Decrease In Blood pH Research Articles

Physiological adaptations of red blood cells during aestivation in the south American lungfish Lepidosiren paradoxa

The South American lungfish Lepidosiren paradoxa inhabits areas with variable pluvial regimes. During aestivation (dormancy state observed in some species during dry seasons), the prolonged period of dryness imposes osmotic stress. We aimed to investigate the physiological and morphological adaptations of RBCs in Lepidosiren paradoxa during aestivation. Here, the lungfish were subjected to aestivation for 20 and 40 days and compared to a control group in an active period. The osmotic fragility, blood osmolality, and pH were measured. Blood smears were performed to assess morphological changes in the RBCs. Lepidosiren paradoxa presented lower hemolysis when compared with a teleost fish and tegu lizard. Hemolysis increased when the lungfish was subjected to 40 days of aestivation (from 6.04 % to 16.51 %; control vs 40-day aestivation). Hematocrit rose in both aestivation groups compared to the control (26.36 %, 41.36 % and 41 %, control, 20 and 40 days, respectively; p < 0.05) indicating changes in RBC volume and hydration status. Moreover, the results revealed increased osmolality in the 40-day aestivation group (244.4 vs 372.1 mmol/Kg; control vs 40-day aestivation). 40 days of aestivation led to a decrease in blood pH when compared to the control and 20-day aestivation groups. Both aestivation durations resulted in a reduction in the perimeter and cell diameters in at least one direction of the RBCs (24 % mean reduction in size from control to 40 days aestivation). These findings suggest that South American lungfish possess remarkable physiological and morphological adaptations in their RBCs during aestivation.

Acute freshwater CO2 exposure does not impair seawater transfer in three different sizes of Atlantic salmon (Salmo salar) subjected to different photoperiod manipulations.

There is a growing interest in Atlantic salmon (Salmo salar) aquaculture to extend the time fish are reared in freshwater (FW) recirculating aquaculture systems (RAS), producing larger FW salmon that can then be induced to undergo smoltification before transfer into marine net pens for grow-out and harvest. Smolts can be produced by photoperiod (PT) manipulation in RASs, but little is known about how delaying smoltification to larger body sizes affects susceptibility to elevated CO2 levels (hypercapnia), which can occur at high stocking densities in FW RAS or during transport from FW RAS rearing facilities to marine net pens. To address this, Atlantic salmon were reared from hatch to one of three different sizes (~230, ~580, or ~1300 g) in FW (3 ppt) under continuous light (24:0, light:dark). Once fish reached the desired sizes, a group of salmon were maintained on continuous light 24L:0D to serve as a control salmon. A second group of salmon were exposed to 8 weeks of 12L:12D and then to 4 weeks of 24L:0D to serve as PT treatment salmon, which is the PT manipulation commonly used in Atlantic salmon aquaculture to induce smoltification. At the end of PT manipulation, both control and PT treatment salmon were exposed to 0% or 1.5% CO2 (30 mg/L) for 96 h in FW and then transferred to air-equilibrated seawater (SW, 35 ppt, normocapnia). Salmon were sampled at the end of the 96-h FW CO2 exposure and at 24 h and 7 days in SW for measurements of blood ion/acid-base status, muscle water content (MWC), and gill and kidney Na+/K+ ATPase (NKA) activity. Exposure to 96 h of CO2 in FW resulted in acid-base disturbances in fish from all three size classes, with decreases in blood pH and increases in blood PCO2 and plasma [HCO3 -] but no mortality. Despite these large acid-base disturbances in FW, after transfer to normocapnic SW, there were no significant effects of CO2 exposure on extracellular blood pH, intracellular red blood cell pH, or plasma osmoregulatory status for all three sizes of post-smolt salmon. In general, SW transfer was associated with significant increases in plasma ions and osmolality, as well as gill and kidney NKA activity after 24 h and 1 week in SW with no significant impacts between different sizes of salmon. Thus, exposure to 30 mg CO2/L that mimics levels experienced during transport from FW RAS to an SW transfer site may have minimal effects on Atlantic salmon smolts up to 1300 g.

Prognostic Significance of Lactate Clearance in Cardiogenic Pulmonary Edema in the Emergency Department.

Background and Objectives: Acute cardiorespiratory failure disrupts the delicate balance of energy supply, demand, and consumption, with elevated lactate levels and decreased blood pH serving as crucial indicators. Acute cardiogenic pulmonary edema (ACPO), a common cause of acute respiratory failure, poses a substantial mortality risk. Lactate, a byproduct of pyruvate reduction, is a pertinent marker in perfusion assessment. Lactate clearance (LC) has proven prognostic efficacy in various conditions but lacks consensus on its predictive power in acute cardiogenic pulmonary edema. Materials and Methods: This prospective observational study, conducted in a metropolitan area's third-level emergency department, involved patients with cardiogenic pulmonary edema from May 2021 to August 2023. The inclusion criteria specified acute cardiogenic pulmonary edema, excluding patients with incomplete data or other respiratory conditions. Lactate clearance, calculated at presentation and after 6 h, served as the primary outcome predictor. Our data analysis employed logistic regression, the ROC curve, and statistical tests. Results: The cohort of 106 patients revealed that a lactate clearance below 14.29% was significantly associated with mortality. While 51.6% of survivors were discharged, LC's predictive success for discharge was inconclusive. Logistic regression underscored the significance of lactate clearance, with a one-unit increase yielding a 5.55-fold probability of survival. The AUC for LC was 0.759. Conclusions: This study pioneers the exploration of lactate clearance in patients with acute cardiogenic pulmonary edema. LC below 14.29% signifies a poor prognosis, emphasizing its potential as an early treatment initiation marker. While acknowledging this study's limitations, we advocate for further multicenter research to refine the understanding of lactate clearance in this context.

Physiological assessment of the effects of experimental capture and transport in Pacific spiny dogfish

Sharks are collected from the wild as live specimens for display in aquariums and use in research. The methods by which live sharks are captured and transported can be associated with sub-lethal physiological outcomes or even mortality, which requires evaluation to determine optimal collection and transport methods for a given species. The present study evaluated the primary (i.e., endocrine) and secondary (i.e., biochemical) stress responses and mortality in Pacific spiny dogfish (Squalus suckleyi) following capture and subsequent transport between experimental rod-and-reel angling and longline fishing. Dogfish were resilient to transport following capture by either method, exhibiting no at-vessel mortality and 0.03% delayed mortality. Longline captured dogfish exhibited signs of primary (i.e., elevated corticosterone) and secondary (i.e., elevated plasma potassium, osmolality, glucose, and lactate; decreased blood pH) stress responses, whereas dogfish that experienced rod-and-reel capture and transport only exhibited a secondary stress response (i.e., elevated plasma potassium, osmolality, and lactate; decreased blood pH). Together, these data demonstrate that Pacific spiny dogfish are robust to capture and transport using experimental hook-and-line fishing techniques.

Short-term hyperoxia induced mitochondrial respiratory chain complexes dysfunction and oxidative stress in lung of rats

Background Oxygen therapy is an alternative for many patients with hypoxemia. However, this practice can be dangerous as oxygen is closely associated with the development of oxidative stress. Methods Male Wistar rats were exposed to hyperoxia with a 40% fraction of inspired oxygen (FIO2) and hyperoxia (FIO2 = 60%) for 120 min. Blood and lung tissue samples were collected for gas, oxidative stress, and inflammatory analyses. Results Hyperoxia (FIO2 = 60%) increased PaCO2 and PaO2, decreased blood pH and caused thrombocytopenia and lymphocytosis. In lung tissue, neutrophil infiltration, nitric oxide concentration, carbonyl protein formation and the activity of complexes I and II of the mitochondrial respiratory chain increased. FIO2 = 60% decreased SOD activity and caused several histologic changes. Conclusion In conclusion, we have experimentally demonstrated that short-term exposure to high FIO2 can cause oxidative stress in the lung.

The Difference In Potassium Levels In Fresh Blood Bags With Blood Bags Stored At Pku Muhammadiyah Gamping Hospital

Blood transfusion, one of them, is a process of transferring blood components containing glucose, lactate, and potassium. During storage, blood cells undergo metabolic changes such as decreased blood pH, hemolysis, and increased potassium levels. One of the complications of transfusion that must be avoided is hyperkalemia due to the release of potassium. This study aimed to determine differences in stored blood potassium levels and PRC QC results during 11 days of storage. This was an analytic observational study with a cross sectional approach. A T-test was used to analyze the difference. In addition, PRC blood quality control (QC) was also carried out for stored blood according to standards. This study used 40 samples of fresh blood bags obtained from UTD PMI Yogyakarta City. The mean potassium level in fresh blood bags was 4.373 ± 0.417 mmol/L (3.70-5.50) and the average potassium level in blood bags stored for 6 days was 8.290 ± 0.275 mmol/L (7.80-8.90). There was a significant difference in potassium levels between fresh blood bags and blood bags stored for 6 days (p = 0.000). The overall QC PRC result is 50% which indicates the need for improvement in terms of the blood component separation process.

Acute-on-chronic liver failure; prevalence, causes, predisposing factors, and outcome.

Until now, there has been disagreement regarding the prevalence, causes, predisposing factors, and outcome of ACLF (Acute-on-chronic liver failure). As a result, we have undertaken this research study. ACLF is a complex syndrome with a poor prognosis. In this cross-sectional study, we evaluated the prevalence, causes, predisposing factors, and outcomes of adult cirrhotic patients with ACLF and acute decompensation (AD). ACLF was defined based on the criteria established by APASL (Asian Pacific Association for the Study of the Liver). The severity of organ failure was assessed using both EASL-CLIF (European Association for the Study of the Liver- Chronic Liver Failure) and NACSELD (North American Consortium for the Study of End-Stage Liver Disease) scores. To investigate the impact of different independent variables on mortality, survival analysis methods were used. A total of 156 patients' data were analyzed in this study. The mean age of patients with ACLF (56.62±16.19 years) was significantly lower compared to the AD group (62.30±14.28 years). Nonalcoholic steatohepatitis and infection were the most common causes and predisposing factors in both AD and ACLF groups, respectively, but the difference between the two groups was not statistically significant. The most common organ failures observed were hepatic encephalopathy and respiratory failure. The probability of death at any given time for was significantly higher in ACLF patients than in the AD group (log rank test; P<0.001). The results of Cox regression analysis revealed that low blood pressure (HR 0.97; 95% CI 0.96-0.99; P<0.001) and decreased blood pH (HR 0.53; 95% CI 0.28-0.99; P=0.04) were significant risk factors associated with increased mortality. ACLF patients had a lower average age and higher mortality rates compared to AD. Nonalcoholic steatohepatitis was found to be the most common underlying disease in ACLF patients, while infections were identified as the predominant predisposing factor. All cases of mortality in the ACLF group were categorized as grade 3 and 4 based on the EASL-CLIF severity score. Hemodynamic instability and metabolic acidosis emerged as the most significant risk factors associated with increased mortality.

The therapeutic effect of a novel parenteral formulation of dihydroxyacetone in aluminum phosphide-intoxicated patients

Background and objectivesAluminum phosphide (AlP), known as “rice tablet,” is widely used as an effective pesticide. However, AlP poisoning is a common cause of mortality in many countries, such as Iran. Unfortunately, there is no specific antidote for AlP toxicity to date. AlP releases phosphine gas when it is exposed to moisture or acid. Phosphine is a potent mitochondrial toxin that could significantly inhibit cellular energy metabolism. AlP poisoning is an emergency condition that needs instant and effective intervention. Dihydroxyacetone (DHA) is a simple saccharide used for several pharmacological as well as cosmetic purposes. Previously, we found that DHA could significantly prevent mitochondrial impairment induced by toxic agents such as cyanide and phosphine in various in vitro and in vivo experimental models. MethodsHospitalized patients (n = 111) were evaluated for eligibility criteria. Among these patients, n = 35 cases were excluded due to incomplete data (n = 11) and suspicion of poisoning with poisons other than AlP (n = 24). Meanwhile, n = 76 cases with confirmed AlP poisoning were included in the study. AlP-poisoned patients who did not receive DHA (n = 18) were used as the control group.Patients (n = 58) received at least one dose of DHA (500 ml of 5 % DHA solution w/v, i.v.) as an adjuvant therapy in addition to the routine treatment of AlP poisoning. Arterial blood gas (ABG), blood pH, bicarbonate levels, and other vital signs and biochemical measurements were monitored. Moreover, the mortality rate and hospitalization time were evaluated in DHA-treated and AlP-poisoned patients without DHA administration. Several biomarkers were assessed before (upon hospitalization) and after DHA treatment. The routine tests for AlP-poisoned patients in this study were the measurement of electrolytes (K+ and Na+), WBC, RBC, hemoglobin, INR, carbonate (HCO3), blood pH, PaCO2, and PaO2 and SGPT, SGOT, BUN, Cr. ResultsUpon patients' admission, significant decreases in blood pH (acidosis), blood PaO2, and HCO3 levels were the hallmarks of AlP poisoning. It was found that DHA significantly alleviated biomarkers of AlP poisoning and tremendously enhanced patients’ survival rate (65.52 % in DHA-treated vs 33.34 % in the control group) compared to patients treated based on hospital routine AlP poisoning protocols (no DHA). No significant adverse effects were evident in DHA-treated patients in the current study. Interpretation and conclusionsThese data suggest that parenteral DHA is a novel and effective antidote against AlP poisoning to be used as an adjuvant in addition to routine supportive treatment. Trial registrationIR.SUMS.REC.1394.102.

DEXMEDETOMIDINE AND MIDAZOLAM INTRAMUSCULAR SEDATION IN BROWNBANDED BAMBOO SHARKS (CHILOSCYLLIUM PUNCTATUM).

Bamboo sharks are some of the most common elasmobranch species in zoos and aquaria and are frequently sedated for medical exams, treatments, and research. This study investigated the use of an IM sedation protocol of a single dose of dexmedetomidine (0.05 mg/kg) and midazolam (2.0 mg/kg) in brownbanded bamboo sharks (Chiloscyllium punctatum). Sharks were serially monitored every 5 min for heart rate, branchial beats, righting reflex, coelomic response, cloacal response, pelvic fin reflex, response to noxious stimulus, voluntary movement, and ability to swim. This sedation dose was effective at rapidly and significantly decreasing responses to tactile and noxious stimuli with minimal respiratory depression and was quickly reversible with atipamezole (0.5 mg/kg) and flumazenil (0.05 mg/kg). Sedated sharks developed a mild metabolic acidosis evidenced by a significant increase in lactic acid (mean < 0.37 mmol/L presedation, 4.2 mmol/L after reversal) and decrease in blood pH (mean 7.464 presedation, 7.277 after reversal); however, clinical intervention was not required. This protocol should be further investigated in different elasmobranch species but is promising for providing sedation for noninvasive procedures in brownbanded bamboo sharks.

Physiochemical Dissolution Governs Early Modifications in Acid-Exposed Murine Bone with Long-term Recovery

Metabolic acidosis (MA), a disease affecting millions annually, is clinically characterized by a decrease in systemic pH and bicarbonate. MA has been shown to have skeletal consequences, such as increased bone loss and fractures. However, the mechanisms impacting the mechanics of bone remain unknown. To determine this, we characterized the skeletal phenotypes resulting from two independent regimes of ammonium chloride (NH4Cl) acid-dosing in skeletally mature CD-1 mice for 1, 3, 7, and 14 days to establish the temporal progression of materials-level skeletal defects. The classical, flat-dose model resulted in a temporary decrease in blood pH but did not reduce blood bicarbonate levels. Minimal alterations were observed in bone composition, structure, mechanics, and cellular behavior. However, the graded administration of NH4Cl maintained MA for up to 14 days. This resulted in decreased bone mineral content, collagen organization, and bone volume while increasing mineral crystallinity at early time points followed by a return to baseline. Changes to the matrix lead to a potential decrease in bone toughness at early time points, which may explain the increased fracture risk seen clinically. However, there were no changes in bone formation rate nor osteoclast number or activity during any time point. After 14 days, the bones were fully recovered even though the mice were still under acidotic conditions. Ultimately, we conclude that physicochemical dissolution is the main mechanism for early changes in murine bone, which is influenced by the dosing of exogenous acid loading. This knowledge will aid the discovery of treatments that prevent acidosis-induced bone dissolution.

Clinical Features and Treatment Outcomes of COVID-19 Admissions in the Can Tho City Hospital of Tuberculosis and Respiratory Diseases, Vietnam: A Hospital-Based Observational Study.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, is among the top global health crises. As confirmed by the Vietnam Ministry of Health on 25th January 2023, Vietnam had a cumulative total of more than 11.52 million COVID-19 patients, including 10.61 million recoveries and 43,186 deaths. This study aimed to describe the clinical and subclinical characteristics, treatment progress, and outcomes of 310 cases of SARS-CoV-2 infection. A total of 310 patients with medical records of SARS-CoV-2 were admitted to Can Tho City Hospital of Tuberculosis and Lung Diseases, Can Tho city, Vietnam, between July 2021 and December 2021. Demographic and clinical data, including laboratory examinations, of all the patients were collected and analyzed. The median duration of hospital stay was 16.4 ± 5.3 days. There were 243 (78.4%) patients with clinical symptoms of COVID-19 and 67 (21.6%) patients without clinical symptoms. The common symptoms included cough (71.6% of 310 patients), fever (35.4%), shortness of breath (22.6%), sore throat (21.4%), loss of smell/taste (15.6%), and diarrhea (14.4%). Regarding treatment outcomes, 92.3% of the patients were discharged from the hospital, 1.9% of the patients suffered a more severe illness and were transferred to a higher-level hospital, and 5.8% of the patients died. The RT-PCR results were negative in 55.2% of the patients, and 37.1% of the patients had positive RT-PCR results with Ct values of >30 on the discharge/transfer day. Multivariate logistic regression analyses showed that comorbidity and decreased blood pH were statistically significantly related to the treatment outcomes of the patients with COVID-19 (p < 0.05). This study provides useful information (i.e., the clinical characteristics and treatment outcomes) on the COVID-19 pandemic in Vietnam during its biggest outbreak; the information may be used for reference and for making improvements in the handling of future health crises.

EVALUATION OF THE EFFICACY OF DIFFERENT RUMEN BUFFERS ON PREVENTION OF RUMINAL ACIDOSIS IN GOATS

This study was realized to evaluate the efficacy of dietary supplementation of sodium bicarbonate plus magnesium oxide "MgO", calcareous marine algae (AcidBuf) and essential oils (Actifor®Boost) on the animal performance and prevention of ruminal acidosis in goats moreover, evaluation the diagnostic accuracy of some biochemical parameters including blood pH, total antioxidant capacity (TAC), bicarbonate (HCO3-), partial pressure of carbon dioxide (pCO2), beta-hydroxybutyric acid (βHBA) and plasma L-lactate versus ruminal pH in diagnosis of ruminal acidosis. A total of 30 goats were divided into five equal groups (G1-5) according to the type of dietary treatment. G1 served as a control group and fed the concentrate diet only, G2 fed the concentrate diet supplemented with 10 g Na bicarbonate plus 4g MgO, G3 supplemented with 4g AcidBuf, G4 supplemented with 10 g Na bicarbonate plus 4g MgO plus 4g AcidBuf and G5 supplemented with 1g Actifor® boost/head/day for five days. Tachycardia, tachypnea and decreased ruminal motility were recorded in G1 only. The ruminal pH tended to return to its toward normal for G3 and G4 with a mean of (6.3±0.03 and 6.3±0.01, respectively) which significantly higher than those of G1 and G2 (6.19±0.01 and 6.17±0.02 respectively). A significant increase in plasma L-lactate and a significant decrease in blood pH, HCO3-, pCO2, TAC, and βHBA were recorded in G1 when compared with other groups. Calcareous marine algae with or without adding other compounds found to be a promising rumen buffer agent, moreover TAC and plasma L-lactate showed better diagnostic performance versus rumen pH in the diagnosis of ruminal acidosis.

Repeated Simulated Match-Induced Changes in Finger Flexor Force and Blood Acid-Base Balance in World-Class Female Judokas.

The aim of this study was to investigate the time course of maximal isometric finger flexor force and blood acid-base balance during repeated simulated matches in world-class judokas. Seven 21- to 28-year-old world-class female judokas (including Olympic and World Championship medalists) repeated four 4-minute judo combats interspersed by 15minutes of passive recovery. Maximal voluntary isometric finger flexor contraction (MVIC) force was measured in both hands after warm-up and immediately after each combat using a handgrip dynamometer. MVIC force was classified as MVIC hikite force (pulling hand) and MVIC tsurite force (lifting hand). Blood lactate concentration, pH, bicarbonate concentration, partial pressure of oxygen, and oxygen saturation were measured between 3 and 5 minutes after each match. At completion of the fourth combat, mean MVIC hikite and tsurite force decreased by 18% and 12%, respectively (g = 0.23 and 0.29, respectively; P < .05), demonstrating that force production was substantial throughout repeated matches. Blood lactate concentration increased ∼5-fold from 2.69 (1.37)mmol·L-1 after warm-up to 13.10 (2.61)mmol·L-1 after the last match (g = 4.13, P = .018). Concurrently, blood pH decreased slightly from 7.44 (0.03) to 7.26 (0.05) (g = 2.34, P = .018), that is, by only 0.18 units. The decreased blood pH was significantly correlated with a decrease in bicarbonate concentration (R2 = .94, P < .001). Finally, partial pressure of oxygen and oxygen saturation remained unchanged during the judo contest. Female world-class judokas were able to maintain a high level of grip strength in both hands and efficiently regulate blood acid-base balance during repeated simulated high-intensity matches.

Fluoxetine-induced perinatal morbidity in a sheep model.

Selective serotonin reuptake inhibitors (SSRI) are the most common antidepressants used by pregnant women. However, adverse pregnancy outcomes have been described in women taking SSRI during pregnancy—placental lesions, premature birth, poor neonatal adaptation. We aimed to investigate the effects of fluoxetine (Prozac® most commonly used SSRI) treatment during the last month of gestation on pregnancy complications, placental and neonatal health in a non-depressed sheep model. On day 119 ± 1 postbreeding (experimental day 0; E0) of a 151-day expected gestation, Hampshire ewes were randomly assigned to receive fluoxetine (n = 9 ewes, 15 lambs; daily intravenously treatment with 10 mg/kg on E0 and E1 and 5 mg/kg daily thereafter until parturition) or to a control group (n = 10; 14 lambs; vehicle only). Blood samples from ewes were collected throughout the experimental period and postpartum; blood from lambs were collected postpartum. Analysis of variance was used for statistical analysis. Fluoxetine treatment reduced placentome growth during the last month of pregnancy. Gestation length was decreased by 4.5 days in fluoxetine-treated ewes. Birthweight was reduced in lambs exposed to fluoxetine in utero; weights remained decreased until postnatal day 3. Placentome diameter by birthweight ratio was not different between groups suggesting that the decreased placentome diameter was accompanied by decreased lamb birthweight. During the first week postnatal, lambs exposed to fluoxetine in utero had decreased blood pH and decreased total carbon dioxide, bicarbonate, and base excess and increased lactate (days 3–6), collectively indicative of metabolic acidemia. Additionally, ionized calcium was decreased between postnatal days 0 to 4 in lambs exposed to fluoxetine in utero. Using a non-depressed animal model clearly defines a role for SSRI on the occurrence of perinatal complications and neonatal morbidity. The decreased placentome diameter, shortened gestation, decreased birthweight, decreased calcium levels, and neonatal acidemia suggest the occurrence of intrauterine growth restriction. The persistence of neonatal acidemia for several days postpartum suggests poor neonatal adaptation to extrauterine environment.

The Use of Intravenous Sodium Bicarbonate in the Treatment of Metabolic Acidosis with Septic Shock

Background: Acute metabolic acidemia, defined as a decrease in blood pH originating from a primary reduction in bicarbonate concentration that is accompanied by an appropriate secondary reduction in PaCO2 and is present for up to a few days, can impair hemodynamics and increase mortality, particularly when severe (arterial blood pH&lt;7.20). Septic shock constitutes an important cause of morbidity and mortality in the critically ill patient. The Surviving Sepsis Campaign recommends against treatment with bicarbonate in patients with lactic acidosis due to hypo perfusion when pH is &gt;7.15 but does not explicate what should be done in cases with lower pH. Methodology: Prospective randomized, Double-blind controlled study was conducted in ICU of Bangalore Medical College and Research Institute, Bangalore for a period of 4 months (November 2020 to February 2021). Sample size calculation was based on previous prospective, randomized double bind, controlled study by Jung B et al, calculated to be 27 in each group. Results: Mean age of subjects in Study group was 43.7 ± 14.0 years and in control group was 43.3 ± 17.1 years. A statistically significant difference was found in mean final pH and HCO3 levels and with respect to need for ventilation and Multi Organ Dysfunction Syndrome among the groups. Conclusion: Metabolic acidosis is a common acid-base disorder and its management should be directed by the current guidelines of therapy. Rational treatment of metabolic acidosis in sepsis is directed towards addressing the underlying causes of acidosis and optimizing tissue oxygen delivery through optimization of cardiopulmonary parameters. Limitations of the previous studies prevent reaching definite conclusions and further investigations are required in order to ensure the validity of this therapeutic approach.

Factores de riesgo de mortalidad en pacientes mayores de 65 años hospitalizados por COVID-19

Background and objectiveCOVID-19 is a disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has caused a global pandemic that we are currently suffering from. Objectiveto identify factors associated with the death of patients aged 65 years or older hospitalized for COVID-19. Materials and methodsRetrospective cohort study. We included patients aged 65 years or older who were hospitalized for COVID-19 and dead o discharged between March 5 and 25, 2020. We used univariable and multivariable logistic regression methods to explore the risk factors associated with in-hospital death. Results277 patients were included in this study. The bivariate analysis showed significant differences (p<0.05) between survivors and non survivors: age, increased dependence and comorbidity, history of ischemic heart disease, renal failure and non-hematological neoplasms, heart failure during admission, leukocytosis, elevated creatinine, PCR, GOT and troponin Ic values, lymphopenia, and decreased blood pH and SatO2. Multivariate logistic regression revealed that age ≥65 years (OR: 4.23 (95% CI: 1.43-12.52; p=0.009), lymphopenia <1000/μL (OR: 2.36 (95% CI: 1.07-5.20; p=0.033), creatinine>1.2mg/dL (OR: 3.08 (95% CI: 1.37-6.92; p=0.006), SatO2 <90% (OR: 2.29 (95% CI: 1.01-5.21; p=0.049) and troponin Ic>11ng/mL (OR: 2.32 (95% CI: 1.04-5.16; p=0.040) were independently associated with higher hospital mortality. ConclusionsOlder age, lymphopenia, SatO2 <90%, elevated creatinine and troponin Ic values were independently associated with higher mortality in hospitalized patients with COVID-19, these factors could help clinicians to identify patients with poor prognosis.

Evaluation of blood electrolyte alterations in cats during elec-tive laparoscopic ovariectomy

In a clinical setting, we tested the hypothesis of whether hypercapnia developed during carbon dioxide pneumoperitoneum is associated with changes in blood electrolytes. This prospective study involved ten female cats that underwent elective laparoscopic ovariectomy. Venous blood samples for assessment of electrolytes were collected in the following sequence: T1- before anaesthesia induction, T2 - 10 minutes after anaesthesia induction, T3 - 30 minutes of pneumoperitoneum and T4 - at the end of pneumoperitoneum. Statistical analysis revealed AB disturbances associated with general anaesthesia and pneumoperitoneum, manifested with decreased blood pH, whereas blood PvCO2, PO2 and BE were increased. A constant increase of K+ concentration was recorded in all animals during pneumoperitoneum (P&lt;0.05), whereas iMg registered a significant increase only at T3 (P&lt;0.05). Correlations were recorded between blood pH and Na+, iCa, iMg, as well as between Na+ and Cl¯ at different time points during anaesthesia. No correlations were noted between pH and K+ or PvCO2 and K+. In conclusion, electrolyte imbalance represents a possible complication associated with laparoscopic surgery in healthy cats. However, further studies should investigate the causes involved in K+ concentration elevation.

The Role of Acidosis in the Pathogenesis of Severe Forms of COVID-19.

Simple SummaryRecently, several studies have shown that acidosis, which is increased acidity in the blood and other body tissues, is often associated with severe COVID-19. In this article, we look at the mechanisms and consequences of acidosis that can lead to an exacerbation of COVID-19. We want to draw the attention of readers to the threshold values of such disease characteristics as hypoxia and acidosis, which are associated with a sharp deterioration in the patient’s condition. Hypoxia and acidosis mutually reinforce each other according to the principle of a vicious cycle (that is, they are involved in a system of positive feedbacks). Elevated blood lactate (lactic acid) levels are associated with poor clinical outcomes in COVID patients. As a practical recommendation, we propose to pay more attention to the prevention of acidosis, including in the early stages of the disease, when the adjustment of homeostasis requires less effort and is less risky.COVID-19 has specific characteristics that distinguish this disease from many other infections. We suggest that the pathogenesis of severe forms of COVID-19 can be associated with acidosis. This review article discusses several mechanisms potentially linking the damaging effects of COVID-19 with acidosis and shows the existence of a vicious cycle between the development of hypoxia and acidosis in COVID-19 patients. At the early stages of the disease, inflammation, difficulty in gas exchange in the lungs and thrombosis collectively contribute to the onset of acidosis. In accordance with the Verigo-Bohr effect, a decrease in blood pH leads to a decrease in oxygen saturation, which contributes to the exacerbation of acidosis and results in a deterioration of the patient’s condition. A decrease in pH can also cause conformational changes in the S-protein of the virus and thus lead to a decrease in the affinity and avidity of protective antibodies. Hypoxia and acidosis lead to dysregulation of the immune system and multidirectional pro- and anti-inflammatory reactions, resulting in the development of a “cytokine storm”. In this review, we highlight the potential importance of supporting normal blood pH as an approach to COVID-19 therapy.

Chronic Metabolic Acidosis Elicits Hypertension via Upregulation of Intrarenal Angiotensin II and Induction of Oxidative Stress

Chronic metabolic acidosis (CMA) can be a consequence of persistent hypertension but could potentially play a role in invoking hypertension. Currently, there is a scarcity of studies examining the outcome of induced chronic acidosis on blood pressure regulation. This study investigates CMA as a cause of hypertension. Chronic acidosis was induced in Sprague Dawley rats (100–150 g) by providing a weak acid solution of 0.28 M ammonium chloride (NH4Cl) in tap water for 8 weeks. To determine whether the rats were acidotic, blood pH was measured, while blood pressure (BP) was monitored by tail-cuff plethysmography weekly. Rats were divided into five groups: control, CMA, CMA ± spironolactone, captopril, and tempol. Serum sodium and potassium; renal interstitial fluid (for Angiotensin II concentration); and kidney proximal tubules (for Na+/K+ ATPase- α1 concentration) were analyzed. Reactive oxygen species (ROS) were detected in renal cortical homogenates using electron paramagnetic resonance (EPR). In the CMA rats, a sustained elevation in mean arterial pressure (MAP) associated with a significant decrease in blood pH was observed compared to that of control over the 8 weeks. A significant decrease in MAP was observed in acidotic rats treated with captopril/tempol, whereas spironolactone treatment caused no decrease in MAP as compared to that of the CMA group. The interstitial angiotensin II was increased in the CMA group but decreased in the CMA with captopril and tempol groups. In addition, the urinary sodium was decreased, and the serum sodium levels increased significantly in the CMA groups as compared to that of control. However, the acidotic groups with captopril and tempol showed reduced levels of serum sodium and an elevation in urinary sodium as compared to that of the CMA group. In addition, there was a significant increase in plasma renin and no change in plasma aldosterone in the CMA group with no significant differences in plasma renin or aldosterone observed during spironolactone, captopril, or tempol treatments. The increased expression of Na+/K+ ATPase-α1 in the CMA group suggests that active transport of Na+ to the blood could be causative of the observed hypertension. Furthermore, the EPR analysis confirmed an elevation in superoxide (O2-) radical levels in the CMA group, but the tempol/captopril treated acidotic groups showed less (O2-) compared to that of either the CMA group or control. Taken together, our data suggest that induction of CMA could potentially be causative of hypertension, while the mechanisms underlying the increased BP could be through the activation of intrarenal Ang II and induction of oxidative stress.

A physiologically validated rat model of term birth asphyxia with seizure generation after, not during, brain hypoxia.

ObjectiveBirth asphyxia (BA) is often associated with seizures that may exacerbate the ensuing hypoxic–ischemic encephalopathy. In rodent models of BA, exposure to hypoxia is used to evoke seizures, that commence already during the insult. This is in stark contrast to clinical BA, in which seizures are typically seen upon recovery. Here, we introduce a term‐equivalent rat model of BA, in which seizures are triggered after exposure to asphyxia.MethodsPostnatal day 11–12 male rat pups were exposed to steady asphyxia (15 min; air containing 5% O2 + 20% CO2) or to intermittent asphyxia (30 min; three 5 + 5‐min cycles of 9% and 5% O2 at 20% CO2). Cortical activity and electrographic seizures were recorded in freely behaving animals. Simultaneous electrode measurements of intracortical pH, Po2, and local field potentials (LFPs) were made under urethane anesthesia.ResultsBoth protocols decreased blood pH to <7.0 and brain pH from 7.3 to 6.7 and led to a fall in base excess by 20 mmol·L–1. Electrographic seizures with convulsions spanning the entire Racine scale were triggered after intermittent but not steady asphyxia. In the presence of 20% CO2, brain Po2 was only transiently affected by 9% ambient O2 but fell below detection level during the steps to 5% O2, and LFP activity was nearly abolished. Post‐asphyxia seizures were strongly suppressed when brain pH recovery was slowed down by 5% CO2.SignificanceThe rate of brain pH recovery has a strong influence on post‐asphyxia seizure propensity. The recurring hypoxic episodes during intermittent asphyxia promote neuronal excitability, which leads to seizures only after the suppressing effect of the hypercapnic acidosis is relieved. The present rodent model of BA is to our best knowledge the first one in which, consistent with clinical BA, behavioral and electrographic seizures are triggered after and not during the BA‐mimicking insult.