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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.

IntroductionVascular dysfunction due to reduced nitric oxide bioavailability plays an important role in the pathogenesis of sepsis. This meta-analysis examines evidence from published literature to evaluate whether in the adult population the presence/severity of sepsis is associated with impaired vasoreactivity.Material and methodsWe performed a search of the Medline, Scopus, and EMBASE databases to identify observational studies using measurement of reactive hyperaemia in adult patients with sepsis. After data extraction using predefined protocol, qualitative synthesis of findings was performed regarding consistency of findings between methods, evidence of association between vascular reactivity and severity of sepsis, multiple organ failure, and death. A meta-analyses of standardised mean differences in vasoreactivity between groups was performed, in which data were available for relevant outcomes.ResultsEighteen studies using four methods to measure vascular reactivity from a total of 466 were included in the analysis. The pooled standardised mean difference estimate showed that septic patients had less reactive hyperaemia than controls (–2.59, 95% CI: –3.46 to –1.72; p < 0.00001), and peak hyperaemic blood flow was lower in patients with sepsis than in the control group (SMD = –1.42, 95% CI: –2.14 to –0.70; p = 0.0001). The combined SMD between non survivors and survivors was –0.36 (95% CI: –0.67 to –0.06; p = 0.02) for reactive hyperaemia and –0.70 (95% CI: –1.13 to –0.27; p = 0.001) for peak hyperaemic blood flow.ConclusionsSeptic patients have attenuated vascular reactivity when compared to healthy volunteers. There are insufficient data indicating that these changes can identify patients at risk of worsening organ failure or death.

Background: The COVID-19 pandemic has disrupted routine hospital services globally. This study estimated the total number of adult elective operations that would be cancelled worldwide during the 12 weeks of peak disruption due to COVID-19. Methods: A global expert response study was conducted to elicit projections for the proportion of elective surgery that would be cancelled or postponed during the 12 weeks of peak disruption. A Bayesian β-regression model was used to estimate 12-week cancellation rates for 190 countries. Elective surgical case-mix data, stratified by specialty and indication (surgery for cancer versus benign disease), were determined. This case mix was applied to country-level surgical volumes. The 12-week cancellation rates were then applied to these figures to calculate the total number of cancelled operations. Results: The best estimate was that 28 404 603 operations would be cancelled or postponed during the peak 12 weeks of disruption due to COVID-19 (2 367 050 operations per week). Most would be operations for benign disease (90·2 per cent, 25 638 922 of 28 404 603). The overall 12-week cancellation rate would be 72·3 per cent. Globally, 81·7 per cent of operations for benign conditions (25 638 922 of 31 378 062), 37·7 per cent of cancer operations (2 324 070 of 6 162 311) and 25·4 per cent of elective caesarean sections (441 611 of 1 735 483) would be cancelled or postponed. If countries increased their normal surgical volume by 20 per cent after the pandemic, it would take a median of 45 weeks to clear the backlog of operations resulting from COVID-19 disruption. Conclusion: A very large number of operations will be cancelled or postponed owing to disruption caused by COVID-19. Governments should mitigate against this major burden on patients by developing recovery plans and implementing strategies to restore surgical activity safely.

Summary Introduction. Unanticipated difficult intubation still exists as a significant problem. El-Ganzouri risk index is a bedside difficult airway evaluation method, which can help determine risk of difficult airways. However, evidence of using of El-Ganzouri risk index in difficult laryngeal visualisation using videolaryngoscopes is limited. Aim of the Study. Determine the specificity and sensitivity of El-Ganzouri multivariate risk index to predict difficult laryngeal exposure using Storz C-MAC videolaryngoscope equipped with D type blade. Material and methods. We conducted a study of 29 patients, which were examined using El-Ganzouri risk index before induction of anaesthesia. After induction of anaesthesia videolaryngoscopy was performed using Storz C-MAC videolaryngoscope equipped with D-blade and laryngeal visualisation was graded using Cormack-Lehane scale. After laryngeal visualisation grading endotracheal tube insertion was performed and numbers of attempts as well as complications during intubation were recorded. Sensitivity, specificity, positive and negative predictive values were calculated, receiver operating characteristic curve and area under curve was obtained. Results. Sensitivity and specificity were 54.2% and 80.0% at El-Ganzouri risk index cut-off value of 2 points. Calculated positive predictive value was 26.7% and negative predictive value was 92.9%. Calculated AUC was 78.3%. Conclusions. El-Ganzouri risk index shows moderate sensitivity and specificity when used with Storz C-MAC videolaryngoscope. It can be used to predict difficult laryngeal visualization during videolaryngoscopic intubation.

The Doctoral thesis was carried out at Rīga Stradiņš University. Defence: at the public session of the Doctoral Council of Clinical Medicine on 30 June 2020 at 15.00 in Hippocrates Lecture Theatre, 16 Dzirciema Street, Rīga Stradiņš University. Sepsis is defined as multiple organ damage caused by dysfunctional systemic host response to infection. It is a frequent cause of admission to intensive care unit and carries high mortality. Vascular dysfunction due to reduced nitric oxide bioavailability plays an important role in the pathogenesis of sepsis and multiple organ failure. Conduit arteries, especially the aorta, play a major role in ensuring efficient cardiac function and optimal flow in the periphery due to their viscoelastic properties. Resistance arteries and arterioles adjust peripheral blood flow according to the metabolic needs of the tissues. Laboratory studies on isolated artery models and animal research show that acute systemic inflammation can cause impaired vasoreactivity in peripheral vascular beds and aortic stiffening of conduit arteries which affects hemodynamic efficiency. This thesis aims to characterize parameters describing functional properties of arteries in intensive care patients with severe sepsis and septic shock and clarify their association with the development of multiple organ dysfunction syndrome and mortality. This thesis consists of three parts. In part 1, systematic review and meta-analysis of published literature were performed to evaluate the measurement of endothelial function using vasoreactivity tests as a risk stratification tool in intensive care patients with sepsis. From the studies included in this review, there is evidence of moderate strength that vascular reactivity is impaired in septic patients, but not enough evidence has been provided to suggest that it is a consequence of endothelial dysfunction or is convincingly related to clinical outcomes. In part 2, the author undertook a prospective observational cohort study examining aortic stiffness in patients with sepsis using carotid-femoral pulse wave velocity measurement. Forty-five adult intensive care patients were recruited to the study within 24 hours of admission to intensive care. Carotid-femoral pulse wave velocity was measured once initial resuscitation was completed. Patients were followed up to hospital discharge or death. This study found that patients with severe sepsis and septic shock have higher aortic stiffness than the general population. No convincing association was found between admission pulse wave velocity and progression of multiple organ failure or mortality, although the group with pulse wave velocity > 24.7 m/s had shorter survival time. Part 3 extends the previous study and examines stiffness of both elastic and muscular arteries at two time points, at admission and after 48 hours of treatment. It also examines confounders associated with changes in carotid-femoral and carotid-radial pulse wave velocity. It found increased aortic and even higher upper limb artery stiffness among the septic population. Higher carotid-femoral pulse wave velocity was associated with higher mean arterial blood pressure and lower C reactive protein concentration. Pulse wave velocity in elastic and muscular arteries decreased after a 48-hour treatment period in survivors. In non-survivors, carotid-radial pulse wave velocity stayed consistently high. Overall, this study has shown that altered static and dynamic parameters of artery function are highly prevalent in patients with sepsis and associated with unfavourable outcome. Longitudinal assessment of these parameters has the potential to be used for risk stratification in patients with early sepsis.

Background In patients with septic shock, the skin is often chosen for the evaluation of peripheral perfusion and oxygenation. Changes in skin microcirculatory vessel oxygen saturation and relative hemoglobin concentration can be described using a mottling score or captured with hyperspectral imaging. However, the effectiveness of the mottling score in assessing microcirculation remains to be shown. We hypothesize that the mottling score in patients with septic shock is related to skin microcirculatory perfusion indices quantified by hyperspectral imaging, biomarkers that reflect endothelium activation and damage, and clinical outcome. Methods Hyperspectral imaging of the knee area was performed in 95 intensive care patients with septic shock enrolled in a single-center observational study to obtain relative oxy/deoxyhemoglobin concentration values and construct anatomical maps of skin microcirculatory saturation. The blood was sampled to obtain concentrations of thrombomodulin, plasminogen activator inhibitor-1 (PAI-1), soluble intercellular adhesion molecule-1 (ICAM-1), soluble vascular cell adhesion molecule-1 (VCAM-1), angiopoietin-2, and syndecan-1. The spectrophotometrically obtained skin microvascular perfusion indices were compared to the mottling score and biomarker concentration. The association between mottling score, skin microcirculatory perfusion indices, and 28-day mortality was also analyzed. Results Microcirculatory oxygen saturation was significantly lower and total hemoglobin concentration was significantly higher in patients with a mottling score of 2 compared to those with a score of 0 (p = 0.02), with no difference between other scores. We found an association between microcirculatory oxygen saturation and PAI-1 levels (rho = − 0.3; p = 0.007). Increased mottling score and decreased microcirculatory oxygen saturation were predictive of 28-day mortality (mottling score 2 vs 0: OR 15.31, 95% CI 4.12–68.11; microcirculatory oxygen saturation: OR 0.90, 95% CI 0.85–0.95). Endothelial biomarkers did not increase the predictive value of skin microcirculatory perfusion indices. Conclusions Higher mottling scores are associated with lower microcirculatory oxygen saturation but with significant overlap between scores. Microcirculatory oxygen saturation is a quantitative measure of peripheral oxygenation and is more specific than the mottling score in predicting 28-day mortality.

Background Heterogeneity of microvascular blood flow leading to tissue hypoxia is a common finding in patients with septic shock. It may be related to suboptimal systemic perfusion pressure and lead to organ failure. Mapping of skin microcirculatory oxygen saturation and relative hemoglobin concentration using hyperspectral imaging allows to identify heterogeneity of perfusion and perform targeted measurement of oxygenation. We hypothesized that increasing mean arterial pressure would result in improved oxygenation in areas of the skin with most microvascular blood pooling. Methods We included adult patients admitted to the intensive care unit within the previous 24 h with sepsis and receiving a noradrenaline infusion. Skin oxygen saturation was measured using hyperspectral imaging-based method at baseline and after the increase in mean arterial pressure by 20 mm Hg by titration of noradrenaline doses. The primary outcome was an increase in skin oxygen saturation depending upon disease severity. Results We studied 30 patients with septic shock. Median skin oxygen saturation changed from 26.0 (24.5–27.0) % at baseline to 30.0 (29.0–31.0) % after increase in mean arterial pressure (p = 0.04). After adjustment for baseline saturation, patients with higher SOFA scores achieved higher oxygen saturation after the intervention (r 2 = 0.21; p = 0.02). Skin oxygen saturation measured at higher pressure was found to be marginally predictive of mortality (OR: 1.10; 95% CI 1.00–1.23; p = 0.053). Conclusions Improvement of microcirculatory oxygenation can be achieved with an increase in mean arterial pressure in most patients. Response to study intervention is proportional to disease severity.

Background Conduit arteries, especially the aorta, play a major role in ensuring efficient cardiac function and optimal microvascular flow due to their viscoelastic properties. Studies in animals and on isolated arteries show that acute systemic inflammation can cause aortic stiffening which affects hemodynamic efficiency. Carotid-femoral pulse wave velocity, a measure of aortic stiffness, may be useful as a bedside investigational method in patients with early sepsis admitted to intensive care, as circulatory changes can lead to multiple organ failure and increased mortality. This study aims to investigate arterial stiffness in early sepsis and its association with clinical outcomes. Methods This prospective observational study included adult patients with severe sepsis or septic shock admitted to our intensive care unit (n = 45). Their carotid-femoral pulse wave velocity was measured within 24 h of admission. We assessed the progression of multiple organ as well as cardiovascular failure by sequential SOFA scores. Prediction models for the progression of multiple organ and cardiovascular failure were constructed using multivariate logistic regression with pulse wave velocity and vasopressor use as predictors. A Cox proportional hazards model was used to examine the relationship between pulse wave velocity and survival time. Results The median pulse wave velocity for the cohort was 14.6 (8.1–24.7) m/s. There was no association between pulse wave velocity and the progression of multiple organ failure, before or after adjustment for vasopressor use. No association was found between pulse wave velocity and subsequent improvement in cardiovascular failure in the subgroup of patients who had cardiovascular instability at baseline. Cox regression and survival analyses with age, APACHE II, and baseline SOFA as confounders showed a shorter hospital survival time for patients with pulse wave velocity > 24.7 m/s (HR = 9.45, 95% CI 1.24–72.2; P = 0.03). Conclusions Patients with severe sepsis and septic shock admitted to intensive care have higher arterial stiffness than in the general population. No convincing association was found between pulse wave velocity at admission and the progression of multiple organ or cardiovascular failure, although the group with pulse wave velocity > 24.7 m/s had shorter survival time. Electronic supplementary material The online version of this article (10.1186/s40635-019-0252-3) contains supplementary material, which is available to authorized users.

Sepsis is a potentially fatal disease with mortality rate as high as 50% in patients with septic shock; mortality rate can increase by 7.6% per hour if appropriate treatment is not started. Internationally accepted guidelines for diagnosis of sepsis rely on vital sign monitoring and laboratory tests in order to recognize organ failure. This pilot study aims to explore the potential of hyperspectral and thermal imaging techniques to identify and quantify early alterations in skin oxygenation and perfusion induced by sepsis. The study comprises both physiological model experiments on healthy volunteers in a laboratory environment, as well as screening case series of patients with septic shock in the intensive care department. Hyperspectral imaging is used to determine one of the main characteristic visual signs of skin oxygenation abnormalities - skin mottling, whereas changes in peripheral perfusion have been visualized by thermal imaging as heterogeneous skin temperature areas. In order to mimic septic skin mottling in a reproducible way in laboratory environment, arterial occlusion provocation test was utilized on healthy volunteers. Visualization of oxygen saturation by hyperspectral imaging allows diagnosing microcirculatory alterations induced by sepsis earlier than visual assessment of mottling. Thermal images of sepsis patients in the clinic clearly reveal hotspots produced by perforating arteries, as well as cold regions of low blood supply. The results of this pilot study show that thermal imaging in combination with hyperspectral imaging allows the determination of oxygen supply and utilization in critically ill septic patients.

Acute and chronic systemic inflammatory conditions are associated with aortic stiffening. Carotid-femoral pulse wave velocity (PWV), a marker of aortic stiffness, increases in patients with inflammatory diseases and independently correlates to levels of C-reactive protein (CRP). The effects of massive inflammatory response in early sepsis on mechanical properties of the aorta have not been investigated. The objective of the current study was to prospectively assess aortic stiffness in patients with early severe sepsis and septic shock and relate it to inflammatory and haemodynamic variables and outcome.