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Kidney International Jul 1984
Topics: Alkalosis; Animals; Bicarbonates; Carbon Dioxide; Carcinoma, Small Cell; Chlorides; Female; Glomerular Filtration Rate; Humans; Hydrogen-Ion Concentration; Hypercapnia; Lung Neoplasms; Middle Aged; Rats
PubMed: 6090757
DOI: 10.1038/ki.1984.139 -
British Medical Journal Oct 1976
Topics: Aged; Alkalosis; Diabetes Complications; Diabetes Mellitus; Female; Humans; Ketones
PubMed: 974680
DOI: 10.1136/bmj.2.6041.943-a -
British Journal of Anaesthesia Nov 2022Acid-base status in full-term pregnant women is characterised by hypocapnic alkalosis. Whether this respiratory alkalosis is primary or consequent to changes in CSF...
BACKGROUND
Acid-base status in full-term pregnant women is characterised by hypocapnic alkalosis. Whether this respiratory alkalosis is primary or consequent to changes in CSF electrolytes is not clear.
METHODS
We enrolled third-trimester pregnant women (pregnant group) and healthy, non-pregnant women of childbearing age (controls) undergoing spinal anaesthesia for Caesarean delivery and elective surgery, respectively. Electrolytes, strong ion difference (SID), partial pressure of carbon dioxide ( [Formula: see text] ), and pH were measured in simultaneously collected CSF and arterial blood samples.
RESULTS
All pregnant women (20) were hypocapnic, whilst only four (30%) of the controls (13) had an arterial [Formula: see text] <4.7 kPa (P<0.001). The incidence of hypocapnic alkalosis was higher in the pregnant group (65% vs 8%; P=0.001). The CSF-to-plasma Pco difference was significantly higher in pregnant women (1.5 [0.3] vs 1.0 [0.4] kPa; P<0.001), mainly because of a decrease in arterial Pco (3.9 [0.3] vs 4.9 [0.5] kPa; P<0.001). Similarly, the CSF-to-plasma difference in SID was less negative in pregnant women (-7.8 [1.4] vs -11.4 [2.3] mM; P<0.001), mainly because of a decreased arterial SID (31.5 [1.2] vs 36.1 [1.9] mM; P<0.001). The major determinant of the reduced plasma SID of pregnant women was a relative increase in plasma chloride compared with sodium.
CONCLUSIONS
Primary hypocapnic alkalosis characterises third-trimester pregnant women leading to chronic acid-base adaptations of CSF and plasma. The compensatory SID reduction, mainly sustained by an increase in chloride concentration, is more pronounced in plasma than in CSF, as the decrease in Pco is more marked in this compartment.
CLINICAL TRIAL REGISTRATION
NCT03496311.
Topics: Female; Humans; Pregnancy; Acid-Base Equilibrium; Alkalosis; Bicarbonates; Carbon Dioxide; Chlorides; Electrolytes; Hydrogen-Ion Concentration; Pregnancy Trimester, Third; Sodium
PubMed: 36096944
DOI: 10.1016/j.bja.2022.07.048 -
Poultry Science Jun 1985The occurrence of respiratory alkalosis and potential benefit derived from treatment were examined in thermostressed 4-week-old broiler chicks. Blood pH was greater (P...
The occurrence of respiratory alkalosis and potential benefit derived from treatment were examined in thermostressed 4-week-old broiler chicks. Blood pH was greater (P less than .05) in heat-stressed (32 C) panting birds (7.395) than either nonpanting (7.28) or birds raised at 24 C (7.28). Acute thermostress, obtained by elevating ambient temperature from 32 to 41 C over a 20-min period further elevated (P less than .05) blood pH to 7.521. Chronic heat-stressed broiler chicks suffer from intermittent respiratory alkalosis during panting; with acute heat stress, chicks pant continuously and suffer from alkalosis. Including .5% sodium bicarbonate (NaHCO3) in the diet of birds subjected to chronic heat stress enhanced body weight gain by 9% even though it tended (P less than .10) to increase blood pH in nonpanting birds. Adding .3 or 1% ammonium chloride (NH4Cl) to diets decreased blood pH (P less than .01) to 7.194 and increased (P less than .05) body weight gains by 9.5 and 25%, respectively. Effects appeared linear with NH4Cl dose to 1% NH4Cl, but 3% NH4Cl elevated weight gains by only 8% and precipitated blood acidosis (pH 7.09) in nonpanting birds. Supplementing the 1% NH4Cl diet with .5% NaHCO3 increased weight gains an additional 9%. Manipulating sodium: chloride ratios by addition of calcium chloride increased body weight gain 8% and slightly reduced severity of alkalosis. Data indicate that blood alkalosis limits growth rate of broiler chicks reared under chronic thermostress and that the respiratory alkalosis and weight gain depressions attributed to thermostress can be partially alleviated dietarily.
Topics: Alkalosis, Respiratory; Ammonium Chloride; Animals; Bicarbonates; Blood Chemical Analysis; Body Weight; Calcium Chloride; Carbon Dioxide; Chickens; Chronic Disease; Hot Temperature; Hydrogen-Ion Concentration; Poultry Diseases; Sodium; Sodium Bicarbonate; Stress, Physiological
PubMed: 2989810
DOI: 10.3382/ps.0641060 -
Acta Medica (Hradec Kralove) 2020Primary hyperaldosteronism (PA) is the most common cause of secondary arterial hypertension and is frequently undiagnosed. It affects all ages but is more frequent...
Primary hyperaldosteronism (PA) is the most common cause of secondary arterial hypertension and is frequently undiagnosed. It affects all ages but is more frequent between 20 and 60 years old. The clinical presentation is variable, and the diagnosis is based on screening and, in equivocal cases, confirmatory tests. A 19-year-old student presented with complaints of extreme fatigue, arterial hypertension, hypokalemia and metabolic alkalosis, raising a high index of suspicion for PA. Screening tests were performed and its expressiveness excluded the need of confirmatory tests. CT-scan showed a unilateral adrenal adenoma and the patient was submitted to laparoscopic adenectomy without complications. Prompt diagnosis and treatment are essential to avoid long term complications of PA.
Topics: Adrenal Cortex Neoplasms; Adrenalectomy; Adrenocortical Adenoma; Alkalosis; Fatigue; Humans; Hyperaldosteronism; Hypertension; Hypokalemia; Male; Tomography, X-Ray Computed; Treatment Outcome; Young Adult
PubMed: 33002402
DOI: 10.14712/18059694.2020.32 -
Critical Care (London, England) Oct 2018Metabolic alkalosis is common in patients with respiratory failure and may delay weaning in mechanically ventilated patients. Carbonic anhydrase inhibitors block renal... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Metabolic alkalosis is common in patients with respiratory failure and may delay weaning in mechanically ventilated patients. Carbonic anhydrase inhibitors block renal bicarbonate reabsorption, and thus reverse metabolic alkalosis. The objective of this systematic review is to assess the benefits and harms of carbonic anhydrase inhibitor therapy in patients with respiratory failure and metabolic alkalosis.
METHODS
We searched the following electronic sources from inception to August 2017: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and SCOPUS. Randomized clinical trials were included if they assessed at least one of the following outcomes: mortality, duration of hospital stay, duration of mechanical ventilation, adverse events, and blood gas parameters. Teams of two review authors worked in an independent and duplicate manner to select eligible trials, extract data, and assess risk of bias of the included trials. We used meta-analysis to synthesize statistical data and then assessed the certainty of evidence using the GRADE methodology.
RESULTS
Six eligible studies were identified with a total of 564 participants. The synthesized data did not exclude a reduction or an increase in mortality (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.57 to 1.56) or in duration of hospital stay (mean difference (MD) 0.42 days, 95% CI -4.82 to 5.66) with the use of carbonic anhydrase inhibitors. Carbonic anhydrase inhibitor therapy resulted in a decrease in the duration of mechanical ventilation of 27 h (95% CI -50 to -4). Also, it resulted in an increase in PaO (MD 11.37 mmHg, 95% CI 4.18 to 18.56) and a decrease in PaCO (MD -4.98 mmHg, 95% CI -9.66, -0.3), serum bicarbonate (MD -5.03 meq/L, 95% CI -6.52 to -3.54), and pH (MD -0.04, 95% CI -0.07 to -0.01). There was an increased risk of adverse events in the carbonic anhydrase inhibitor group (RR 1.71, 95% CI 0.98 to 2.99). Certainty of evidence was judged to be low for most outcomes.
CONCLUSION
In patients with respiratory failure and metabolic alkalosis, carbonic anhydrase inhibitor therapy may have favorable effects on blood gas parameters. In mechanically ventilated patients, carbonic anhydrase inhibitor therapy may decrease the duration of mechanical ventilation. A major limitation of this finding was that only two trials assessed this clinically important outcome.
Topics: Alkalosis; Carbonic Anhydrase Inhibitors; Humans; Metabolic Diseases; Odds Ratio; Randomized Controlled Trials as Topic; Respiratory Insufficiency; Ventilator Weaning
PubMed: 30371345
DOI: 10.1186/s13054-018-2207-6 -
Critical Care (London, England) Aug 2012Patients with chronic obstructive pulmonary disease (COPD) are affected by episodes of respiratory exacerbations, some of which can be severe and may necessitate... (Review)
Review
Patients with chronic obstructive pulmonary disease (COPD) are affected by episodes of respiratory exacerbations, some of which can be severe and may necessitate respiratory support. Prolonged invasive mechanical ventilation is associated with increased mortality rates. Persistent failure to discontinue invasive mechanical ventilation is a major issue in patients with COPD. Pure or mixed metabolic alkalosis is a common finding in the intensive care unit (ICU) and is associated with a worse outcome. In patients with COPD, the condition is called post-hypercapnic alkalosis and is a complication of mechanical ventilation. Reversal of metabolic alkalosis may facilitate weaning from mechanical ventilation of patients with COPD. Acetazolamide, a non-specific carbonic anhydrase inhibitor, is one of the drugs employed in the ICU to reverse metabolic alkalosis. The drug is relatively safe, undesirable effects being rare. The compartmentalization of the different isoforms of the carbonic anhydrase enzyme may, in part, explain the lack of evidence of the efficacy of acetazolamide as a respiratory stimulant. Recent findings suggest that the usually employed doses of acetazolamide in the ICU may be insufficient to significantly improve respiratory parameters in mechanically ventilated patients with COPD. Randomized controlled trials using adequate doses of acetazolamide are required to address this issue.
Topics: Acetazolamide; Alkalosis; Carbonic Anhydrase Inhibitors; Humans; Intensive Care Units; Pulmonary Disease, Chronic Obstructive; Respiration, Artificial
PubMed: 22866939
DOI: 10.1186/cc11323 -
European Journal of Pediatric Surgery :... Dec 2023Normalization of metabolic alkalosis is an important pillar in the treatment of infantile hypertrophic pyloric stenosis (IHPS) because uncorrected metabolic alkalosis...
BACKGROUND
Normalization of metabolic alkalosis is an important pillar in the treatment of infantile hypertrophic pyloric stenosis (IHPS) because uncorrected metabolic alkalosis may lead to perioperative respiratory events. However, the evidence on the incidence of respiratory events is limited. We aimed to study the incidence of peroperative hypoxemia and postoperative respiratory events in infants undergoing pyloromyotomy and the potential role of metabolic alkalosis.
MATERIALS AND METHODS
We retrospectively reviewed all patients undergoing pyloromyotomy between 2007 and 2017. All infants received intravenous fluids preoperatively to correct metabolic abnormalities close to normal. We assessed the incidence of perioperative hypoxemia (defined as oxygen saturation [SpO] < 90% for > 1min) and postoperative respiratory events. Additionally, the incidence of difficult intubations was evaluated. We performed a multivariate logistic regression analysis to evaluate the association between admission or preoperative serum pH values, bicarbonate or chloride, and peri- and postoperative hypoxemia or respiratory events.
RESULTS
Of 406 included infants, 208 (51%) developed 1 or more episodes of hypoxemia during the perioperative period, of whom 130 (32%) experienced it during induction, 43 (11%) intraoperatively, and 112 (28%) during emergence. About 7.5% of the infants had a difficult intubation and 17 required more than 3 attempts by a pediatric anesthesiologist. Three patients developed respiratory insufficiency and 95 postoperative respiratory events were noticed. We did not find a clinically meaningful association between laboratory values reflecting metabolic alkalosis and respiratory events.
CONCLUSIONS
IHPS frequently leads to peri- and postoperative hypoxemia or respiratory events and high incidence of difficult tracheal intubations. Preoperative pH, bicarbonate, and chloride were bad predictors of respiratory events.
Topics: Infant; Humans; Child; Pyloric Stenosis, Hypertrophic; Retrospective Studies; Bicarbonates; Chlorides; Hypoxia; Alkalosis
PubMed: 36417975
DOI: 10.1055/a-1984-9803 -
PloS One 2021Point-of-care arterial blood gas (ABG) is a blood measurement test and a useful diagnostic tool that assists with treatment and therefore improves clinical outcomes.... (Observational Study)
Observational Study
BACKGROUND
Point-of-care arterial blood gas (ABG) is a blood measurement test and a useful diagnostic tool that assists with treatment and therefore improves clinical outcomes. However, numerically reported test results make rapid interpretation difficult or open to interpretation. The arterial blood gas algorithm (ABG-a) is a new digital diagnostics solution that can provide clinicians with real-time interpretation of preliminary data on safety features, oxygenation, acid-base disturbances and renal profile. The main aim of this study was to clinically validate the algorithm against senior experienced clinicians, for acid-base interpretation, in a clinical context.
METHODS
We conducted a prospective international multicentre observational cross-sectional study. 346 sample sets and 64 inpatients eligible for ABG met strict sampling criteria. Agreement was evaluated using Cohen's kappa index, diagnostic accuracy was evaluated with sensitivity, specificity, efficiency or global accuracy and positive predictive values (PPV) and negative predictive values (NPV) for the prevalence in the study population.
RESULTS
The concordance rates between the interpretations of the clinicians and the ABG-a for acid-base disorders were an observed global agreement of 84,3% with a Cohen's kappa coefficient 0.81; 95% CI 0.77 to 0.86; p < 0.001. For detecting accuracy normal acid-base status the algorithm has a sensitivity of 90.0% (95% CI 79.9 to 95.3), a specificity 97.2% (95% CI 94.5 to 98.6) and a global accuracy of 95.9% (95% CI 93.3 to 97.6). For the four simple acid-base disorders, respiratory alkalosis: sensitivity of 91.2 (77.0 to 97.0), a specificity 100.0 (98.8 to 100.0) and global accuracy of 99.1 (97.5 to 99.7); respiratory acidosis: sensitivity of 61.1 (38.6 to 79.7), a specificity of 100.0 (98.8 to 100.0) and global accuracy of 98.0 (95.9 to 99.0); metabolic acidosis: sensitivity of 75.8 (59.0 to 87.2), a specificity of 99.7 (98.2 to 99.9) and a global accuracy of 97.4 (95.1 to 98.6); metabolic alkalosis sensitivity of 72.2 (56.0 to 84.2), a specificity of 95.5 (92.5 to 97.3) and a global accuracy of 93.0 (88.8 to 95.3); the four complex acid-base disorders, respiratory and metabolic alkalosis, respiratory and metabolic acidosis, respiratory alkalosis and metabolic acidosis, respiratory acidosis and metabolic alkalosis, the sensitivity, specificity and global accuracy was also high. For normal acid-base status the algorithm has PPV 87.1 (95% CI 76.6 to 93.3) %, and NPV 97.9 (95% CI 95.4 to 99.0) for a prevalence of 17.4 (95% CI 13.8 to 21.8). For the four-simple acid-base disorders and the four complex acid-base disorders the PPV and NPV were also statistically significant.
CONCLUSIONS
The ABG-a showed very high agreement and diagnostic accuracy with experienced senior clinicians in the acid-base disorders in a clinical context. The method also provides refinement and deep complex analysis at the point-of-care that a clinician could have at the bedside on a day-to-day basis. The ABG-a method could also have the potential to reduce human errors by checking for imminent life-threatening situations, analysing the internal consistency of the results, the oxygenation and renal status of the patient.
Topics: Acid-Base Equilibrium; Acid-Base Imbalance; Acidosis; Adolescent; Adult; Aged; Algorithms; Alkalosis; Alkalosis, Respiratory; Arterial Pressure; Blood Gas Analysis; Child; Child, Preschool; Cross-Sectional Studies; Female; Humans; Hydrogen-Ion Concentration; Male; Middle Aged; Models, Theoretical; Point-of-Care Testing; Predictive Value of Tests; Prevalence; Prospective Studies; Reproducibility of Results; Sensitivity and Specificity
PubMed: 33690724
DOI: 10.1371/journal.pone.0248264 -
Brazilian Journal of Medical and... Jun 2008Acid-base homeostasis maintains systemic arterial pH within a narrow range. Whereas the normal range of pH for clinical laboratories is 7.35-7.45, in vivo pH is... (Review)
Review
Acid-base homeostasis maintains systemic arterial pH within a narrow range. Whereas the normal range of pH for clinical laboratories is 7.35-7.45, in vivo pH is maintained within a much narrower range. In clinical and experimental settings, blood pH can vary in response to respiratory or renal impairment. This altered pH promotes changes in vascular smooth muscle tone with impact on circulation and blood pressure control. Changes in pH can be divided into those occurring in the extracellular space (pHo) and those occurring within the intracellular space (pHi), although, extracellular and intracellular compartments influence each other. Consistent with the multiple events involved in the changes in tone produced by altered pHo, including type of vascular bed, several factors and mechanisms, in addition to hydrogen ion concentration, have been suggested to be involved. The scientific literature has many reports concerning acid-base balance and endothelium function, but these concepts are not clear about acid-base disorders and their relations with the three known mechanisms of endothelium-dependent vascular reactivity: nitric oxide (NO/cGMP-dependent), prostacyclin (PGI2/cAMP-dependent) and hyperpolarization. During the last decades, many studies have been published and have given rise to confronting data on acid-base disorder and endothelial function. Therefore, the main proposal of this review is to provide a critical analysis of the state of art and incentivate researchers to develop more studies about these issues.
Topics: Acid-Base Equilibrium; Acidosis; Alkalosis; Animals; Blood Vessels; Endothelium, Vascular; Epoprostenol; Humans; Hydrogen-Ion Concentration; Muscle, Smooth, Vascular; Nitric Oxide; Vasodilation
PubMed: 18592120
DOI: 10.1590/s0100-879x2008005000026