Application of Intelligent Monitoring of Percutaneous Partial Oxygen Pressure in Evaluating the Evolution of Scar Hyperplasia

The study aimed to investigate the dynamic changes of percutaneous partial oxygen pressure during the development and evolution of a hypertrophic scar. Twenty cases of hypertrophic scar patients at different stages were selected. A percutaneous oxygen monitor was used to measure oxygen partial pressure in the scar and normal skin tissue at 14, 30, 60, and 90 days after surgery. The changes of oxygen partial pressure, tissue structure, HIF-1α, and VEGF expression in the scar tissue were observed, and the correlation was analyzed. In the scar maturation process, with the prolongation of time, the partial oxygen pressure in the tissue increased gradually. The expression intensity of HIF-1α and VEGF decreased gradually, HIF-1α was positively correlated with VEGF (r = 0.98, P < 0.01 ), there was a negative correlation between oxygen partial pressure and HIF-1 α expression (r = −0.92, P < 0.01 ), and it was negatively correlated with VEGF (r = −0.88, P < 0.01 ). TcPO2 measurement can be used to assess scar maturity; HIF-1 α and VEGF may play an essential role in regulating partial oxygen pressure in the scar tissue.

Quality of Death in Fighting Bulls during Bullfights: Neurobiology and Physiological Responses

During bullfights, bulls undergo physiometabolic responses such as glycolysis, anaerobic reactions, cellular oedema, splenic contraction, and hypovolemic shock. The objective of this review article is to present the current knowledge on the factors that cause stress in fighting bulls during bullfights, including their dying process, by discussing the neurobiology and their physiological responses. The literature shows that biochemical imbalances occur during bullfights, including hypercalcaemia, hypermagnesaemia, hyperphosphataemia, hyperlactataemia, and hyperglycaemia, associated with increased endogenous cortisol and catecholamine levels. Creatine kinase, citrate synthase, and lactate dehydrogenase levels also increase, coupled with decreases in pH, blood bicarbonate levels, excess base, partial oxygen pressure, and oxygen saturation. The intense exercise also causes a marked decrease of glycogen in type I and II muscle fibres that can produce myoglobinuria and muscular necrosis. Other observations suggest the presence of osteochondrosis. The existing information allows us to conclude that during bullfights, bulls face energy and metabolic demands due to the high intensity and duration of the exercise performed, together with muscular injuries, physiological changes, and high enzyme concentrations. In addition, the final stage of the bullfight causes a slow dying process for an animal that is sentient and conscious of its surroundings.

A new approach to calculating the time to the blocking of the escape routes due to the loss of visibility in the smoke of an indoor fire

Introduction. The accuracy of the visibility analysis in the event of an indoor fire strongly depends on the smoke-generating ability of substances and materials obtained experimentally in small-scale units. Therefore, the task is to develop a method of analysis that takes account of the scale factor and does not use the specific coefficient of smoke generation to identify the range of visibility in a full-scale room.Goals and objectives. The goal of the research project is a new approach to the calculation of the time to the blocking of the escape routes due to the loss of visibility with due regard for the scale factor and without regard for the specific coefficient of smoke generation. To achieve this goal, the analysis of fire development patterns in small-scale and full-scale rooms was carried out; theoretical dependences between the volumetric average optical smoke density and other volumetric average parameters of the indoor gas environment were obtained for these patterns, and calculation results, based on the obtained dependences, were compared with the experimental data.Methods. Methods, employed by the co-authors, included solving non-stationary equations based on the principle of conservation of indoor gas energy, optical density of smoke and oxygen mass for the cases of closed and open-type indoor heat and mass transfer. Fire tests were conducted in a small-scale facility. Theoretical and experimental data were compared.Results. Analytical dependences between the volumetric average optical density of smoke, a change in the volumetric average temperature, and the volumetric average partial oxygen density for closed and open indoor fire patterns were obtained. The series of fire tests involving the PVC insulated and sheathed bare (coverless) cable, exposed to the effect of the varying density incident heat flux, were carried out. Experimental dependences between the time, the optical density of smoke, and the specific coefficient of smoke generation were obtained. The obtained volumetric average optical density of smoke was compared with the experimental data using the proposed analytical expressions.Conclusions. The co-authors suggest using experimental dependences between the volumetric average optical density of smoke, changes in the volumetric average temperature or the volumetric average partial oxygen density obtained in a small-scale facility without solving the differential equation based on the principle of conservation of optical density of smoke.

Medium-term impact of COVID-19 on pulmonary function, functional capacity and quality of life

BackgroundCoronavirus disease 2019 (COVID-19) has spread worldwide determining a dramatic impact on the healthcare system. Aim of this study is to evaluate mid-term clinical impact of COVID-19 on respiratory function.Methods379 patients were evaluated 4 months after SARS-COV-2 diagnosis. Patients were divided in two groups based on the presence of pneumonia during COVID. Clinical conditions, quality of life, symptomatology, 6-min walking test, pulmonary function test with spirometry and diffusing capacity of carbon monoxide were analysed. Data were compared to clinical evolution during COVID (development of acute respiratory distress syndrome [ARDS], needing of invasive mechanical ventilation [IMV], partial oxygen saturation/ fraction of inspired oxygen [SpO2/FiO2] ratio and pneumonia severity index [PSI]).ResultsAfter a median of 135 days, 260 (68.6%) of 379 patients referred almost one symptom. Patients who developed pneumonia during COVID-19 showed lower SpO2 at rest (p<0.001), SpO2 during 6-min walking test (p<0.001), total lung capacity (p<0.001), airway occlusion pressure after 0.1 s [P0.1] (p=0.02), P0.1/maximal inspiratory pressure [MIP] ratio (p=0.005) and higher Borg category-ratio scale (p=0.006) and modified Medical Research Council breathlessness scale (p=0.003), compared to patients without pneumonia. SpO2/FiO2 ratio and PSI during SARS-COV-2 pneumonia were directly associated with mid-term alteration of partial oxygen saturation at rest (p<0.001), SpO2 during 6-min walking test (p<0.001), residual volume (p<0.001), total lung capacity (respectively p<0.001 and p=0.003) and forced vital capacity (respectively p=0.004, p=0.03).ConclusionLung damage during COVID-19 correlates to the reduction of pulmonary function after 4 months from acute infection.

Mismatch between Tissue Partial Oxygen Pressure and Near-Infrared Spectroscopy Neuromonitoring of Tissue Respiration in Acute Brain Trauma: The Rationale for Implementing a Multimodal Monitoring Strategy

The brain tissue partial oxygen pressure (PbtO2) and near-infrared spectroscopy (NIRS) neuromonitoring are frequently compared in the management of acute moderate and severe traumatic brain injury patients; however, the relationship between their respective output parameters flows from the complex pathogenesis of tissue respiration after brain trauma. NIRS neuromonitoring overcomes certain limitations related to the heterogeneity of the pathology across the brain that cannot be adequately addressed by local-sample invasive neuromonitoring (e.g., PbtO2 neuromonitoring, microdialysis), and it allows clinicians to assess parameters that cannot otherwise be scanned. The anatomical co-registration of an NIRS signal with axial imaging (e.g., computerized tomography scan) enhances the optical signal, which can be changed by the anatomy of the lesions and the significance of the radiological assessment. These arguments led us to conclude that rather than aiming to substitute PbtO2 with tissue saturation, multiple types of NIRS should be included via multimodal systemic- and neuro-monitoring, whose values then are incorporated into biosignatures linked to patient status and prognosis. Discussion on the abnormalities in tissue respiration due to brain trauma and how they affect the PbtO2 and NIRS neuromonitoring is given.

Trajectories of vital status parameters and risk of mortality among acute organophosphorus poisoning patients – a latent class growth analysis

Background Acute organophosphorus (OP) poisoning is one of the major causes of mortality among patients presenting to emergency departments in developing countries. Although various predictors of mortality among OP poisoning patients have been identified, the role of repeated measurements of vital signs in determining the risk of mortality is not yet clear. Therefore, the present study examined the relationship between trajectories of vital signs and mortality among OP poisoning patients using latent class growth analysis (LCGA). Methods This was a retrospective cohort study using data for 449 OP poisoning patients admitted to Civil-Hospital Karachi from Aug’10 to Sep’16. Demographic data and vital signs, including body temperature, blood pressure, heart rate, respiratory rate, and partial-oxygen pressure, were retrieved from medical records. The trajectories of vital signs were formed using LCGA, and these trajectories were applied as independent variables to determine the risk of mortality using Cox-proportional hazards models. P-values of < 0.05 were considered statistically significant. Results Data for 449 patients, with a mean age of 25.4 years (range 13–85 years), were included. Overall mortality was 13.4%(n = 60). In trajectory analysis, a low-declining systolic blood pressure, high-declining heart rate trajectory, high-remitting respiratory rate trajectory and normal-remitting partial-oxygen pressure trajectory resulted in the greatest mortality, i.e. 38.9,40.0,50.0, and 60.0%, respectively, compared with other trajectories of the same parameters. Based on multivariable analysis, patients with low-declining systolic blood pressure were three times [HR:3.0,95%CI:1.2–7.1] more likely to die compared with those who had a normal-stable systolic blood pressure. Moreover, patients with a high-declining heart rate were three times [HR:3.0,95%CI:1.5–6.2] more likely to die compared with those who had a high-stable heart rate. Patients with a high-remitting respiratory rate were six times [HR:5.7,95%CI:1.3–23.8] more likely to die than those with a high-stable respiratory rate. Patients with normal-remitting partial oxygen pressure were five times [HR:4.7,95%CI:1.4–15.1] more likely to die compared with those who had a normal-stable partial-oxygen pressure. Conclusion The trajectories of systolic blood pressure, heart rate, respiratory rate and partial-oxygen pressure were significantly associated with an increased risk of mortality among OP poisoning patients.

Effects of perioperative respiratory rehabilitation in lung cancer resection: a pilot study

The aim of this study is to evaluate the impact of short term Preoperative Respiratory Rehabili-tation (PRR) on the changes of respiratory functions and clinical conditions in patients with ma-lignant lung cancer lesion and reduced respiratory functions, with high risk to develop postop-erative pulmonary complications (PPCs). A total of 15 patients were treated with PRR protocol. The rehabilitation programme was concluded by all patients. They showed a statistically signifi-cant improvement of lung functionality Forced Vital Capacity (FVC) (p=0,004), Forced Expira-tion Value in the first second (FEV1) (p<0,001) and walking distance (p<0,001). In addition, there was a significant enhancement of Partial Oxygen Saturation (SpO2) (p=0,002), Hart Rate (HR) (p=0,002) and Borg Dyspnoea Scale values (p=0,003) indicate a better cardiorespiratory functionality. In conclusion a short feasible PRR is suitable in patients’ candidate to thoracic surgery.

Mortality Attributed to COVID-19 in High-Altitude Populations

ABSTRACTBackgroundSince partial oxygen pressure decreases as altitude increases, environmental hypoxia could worsen COVID-19 patient’s hypoxemia. We compared COVID-19 mortality at different altitudes.MethodsRetrospective analysis of population-level data on COVID-19 deaths in the U.S. (1,016 counties) and Mexico (567 municipalities). Mixed-model Poisson regression analysis of the association between altitude and COVID-19 mortality using individual-level data from 40,168 Mexican subjects with COVID-19, adjusting for multiple covariates.ResultsBetween January 20 and April 13, 2020, mortality rates were higher in U.S. counties located at ≥2,000 m elevation vs. those located below 1,500 m (12.3 vs. 3.2 per 100,000; P<0.001). In Mexico, between March 13 and May 13, 2020, mortality rates were higher in municipalities located at ≥2,000 m vs. <1,500 m (5.3 vs. 3.9 per 100,000; P<0.001). Among Mexican subjects <65 years old, the risk of death was 36% higher in those living at ≥2,000 m vs. <1,500 m (adjusted incidence rate ratio: 1.36; 95% CI, 1.05-1.78; P=0.022). Among men, the risk of death was 31% higher at ≥2,000 m vs. <1,500 m (adjusted IRR: 1.31; 95% CI, 1.03-1.66; P=0.025). No association was found among women.ConclusionAltitude is associated with COVID-19 mortality in men younger than 65 years.