Transcutaneous Oxygen Pressure Research Articles

Current Opinion on Diagnosis of Peripheral Artery Disease in Diabetic Patients.

Peripheral arterial disease (PAD) prevalence and diabetes mellitus (DM) prevalence are continuously increasing worldwide. The strong relationship between DM and PAD is highlighted by recent evidence. PAD diagnosis in diabetic patients is very important, particularly in patients with diabetic foot disease (DFD); however, it is often made difficult by the characteristics of such diseases. Diagnosing PAD makes it possible to identify patients at a very high cardiovascular risk who require intensive treatment in terms of risk factor modification and medical therapy. The purpose of this review is to discuss the diagnostic methods that allow for a diagnosis of PAD in diabetic patients. Non-invasive tests that address PAD diagnosis will be discussed, such as the ankle-brachial index (ABI), toe pressure (TP), and transcutaneous oxygen pressure (TcPO2). Furthermore, imaging methods, such as duplex ultrasound (DUS), computed tomography angiography (CTA), magnetic resonance angiography (MRA), and digital subtraction angiography (DSA), are described because they allow for diagnosing the anatomical localization and severity of artery stenosis or occlusion in PAD. Non-invasive tests will also be discussed in terms of their ability to assess foot perfusion. Foot perfusion assessment is crucial in the diagnosis of critical limb ischemia (CLI), the most advanced PAD stage, particularly in DFD patients. The impacts of PAD diagnosis and CLI identification in diabetic patients are clinically relevant to prevent amputation and mortality.

Gene Therapy of Thromboangiitis Obliterans with Growth Factor Plasmid (VEGF165) and Autologous Bone Marrow Cells.

We performed gene therapy for critical limb ischemia in thromboangiitis obliterans (TAO) by the intramuscular administration of plasmids of the vascular endothelial growth factor gene (VEGF 165) with or without bone marrow-derived stem cells. The 21 patients were randomly assigned to three groups: A-with dual therapy, cells and plasmid; B-plasmid only; and C-control group, where patients received intramuscular injections of saline. Serum VEGF levels, the ankle-brachial index (ABI), transcutaneous oxygen pressure (TcPO2), and the rest pain measured by the visual analog scale (VAS) were determined sequentially before treatment, and then 1 and 3 months after treatment. In the treatment groups, serum VEGF levels increased by 4 weeks and returned to baseline values after 3 months. ABI after 12 weeks increased by an average of 0.18 in group A, and 0.09 in group B and group C. TcPO2 increased by an average of 17.3 mmHg in group A, 14.1 mmHg in group B, and 10.7 mmHg in group C. The largest pain decrease was observed in group A and averaged 5.43 less pain intensity. Gene therapy using the VEGF plasmid along with or without bone marrow-derived mononuclear cells administered intramuscularly into an ischemic limb in TAO is a safe and effective therapy.

Gene Therapy of Thromboangiitis Obliterans with Growth Factor Plasmid (VEGF165) and Autologous Bone Marrow Cells

Background: We performed gene therapy for critical limb ischemia in thromboangiitis obliterans (TAO) by the intramuscular administration of plasmids of the vascular endothelial growth factor gene (VEGF 165) with or without bone marrow-derived stem cells. Methods: The 21 patients were randomly assigned to three groups: A—with dual therapy, cells and plasmid; B—plasmid only; and C—control group, where patients received intramuscular injections of saline. Serum VEGF levels, the ankle–brachial index (ABI), transcutaneous oxygen pressure (TcPO2), and the rest pain measured by the visual analog scale (VAS) were determined sequentially before treatment, and then 1 and 3 months after treatment. Results: In the treatment groups, serum VEGF levels increased by 4 weeks and returned to baseline values after 3 months. ABI after 12 weeks increased by an average of 0.18 in group A, and 0.09 in group B and group C. TcPO2 increased by an average of 17.3 mmHg in group A, 14.1 mmHg in group B, and 10.7 mmHg in group C. The largest pain decrease was observed in group A and averaged 5.43 less pain intensity. Conclusion: Gene therapy using the VEGF plasmid along with or without bone marrow-derived mononuclear cells administered intramuscularly into an ischemic limb in TAO is a safe and effective therapy.

Participation of Arterial Ischemia in Positional-Related Symptoms among Patients Referred for Thoracic Outlet Syndrome.

Objectives: The coexistence of arterial compression with neurogenic thoracic outlet syndrome (TOS) is associated with a better post-surgical outcome. Forearm transcutaneous oxygen pressure (TcpO2) using the minimal decrease from rest of oxygen pressure (DROPmin) can provide an objective estimation of forearm ischemia in TOS. We hypothesized that a linear relationship exists between the prevalence of symptoms (PREVs) and DROPmin during 90° abduction external rotation (AER) provocative maneuvers. Thereafter, we aimed to estimate the proportion of TOS for which arterial participation is present. Methods: Starting in 2019, we simultaneously recorded forearm TcpO2 recordings (PF6000 Perimed®) and the presence/absence of ipsilateral symptoms during two consecutive 30 s AER maneuvers for all patients with suspected TOS. We retrospectively analyzed the relationship between the prevalence of symptoms and DROPmin results. We estimated the number of cases where ischemia likely played a role in the symptoms, assuming that the relationship should start from zero in the absence of ischemia and increase linearly to a plateau of 100% for the most severe ischemia. Results: We obtained 2560 TcpO2 results in 646 subjects (69% females). The correlation between PREVs and DROPmin was 0.443 (p < 0.001). From these results, we estimated the arterial participation in TOS symptoms to be 22.2% of our 1669 symptomatic upper limbs. Conclusions: TcpO2 appears to be an interesting tool to argue for an arterial role in symptoms in TOS. Arterial participation is frequent in TOS. Whether DROPmin could predict treatment outcomes better than the sole presence of compression is an interesting direction for the future.

Transcutaneous oxygen tension-guided hyperbaric oxygen therapy for preventing skin necrosis after hyaluronic acid filler injections.

Hyaluronic acid (HA) fillers, popular for facial cosmetic enhancements, pose risks of vascular complications like skin necrosis due to arterial blockage, necessitating effective treatments such as hyperbaric oxygen therapy (HBOT). This study presents a series of cases where measurements of transcutaneous oxygen pressure (TcPO2) informed the application of HBOT for skin necrosis induced by HA. In cases 1 and 3, following the injection of HA, potential skin necrosis was observed. In addition to standard treatment, TcPO2 revealed values below 40mmHg, indicating tissue hypoxia. Treatment with HBOT increased TcPO2 levels to above 200mmHg, suggesting that HBOT could correct the hypoxia. Monitoring TcPO2 levels also aided in determining the optimal time to discontinue HBOT. In cases 2 and 4, patients received standard treatment, resulting in TcPO2 levels above 40mmHg, indicating adequate tissue oxygenation, and no additional HBOT was administered. All four patients mentioned above showed good clinical recovery. This study investigates the application of TcPO2 measurement technology in aiding decisions on whether to utilize HBOT in the treatment of complications arising from HA fillers, as well as in optimizing HBOT protocols.

Gender-Related Difference in Skin Oxygenation in Young Patients with Uncomplicated Type 1 Diabetes.

Gender, through genetic, epigenetic and hormonal regulation, is an important modifier of the physiological mechanisms and clinical course of diseases. In diabetes mellitus, there are gender differences in incidence, prevalence, morbidity, and mortality. This disease also has an impact on the microvascular function. Therefore, this cross-sectional study was designed to investigate how gender affects the cutaneous microcirculation. We hypothesized that gender should be an important factor in the interpretation of capillaroscopy and transcutaneous oxygen saturation results. The study group consisted of 42 boys and 55 girls, uncomplicated diabetic pediatric patients. Females (F) and males (M) did not differ in terms of age, age at onset of diabetes, or diabetes duration. Furthermore, they did not differ in metabolic parameters. The comparison showed that group F had lower BP, higher pulse, and higher HR than group M. Group F had significantly lower creatinine and hemoglobin levels than group M. In children and adolescents with type 1 diabetes without complications, there was a gender difference in microcirculatory parameters. The resting transcutaneous partial pressure of oxygen was significantly higher in females than in males. However, there were no gender-related differences in basal capillaroscopic parameters or vascular reactivity during the PORH test. Our results indicate that studies investigating the structure and function of the microcirculation should consider the role of gender in addition to known cofactors such as puberty, body mass index, physical activity, and cigarette smoking.

TcPO2 changes are more pronounced than SpO2 changes during simulated altitude changes in a hypobaric oxygen chamber: a nonrandomized controlled trial

Abstract Background Hypoxia is a significant risk factor of hypertension. However, no studies have used transcutaneous tissue partial pressure of oxygen (TcPO2) and partial pressure of carbon dioxide (TcPCO2) monitors to measure the respective partial pressures in healthy individuals. Oxygen saturation (SpO2) is often used for traditional monitoring of vital signs. This study investigated the changes in TcPO2 and SpO2 values during rapid changes in altitude. The trial was registered at ClinicalTrials.gov (registration no. NCT06076057). Methods Healthy adult volunteers were instructed to sit vertically in a hypobaric oxygen chamber, which ascended from 0 m to 2500 m at a uniform speed within 10 min. The Danish Radiometer TCM4 was used to measure TcPO2 and TcPCO2 with the ventral side of the upper arm as the measurement site. The Shenzhen Kerokan P0D-1 W pulse oximeter was used to measure heart rate and SpO2, with values recorded once every 500 m. Results Altogether, 49 healthy volunteers were recruited between March 2023 and August 2023. With increasing altitude, TcPO2 and SpO2 decreased significantly (P &lt; 0.01). During the ascent from 0 m, TcPO2 began to change statistically at 500 m (P &lt; 0.05), whereas SpO2 began to change statistically at 1000 m (P &lt; 0.05). At the same altitude, the difference in TcPO2 was greater than the difference in SpO2. At 1000 m, there were statistically significant changes in TcPO2 and SpO2 (P &lt; 0.001). At altitudes &gt;500 m, statistical significance was identified between TcPO2 in both sexes (P &lt; 0.05). Statistical significance in TcPCO2 and heart rate was observed at the different elevations (P &lt; 0.05). Conclusion In acutely changing low-pressure hypoxic environments, TcPO2 changed more dramatically than SpO2.

Exercise transcutaneous oximetry in functional popliteal artery entrapment syndrome diagnosis.

Functional poplitealartery entrapment syndrome is a subtype of poplitealartery entrapment syndrome (PAES) without vascular disease or musculotendinous anomaly behind the knee. Symptoms are induced by popliteal artery extrinsic compression, leading to calf pain during lower limbs exercise. Non-invasive tests are still required to improve the diagnostic management of functional PAES. Exercise transcutaneous oxygen pressure (Ex-tcpO2) is of interest to provide objective arguments for the presence of regional blood flow impairment. The aim of the study was to analyze whether Ex-tcpO2 could serve as a non-invasive technique for detecting ischemia resulting from PAES. Patients with suspected PAES were recruited between 2017 and 2020. The diagnosis was confirmed or rejected, according to the surgical decision based on our diagnosis management involving a multidisciplinary team. Each patient underwent Ex-tcpO2 with specific maneuvers. The decrease from rest of oxygen pressure (DROP) index served for the interpretation of exercise results. Sixty-five legs with suspected PAES were recruited. Diagnosis was confirmed in 34 (52.3%) and rejected in 32 (47.7%). The average DROP values found in confirmed and rejected group at left leg were -21.6 ± 15.4mmHg and -10.9 ± 11.1mmHg, respectively (p for Mann-Whitney 0.004), and -15.8 ± 11mmHg and -11.1 ± 7.5mmHg, respectively, at right leg (p = 0.088). Ex-tcpO2 sensitivity and specificity were 52.9% and 78.1%, respectively. Ex-tcpO2 is an original non-invasive investigation for patients with claudication of doubtful arterial origin. The sensitivity and specificity are 52.9% and 78.1% in functional PAES diagnosis using 15mmHg as threshold to detect ischemia during tiptoeing elevations.

#2851 Effects of dialysis on various microcirculatory beds in end-stage kidney disease (ESKD): a systematic review and meta-analysis

Abstract Background and Aims Microcirculatory dysfunction is common in ESKD-patients and may play a pivotal role in their cardiovascular burden. Besides traditional and chronic-kidney-disease (CKD)-specific risk factors, dialysis itself might contribute to the dysfunction of the microcirculation (MC). Although an intradialytic fall in systemic blood pressure (BP) may directly influence the microcirculatory perfusion, vascular beds in different organs may not react uniformly. This systematic review and meta-analysis evaluated the acute impact of hemodialysis (HD) and hemodiafiltration (HDF) on the MC in various vascular beds. Methods Pubmed and Embase databases were systematically explored until June 2023 by two independent researchers. All observational and interventional studies in ESKD patients that reported dialysis-induced alterations of the MC, measured at the cutaneous, sublingual, retinal, muscle or coronary beds were eligible. Dialysis-induced changes were extracted and pooled, using a fixed-effects meta-analysis when the studies were reasonably homogeneous in terms of outcomes and methodology. Results 17 Studies with 493 participants were included. Virtually all patients (99.8%) were treated with HD. No eligible studies on coronary or muscle MC were identified. Cutaneous MC was investigated in 7 studies, showing a mean reduction in transcutaneous oxygen pressure of −7.9 mmHg (95% CI −10.5 to –5.3, n = 4 studies) and a mean reduction in blood flow of −0.9 arbitrary units (95% CI −1.2 to −0.6, n = 3 studies). Cutaneous vasoreactivity was diminished in 2 out of 3 studies (reactive maximum microvascular hyperemia: −36% (p &amp;lt; 0.05); time to reach baseline skin temperature after standardized cooling: 65.6 seconds (p-value not reported); vs. no significant change in post-ischemic maximal flow (2.5, p = not significant (N.S.)). Sublingual MC was assessed in 3 studies, showing a mean decrease in microvascular flow index of −0.6 in small microvessels (vessel diameter (VD) &amp;lt;20-25 µm, 95% CI −1.0 to −0.2, n = 3 studies), but no significant change in proportion of perfused vessels (−0.5%, 95% CI −1.2 to 0.2, n = 2 studies). One study showed a significant reduction in sublingual perfused vessel density after treatment (VD &amp;lt;20 µm: −1.6 ± 3.1, p &amp;lt; 0.05; VD &amp;gt;20 µm: −0.6 ± 1.1, p &amp;lt; 0.05), whereas total vessel density was unaffected in another study (VD &amp;lt;20 µm: 0.5, p = N.S.). Retinal MC was investigated in 7 studies, showing that the perfused vessel density (PVD) remained unchanged in both the superficial and deep capillary plexus (PVD SCP −0.48, 95% CI (−0.99; 0.03); PVD DCP −0.48, 95% CI (−1.18; 0.23), n = 4 studies). One study reported a decreased PVD at the outer retina (−1.3 ± 5.7, p &amp;lt; 0.05), while conflicting results were observed in 2 studies (0.1, p = N.S.; vs. −2.9 ± 4.3, p &amp;lt; 0.001), reporting the PVD at the choriocapillaris level. One study found no change in retinal blood flow (0.4, p = N.S.). With regard to vessel diameter changes, an increase in retinal venular diameter was observed in 3 studies (retinal venular diameter: 11.2 µm, p = 0.002; central retinal vein equivalent: 12.7 µm, p &amp;lt; 0.001; retinal vessel diameter: 4.4, p &amp;lt; 0.01), and one study described impaired venular dilatation in response to flicker light (−4.0, p = 0.04). Conclusions Hemodialysis induces microvascular dysfunction in different organs, but its impact varies between vascular beds. Microvascular perfusion was most significantly impaired in the cutaneous and sublingual regions, whereas the retinal microcirculatory perfusion remained unaltered. Literature on the effect of hemodiafiltration on the MC is lacking.

Pedal Acceleration Time An Alternative Tool To Ankle-Brachial Index In Peripheral Arterial Disease.

Ankle-Brachial Index (ABI) is a well-established diagnostic tool for evaluating peripheral arterial disease (PAD). Limitations in its application led to the development of alternative diagnostic methods, including Toe-Brachial Index (TBI) and Transcutaneous Pressure of Oxygen (TcPO2), yet these are not as widely available as ABI. Recently, Pedal Acceleration Time (PAT), has gained popularity as a new tool to assess PAD, requiring only an ultrasound. This study seeks to further establish the correlation between ABI and PAT, determining whether PAT can be a reliable alternative for diagnosing and assessing the severity of PAD. ABI and PAT were measured in patients attending our consult with no history of vascular or endovascular surgery. Limbs with unmeasurable ABI were excluded. Patients were categorized into groups based on their PAD stage according to the Fontaine classification. Patient demographics, comorbidities and respective ABI and PAT were analysed. Sixty-nine patients (114 limbs) were included in the study. Mean age 68 ± 11.7 years, 78.3% male and 33.3% diabetic patients. Fifty-three claudicant limbs (46.5%) and 26 limbs (22.8%) with chronic limb threatening ischemia. Pearson correlation coefficient between ABI and PAT, showed a strong negative correlation (r= -0.78; p<0.01). Mean ABI and PAT for limbs in Fontaine stage I were 0.94 ± 0.17 and 82.0 ± 27.4 ms; Fontaine stage IIa 0.69 ± 0.21 and 141.3 ± 57.8 ms; Fontaine stage IIb 0.54 ± 0.14 and 173.4 ± 65.1 ms; Fontaine stage III 0.43 ± 0.15 and 216 ± 33.2 ms; Fontaine stage IV 0.49 ± 0.17 and 206.7 ± 78.1 ms, respectively. Our study suggests an inverse correlation between ABI and PAT, in accordance with the findings published in the literature, thus supporting the use of PAT as an easily reproducible and efficient alternative to ABI for evaluating the severity of PAD.

Does PAD and microcirculation status impact the tissue availability of intravenously administered antibiotics in patients with infected diabetic foot? Results of the DFIATIM substudy.

The aim of this substudy (Eudra CT No:2019-001997-27)was to assess ATB availability in patients with infected diabetic foot ulcers(IDFUs)in the context of microcirculation and macrocirculation status. For this substudy, we enrolled 23 patients with IDFU. Patients were treated with boluses of amoxicillin/clavulanic acid(AMC)(12patients) or ceftazidime(CTZ)(11patients). After induction of a steady ATB state, microdialysis was performed near the IDFU. Tissue fluid samples from the foot and blood samples from peripheral blood were taken within 6 hours. ATB potential efficacy was assessed by evaluating the maximum serum and tissue ATB concentrations(Cmax and Cmax-tissue)and the percentage of time the unbound drug tissue concentration exceeds the minimum inhibitory concentration (MIC)(≥100% tissue and ≥50%/60% tissue fT>MIC). Vascular status was assessed by triplex ultrasound, ankle-brachial and toe-brachial index tests, occlusive plethysmography comprising two arterial flow phases, and transcutaneous oxygen pressure(TcPO2). Following bolus administration, the Cmax of AMC was 91.8 ± 52.5 μgmL-1 and the Cmax-tissue of AMC was 7.25 ± 4.5 μgmL-1(P<0.001). The Cmax for CTZ was 186.8 ± 44.1 μgmL-1 and the Cmax-tissue of CTZ was 18.6 ± 7.4 μgmL-1(P<0.0001). Additionally, 67% of patients treated with AMC and 55% of those treated with CTZ achieved tissue fT>MIC levels exceeding 50% and 60%, respectively. We observed positive correlations between both Cmax-tissue and AUCtissue and arterial flow. Specifically, the correlation coefficient for the first phase was r=0.42; (P=0.045), and for the second phase, it was r=0.55(P=0.01)and r=0.5(P=0.021). Bactericidal activity proved satisfactory in only half to two-thirds of patients with IDFUs, an outcome that appears to correlate primarily with arterial flow.

The Impact of Disease Duration on Microcirculatory Dysfunction in Young Patients with Uncomplicated Type 1 Diabetes.

This study aimed to evaluate the earliest changes in the structure and function of the peripheral microcirculation using capillaroscopy and transcutaneous oxygen pressure measurement in children and adolescents with type 1 diabetes mellitus at baseline and during post-occlusive reactive hyperemia (PORH) in the function of diabetes duration. Sixty-seven patients with type 1 diabetes mellitus (T1D), aged 8 to 18 years, and twenty-eight age- and sex-matched healthy subjects were included in the analysis. Diabetic patients were divided into subgroups based on median disease duration. The subgroups differed in chronological age, lipid levels, and thyroid hormones. Capillaroscopy was performed twice: at baseline and then again after the PORH test. Transcutaneous oxygen pressure also was recorded under baseline conditions during and after the PORH test. Comparison of capillaroscopy and transcutaneous oxygen pressure parameters at rest and after the PORH showed no statistically significant difference between the subgroups. This remained true after adjusting for variables that differentiated the two subgroups. However, in the group of patients with long-standing diabetes, significant negative correlations were observed between the Coverage value after the PORH test and capillary reactivity with TcPO2_zero (biological zero). Significant positive correlations were also found between distance after the PORH test and TcPO2_zero. The results of our study indicate that in patients with a shorter duration of diabetes, the use of multiple tests provides a better characterization of the structure and function of microcirculation because the onset of dysfunction does not occur at the same time in all the tests.

Treatment of hard-to-heal wounds in ischaemic lower extremities with a novel fish skin-derived matrix.

To evaluate the efficacy of treatment of hard-to-heal wounds of patients with ischaemia of the lower extremities, and compare an omega-3 wound matrix product (Kerecis, Iceland) with a standard dressing. A single-centre, prospective, randomised, controlled clinical trial of patients with hard-to-heal wounds following three weeks of standard care was undertaken. The ischaemic condition of the wound was confirmed as a decreased transcutaneous oxygen pressure (TcPO2) of <40mmHg. After randomising patients into either a case (omega-3 dressing) or a control group (standard dressing), the weekly decrease in wound area over 12 weeks and the number of patients that achieved complete wound closure were compared between the two groups. Patients with a TcPO2 of ≤32mmHg were taken for further analysis of their wound in a severe ischaemic context. A total of 28 patients were assigned to the case group and 22 patients to the control group. Over the course of 12 weeks, the wound area decreased more rapidly in the case group than the control group. Complete wound healing occurred in 82% of patients in the case group and 45% in the control group. Even in patients with a severe ischaemic wound with a TcPO2 value of <32 mmHg, wound area decreased more rapidly in the case group than the control group. The proportions of re-epithelialised area in the case and control groups were 80.24% and 57.44%, respectively. Considering the more rapid decrease in wound area and complete healing ratio in the case group, application of a fish skin-derived matrix for treating lower-extremity hard-to-heal wounds, especially with impaired vascularity, would appear to be a good treatment option.

Correlation Between Pedal Acceleration Time and Transcutaneous Oxygen Pressures – A Prognostic Tool for Wound Healing in the Diabetic Foot Population

INTRODUCTIONPedal arch interrogation by ultrasound through systolic acceleration time measurement (Pedal Acceleration Time – PAT) is a recently described technique, that offers valuable insights into foot hemodynamics. Previous studies have demonstrated a correlation between PAT and the ankle-brachial index (ABI) and PAT has been proposed as a prognostic tool for wound healing in patients with peripheral artery disease (PAD). This study aims to assess the correlation between PAT and Transcutaneous Oxygen Pressures (TcPO2) in the diabetic foot population. STUDY DESIGNSingle-center cross-sectional study. MATERIALS AND METHODSPedal acceleration time and transcutaneous oxygen pressures were measured in 60 limbs of 53 diabetic patients with ischemic foot ulcers. The assessment of wound status was performed between the 12th and 16th week after the first evaluation. The primary outcome was to assess the correlation between the values obtained for PAT and TcPO2. The secondary outcome was to establish a cut-off value for wound healing. RESULTSSixty limbs with ischemic foot ulcers were evaluated. The results showed a correlation between PAT and TcPO2 [F(1.52)=16.928; R2=0.246; p<0.001]. The ROC analysis showed an optimal cut-off value at PAT>186 ms for predicting a non-healing ulcer with a 96% specificity (AUC=0.774; CI 0.648-0.872; p<0.001). CONCLUSIONPAT showed a significant correlation with TcPO2 with high specificity to identify non-healing foot ulcers due to insufficient foot perfusion with a potential prognostic value in the diabetic foot population.

Time delays between physiological signals in interpreting the body’s responses to intermittent hypoxia in obstructive sleep apnea

Objective. Intermittent hypoxia, the primary pathology of obstructive sleep apnea (OSA), causes cardiovascular responses resulting in changes in hemodynamic parameters such as stroke volume (SV), blood pressure (BP), and heart rate (HR). However, previous studies have produced very different conclusions, such as suggesting that SV increases or decreases during apnea. A key reason for drawing contrary conclusions from similar measurements may be due to ignoring the time delay in acquiring response signals. By analyzing the signals collected during hypoxia, we aim to establish criteria for determining the delay time between the onset of apnea and the onset of physiological parameter response. Approach. We monitored oxygen saturation (SpO2), transcutaneous oxygen pressure (TcPO2), and hemodynamic parameters SV, HR, and BP, during sleep in 66 patients with different OSA severity to observe body’s response to hypoxia and determine the delay time of above parameters. Data were analyzed using the Kruskal–Wallis test, Quade test, and Spearman test. Main results. We found that simultaneous acquisition of various parameters inevitably involved varying degrees of response delay (7.12–25.60 s). The delay time of hemodynamic parameters was significantly shorter than that of SpO2 and TcPO2 (p< 0.01). OSA severity affected the response delay of SpO2, TcPO2, SV, mean BP, and HR (p < 0.05). SV delay time was negatively correlated with the apnea-hypopnea index (r = −0.4831, p< 0.0001). Significance. The real body response should be determined after removing the effect of delay time, which is the key to solve the problem of drawing contradictory conclusions from similar studies. The methods and important findings presented in this study provide key information for revealing the true response of the cardiovascular system during hypoxia, indicating the importance of proper signal analysis for correctly interpreting the cardiovascular hemodynamic response phenomena and exploring their physiological and pathophysiological mechanisms.

Multimodal imaging device to comprehensively assess infection, oxygenation, and wound analytics-A pilot study.

Wound analytics, infection detection, and oxygenation measurement are the three critical prerequisites for appropriate wound care. Although devices that rapidly detect the above-mentioned parameters independently exist, there is no single point-of-care device that is enabled with all the three functionalities. Through this study, we are introducing and evaluating the performance of Illuminate Pro Max-a novel, rapid, hand-held non-contact, point-of-care multimodal imaging device that is equipped to measure the three wound assessment parameters. Here, a total of 60 diabetic foot ulcer patients were imaged using Illuminate Pro Max to detect bioburden and measure StO2 levels and wound dimensions (size and depth). The results were further evaluated against the current gold standard technique for each parameter, that is, culture test to detect bioburden, a transcutaneous oxygen pressure (TcPO2) measuring device-Perimed Periflux 5000 to measure oxygenation, and paper ruler to measure wound size. Culture tests reported 42 samples as infection-positive and 18 samples as infection-negative. On comparing with the culture report, the device showed 88% sensitivity and 86% PPV in detecting the bioburden. Wound dimensions (length and width) were comparable with the paper scale measurements. Wound depth was also reported by the device. The StO2 map generated by the device depicted the tissue oxygenation levels in various regions of the wound. In conclusion, this novel, comprehensive point-of-care multispectral imaging device can be an effective tool for rapid wound assessment which can help in prompt treatment.

Atorvastatin Treatment Significantly Increased the Concentration of Bone Marrow-Derived Mononuclear Cells and Transcutaneous Oxygen Pressure and Lowered the Pain Scale after Bone Marrow Cells Treatment in Patients with "No-Option" Critical Limb Ischaemia.

The present study investigated the outcomes and possible predictive factors of autologous bone marrow cells (BMCs) therapy in patients with "no-option" critical limb ischaemia (CLI). It was focused on exploring the clinical background and prior statin and renin-angiotensin system (RAS)-acting agents pharmacotherapy related to the therapeutic efficacy of BMCs treatment. In the present study, we reviewed thirty-three patients (mean age 64.9 ± 10 years; 31 males) with advanced CLI after failed or impossible revascularisation, who were treated with 40 mL of autologous BMCs by local intramuscular application. Patients with limb salvage and wound healing (N = 22) were considered as responders to BMCs therapy, and patients with limb salvage and complete ischemic wound healing (N = 13) were defined as super-responders. Logistic regression models were used to screen and identify the prognostic factors, and a receiver operating characteristics (ROC) curve, a linear regression, and a survival curve were drawn to determine the predictive accuracy, the correlation between the candidate predictors, and the risk of major amputation. Based on the univariate regression analysis, baseline C-reactive protein (CRP) and transcutaneous oxygen pressure (TcPO2) values were identified as prognostic factors of the responders, while CRP value, ankle-brachial index (ABI), and bone marrow-derived mononuclear cells (BM-MNCs) concentration were identified as prognostic factors of the super-responders. An area under the ROC curve of 0.768 indicated good discrimination for CRP > 8.1 mg/L before transplantation as a predictive factor for negative clinical response. Linear regression analysis revealed a significant dependence between the levels of baseline CRP and the concentration of BM-MNCs in transplanted bone marrow. Patients taking atorvastatin before BMCs treatment (N = 22) had significantly improved TcPO2 and reduced pain scale after BMCs transplant, compared to the non-atorvastatin group. Statin treatment was associated with reduced risk for major amputation. However, the difference was not statistically significant. Statin use was also associated with a significantly higher concentration of BM-MNCs in the transplanted bone marrow compared to patients without statin treatment. Patients treated with RAS-acting agents (N = 20) had significantly reduced pain scale after BMCs transplant, compared to the non-RAS-acting agents group. Similar results, reduced pain scale and improved TcPO2, were achieved in patients treated with atorvastatin and RAS-acting agents (N = 17) before BMCs treatment. Results of the Spearman correlation showed a significant positive correlation between CLI regression, responders, and previous therapy before BMCs transplant with RAS-acting agents alone or with atorvastatin. CRP and TcPO2 were prognostic factors of the responders, while CRP value, ABI, and BM-MNCs concentration were identified as predictive factors of the super-responders. Atorvastatin treatment was associated with a significantly increased concentration of BM-MNCs in bone marrow concentrate and higher TcPO2 and lower pain scale after BMCs treatment in CLI patients. Similarly, reduced pain scales and improved TcPO2 were achieved in patients treated with atorvastatin and RAS-acting agents before BMCs treatment. Positive correlations between responders and previous treatment before BMCs transplant with RAS-acting agents alone or with atorvastatin were significant.

Undiagnosed and Untreated Peripheral Complications of Diabetes: Findings from a Pilot Study on Diabetes-Related Foot Diseases (DFD) in Patients with Glycemic Disorders.

BACKGROUND Diabetes-related foot disease (DFD) is a serious complication of diabetes, increasing the risk of amputation. Coimplications are preventable, but most diabetics do not receive proper screening and treatment, despite indications. This study was a pilot screening of diabetes-related foot disease in a group of people with glycemic disorders. MATERIAL AND METHODS We recruited 143 volunteers over 40 years of age. In the final analysis, we included 85 people diagnosed with glycemic disorders (diabetes or prediabetes), for whom we performed a total of 170 foot measurements. We screened for peripheral artery disease using: foot pulse, ankle-brachial index (manual and automatic), toe-brachial index, and transcutaneous oxygen pressure (TcPO2). To screen for diabetic peripheral neuropathy, we used indicators of loss of protective sensation: pressure perception and temperature perception, and plantar pressure distribution. RESULTS A history of diabetes was reported by 26 (30.6%) of the subjects. Disorders of at least 1 foot occurred in 20 (66.7%) subjects with diagnosed diabetes and in 10 (17%) subjects declaring no diabetes. Higher risk and DFD category were correlated with duration of diabetes (r=0.68, p=0.007), glycemic levels (r=0.56, p=0.001), age (r=0.57, p=0.007), and the presence of other diabetes complications. The best predictor of risk in DFD was manual ABI, p=0.001; followed by automatic ABI, p=0.006. CONCLUSIONS Our results showed that peripheral complications of diabetes, such as DFD, often remain undiagnosed and untreated despite the high risk of developing ulcers. There is a need for multi-center screening studies.

Transcutaneous oximetry of angiosomes of maxillary and facial arteries

Aim. To qualitatively predict and control the quality of periodontal diseases treatment, to determine changes in the transcutaneous pressure of oxygen and carbon dioxide in angiosomes of maxillary and facial arteries in healthy adults. Materials and methods. 17 healthy people participated in this study. There were 10 (58 %) men aged 24 (22–27), weight 66 (62–80) kg and height 175 (169–182) cm and 7 (42 %) women, whose average age was 23 (20–26) years old, weight 58 (47–72) kg, height 165 (160–178) cm. Results. The highest values of tissue perfusion with oxygen were observed in the angiosomes of the upper jaw compared to the angiosomes of the lower jaw, where this indicator ranged from 105 to 153 mm Hg. On the lower jaw, the maximum value of the regional perfusion index (RPI) of 1.70 ± 0.04 was observed at the point of measurement where a. mentalis exits through the homonymous chin orifice, anastomosing with the branches of a. facialis. The highest values of tissue perfusion with carbon dioxide were observed in angiosomes of the lower jaw (28–36 mm Hg). In general, non-invasive measurements of oxygen and carbon dioxide pressure in tissues allow more accurate and direct visualization and control of microcirculation in the tissues of the corresponding angiosomes. Conclusions. The index of regional perfusion on the upper jaw is normally in the range of 2.2 to 2.6 (р &lt; 0.0001). In the angiosome of the lower jaw, the RPI value is within 1.3–1.7, respectively (p &lt; 0.0001). The tension of carbon dioxide in the tissues of the upper and lower jaw averages 31–34 mm Hg (р &lt; 0.05), reaches its maximum in the zones of the lowest oxygen perfusion.

Liraglutide for Lower Limb Perfusion in People With Type 2 Diabetes and Peripheral Artery Disease

Peripheral artery disease (PAD) in diabetes may lead to diabetic foot ulcer and lower-extremities amputation. Glucagon-like peptide 1 receptor agonists have proven cardiovascular benefits in trials of people with type 2 diabetes at high cardiovascular risk. To examine the effect of liraglutide on peripheral perfusion measured as peripheral transcutaneous oxygen pressure (TcPo2) in individuals with type 2 diabetes and PAD. This open-label randomized clinical trial was conducted between February 1, 2021, and June 30, 2022, with a final follow-up on December 30, 2022, at University of Campania "Luigi Vanvitelli," Naples, Italy. Fifty-five individuals with type 2 diabetes, PAD, and TcPo2 between 30 and 49 mm Hg were included. Patients were randomized to receive 1.8 mg of subcutaneous liraglutide or conventional treatment of cardiovascular risk factors (control group) for 6 months. Coprimary outcomes were the change from baseline of peripheral perfusion between groups and the comparison of the proportion of individuals who reached 10% increase of TcPo2 from baseline in each group. Fifty-five participants (mean [SD] age, 67.5 [8.5] years; 43 [78%] male) were randomized (27 to the liraglutide group and 28 to the control group) and analyzed. Participants had a median (IQR) hemoglobin A1c level of 6.9% (6.5%-7.8%) and a mean (SD) TcPo2 of 40.3 (5.7) mm Hg. Transcutaneous Po2 increased over time in both groups, with significant differences favoring the liraglutide group after 6 months (estimated treatment difference, 11.2 mm Hg; 95% CI, 8.0-14.5 mm Hg; P < .001). The 10% increase of TcPo2 occurred in 24 participants (89%) in the liraglutide group and 13 (46%) in the control group (relative risk, 1.91; 95% CI, 1.26-2.90; P < .001). Compared with the control group, individuals in the liraglutide group had a significant reduction of C-reactive protein (-0.4 mg/dL; 95% CI, -0.7 to -0.07 mg/dL; P = .02), urinary albumin to creatinine ratio (-119.4 mg/g; 95% CI, -195.0 to -43.8 mg/g; P = .003), and improvement of 6-minute walking distance (25.1 m; 95% CI, 21.8-28.3 m; P < .001). In this randomized clinical trial of people with type 2 diabetes and PAD, liraglutide increased peripheral perfusion detected by TcPo2 measurement during 6 months of treatment. These results support the use of liraglutide to prevent the clinical progression of PAD in individuals with type 2 diabetes. ClinicalTrials.gov Identifier: NCT04881110.