Extreme Acidosis Research Articles

Prognosis of patients with extreme acidosis on admission to the emergency department: A retrospective cohort study

Aim of the studyThe development of acidosis in critically ill patients is considered to be a negative prognostic factor, and when extreme, even incompatible with life. We aimed to test the prognosis of patients with a pH lower than 6.9 on emergency department admission. MethodsA retrospective cohort study in adult patients admitted to two emergency departments with a pH < 6.9 during the first 12 h of admission. Primary outcome was mortality within 24 h from emergency department admission. We performed a regression analysis of clinical and laboratory data in order to identify factors associated with mortality in this population. ResultsWe analyzed data of 206 admissions to the emergency departments between 2008 and 2018 with extreme acidosis. pH Values ranged from 6.898 to 6.35 (mean 6.8 and median 6.83). 60 (29%) of the patients survived the first 24 h. 35 patients (58%) of those also survived to hospital discharge, and of them 80% have returned to their previous functional status. Patient's age, type of acidosis, cardio-pulmonary resuscitation on arrival, and diagnosis on admission were correlated with survival. ConclusionsA small but significant portion of patients with extreme acidosis on emergency department admission survive at least to 24 h and until hospital discharge. The clinical decision making should be based on other prognostic factors rather than pH value by itself.

Prognosis of critically ill patients with extreme acidosis: A retrospective study

ObjectiveThis study aims to assess the impact of different subtypes of extreme acidosis on the mortality of critically ill patients. MethodsThis retrospective cohort study included critically ill patients who were admitted to the intensive care unit (ICU) with a pH level <7. Clinical data and blood gas analyses were collected from electronic medical records. The primary outcome was in-hospital mortality. The use of vasopressors, mechanical ventilation (MV), and renal replacement therapy (RRT), the duration of MV and RRT, and the length of ICU and hospital stay were secondary outcomes. The simplified Stewart approach to acid-base disorders was used to analyze the causes of acidosis. ResultsA total of 231 patients with 371 arterial blood gas analyses with pH < 7 were admitted from January 2012 to December 2021 and 222 were included in the study. Out of the 222 patients analyzed, respiratory acidosis was the primary disorder in 11.3% of patients (n = 25), metabolic acidosis in 33.8% (n = 75), and mixed acidosis in 55% (n = 122). Overall mortality was 42.8% (n = 95). No significant difference was observed in mortality among patients with respiratory, metabolic, or mixed acidosis (28%, 42.7%, and 45.9%, respectively; p = 0.26). The primary disorder affected the use of vasopressors and MV, the duration of MV, and the length of ICU and hospital stay. Patients with extreme acidosis due to unmeasured anions with lactate levels of 4 mmol/L or higher had higher mortality compared with patients with lactate levels <4 mmol/L (55.6% and 27.7%, respectively; p = 0.007). ConclusionAmong critically ill patients with extreme acidosis, the primary disorder is not associated with mortality, but it is associated with the use of vasopressors and MV, the duration of MV, and the length of ICU and hospital stay. Additionally, hyperlactatemia is a predictor of poor prognosis in patients with extreme acidosis.

Electrolyte derangements in critically ill children receiving balanced versus unbalanced crystalloid fluid resuscitation

BackgroundAdult studies have demonstrated potential harm from resuscitation with 0.9% sodium chloride (0.9%NaCl), resulting in increased utilization of balanced crystalloids like lactated ringers (LR). The sodium and potassium content of LR has resulted in theoretical safety concerns, although limited data exists in pediatrics. We hypothesized that use of LR for resuscitation would not be associated with increased electrolyte derangements compared to 0.9%NaCl.MethodsA prospective, observational cohort study of critically ill children who received ≥ 20 ml/kg of fluid resuscitation and were admitted to two pediatric intensive care units from November 2017 to February 2020. Fluid groups included patients who received > 75% of fluids from 0.9%NaCl, > 75% of fluids from LR, and a mixed group. The primary outcome was incidence of electrolyte derangements (sodium, chloride, potassium) and acidosis.ResultsAmong 559 patients, 297 (53%) received predominantly 0.9%NaCl, 74 (13%) received predominantly LR, and 188 (34%) received a mixture. Extreme hyperkalemia (potassium ≥ 6 mmol/L) was more common in 0.9%NaCl group (5.8%) compared to LR group (0%), p 0.05. Extreme acidosis (pH > 7.1) was more common in 0.9%NaCl group (11%) compared to LR group (1.6%), p 0.016.ConclusionsLR is associated with fewer electrolyte derangements compared to 0.9%NaCl. Prospective interventional trials are needed to validate these findings.

Live transport of Atlantic salmon in open and closed systems: Water quality, stress and recovery

The goal of the study was to compare open and closed transports of adult Atlantic salmon in terms of water quality and stress (blood chemistry and white muscle biochemistry). The study comprised of two phases: (i) live transport from a commercial farm by vessel (open system) and vehicle (closed system) to flow-through laboratory tanks and (ii) after post-transport recovery, simulated live transports in open and closed systems. The stress reaction the salmon experienced during transfer from fish farm to laboratory tanks was severe. Some delayed mortalities were observed possibly related to extreme acidosis. The fish were left to recover for 65 h before the simulated open and closed transports were carried out. By then, they had not yet fully recovered to baseline levels. The simulated transports did not cause excessive stress reactions relative to the partially recovered fish. However, deteriorating water quality during closed transport eventually affected fish behaviour where fish welfare could be questioned. The main finding was that crowding and transport due to commercial transport overshadowed stress-related results obtained during the laboratory study. The results may also be viewed as effects of repeated fish handling operations, a typical feature of salmon farming.

Surviving Fatal Acidemia: A Case of Extreme Acidosis In a Patient With an Arterial Ph of 6.25 who Survived

Severe acidosis has significant adverse consequences on many aspects of human physiology. Most texts would argue that an arterial pH of less than 6.8 is not compatible with life...

Suspected thyroid storm in a cat anaesthetised for bilateral thyroidectomy

A 14‐year‐old female neutered domestic short hair cat was referred for assessment of uncontrolled hyperthyroidism. The owners were advised that a bilateral thyroidectomy was required due to the presence of comorbidities that rendered radioiodine therapy inappropriate. During the procedure the cat exhibited unexpected extreme tachycardia, hypertension, hypercapnia, severe respiratory and metabolic acidosis and ventricular arrhythmias, which all resolved after removal of the thyroid glands. Recovery was complicated by the development of congestive heart failure and hypertension which were successfully managed and the cat was discharged five weeks after presentation. Thyroid storm was considered a possible explanation for the events that occurred during anaesthesia as well as the subsequent congestive heart failure and hypertension. Thyroid storm during anaesthesia has not been reported in animals. The similarities between the reported case and thyroid storm events in humans are discussed.

On-board study of gas embolism in marine turtles caught in bottom trawl fisheries in the Atlantic Ocean

Decompression sickness (DCS) was first diagnosed in marine turtles in 2014. After capture in net fisheries, animals typically start showing clinical evidence of DCS hours after being hauled on-board, often dying if untreated. These turtles are normally immediately released without any understanding of subsequent clinical problems or outcome. The objectives of this study were to describe early occurrence and severity of gaseous embolism (GE) and DCS in marine turtles after incidental capture in trawl gear, and to provide estimates of on-board and post-release mortality. Twenty-eight marine turtles were examined on-board fishing vessels. All 20 turtles assessed by ultrasound and/or post-mortem examination developed GE, independent of season, depth and duration of trawl and ascent speed. Gas emboli were obvious by ultrasound within 15 minutes after surfacing and worsened over the course of 2 hours. Blood data were consistent with extreme lactic acidosis, reduced glomerular filtration, and stress. Twelve of 28 (43%) animals died on-board, and 3 of 15 (20%) active turtles released with satellite tags died within 6 days. This is the first empirically-based estimate of on-board and post-release mortality of bycaught marine turtles that has until now been unaccounted for in trawl fisheries not equipped with turtle excluder devices.

Resuscitation from a pH of 6.5: A Case Report and Review of Pathophysiology and Management of Extreme Acidosis from Hypovolemic Shock after Trauma

Extreme acidosis is a life-threatening physiological state that causes disturbances in the cardiovascular, pulmonary, immune, and hematological systems. Trauma patients commonly present to the operating room (OR) in hypovolemic shock, leading to tissue hypoperfusion and the development of acute metabolic acidosis with or without a respiratory component. It is often believed that trauma patients presenting to the OR in severe metabolic acidosis (pH <7.0) will have a nearly universal mortality rate despite aggressive resuscitation and damage control. The current literature does not include reports of successful resuscitations from a lower pH, which may lead providers to assume that a good outcome is not possible. However, here we describe a case of successful resuscitation from an initial pH of 6.5 with survival to discharge home 95 days after admission with almost full recovery. We describe the effects of acute acidosis on the respiratory and cardiovascular systems and hemostasis. Finally, we discuss the pillars of management in patients with extreme acute acidosis due to hemorrhage: transfusion, treatment of hyperkalemia, and consideration of buffering acidosis with bicarbonate and hyperventilation.

Bone as a buffer: Consequences for vertebrate design and anaerobic physiological performance

Conventional wisdom usually states that mineralized tissues are primarily used by vertebrates as sites for respiratory and locomotory muscle attachment or for physical protection from predators. Often ignored is the role these tissues play in maintaining ionic and acid‐base homeostasis and how this might have shaped vertebrate evolution. We have argued that this latter function may have been important in shaping vertebrate design in early tetrapods, particularly the maintenance of dermal armor in early tetrapods, and is still important for anaerobic physiological performance in many extant vertebrates, especially in reptiles and amphibians. We use physiological, biomechanical, and mineralogical approaches to understand how vertebrate bone, especially that of turtles, interacts with and is affected by extreme deviations in acid‐base homeostasis. Our work, and that of others, has shown that the mineral composition of turtle bone can predict tolerance to extreme acidosis, and that the most derived of these vertebrates, the anoxia‐tolerant painted turtle, is able to utilize calcium and magnesium carbonates within its bone to prevent lethal decreases in body fluid pH in the face of a 180 mM lactic acid load, with minimal effect on whole‐bone material properties.Support or Funding InformationThis work is funded by a CAREER Award from the National Science Foundation.

Prognosis of patients presenting extreme acidosis (pH < 7) on admission to intensive care unit

PurposeThe purpose was to determine prognosis of patients presenting extreme acidosis (pH <7) on admission to the intensive care unit (ICU) and to identify mortality risk factors. Materials and methodsWe retrospectively analyzed all patients who presented with extreme acidosis within 24 hours of admission to a polyvalent ICU in a university hospital between January 2011 and July 2013. Multivariate analysis and survival analysis were used. ResultsAmong the 2156 patients admitted, 77 patients (3.6%) presented extreme acidosis. Thirty (39%) patients suffered cardiac arrest before admission. Although the mortality rate predicted by severity score was 93.6%, death occurred in 52 cases (67.5%) in a median delay of 13 (5-27) hours. Mortality rate depended on reason for admission, varying between 22% for cases linked to diabetes mellitus and 100% for cases of mesenteric infarction (P = .002), cardiac arrest before admission (P < .001), type of lactic acidosis (P = .007), high Simplified Acute Physiology Score II (P = .008), and low serum creatinine (P = .012). ConclusionsPatients with extreme acidosis on admission to ICU have a less severe than expected prognosis. Whereas mortality is almost 100% in cases of cardiac arrest before admission, mortality is much lower in the absence of cardiac arrest before admission, which justifies aggressive ICU therapies.

Continuous veno-venous hemofiltration in patients with metformin associated lactic acidosis

Metformin is frequently used by type II diabetics. A rare complication of its use is metformin associated lactic acidosis (MALA). This condition is often accompanied by extreme metabolic acidosis and hemodynamic instability for which ICU treatment is mandatory. Guidelines advice intermittent hemodialysis for correction of metabolic acidosis and to clear metformin. However, haemodynamic instability may prefer continuous veno-venous hemofiltration (CVVH). We evaluated the effect of CVVH in critically ill patients admitted with MALA.

Hyperglycemic Emergencies in Adults

Hyperglycemic Emergencies in Adults

Extreme Maternal Metabolic Acidosis Leading to Fetal Distress and Emergency Caesarean Section

A 31-year-old pregnant woman (32 + 3 weeks) was admitted with extreme tachypnea. She had a previous history of congenital muscular dystrophy (Ullrich's disease) and isolated glucosuria. The patient had reduced food intake during the last 24 hours prior to admission and vomited twice. Serum glucose level was normal (112 mg/dL), while urinalysis revealed glucosuria 4+ and ketonuria 4+. ABG revealed pH 7.06, PCO2 9 mm Hg, and bicarbonate 2 mmol/L. Anion gap was 28 mmol/L. Tachypnea was a compensatory mechanism for a severe nonlactic metabolic acidosis. The diagnosis of starvation ketoacidosis was established. The patient received supplemental dextrose 10% intravenously and sodium bicarbonate. As fetal heart monitoring was pathological, an emergency caesarean section was performed. Umbilical cord venous pH was 7.01, with PCO2 34 mm Hg and bicarbonate 8 mmol/L. Starvation ketoacidosis is a rare metabolic disorder that may occur mainly in the third trimester of pregnancy. Muscular dystrophy and renal glucosuria were precipitating factors.

Effect of Magnesium Sulfate Concentration on Serum Ionized Magnesium In Vitro

We undertook this in vitro study to quantify the effect that addition of magnesium (Mg) sulfate to neonatal serum, as compared with adult serum, might have on ionized Mg (Mg (2+)) concentration. We used one cord blood sample and one adult blood sample that we made hypermagnesemic by adding various amounts of magnesium sulfate to study five levels of serum Mg. Each sample was then studied at one of three levels of pH, from extreme alkalosis to extreme acidosis. We measured the changes in serum Mg (2+) and serum ionized calcium (Ca (2+)) in reaction to these changes in pH and Mg. At each pH level, there was an exponential increase in the serum Mg (2+) (and no significant change in serum Ca (2+)) with increasing serum Mg. Multiple regression analysis using Mg (2+) as the dependent variable and baseline Ca (2+), phosphorous, albumin, and blood type (adult versus cord blood) as well as blood pH and serum Mg as independent variables indicated that serum Mg and pH were the only variables significantly influencing serum Mg (2+). Within the range of serum Mg considered, the addition of magnesium sulfate in vitro causes an exponential increase in Mg (2+) and no significant change in serum Ca (2+).

Electrophysiological Characteristics of Neonatal Nav1.5 Expressed in a Highly Invasive Human Breast Cancer Cell Line: Sensitivity to pH and Divalent Cations

Electrophysiological recordings from human carcinoma cell lines have shown consistently that strongly metastatic cells express functional voltage-gated sodium channels (VGSCs). The predominant VGSC in metastatic breast cancer, in vitro and in vivo, is the ‘neonatal’ splice form of Nav1.5. In this developmentally regulated D1:S3 splice variant of Nav1.5, there are 31 nucleotide differences between the 5’-exon (‘neonatal’) and the 3’-exon (‘adult’) forms, resulting in 7 amino acid differences in D1:S3-S3/S4 linker. In particular, a conserved negative aspartate residue in the ‘adult’ is replaced with a positive lysine. ‘Neonatal’ and ‘adult’ Nav1.5 α-subunit splice variants were stably transfected into EBNA-293 cells and their electrophysiological properties were investigated by whole-cell patch-clamp recording. Compared with the ‘adult’ isoform, the ‘neonatal’ channel exhibited (1) depolarized threshold of activation and voltage at which current peaked; (2) much slower kinetics of activation and inactivation; (3) ∼50% greater transient charge (Na+) influx; (4) a slower recovery from inactivation; and (5) larger persistent Na+ currents. Mutating the lysine in the ‘neonatal’ channel back to aspartate resulted in the electrophysiological parameters studied reverting strongly back towards the ‘adult’, i.e. the lysine residue was primarily responsible for the electrophysiological differences. The charge difference between the two Nav1.5 isoforms was ‘challenged’ by H+ and Cd2+. The main differential effect occurred at pH 5.25-5.75 in which the activation parameters of ‘neonatal’ Nav1.5 were affected significantly less. The biophysical characteristics of ‘neonatal’ Nav1.5 observed could have significant developmental and pathophysiological consequences. In particular, the prolonged Na+ influx can alter intracellular Ca2+ and/or pH homeostasis, at least in microdomains, and channel activation remains relatively efficient under extreme acidosis.

Erfolgreiche Behandlung einer extremen metabolischen Acidose mit ausgeprägter Hypothermie

A case of extreme metabolic acidosis (pH 6.6) and severe hypothermia (27.3 degrees C) is reported. The patient's anamnesis and medical examination led to the assumption of ketoacidosis. Pronounced ketoacidosis is not unusual in juvenile diabetics type 1 and the incidence in Europe is reported to be between 15 and 70% for all type 1 diabetics. The case describes the targeted therapy of controlled re-warming to avoid neurological damage.

Survival after extracorporeal cardiopulmonary resuscitation in infants and children with heart disease

We investigated survival and predictors of mortality for infants and children with heart disease treated with extracorporeal membrane oxygenation as an aid to cardiopulmonary resuscitation. Children (<18 years) with heart disease who received extracorporeal cardiopulmonary resuscitation and were reported to the Extracorporeal Life Support Organization database were evaluated. Patients were classified into one of 3 groups based on underlying cardiac physiology: single ventricle, 2 ventricles, and cardiac muscle disease. Patients with eligible procedure codes were assigned a Risk Adjustment for Congenital Heart Surgery-1 classification. Four hundred ninety-two patients were eligible for analysis, and 279 (57%) were assigned a Risk Adjustment for Congenital Heart Surgery-1 category. Overall survival was 42%. In a multivariable logistic regression analysis, significant pre-extracorporeal predictors for mortality included single-ventricle physiology (odds ratio, 1.6; 95% confidence interval, 1.05-2.4), a history of a stage 1-type procedure (odds ratio, 2.7; 95% confidence interval, 1.2-6.2), and extreme acidosis (arterial blood gas pH < 7.01; odds ratio, 2.2; 95% confidence interval, 1.3-3.7). Right carotid artery cannulation was associated with decreased mortality risk (odds ratio, 0.6; 95% confidence interval, 0.4-0.9). During extracorporeal support, complications, including renal injury, evidence of neurologic injury, and persistent acidosis, were associated with an increased risk of hospital mortality. Use of extracorporeal membrane oxygenation as an adjunct to cardiopulmonary resuscitation resulted in hospital survival in 42% of infants and children with heart disease. Underlying cardiac physiology and associated cardiac surgical procedures influenced mortality, as did pre-extracorporeal resuscitation status and extracorporeal membrane oxygenation-associated complications.

Lebensbedrohliche Lactatacidosen bei totaler parenteraler Ernährung: Therapieerfolg mit Thiamin

Two patients, 37 and 44 years old, respectively, developed severe metabolic acidosis after abdominal surgery which was followed by three weeks of total parenteral nutrition. Septicaemia, peritonitis or hypoxia were excluded as possible causes. Both patients had very high serum lactate concentrations (24.3 and 22.8 mmol/l, respectively). Conventional treatment with buffer agents was unsuccessful. Because vitamin B1 deficiency was suspected, two doses of 400 mg thiamine were administered. In both patients the extreme lactic acidosis disappeared immediately after the injections. Both patients were later discharged without any symptoms.

Sobredosis de metformina secundaria a insuficiencia renal aguda. A propósito de 6 observaciones

Metformin is a biguanide used in the treatment of obese adults with type 2 diabetes mellitus; metformin decreases mortality by 36% in comparison to conventional treatment. Metformin administration has certain contraindications that, when ignored, especially in the case of acute renal insufficiency, leads to the accumulation of the drug and consequent lactic acidosis that can be fatal. We present 6 patients with acute renal insufficiency that experienced extreme acute metabolic acidosis (pH <6.90 and bicarbonate <5 mEq/l) and increased anion gap while receiving metformin for the treatment of diabetes. Serum lactic acid, only evaluated in the 4 patients that survived, was high. Two patients died after cardiac arrest that could have been avoided. In conclusion, lactic acidosis appearing during metformin treatment for diabetes requires rapid diagnosis and treatment to enable the drug to be withdrawn and prolonged continuous hemofiltration or hemodialysis with bicarbonate to be initiated.

Movement of acid equivalents across the mammalian smooth muscle cell membrane.

Factors affecting intracellular pH (pHi) in the smooth muscle of guinea pig ureter have been investigated using pH-sensitive microelectrodes. Associated acids and bases appear to have free passage across the cell membrane but results suggest very low permeability to charged acid equivalents, thus implicating carrier-mediated movements in many of the observed pHi transients. Recovery from acidosis in the nominal absence of CO2 was inhibited by removal of Na+ and by the presence of amiloride, indicating that Na+/H+ exchange was responsible. The presence of CO2 resulted in a faster recovery from acidosis but, since intracellular buffering power was not increased, not a substantially faster effective extrusion of protons. Surprisingly, amiloride no longer caused discernable inhibition. Recovery from moderate acidosis remained Na+ dependent but was not inhibited by DIDS or acetazolamide or by the absence of Cl-, suggesting a dominant Na+-, and HCO3(-)-dependent mechanism unlike any hitherto described. Recovery from alkalosis was inhibited by DIDS and Cl(-)-free conditions, indicating that Cl-/HCO3- exchange was involved. Results suggest reversal of this mechanism on extreme acidosis. Experiments in vascular smooth muscle with fluorescent indicators confirm the presence of Na+/H+ exchange but provide conflicting evidence about the presence and properties of the HCO3(-)-dependent mechanism.