0.43; 0.80]). SpO2 should be measured using either the earlobe or forehead during the 6MWT in patients with SSc. Clinical Trials.Gov (NCT04650659).

Umbilical cord mesenchymal stem cells transplantation in patients with systemic sclerosis: a 5-year follow-up study

OBJECTIVE

To assess the long-term safety and efficacy of umbilical cord mesenchymal stem cells transplantation (UMSCT) in patients with systemic sclerosis (SSc).

METHODS

Forty-one patients with moderate to severe SSc underwent UMSCT at the Affiliated Drum Tower Hospital of Nanjing University Medical School from 2009 to 2017. In this study, we conducted a longitudinal and retrospective analysis and compared the clinical and laboratory manifestations before and after UMSCT. The main outcome of the study was overall survival. We evaluated changes in the modified Rodnan Skin Score (mRSS), as well as the changes in the pulmonary examination by using high-resolution computed tomography (HRCT) and ultrasound cardiogram (UCG). Additionally, we assessed the Health Assessment Questionnaire-Disability Index (HAQ-DI) and the severity of peripheral vascular involvement during the first year after treatment.

RESULTS

The overall 5-year survival rate was 92.7% (38 out of 41 patients). Following UMSCT, the mean mRSS significantly decreased from 18.68 (SD = 7.26, n = 41) at baseline to 13.95 (SD = 8.49, n = 41), 13.29 (SD = 7.67, n = 38), and 12.39 (SD = 8.49, n = 38) at 1, 3, and 5 years, respectively. Improvement or stability in HRCT images was observed in 72.0% of interstitial lung disease (ILD) patients. Pulmonary arterial hypertension (PAH) remained stable in 5 out of 8 patients at the 5-year follow-up. No adverse events related to UMSCT were observed in any of the patients during the follow-up period.

CONCLUSION

UMSCT may provide a safe and feasible treatment option for patients with moderate to severe SSc based on long-term follow-up data. The randomized controlled study will further confirm the clinical efficacy of UMSCT in SSc.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00962923. Key Point • UMSCT is safe and effective for SSc patients.

MRI Digital Artery Volume Index (DAVIX) as a surrogate outcome measure of digital ulcer disease in patients with systemic sclerosis: a prospective cohort study

BACKGROUND

Vascular fibrosis is a key manifestation of systemic sclerosis that leads to the narrowing of small and medium arteries, causing vascular clinical manifestations including digital ulcers and pulmonary arterial hypertension. We investigated the potential of the MRI-based Digital Artery Volume Index (DAVIX) as a surrogate outcome measure of vascular fibrosis by using it to quantify and predict the burden of digital ulcer disease in patients with systemic sclerosis.

METHODS

Two independent cohorts of patients participating in the prospective observational study STRIKE were consecutively enrolled from the Scleroderma Clinic of the Leeds Teaching Hospitals Trust, Leeds, UK. Eligible patients were aged 18 years or older and fulfilled the very early diagnosis of systemic sclerosis (VEDOSS) or the 2013 American College of Rheumatology (ACR)-European Alliance of Associations for Rheumatology (EULAR) systemic sclerosis classification criteria. DAVIX was calculated as the percentage mean of the ratio of digital artery volume to finger volume in the four fingers of the dominant hand. Data were collected at baseline and 12-month follow-up, and the primary outcome was the presence of digital ulcers at 12-month follow-up.

FINDINGS

Between Feb 7, 2018, and April 11, 2022, we included 85 patients in the exploratory cohort and 150 in the validation cohort. In the exploratory cohort, the mean age was 54·5 years (SD 11·6), 75 (88%) of 85 patients were women, ten (12%) were men, and 69 (82%) were White. In the validation cohort, the mean age was 53·5 years (SD 13·8), 136 (91%) of 150 patients were women, 14 (9%) were men, and 127 (85%) were White. In the exploratory cohort, DAVIX was significantly lower in patients with previous or active digital ulcers (0·34% [IQR 0·16-0·69]) than in those without digital ulcer disease (0·65% [0·42-0·88]; p=0·015); this finding was substantiated in the validation cohort (0·43% [0·20-0·73] vs 0·73% [0·53-0·97]; p<0·0001). Patients who developed new digital ulcers during 12-month follow-up had a lower DAVIX (0·23% [0·10-0·66]) than those who did not (0·65% [0·45-0·91]; p=0·0039). DAVIX was negatively correlated with disease duration (r=-0·415; p<0·0001), the ratio of forced vital capacity to the diffusing capacity of the lungs for carbon monoxide (r=-0·334; p=0·0091), nailfold capillaroscopy pattern (r=-0·447; p<0·0001), and baseline modified Rodnan skin score (r=-0·305; p=0·014) and was positively correlated with the diffusing capacity of carbon monoxide (r=0·368; p=0·0041). DAVIX was negatively correlated with change in score on the Scleroderma Health Assessment Questionnaire-Disability Index (r=-0·308; p=0·024), Visual Analogue Scale (VAS) Raynaud's (r=-0·271; p=0·044), and VAS digital ulcers (r=-0·291; p=0·044).

INTERPRETATION

DAVIX is a promising surrogate outcome measure of digital ulcer disease in patients with systemic sclerosis. The ability of DAVIX to non-invasively predict future digital ulcers and worsening of patient-reported outcomes could aid patient enrichment and stratification in clinical trials. Clinically, DAVIX could offer insights into the assessment of vascular activity. The sensitivity of DAVIX to change over time and with treatment will establish its value as an imaging outcome measure of vascular disease.

FUNDING

National Institute for Health Research Biomedical Research Centre and University of Leeds Industry Engagement Accelerator Fund.

Angiographic characteristics of vasculopathy in patients with idiopathic inflammatory myopathies and systemic sclerosis

To describe the peripheral angiographic features of vasculopathy in idiopathic inflammatory myopathies (IIM) and systemic sclerosis (SSc) in comparison to polyarteritis nodosa (PAN). Angiograms of 47 extremities (24 upper and 23 lower) of 11 patients with IIM (n = 5) and SSc (n = 6), and 12 patients with PAN who presented with critical limb ischemia were retrospectively analyzed with regards to the presence of stenosis, occlusion, aneurysms and delayed distal flow, and degree of neovascularization. Diffuse narrowing was more frequent (66.1 vs. 38.0%, p = 0.001), whereas multifocal stenosis (6.5% vs. 26.8%, p = 0.002), abrupt occlusion (11.3% vs. 29.6%, p = 0.010) and aneurysm formation (1.6% vs. 11.3%, p = 0.037) were less frequent in IIM/SSc than PAN. In distal arteries, tapered occlusion (95.5% vs. 76.0%, p = ns) and delayed flow (77.3% vs. 48.0%, p = 0.039) were more common in IIM/SSc than PAN. After 1 year, auto- or surgical amputation tended to be more frequent in IIM/SSc than PAN (36.4% vs. 16.7%, p = ns). In conclusion, diffuse narrowing, tapered occlusion and delayed distal flow on conventional angiograms tend to be more frequent in IIM/SSc than PAN. Further studies are needed to verify these findings in a larger prospective cohort.

High-resolution, non-contrast-enhanced magnetic resonance angiography of the wrist, hand and digital arteries using optimized implementation of Cartesian quiescent interval slice selective (QISS) at 1.5 T

PURPOSE

Non-contrast-enhanced (CE) magnetic resonance angiography (MRA) techniques are of considerable interest for diagnosing vascular diseases in the upper extremities owing to the possibility of repeated examinations, sufficient coverage of the measurement volume, and because possible side effects of administering iodine- or gadolinium-based contrast agents and radiation exposure can be avoided. The aim of this study was to investigate the feasibility of an optimized electrocardiogram (ECG) triggered Cartesian quiescent interval slice selective (QISS) technique for MRA of hand arteries.

MATERIAL AND METHODS

Both hands of 20 healthy volunteers (HVs) were examined using an optimized QISS-MRA pulse sequence at 1.5 Tesla. The wrist and hand arterial trees were divided into 36 segments. Cross-sectional areas (CSA) of all arterial segments were measured. For the technical evaluation of the pulse sequence, the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were computed and six imaging artifacts were graded. Two experienced observers used an ordinal scoring system to assess the image quality of each arterial segment. Interobserver agreement was determined.

RESULTS

The median CSA was 7.3 mm2 in the ulnar and radial artery, 3.2 mm2 in the four common digital arteries, and 1.5 mm2 in five proper digital arteries. The median SNR and CNR of the third common proper arteries were 45.9 and 20.3, respectively. None of the arterial segments were contaminated by venous enhancement. The image quality of arterial segments for both hands was considered as diagnostic in 87.2% of all 1440 segments. An interobserver agreement of 0.67 for both hands was determined for image quality of arterial segments using a five-grade scoring system. Optimized QISS-MRA allows as the first MRA technique the classification of superficial palmar arch (SPA) and deep palmar arch (DPA) variants. 5 new SPA and 6 new DPA variants could be classified using QISS-MRA in comparison with previous studies using CE computed tomography angiography and using fixed cadaver hands.

CONCLUSIONS

By using this optimized 2D Cartesian QISS-MRA protocol, contrast agent-free angiography of the wrist and hand arteries provided a high in-plane spatial resolution and an excellent visualization of small digital arteries.

Noncontrast Magnetic Resonance Angiography in the Era of Nephrogenic Systemic Fibrosis and Gadolinium Deposition

ABSTRACT

Gadolinium-based contrast agents for clinical magnetic resonance imaging are overall safe. However, the discovery of nephrogenic systemic fibrosis in patients with severe renal impairment and gadolinium deposition in patients receiving contrast have generated developments in contrast-free imaging of the vasculature, that is, noncontrast magnetic resonance angiography. This article presents an update on noncontrast magnetic resonance angiography techniques, with comparison to other imaging alternatives. Potential benefits and challenges to implementation, and evidence to date for various clinical applications are discussed.

Combining optical coherence tomography with magnetic resonance angiography and Doppler ultrasonography for clinical detection of scleroderma

Scleroderma (SD) is a rare and agnogenic autoimmune disease whose progression can be modified by medical or surgical intervention if detected early. Multimodality imaging makes early detection of SD possible based on the structural and functional findings from different imaging methods. Combining optical coherence tomography (OCT) with magnetic resonance angiography (MRA) and Doppler ultrasonography (DUS) to identify the typical structural and functional features that can exhibit significant differences between SD patients and healthy controls. In this study, six participants (three healthy volunteers and three SD patients) were recruited and clinically examined by a rheumatologist. Participants' fingers were scanned by MRA, DUS, and OCT, respectively. MRA and DSU imaging results showed that SD patients exhibited thicker finger skin, a loss of blood vessels, and lower blood flow, whereas OCT captured the high-resolution morphology changes of the skin, epidermal, dermis, and subcutaneous layers, demonstrating a distinct loss of the dermo-epidermal junction in SD patients. Multimodal imaging techniques offer a more comprehensive characterization of the morphological and functional information of biological tissues, which can assist physicians to achieve a more accurate SD diagnosis.

Biomarkers as an opportunity to stratify for outcome in systemic sclerosis

Systemic sclerosis (SSc) is a highly complex disease whose heterogeneity includes multiple aspects of the condition, such as clinical presentation, progression, extent and type of organ involvement, and clinical outcomes. Thus far, these features remain not easily predictable both at the patient group level and in a given patient with regard to age at onset and clinical course. The unpredictable clinical course represents an obstacle to focusing potentially effective treatment in patients that need it the most. At the time of organ involvement and clinical diagnosis, most of the clinical manifestations are irreversible; therefore, predicting outcomes becomes crucial. This can explain the multiple attempts to identify prognostic, predictive, and monitoring-both soluble and imaging-biomarkers over the past years. They range from the currently most used biomarkers, the autoantibodies associated with disease-specific clinical features and course, to the single recently proposed skin, lung, cardiac involvement biomarkers and to the composite scores capturing multiple aspects of the disease. This review will focus on soluble and imaging biomarkers that recently showed promising evidence for outcome stratification in patients with SSc.

Scleroderma of the Hand: Evaluation and Treatment

Scleroderma is derived from Latin meaning hard skin. It is an uncommon, noninflammatory connective tissue disorder characterized by increased fibrosis of the skin and in certain variants, multiple other organ systems. Scleroderma involves a spectrum of pathologic changes and anatomic involvement. It can be divided into localized and systemic scleroderma. Hand involvement is common and can include calcium deposits within the soft tissues, digital ischemia, and joint contracture. Nonsurgical management consists of lifestyle modifications, biofeedback, therapy for digital stiffness/contracture, and various pharmacologic medications. When nonsurgical measures are unsuccessful, certain surgical options may be indicated, each with their inherent advantages and pitfalls. Patients with scleroderma who are undergoing surgical intervention pose unique difficulties because of their poorly vascularized tissue and deficient soft-tissue envelopes, thus increasing their susceptibility to wound healing complications and infection. Some subgroups of patients are frequently systemically ill, and specific perioperative measures should be considered to reduce their surgical risk. The spectrum of hand manifestations seen in patients with scleroderma will be reviewed with the focus on evaluation and management.

A Numerical Model of Blood Flow Velocity Measurement Based on Finger Ring

Aiming to measure the blood flow velocity in a finger, a novel noninvasive method, i.e., a ring with a heat source chip and a temperature sensor, is designed in this paper. The heat source chip is used to heat the finger and generate heat diffusion between the chip and the temperature sensor. And the temperature sensor is designed to measure the temperature difference. Since the blood flow is the main medium of heat diffusion in bodies, part from the heat energy in the tissue will be taken away by the flowing blood. Therefore, the blood flow velocity can be acquired via its relationship with the temperature difference. Compared to the ultrasound Doppler method and the laser Doppler method, the proposed method guarantees a more convenient operation in more flexible work sites. We also analyze the theory between heat transfer and laminar flow. Finally, several simulations are conducted, and the influence of the relevant factors (i.e., the number of blood vessels, the radius, etc.) corresponding to the simulation results is also discussed.

Photoacoustic Oxygenation Quantification in Patients with Raynaud's: First-in-Human Results

The purpose of this study was to investigate the use of photoacoustic imaging for quantifying fingertip oxygenation as an approach to diagnosing and monitoring Raynaud's phenomenon. After 30 min of acclimation to room temperature, 22 patients (7 patients with secondary Raynaud's associated to Scleroderma and 15 healthy controls) provided informed consent to undergo fingertip Doppler imaging and high-frequency photoacoustic imaging before and 5, 15 and 30 min after cold stimulus (submerged hand in a 15 °C water bath for 1 min). High-frequency ultrasound and photoacoustic imaging was performed on the nail bed of each patient's second through fifth finger on their dominant hand, using a Vevo 2100 LAZR system with an LZ-250 probe (Fujifilm VisualSonics, Toronto, ON, Canada) in oxy-hemoglobin quantification mode. During each exam, volumetric data across a 3-mm span of data was acquired to produce a volumetric image of percent oxygenation and hemoglobin concentration. Changes in fingertip oxygenation between Raynaud's patients and healthy volunteers were compared, using receiver operator characteristic (ROC) analysis. Photoacoustic signal was detected in both the nail bed and nailfold in all study participants. Doppler ultrasound resulted in poor differentiation of Raynaud's patients from healthy volunteers, with an area under the ROC curve (A_z) of 0.51. Photoacoustic imaging demonstrated improved accuracy at baseline (A_z = 0.72), which improved when quantifying normalized changes after cold stimulus (A_z = 0.89 5-min post stimulus, A_z = 0.91 15-min post stimulus, and A_z = 0.85 after stimulus). Oxygenation levels derived using photoacoustic imaging are able to identify patients with Raynaud's and safely evaluate their response to a cold stimulus over time.

Follow-Up of Treatment Response With Dynamic Doppler Ultrasound in Raynaud Phenomenon

OBJECTIVE

The purpose of this study was to investigate the role of flow parameters obtained with dynamic Doppler ultrasound in the objective follow-up of treatment response in patients with Raynaud phenomenon (RP).

SUBJECTS AND METHODS

The study included 33 patients with newly diagnosed primary RP, 31 with secondary RP, and 26 healthy participants (control subjects). Both groups of patients with RP underwent sonography before and after treatment. The control group underwent sonography once. Baseline digital arterial diameter and flow volume were measured at room temperature. After cold provocation, diameter and flow volume were measured again, and flow starting time and flow normalizing time were recorded. Data were measured as mean (± SD) values.

RESULTS

Baseline diameter did not significantly increase in either group after treatment (p > 0.05) (primary RP pretreatment, 0.79 ± 0.17 mm; posttreatment, 0.82 ± 0.19 mm; secondary RP pretreatment, 0.66 ± 0.13 mm; posttreatment, 0.68 ± 0.14 mm). Baseline flow volume increased significantly in both groups (p < 0.01) (primary RP pretreatment, 3.08 ± 2.96 mL/min; posttreatment, 3.91 ± 3.39 mL/min; secondary RP pretreatment, 2.14 ± 1.94 mL/min; posttreatment, 2.80 ± 2.15 mL/min). Cold provocation diameter increased significantly in both groups after treatment (p < 0.01) (primary RP pretreatment, 0.63 ± 0.15 mm; posttreatment, 0.70 ± 0.16 mm; secondary RP pretreatment, 0.56 ± 0.15 mm; posttreatment, 0.63 ± 0.13 mm). Cold provocation flow volume increased significantly in both groups after treatment (p < 0.01) (primary RP pretreatment, 1.18 ± 1.26 mL/min; posttreatment, 2.17 ± 2.16 mL/min; secondary RP pretreatment, 1.07 ± 1.40 mL/min; posttreatment, 1.46 ± 1.67 mL/min). After treatment, there was no statistically significant increase in flow starting time in patients with primary RP (p > 0.05), but there was a significant increase in patients with secondary RP (p < 0.05) (primary RP pretreatment, 1.15 ± 2.27 minutes; posttreatment, 0.61 ± 1.41 minutes; secondary RP pretreatment, 3.13 ± 4.81 minutes; posttreatment, 1.58 ± 2.36 minutes). After treatment, flow volume normalizing time improved significantly in both groups (p < 0.01) (primary RP pretreatment, 7.24 ± 7.60 minutes; posttreatment, 3.84 ± 3.39 minutes; secondary RP pretreatment, 9.58 ± 8.49 minutes; posttreatment, 4.32 ± 3.56 minutes). Among patients with primary RP, the posttreatment flow starting time was similar to that in the control group. Despite improvements, all remaining parameters differed in the treatment group compared with the control group.

CONCLUSION

Doppler ultrasound can be used effectively to monitor RP treatment. Blood flow volume can be measured without cold provocation to facilitate follow-up care of patients with RP.

Ultra-high field upper extremity peripheral nerve and non-contrast enhanced vascular imaging

OBJECTIVE

The purpose of this study was to explore the efficacy of Ultra-high field [UHF] 7 Tesla [T] MRI as compared to 3T MRI in non-contrast enhanced [nCE] imaging of structural anatomy in the elbow, forearm, and hand [upper extremity].

MATERIALS AND METHOD

A wide range of sequences including T1 weighted [T1] volumetric interpolate breath-hold exam [VIBE], T2 weighted [T2] double-echo steady state [DESS], susceptibility weighted imaging [SWI], time-of-flight [TOF], diffusion tensor imaging [DTI], and diffusion spectrum imaging [DSI] were optimized and incorporated with a radiofrequency [RF] coil system composed of a transverse electromagnetic [TEM] transmit coil combined with an 8-channel receive-only array for 7T upper extremity [UE] imaging. In addition, Siemens optimized protocol/sequences were used on a 3T scanner and the resulting images from T1 VIBE and T2 DESS were compared to that obtained at 7T qualitatively and quantitatively [SWI was only qualitatively compared]. DSI studio was utilized to identify nerves based on analysis of diffusion weighted derived fractional anisotropy images. Images of forearm vasculature were extracted using a paint grow manual segmentation method based on MIPAV [Medical Image Processing, Analysis, and Visualization].

RESULTS

High resolution and high quality signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]-images of the hand, forearm, and elbow were acquired with nearly homogeneous 7T excitation. Measured [performed on the T1 VIBE and T2 DESS sequences] SNR and CNR values were almost doubled at 7T vs. 3T. Cartilage, synovial fluid and tendon structures could be seen with higher clarity in the 7T T1 and T2 weighted images. SWI allowed high resolution and better quality imaging of large and medium sized arteries and veins, capillary networks and arteriovenous anastomoses at 7T when compared to 3T. 7T diffusion weighted sequence [not performed at 3T] demonstrates that the forearm nerves are clearly delineated by fiber tractography. The proper digital palmar arteries and superficial palmar arch could also be clearly visualized using TOF nCE 7T MRI.

CONCLUSION

Ultra-high resolution neurovascular imaging in upper extremities is possible at 7T without use of renal toxic intravenous contrast. 7T MRI can provide superior peripheral nerve [based on fiber anisotropy and diffusion coefficient parameters derived from diffusion tensor/spectrum imaging] and vascular [nCE MRA and vessel segmentation] imaging.

Novel photoplethysmography cardiovascular assessments in patients with Raynaud's phenomenon and systemic sclerosis: a pilot study

OBJECTIVE

Multisite photoplethysmography (PPG) cardiovascular assessments can evaluate endothelial, peripheral autonomic and arterial dysfunction. The aim of this pilot study was to investigate the potential clinical utility of the technology in assessing patients with SSc and primary RP (PRP).

METHODS

Multisite PPG pulse measurements, a reference ankle brachial pressure index (ABPI) and a full clinical assessment were undertaken for three subject groups: SSc, PRP and controls. Endothelial and autonomic function and arterial disease measures were obtained using pulse wave analysis.

RESULTS

Nineteen SSc, 19 PRP and 23 control subjects were assessed and compared. Endothelial function was significantly impaired in SSc (P < 0.02), but with no difference between controls and PRP. Receiver operating characteristic-based classification accuracy was 81% (sensitivity 90%, specificity 74%) for separating SSc from controls and 82% (sensitivity 84%, specificity 79%) for separating SSc from PRP. SSc patients with digital ulcers had significantly lower endothelial function compared with those without ulcers (P < 0.05). Autonomic dysfunction was suggested in both SSc and PRP and was most exaggerated in patients with diffuse SSc. All groups had overall normal ABPI and arterial stiffness timing measures. Bilateral timing differences at the toes, which represents peripheral occlusive arterial disease, did show increased asymmetry in SSc (P < 0.02).

CONCLUSION

Multisite PPG pulse technology showed potential diagnostic ability. By using measures of endothelial function, it differentiated SSc from control and PRP subjects with an accuracy of at least 81%. Objective pulse-derived measures of autonomic function and arterial disease in SSc have also been reported in this pilot study.

Effect of capillaroscopic patterns on the pulse oximetry measurements in systemic sclerosis patients

Nailfold capillaroscopy is a simple method for determining microvascular damage in systemic sclerosis (SSc). The pulse oximeter is a noninvasive tool that is used to estimate a patient's arterial blood oxygen saturation. The aim of this study was to investigate the effect of capillaroscopic patterns on pulse oximetry measurements in SSc patients. The nailfolds from 2nd to 5th fingers in both hands were examined in all subjects by using capillaroscopy. Patients were categorized according to their capillaroscopy findings in 3 groups as having early, active or late patterns. Oxygen saturation (SpO2) measurements were performed from 2nd to 5th fingers in both hands with a finger probe. We studied 53 SSc patients (F/M: 48/5). According to capillaroscopy findings 18 patients were classified as having early pattern (34.0%), 19 active pattern (35.8%), and 15 late pattern (28.3%). Only 1 (1.9%) patient had normal capillaroscopy findings. SpO2 could not be measured in 47 (11.0%) fingers and in 20 (37.7%) SSc patients. There were 20 (37.7%) patients with a ≥4% difference between the minimum and maximum SpO2 measurements among fingers. There were no difference between the groups of SSc patients defined by capillaroscopy findings in terms of mean maximal SpO2 or mean minimal SpO2 measured from fingers (p NS, for all). Assessment of SpO2 values in patients with SSc is challenging. We did not detect any effect of capillaroscopic patterns on mean SpO2 values. On the other hand ≥4% difference between minimum and maximum SpO2 values measured from fingers of a patient may be considered as an indirect sign of microvascular damage. Assessment of the highest measured SpO2 values among the fingers of a patient may be more suitable in practice.

Management of Raynaud's phenomenon and digital ischemia

This review focuses on new findings and developments relevant to the clinician caring for patients with primary and secondary [especially systemic sclerosis (SSc)-related] Raynaud phenomenon (RP). In the last 18 months, several clinical trials and observational studies of RP and of SSc-related digital ulceration have been published, reflecting increased awareness of disease burden and increased interest by pharmaceutical companies: new insights into pathophysiology are driving new approaches to treatment. Key developments are the increased use of phosphodiesterase type V inhibitors in severe RP, and of bosentan (an endothelin-1 receptor antagonist) for prevention of recurrent SSc-related digital ulcers. Other treatments being researched include topical glyceryl trinitrate (applied locally to the digits), botulinum toxin (for severe digital ischemia/ulceration), and several other drugs including oral prostanoids. Increased availability and interest in nailfold capillaroscopy, by facilitating early diagnosis of SSc, should pave the way for studies of early intervention and vascular protection.