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Clinical Journal of the American... Jan 2023Acid-base disorders are common in the intensive care unit. By utilizing a systematic approach to their diagnosis, it is easy to identify both simple and mixed...
Acid-base disorders are common in the intensive care unit. By utilizing a systematic approach to their diagnosis, it is easy to identify both simple and mixed disturbances. These disorders are divided into four major categories: metabolic acidosis, metabolic alkalosis, respiratory acidosis, and respiratory alkalosis. Metabolic acidosis is subdivided into anion gap and non-gap acidosis. Distinguishing between these is helpful in establishing the cause of the acidosis. Anion gap acidosis, caused by the accumulation of organic anions from sepsis, diabetes, alcohol use, and numerous drugs and toxins, is usually present on admission to the intensive care unit. Lactic acidosis from decreased delivery or utilization of oxygen is associated with increased mortality. This is likely secondary to the disease process, as opposed to the degree of acidemia. Treatment of an anion gap acidosis is aimed at the underlying disease or removal of the toxin. The use of therapy to normalize the pH is controversial. Non-gap acidoses result from disorders of renal tubular H + transport, decreased renal ammonia secretion, gastrointestinal and kidney losses of bicarbonate, dilution of serum bicarbonate from excessive intravenous fluid administration, or addition of hydrochloric acid. Metabolic alkalosis is the most common acid-base disorder found in patients who are critically ill, and most often occurs after admission to the intensive care unit. Its etiology is most often secondary to the aggressive therapeutic interventions used to treat shock, acidemia, volume overload, severe coagulopathy, respiratory failure, and AKI. Treatment consists of volume resuscitation and repletion of potassium deficits. Aggressive lowering of the pH is usually not necessary. Respiratory disorders are caused by either decreased or increased minute ventilation. The use of permissive hypercapnia to prevent barotrauma has become the standard of care. The use of bicarbonate to correct the acidemia is not recommended. In patients at the extreme, the use of extracorporeal therapies to remove CO 2 can be considered.
Topics: Humans; Bicarbonates; Critical Illness; Acidosis; Acid-Base Equilibrium; Acid-Base Imbalance; Alkalosis
PubMed: 35998977
DOI: 10.2215/CJN.04500422 -
Nefrologia : Publicacion Oficial de La... 2016Hyperchloremia is a common electrolyte disorder that is associated with a diverse group of clinical conditions. The kidney plays an important role in the regulation of... (Review)
Review
Hyperchloremia is a common electrolyte disorder that is associated with a diverse group of clinical conditions. The kidney plays an important role in the regulation of chloride concentration through a variety of transporters that are present along the nephron. Nevertheless, hyperchloremia can occur when water losses exceed sodium and chloride losses, when the capacity to handle excessive chloride is overwhelmed, or when the serum bicarbonate is low with a concomitant rise in chloride as occurs with a normal anion gap metabolic acidosis or respiratory alkalosis. The varied nature of the underlying causes of the hyperchloremia will, to a large extent, determine how to treat this electrolyte disturbance.
Topics: Acid-Base Equilibrium; Acidosis; Alkalosis, Respiratory; Bicarbonates; Cell Membrane Permeability; Chlorides; Formates; Humans; Ion Transport; Kidney Tubules, Proximal; Membrane Transport Proteins; Natriuresis; Nephrons; Oxalates; Water-Electrolyte Imbalance
PubMed: 27267918
DOI: 10.1016/j.nefro.2016.04.001 -
European Respiratory Review : An... Sep 2016Dysfunctional breathing is a term describing breathing disorders where chronic changes in breathing pattern result in dyspnoea and other symptoms in the absence or in... (Review)
Review
Dysfunctional breathing is a term describing breathing disorders where chronic changes in breathing pattern result in dyspnoea and other symptoms in the absence or in excess of the magnitude of physiological respiratory or cardiac disease. We reviewed the literature and propose a classification system for the common dysfunctional breathing patterns described. The literature was searched using the terms: dysfunctional breathing, hyperventilation, Nijmegen questionnaire and thoraco-abdominal asynchrony. We have summarised the presentation, assessment and treatment of dysfunctional breathing, and propose that the following system be used for classification. 1) Hyperventilation syndrome: associated with symptoms both related to respiratory alkalosis and independent of hypocapnia. 2) Periodic deep sighing: frequent sighing with an irregular breathing pattern. 3) Thoracic dominant breathing: can often manifest in somatic disease, if occurring without disease it may be considered dysfunctional and results in dyspnoea. 4) Forced abdominal expiration: these patients utilise inappropriate and excessive abdominal muscle contraction to aid expiration. 5) Thoraco-abdominal asynchrony: where there is delay between rib cage and abdominal contraction resulting in ineffective breathing mechanics.This review highlights the common abnormalities, current diagnostic methods and therapeutic implications in dysfunctional breathing. Future work should aim to further investigate the prevalence, clinical associations and treatment of these presentations.
Topics: Comorbidity; Dyspnea; Humans; Lung; Predictive Value of Tests; Respiration Disorders; Respiratory Mechanics; Risk Factors; Terminology as Topic
PubMed: 27581828
DOI: 10.1183/16000617.0088-2015 -
BMJ (Clinical Research Ed.) Mar 2020To delineate the clinical characteristics of patients with coronavirus disease 2019 (covid-19) who died.
OBJECTIVE
To delineate the clinical characteristics of patients with coronavirus disease 2019 (covid-19) who died.
DESIGN
Retrospective case series.
SETTING
Tongji Hospital in Wuhan, China.
PARTICIPANTS
Among a cohort of 799 patients, 113 who died and 161 who recovered with a diagnosis of covid-19 were analysed. Data were collected until 28 February 2020.
MAIN OUTCOME MEASURES
Clinical characteristics and laboratory findings were obtained from electronic medical records with data collection forms.
RESULTS
The median age of deceased patients (68 years) was significantly older than recovered patients (51 years). Male sex was more predominant in deceased patients (83; 73%) than in recovered patients (88; 55%). Chronic hypertension and other cardiovascular comorbidities were more frequent among deceased patients (54 (48%) and 16 (14%)) than recovered patients (39 (24%) and 7 (4%)). Dyspnoea, chest tightness, and disorder of consciousness were more common in deceased patients (70 (62%), 55 (49%), and 25 (22%)) than in recovered patients (50 (31%), 48 (30%), and 1 (1%)). The median time from disease onset to death in deceased patients was 16 (interquartile range 12.0-20.0) days. Leukocytosis was present in 56 (50%) patients who died and 6 (4%) who recovered, and lymphopenia was present in 103 (91%) and 76 (47%) respectively. Concentrations of alanine aminotransferase, aspartate aminotransferase, creatinine, creatine kinase, lactate dehydrogenase, cardiac troponin I, N-terminal pro-brain natriuretic peptide, and D-dimer were markedly higher in deceased patients than in recovered patients. Common complications observed more frequently in deceased patients included acute respiratory distress syndrome (113; 100%), type I respiratory failure (18/35; 51%), sepsis (113; 100%), acute cardiac injury (72/94; 77%), heart failure (41/83; 49%), alkalosis (14/35; 40%), hyperkalaemia (42; 37%), acute kidney injury (28; 25%), and hypoxic encephalopathy (23; 20%). Patients with cardiovascular comorbidity were more likely to develop cardiac complications. Regardless of history of cardiovascular disease, acute cardiac injury and heart failure were more common in deceased patients.
CONCLUSION
Severe acute respiratory syndrome coronavirus 2 infection can cause both pulmonary and systemic inflammation, leading to multi-organ dysfunction in patients at high risk. Acute respiratory distress syndrome and respiratory failure, sepsis, acute cardiac injury, and heart failure were the most common critical complications during exacerbation of covid-19.
Topics: Adult; Age Factors; Aged; Betacoronavirus; Biomarkers; COVID-19; COVID-19 Testing; Cardiovascular Diseases; China; Clinical Laboratory Techniques; Comorbidity; Consciousness Disorders; Coronavirus Infections; Dyspnea; Female; Humans; Inflammation; Male; Middle Aged; Pandemics; Pneumonia, Viral; Respiration Disorders; Retrospective Studies; Risk Factors; SARS-CoV-2; Sex Factors; Time Factors; Treatment Outcome; COVID-19 Drug Treatment
PubMed: 32217556
DOI: 10.1136/bmj.m1091 -
Journal of Applied Physiology... Apr 2007Acetazolamide, a potent carbonic anhydrase (CA) inhibitor, is the most commonly used and best-studied agent for the amelioration of acute mountain sickness (AMS). The... (Review)
Review
Acetazolamide, a potent carbonic anhydrase (CA) inhibitor, is the most commonly used and best-studied agent for the amelioration of acute mountain sickness (AMS). The actual mechanisms by which acetazolamide reduces symptoms of AMS, however, remain unclear. Traditionally, acetazolamide's efficacy has been attributed to inhibition of CA in the kidneys, resulting in bicarbonaturia and metabolic acidosis. The result is offsetting hyperventilation-induced respiratory alkalosis and allowance of chemoreceptors to respond more fully to hypoxic stimuli at altitude. Studies performed on both animals and humans, however, have shown that this explanation is unsatisfactory and that the efficacy of acetazolamide in the context of AMS is likely due to a multitude of effects. This review summarizes the known systemic effects of acetazolamide and incorporates them into a model encompassing several factors that are likely to play a key role in the drug's efficacy. Such factors include not only metabolic acidosis resulting from renal CA inhibition but also improvements in ventilation from tissue respiratory acidosis, improvements in sleep quality from carotid body CA inhibition, and effects of diuresis.
Topics: Acetazolamide; Adaptation, Physiological; Altitude Sickness; Carbonic Anhydrase Inhibitors; Humans; Oxygen; Oxygen Consumption
PubMed: 17023566
DOI: 10.1152/japplphysiol.01572.2005