Peripheral Perfusion Research Articles

Clinical evaluation of peripheral tissue perfusion as a predictor of mortality in sepsis and septic shock in the intensive care unit: Systematic review and meta-analysis

ObjectiveTo determine the diagnostic performance of the clinical evaluation of peripheral tissue perfusion in the prediction of mortality. DesignSystematic review and meta-analysis. SettingIntensive care unit. Patients and participantsPatients with sepsis and septic shock. InterventionsStudies of patients with sepsis and/or septic shock that associated clinical monitoring of tissue perfusion with mortality were included. A systematic review was performed by searching the PubMed/MEDLINE, Cochrane Library, SCOPUS, and OVID databases. Main variables of interestThe risk of bias was assessed with the QUADAS-2 tool. Sensitivity and specificity were calculated to evaluate the predictive accuracy for mortality. Review Manager software version 5.4 was used to draw the forest plot graphs, and Stata version 15.1 was used to build the hierarchical summary receiver operating characteristic model. ResultsThirteen studies were included, with a total of 1667 patients and 17 analyses. Two articles evaluated the temperature gradient, four evaluated the capillary refill time, and seven evaluated the mottling in the skin. In most studies, the outcome was mortality at 14 or 28 days. The pooled sensitivity of the included studies was 70%, specificity 75.9% (95% CI, 61.6%–86.2%), diagnostic odds ratio 7.41 (95% CI, 3.91–14.04), and positive and negative likelihood ratios 2.91 (95% CI, 1.80–4.72) and 0.39 (95% CI, 0.30–0.51), respectively. ConclusionsClinical evaluation of tissue perfusion at the bedside is a useful tool, with moderate sensitivity and specificity, to identify patients with a higher risk of death among those with sepsis and septic shock. RegistrationPROSPERO CRD42019134351.

Comparison of different forms of Raynaud's phenomenon by LASCA proximal-distal gradient perfusion.

To evaluate finger proximal-distal gradient (PDG) perfusion in subjects with primary Raynaud's phenomenon (PRP), then making comparisons with systemic sclerosis (SSc) patients and healthy controls (HC). Consecutive adult PRP subjects were enrolled, along with an equal number of SSc and HC. Peripheral blood perfusion of the hands was assessed by laser speckle contrast analysis (LASCA). PDG was then calculated applying a generalizable formula independent of both intra- and inter-personal factors. Non-specific anti-nuclear autoantibody (ANA) isolated positivity was assessed. Fifty PRP patients (88 % female, mean age 45 ± 17.9 years) were enrolled, along with 50 SSc patients and 50 HC. After adjusting mean PDG results for age and sex, no significant differences emerged between PRP and SSc (1.80 ± 0.43 vs 1.76 ± 0.53; p = 0.294). Conversely, PRP values were significantly reduced when compared to HC (2.72 ± 0.37; p < 0.001). Among PRP subjects, no significant differences were found regarding isolated ANA positivity (1.86 ± 0.44 vs 1.74 ± 0.44; p = 0.42). PRP and SSc seems to share the same basal PDG perfusion impairment assessed by LASCA. Isolated ANA positivity, in the absence of clinical and capillaroscopic suspicion for secondary causes, should not be considered an exclusion criterion for PRP classification.

Serum kynurenic acid is lower in systemic sclerosis patients with microvascular damage of hands.

Endothelial dysfunction occurs early in systemic sclerosis (SSc), leading to tissue hypoxia, vasoconstriction and fibrosis. It has been demonstrated that endothelial cells (ECs) are able to produce kynurenic acid (KYNA) in response to vascular inflammation, due to its anti-inflammatory and anti-oxidants activity. In SSc patients, blood perfusion of hands, assessed by laser speckle contrast analysis (LASCA), correlated negatively with the extent of the nailfold microvascular damage, scored according to nailfold videocapillaroscopy (NVC) classification. Aim of this study was to evaluate the difference of serum KYNA in SSc patients with different stages of microvascular damage. Serum KYNA was assessed in 40 SSc patients at the enrolment. NVC was performed to evaluate capillaroscopic patterns (early, active and late). LASCA was performed to evaluate mean peripheral blood perfusion (PBP) of both hands and to evaluate the proximal-distal gradient (PDG). Median PDG was significantly lower in SSc patients with late NVC pattern compared to SSc patients with early and active NVC pattern [3.79pU (IQR -8.55-18.16) vs 23.55pU (IQR 14.92-43.80), p<0.01]. Serum KYNA was significantly lower in SSc patients with late NVC pattern compared to SSc patient with early and active NVC pattern [45.19ng/mL (IQR 42.70-54.74) vs 52.65ng/mL (IQR 49.99-60.29), p<0.05]. Moreover, SSc patients without PDG had significantly lower serum KYNA than in SSc patients with PDG [48.03ng/mL (IQR 43.87-53.68) vs 59.27ng/mL (IQR 49.15-71.00), p<0.05]. KYNA is lower in SSc patients with late NCV pattern and without PDG. KYNA may be associated with early endothelial dysfunction.

Perfusion index in newborns with CHD without clinical signs of hypoperfusion and heart failure: comparison with healthy newborns.

Peripheral perfusion index has been proposed as a possible method for detecting circulatory impairment. We aimed to determine the normal range of peripheral perfusion index in healthy newborns and compare it with that of newborns with CHD. Right-hand saturation and right-hand peripheral perfusion index levels were recorded, and physical examination and echocardiography were performed in newborns who were 0-28 days old and whom were evaluated in our paediatric cardiology outpatient clinic. The saturation and peripheral perfusion index levels of newborns with normal heart anatomy and function were compared with those of newborns with CHD. Out of 358 newborns (238 mature and 75 premature) enrolled in the study, 39 had CHD (20 mild CHD, 13 moderate CHD, and 6 severe CHD), of which 29 had CHD with left-to-right shunting, 5 had obstructive CHD, and 5 had cyanotic CHD. No newborn had clinical signs of hypoperfusion or heart failure, such as prolonged capillary refill, weakened pulses, or coldness of extremities. Peripheral perfusion index level was median (interquartile range) 1.7 (0.6) in healthy newborns, 1.8 (0.7) in newborns with mild CHD, and 1.8 (0.4) in newborns with moderate and severe CHD, and there was no significant difference between the groups regarding peripheral perfusion index level. Peripheral perfusion index remains unchanged in newborns with CHD without the clinical signs of hypoperfusion or heart failure. Larger studies with repeated peripheral perfusion index measurements can determine how valuable this method will be in the follow-up of newborns with CHD.

Infrared Thermography Imaging for Assessment of Peripheral Perfusion in Patients with Septic Shock.

Skin temperature changes can be used to assess peripheral perfusion in circulatory shock patients. However, research has been limited to point measurements from acral parts of the body. Infrared thermography allows non-invasive evaluation of temperature distribution over a larger surface. Our study aimed to map thermographic patterns in the knee and upper thigh of 81 septic shock patients within 24 h of admission and determine the relationship between skin temperature patterns, mottling, and 28-day mortality. We extracted skin temperature measurements from zones corresponding to mottling scores and used a linear mixed model to analyze the distribution of skin temperature in patients with different mottling scores. Our results showed that the distribution of skin temperature in the anterior thigh and knee is physiologically heterogeneous and has no significant association with mottling or survival at 28 days. However, overall skin temperature of the anterior thigh and knee is significantly lower in non-survivors when modified by mottling score. No differences were found in skin temperature between the survivor and non-survivor groups. Our study shows the potential usefulness of infrared thermography in evaluating skin temperature patterns in resuscitated septic shock patients. Overall skin temperature of the anterior thigh and knee may be an important indicator of survival status when modified by mottling score.

Arterial occlusion duration affects the cuff-induced hyperemic response in skeletal muscle BOLD perfusion imaging as shown in young healthy subjects

ObjectiveDynamic BOLD MRI with cuff compression, inducing ischemia and post-occlusive hyperemia in skeletal muscle, has been pointed out as a potential diagnostic tool to assess peripheral limb perfusion. The objective was to explore the robustness of this technique and its sensitivity to the occlusion duration.Materials and methodsBOLD images were acquired at 3 T in 14 healthy volunteers. {mathrm{T}}_{2}^{*}-imaging with 5- and 1.5-min occlusions were acquired and several semi-quantitative BOLD parameters were derived from ROI-based {mathrm{T}}_{2}^{*}-time curves. Differences in parameters from the two different occlusion durations were evaluated in the gastrocnemius and soleus muscles using non-parametrical tests. Intra- and inter-scan repeatability were evaluated with coefficient of variation.ResultsLonger occlusion duration resulted in an increased hyperemic signal effect yielding significantly different values (p < 0.05) in gastrocnemius for all parameters describing the hyperemic response, and in soleus for two of these parameters. Specifically, 5-min occlusion yielded steeper hyperemic upslope in gastrocnemius (41.0%; p < 0.05) and soleus (59.7%; p = 0.03), shorter time to half peak in gastrocnemius (46.9%; p = 0.00008) and soleus (33.5%; p = 0.0003), and shorter time to peak in gastrocnemius (13.5%; p = 0.02). Coefficients of variation were lower than percentage differences that were found significant.DiscussionFindings show that the occlusion duration indeed influences the hyperemic response and thus should play a part in future methodological developments.

Impact of Care Interventions on the Survival of Patients with Cardiac Chest Pain.

Chest pain is considered the second most frequent complaint among patients seeking emergency services. However, there is limited information in the literature about how the care provided to patients with chest pain, when being attended to in the emergency room, influences their clinical outcomes. To assess the relationship between care interventions performed on patients with cardiac chest pain and their immediate and late clinical outcomes and to identify which care interventions were essential to survival. In this retrospective study. We analyzed 153 medical records of patients presenting with chest pain at an emergency service center, São Paulo, Brazil. Participants were divided into two groups: (G1) remained hospitalized for a maximum of 24 h and (G2) remained hospitalized for between 25 h and 30 days. Most of the participants were male 99 (64.7%), with a mean age of 63.2 years. The interventions central venous catheter, non-invasive blood pressure monitoring, pulse oximetry, and monitoring peripheral perfusion were commonly associated with survival at 24 h and 30 days. Advanced cardiovascular life support and basic support life (p = 0.0145; OR = 8053; 95% CI = 1385-46,833), blood transfusion (p < 0.0077; OR = 34,367; 95% CI = 6489-182,106), central venous catheter (p < 0.0001; OR = 7.69: 95% CI 1853-31,905), and monitoring peripheral perfusion (p < 0.0001; OR = 6835; 95% CI 1349-34,634) were independently associated with survival at 30 days by Cox Regression. Even though there have been many technological advances over the past decades, this study demonstrated that immediate and long-term survival depended on interventions received in an emergency room for many patients.

Integration of foot massage and diabetic foot gymnastic on peripheral perfusion in patients with diabetes mellitus 2

The prevalence of Type 2 Diabetes Mellitus (DMT2) is increasing yearly. Peripheral neuropathy of the foot is a complication that often appears in people with diabetes. Neuropathy disorders that are not treated properly can risk causing diabetic ulcers and even amputations. Complementary therapies that can be done to overcome this are foot massage and diabetic foot exercises. This study aims to determine the effect of integrating foot massage and diabetic foot gymnastics to overcome complaints of peripheral tissue perfusion in the feet of DMT2 patients at the Polyclinic of Panti Nugroho Hospital. Quasi-experimental research method with Pretest-Posttest Control Group Design design. The intervention and control groups each consisted of 15 respondents. The intervention group was given foot massage treatment and diabetic foot exercises for three consecutive days for 15 minutes. The independent t-test and Mann-Whitney test were used to analyze the data. There were significant differences in ABI scores, oxygen saturation, and monofilament scores in the intervention group's left and right legs against the control group (p-value &lt; 0.05). There is a significant effect of the integration of foot massage and diabetic foot gymnastics on peripheral tissue perfusion in both the left leg and right foot of T2DM patients. The contribution of this study needs further research with a larger number of respondents and a longer time to ascertain its effectiveness before it is used as part of local nursing intervention standards.

Clinical utility of ultra-widefield fluorescein angiography and optical coherence tomography angiography for retinal vein occlusions.

Retinal vein occlusions (RVOs) are the second most common retinal vascular disease after diabetic retinopathy, and are a significant cause of visual impairment, especially in the elderly population. RVOs result in visual loss due to macular ischemia, cystoid macular edema (CME), and complications related to neovascularization. Vascular assessment in RVOs traditionally relies on standard fluorescein angiography (FA) for assessment of macular and retinal ischemia, which aids in prognostication and guides intervention. Standard FA has significant limitations-it is time-consuming, requires invasive dye administration, allows for limited assessment of the peripheral retina, and is usually evaluated semi-qualitatively, by ophthalmologists with tertiary expertise. More recently, the introduction of ultra-widefield FA (UWF FA) and optical coherence tomography angiography (OCTA) into clinical practice has changed the tools available for vascular evaluation in RVOs. UWF FA allows for evaluation of peripheral retinal perfusion, and OCTA is non-invasive, rapidly-acquired, and provides more information on capillary perfusion. Both modalities can be used to provide more quantitative parameters related to retinal perfusion. In this article, we review the clinical utility and impact of UWF FA and OCTA in the evaluation and management of patients with RVOs.

“The peripheral perfusion index discriminates haemodynamic responses to induction of general anaesthesia”

Induction of general anaesthesia is often accompanied by hypotension. Standard haemodynamic monitoring during anaesthesia relies on intermittent blood pressure and heart rate. Continuous monitoring systemic blood pressure requires invasive or advanced modalities creating a barrier for obtaining important information of the circulation. The Peripheral Perfusion Index (PPI) is obtained non-invasively and continuously by standard photoplethysmography. We hypothesized that different patterns of changes in systemic haemodynamics during induction of general anaesthesia would be reflected in the PPI. Continuous values of PPI, stroke volume (SV), cardiac output (CO), and mean arterial pressure (MAP) were evaluated in 107 patients by either minimally invasive or non-invasive means in a mixed population of surgical patients. 2 min after induction of general anaesthesia relative changes of SV, CO, and MAP was compared to the relative changes of PPI. After induction total cohort mean(± st.dev.) MAP, SV, and CO decreased to 65(± 16)%, 74(± 18)%, and 63(± 16)% of baseline values. In the 38 patients where PPI decreased MAP was 57(± 14)%, SV was 63(± 18)%, and CO was 55(± 18)% of baseline values 2 min after induction. In the 69 patients where PPI increased the corresponding values were MAP 70(± 15)%, SV 80(± 16)%, and CO 68(± 17)% (all differences: p < 0,001). During induction of general anaesthesia changes in PPI discriminated between the degrees of reduction in blood pressure and algorithm derived cardiac stroke volume and -output. As such, the PPI has potential to be a simple and non-invasive indicator of the degree of post-induction haemodynamic changes.

Penerapan Perawatan Kaki Dan Kuku Terhadap Peningkatan Sirkulasi Perifer Pada Penderita Critical Limb Ischemia (CLI)

Background . Critical limb ischemia (CLI) is the most severe stages disease vessels blood chronic , oriented CLI management on effort to anticipate doing amputation by pushing a severe infection happens on wound and healing the wound easier. One wrong possible intervention done to increase peripheral circulation and prevent the occurance of amputation consequence on severe infection is circulation maintenance. Purpose Describe feet application and nail care _ enhancement of peripheral circulation to fill a need safety of patients with Critical Limb Ischemia (CLI) . Method : This is a descriptive study uses a study case approach with a Nursing process approach . Subject of the study was one participant . Results the client felt painful on the feet , it started by feeling numb and cold on her left toes, then purple spots and several days later the spots were changed to be black and widespread to her calf . cold acral, nursing diagnosis enforced impaired peripheral tissue perfusion. Nursing Intervention: feet and nail care, Evaluation: decreased pain scale, increased muscle strength, changed in acral temperature and no changed in capillary refill. Conclusion : Giving circulation maintenance on client Mrs. S with CLI (Critical Limb Ischemia) for 5 days management was effective because on the fifth day client said painful on her left lower extremity decreased so that she could move , and client said she felt comfortable and relax after washing and cleaning her feet using warm water , soap , body lotion and cuting her toenails.&#x0D; Keywords : CLI, foot care , peripheral circulation, pain

Monitoring Muscle Perfusion in Rodents During Short-Term Ischemia Using Power Doppler Ultrasound.

The aim of this work was to evaluate the reliability of power Doppler ultrasound (PD-US) measurements made without contrast enhancement to monitor temporal changes in peripheral blood perfusion. On the basis of pre-clinical rodent studies, we found that combinations of spatial registration and clutter filtering techniques applied to PD-US signals reproducibly tracked blood perfusion in skeletal muscle. Perfusion is monitored while modulating hindlimb blood flow. First, in invasive studies, PD-US measurements in deep muscle with laser speckle contrast imaging (LSCI) of superficial tissues made before, during and after short-term arterial clamping were compared. Then, in non-invasive studies, a pressure cuff was employed to generate longer-duration hindlimb ischemia. Here, B-mode imaging was also applied to measure flow-mediated dilation of the femoral artery while, simultaneously, PD-US was used to monitor downstream muscle perfusion to quantify reactive hyperemia. Measurements in adult male and female mice and rats, some with exercise conditioning, were included to explore biological variables. PD-US methods are validated through comparisons with LSCI measurements. As expected, no significant differences were found between sexes or fitness levels in flow-mediated dilation or reactive hyperemia estimates, although post-ischemic perfusion was enhanced with exercise conditioning, suggesting there could be differences between the hyperemic responses of conduit and resistive vessels. Overall, we found non-contrast PD-US imaging can reliably monitor relative spatiotemporal changes in muscle perfusion. This study supports the development of PD-US methods for monitoring perfusion changes in patients at risk for peripheral artery disease.

Role of Nursing in the Early Detection and Prevention of Stent Thrombosis in Patients Undergoing Coronary Angioplasty

Introduction: stent thrombosis is one of the serious complications after coronary angioplasty. It can present with chest pain and electrocardiographic changes or even sudden death and is characterized by angiographic or postmortem evidence of a newly formed thrombus in a previously stented segment and can occur from intraprocedurally to years after implantation. There are several risk factors, both related to the lesion and the procedure, as well as adherence to antiplatelet therapy and personal history. The objective of this case is to present a care plan to detect and prevent stent thrombosis in patients undergoing coronary angioplasty. Material and methods: an assessment is made through the model of the 14 needs of Virginia Henderson and the care plan is prepared with its respective diagnoses (NANDA), objectives (NOC) and interventions (NIC) with the indicators of results and activities. It will be evaluated using the Likert scale. Results and conclusions: the following diagnoses stand out: decreased cardiac output, ineffective peripheral tissue perfusion and deficient knowledge. Nursing intervenes in the early detection of signs and symptoms that may point us towards stent thrombosis, observing any change immediately, and in its prevention, carrying out health education after angioplasty, highlighting the importance of antithrombotic treatment and in modifying modifiable risk factors.

Smartphone-Based Infrared Thermography as an Option for Evaluating the Treatment Effect of Revascularization Procedure in Patients With Peripheral Arterial Disease, a Prospective Study

Infrared imaging has been used to assess peripheral perfusion; however, large, heavy, and prohibitively expensive cameras have precluded its adoption for widespread clinical applications. With advent of more affordable and portable infrared cameras in recent years, they have become more accessible for clinical use. In this study, we aim to introduce the use of smart phone based thermal camera using thermal ankle-brachial index (TABI) to assess the perfusion in peripheral arterial disease (PAD)-affected lower extremities both preintervention and postintervention and simultaneously comparing with ABI. To our knowledge, this is the first study in the Indian scenario. We included 52 patients with 67 lower limbs with PAD requiring revascularization who presented to our institute between July 2020 and December 2021 in the study. Revascularization procedures included endovascular or open surgical bypass. ABI was measured in affected lower limb using Handheld Doppler device before revascularization, after revascularization at discharge and at 1-month follow-up after revascularization. Thermal images of upper and lower limbs were obtained using FLIR ONE PRO (a smartphone-based infrared thermal camera) at the time of measuring ABI. TABI was calculated by dividing maximum lower limb temperature by maximum upper limb temperature. ABI and TABI were compared for correlation using Pearson analysis. After revascularization, there was statistically significant improvement in ABI, 0.38 ± 0.20, t(66) = 15.1; P < .001, and TABI, 0.09 ± 0.053, t(66)=14.2; P < .001, at discharge when compared with before intervention (Table). Before intervention, positive correlation was found between ABI and Lower limb temperature (r = 0.973; P < .001) and ABI and TABI (r = 0.810; P < .001). After intervention at discharge, positive correlation was found between ABI and Lower limb temperature (r = 0.682; P < .001) and ABI and TABI (r = 0.662; P < .001). At the 1-month follow-up after intervention, positive correlation was found between ABI and Lower limb temperature (r = 0.874; P < .001) and ABI and TABI (r = 0.663; P < .001). Smart phone-based thermal imaging can be used to assess perfusion status in PAD in clinical settings as non-invasive, portable, cost effective and reproducible alternative to ABI. It has shown improvement in perfusion status corresponding to standard Doppler ABI.TableShowing descriptive analysis of revascularized lower limbsBefore interventionAfter intervention at dischargeAt the 1-month follow-upABITABILower extremity temperature (℉)Ambient temperature (℉)ABITABILower extremity temperature (℉)Ambient temperature (℉)ABITABILower extremity temperature (℉)Ambient temperature (℉)Mean.28.8382.786.4.67.9392.986.8.68.9492.987.7Median.27.8382.988.4.67.9592.688.4.67.9692.688.2Std deviation.21.044.219.40.22.065.779.54.17.055.348.64Minimum.00.7574.864.0.00.7879.560.8.00.7878.664.2Maximum.83.9796.6101.41.11.02103.6102.31.11.02103.1102.3Range.83.2221.837.41.1.2424.141.51.1.2424.538.1Interquartile range.28.045.37.90.21.1010.137.35.19.099.456.67TABI, Thermal ankle-brachial index. Open table in a new tab

Reliability and reproducibility of the DICART device to assess capillary refill time: a bench and in-silico study.

Capillary refill time (CRT) is an important indicator of peripheral perfusion with a strong prognostic value, but it is sensitive to environmental factors and numerous measurement methods are reported in the litterature. DiCARTECH has developed a device that assesses CRT. We sought to investigate the robustness of the device and the reproducibility of the algorithm in a bench and in-silico study. We used the video acquired from a previous clinical study on healthy volunteers. For the bench study, the measurement process was performed by a robotic system piloted by a computer that analyzed 250 times nine previously acquired videos. For the in-silico study, we used 222 videos to test the algorithm's robustness. We created 30 videos from each video with a large blind spot and used the "color jitter" function to create a hundred videos from each video. In the bench study, the coefficient of variation was 11% (95%CI: 9-13). The correlation with human-measured CRT was good (R2 = 0.91, P < 0.001). In the in-silico study, for the blind spotted video, the coefficient of variation was 13% (95%CI: 10-17). For the color-jitter modified video the coefficient of variation was 62% (95%CI: 55-70). We confirmed the ability of the DiCART™ II device to perform multiple measurements without mechanical or electronic dysfunction. The precision and reproducibility of the algorithm are compatible with the assessment of clinical small changes in CRT.

Spatial-Temporal Oxygenation Mapping Using a Near-Infrared Optical Scanner: Towards Peripheral Vascular Imaging.

Near-infrared spectroscopy (NIRS)-based peripheral perfusion, or microcirculation, can be used to assess the severity of peripheral vascular dysfunction. A low-cost, portable non-contact near-infrared optical scanner (NIROS) was developed for spatio-temporal mapping of tissue oxygenation and perfusion in tissues. In vivo validation studies were carried out on control subjects (n = 3) to assess the ability of NIROS to measure real-time oxygenation changes in response to an occlusion paradigm on the dorsum of the hand. NIROS captured real-time tissue oxygenation changes with 95% correlation when compared to a commercial device. A feasibility peripheral imaging study was performed in a mouse model (n = 5) of chronic kidney disease (CKD) induced vascular calcification to assess differences in microcirculatory peripheral tissue oxygenation. The tissue oxygenation (in terms of oxy-, deoxy-, and total hemoglobin changes) due to the occlusion paradigm was distinctly different prior to (week-6) and after the onset of vascular calcification (week-12) in the murine tails. Future work will involve extensive studies to correlate these microcirculatory tissue oxygenation changes in the peripheral tail to the vascular calcification in the heart.

Peripheral perfusion index in critically ill COVID-19 and its association with multiorgan dysfunction

Introduction: Severe cases of COVID-19 presented a high incidence of multi-organ dysfunction syndrome (MODS) during their evolution. This was attributed to a theoretical cytokine storm, where microcirculatory disorders would play a fundamental role, causing these patients to present a sepsis-like pattern as observed in sublingual microcirculation studies. The evidence in this regard is controversial. The Peripheral Perfusion Index is a reliable method to continuously and non-invasively assess the microcirculatory bed, which assesses the pulsatile (PPI) component of the plethysmographic pulse curve. Methods: We conducted a prospective observational study to evaluate the behavior of the PPI in patients with severe respiratory failure due to SARS-CoV-2 and its association with SDOM. Results: We evaluated 60 patients with APACHE II 14.6 ± 4.4 and SOFA 4.7 ± 2.1. 55% of the patients presented SDOM. Perfusion monitoring showed IP values of 5.32 ± 1.87 that were associated with normal lactate levels of 1.49 mmol/L (min 0.89/ max 2.20 mmol/L). The PPI values between the living and the dead did not show a significant difference (p = 0.854) or the presence of SDOM. The PPI values between the patients who presented renal failure, hemodynamics, or perfusion disorders were determined by the presence of hyperlactatemia, and for those who did not present these characteristics, no statistical difference was found; neither when stratified by PaFiO2 ratio. Mortality was 55%. Conclusion: In our series of patients with severe pneumonia due to COVID-19, we found high PPI values, which would correspond to a pattern of capillary recruitment, and the associated organ injury could not be substantiated by this phenomenon.

Modifications of peripheral perfusion in patients with vasopressor-dependent septic shock treated with polymyxin B-direct hemoperfusion

Abnormal peripheral perfusion (PP) worsens the prognosis of patients with septic shock. Polymyxin B-direct hemoperfusion (PMX-DHP) increases blood pressure and reduces vasopressor doses. However, the modification of PP following administration of PMX-DHP in patients with vasopressor-dependent septic shock have not yet been elucidated. A retrospective exploratory observational study was conducted in patients with septic shock treated with PMX-DHP. Pulse-amplitude index (PAI), vasoactive inotropic score (VIS), and cumulative fluid balance data were extracted at PMX-DHP initiation (T0) and after 24 (T24) and 48 (T48) h. Changes in these data were analyzed in all patients and two subgroups (abnormal PP [PAI < 1] and normal PP [PAI ≥ 1]) based on the PAI at PMX-DHP initiation. Overall, 122 patients (abnormal PP group, n = 67; normal PP group, n = 55) were evaluated. Overall and in the abnormal PP group, PAI increased significantly at T24 and T48 compared with that at T0, with a significant decrease in VIS. Cumulative 24-h fluid balance after PMX-DHP initiation was significantly higher in the abnormal PP group. PMX-DHP may be an effective intervention to improve PP in patients with abnormal PP; however, caution should be exercised as fluid requirements may differ from that of patients with normal PP.

Deferoxamine ameliorates neurological dysfunction by inhibiting ferroptosis and neuroinflammation after traumatic brain injury

Traumatic brain injury (TBI) is an important reason of neurological damage and has high morbidity and mortality rates. The secondary damage caused by TBI leads to a poor clinical prognosis. According to the literature, TBI leads to ferrous iron aggregation at the site of trauma and may be a key factor in secondary injury. Deferoxamine (DFO), which is an iron chelator, has been shown to inhibit neuron degeneration; however, the role of DFO in TBI is unclear. The purpose of this study was to explore whether DFO can ameliorate TBI by inhibiting ferroptosis and neuroinflammation. Here, our findings suggest that DFO can reduce the accumulation of iron, lipid peroxides, and reactive oxygen species (ROS) and modulate the expression of ferroptosis-related indicators. Moreover, DFO may reduce NLRP3 activation via the ROS/NF-κB pathway, modulate microglial polarization, reduce neutrophil and macrophage infiltration, and inhibit the release of inflammatory factors after TBI. Additionally, DFO may reduce the activation of neurotoxic responsive astrocytes. Finally, we demonstrated that DFO can protect motor memory function, reduce edema and improve peripheral blood perfusion at the site of trauma in mice with TBI, as shown by behavioral experiments such as the Morris water maze test, cortical blood perfusion assessment and animal MRI. In conclusion, DFO ameliorates TBI by reducing iron accumulation to alleviate ferroptosis and neuroinflammation, and these findings provide a new therapeutic perspective for TBI.

Mean value of Perfusion Index in patients resuscitated from an out-of-hospital cardiac arrest predict the incidence of lactic acidosis on ICU admission

Abstract Funding Acknowledgements Type of funding sources: None. Backround Regional and general hypoperfusion cause hypoxia, resulting in excess production of lactate secondary to reduced mitochondrial oxidation. Peripheral perfusion index (PI) is the fraction of the pulsatile blood flow to the non-pulsatile blood in peripheral tissue obtained by standard pulse-oximetry. Recent literature has highlighted its association with both survival and ECG reliability in patients resuscitated from an out-of-hospital cardiac arrest (OHCA). Purpose We raised the hypothesis that the mean value of PI over 30-minutes monitoring (MPI30) after ROSC in patients resuscitated from an OHCA is associated with the probability of detecting a lactic acidosis (LA) at the first arterial blood gas analysis available after ICU admission. Materials and Methods This was a retrospective study, obtaining data from our cardiac arrest registry. Among 172 post-ROSC patients admitted to the ICU (between 1st January 2017 and May 2021) post-ROSC MPI30 was available in 76 patients: 54 (72%) males; median age 70 years (IQR 59-77). PI was automatically and continuously measured by the manual monitor/defibrillator (Corpuls by GS Elektromedizinische Geräte G. Stemple GmbH, Germany) once the pulse oximeter was placed, then registered in the report. The population was divided in quartiles according to MPI30 values, then the incidence along the quartiles were compared with chi-squared test. The association between MPI30 and LA incidence was investigated both with univariate and multivariate logistic regression. Results LA was documented in 57% of the study population. We found a significant trend toward reduction of incidence of LA along the four quartiles (p=0.0386). Univariate logistic regression showed a statistically significant association between MPI30 and LA on admission [OR 0.62 (95%CI 0.44-0.89), p=0.005] which was confirmed after correction for age and sex [OR 0.63 (95%CI 0.43-0.91), p=0.009]. Conclusions Low perfusion as measured by MPI30 after ROSC predicts a higher incidence of lactic acidosis in patients on admission to the ICU. Our results could help clinicians in identifying patients at risk for metabolic derangements even before a blood gas analysis is obtained.