Bidirectional ventricular tachycardia induced by respiratory alkalosis mediated hypokalemia in a patient with acute ischemic heart failure.

Bidirectional ventricular tachycardia (BVT) is a rare arrhythmia that is generally observed in patients with catecholaminergic ventricular tachycardia or digoxin overdose. Herein, we present a case of BVT and electrical storm (ES) in an acute ischemic heart failure patient that is typically induced by hypokalemia. The patient was in invasive mechanical ventilator (MV) support and hypokalemia was related to acute respiratory alkalosis and that caused refractory hypokalemia despite intravenous (IV) potassium replacement. We also discuss our approach to solve refractory hypokalemia caused by respiratory alkalosis.

Cardiogenic Auto-Triggering as a Consequence of Hemoperitoneum.

A 70-year-old woman presented with hemorrhagic shock secondary to hemoperitoneum following a paracentesis. On hospital day 3, she developed respiratory alkalosis and increased respiratory rates observed on the ventilator despite no spontaneous inspiratory effort. Converting to pressure support mode uncovered a cardiogenic oscillatory flow that had been auto-triggering the ventilator. This cardiogenic auto-triggering resolved with large-volume paracentesis. Cardiogenic auto-triggering leads to patient-ventilator dyssynchrony, respiratory alkalosis, lung distension, and difficulty with weaning from the ventilator, and it may be unrecognized in ICUs.

Respiratory Acid-Base Disorders in the Critical Care Unit.

The incidence of respiratory acid-base abnormalities in the critical care unit (CCU) is unknown, although respiratory alkalosis is suspected to be common in this population. Abnormal carbon dioxide tension can have many physiologic effects, and changes in Pco2 may have a significant impact on outcome. Monitoring Pco2 in CCU patients is an important aspect of critical patient assessment, and identification of respiratory acid-base abnormalities can be valuable as a diagnostic tool. Treatment of respiratory acid-base disorders is largely focused on resolution of the primary disease, although mechanical ventilation may be indicated in cases with severe respiratory acidosis.

A Case of Salicylate Intoxication Complicated by Coagulopathy, Pulmonary Edema, and Pancreatitis.

The large availability of salicylic acid products makes them an often encountered source of poisoning in the emergency department. Even though in most cases the prognosis is good, with a low incidence of long-term morbidity and mortality, complications do occur, and some of those can be life threatening. We present an unusual case of salicylate intoxication in an adolescent in which several uncommon complications (severe coagulopathy, pulmonary edema, and pancreatitis) conjoined together. We review the literature and discuss the complications pathogenesis and differential diagnosis. We suggest that these potentially life-threatening complications be acknowledged, investigated, and rapidly treated.

Effect of Acetazolamide vs Placebo on Duration of Invasive Mechanical Ventilation Among Patients With Chronic Obstructive Pulmonary Disease: A Randomized Clinical Trial.

IMPORTANCE: Acetazolamide has been used for decades as a respiratory stimulant for patients with chronic obstructive pulmonary disease (COPD) and metabolic alkalosis, but no large randomized placebo-controlled trial is available to confirm this approach. OBJECTIVE: To determine whether acetazolamide reduces mechanical ventilation duration in critically ill patients with COPD and metabolic alkalosis. DESIGN, SETTING, AND PARTICIPANTS: The DIABOLO study, a randomized, double-blind, multicenter trial, was conducted from October 2011 through July 2014 in 15 intensive care units (ICUs) in France. A total of 382 patients with COPD who were expected to receive mechanical ventilation for more 24 hours were randomized to the acetazolamide or placebo group and 380 were included in an intention-to treat analysis. INTERVENTIONS: Acetazolamide (500-1000 mg, twice daily) vs placebo administered intravenously in cases of pure or mixed metabolic alkalosis, initiated within 48 hours of ICU admission and continued during the ICU stay for a maximum of 28 days. MAIN OUTCOMES AND MEASURES: The primary outcome was the duration of invasive mechanical ventilation via endotracheal intubation or tracheotomy. Secondary outcomes included changes in arterial blood gas and respiratory parameters, weaning duration, adverse events, use of noninvasive ventilation after extubation, successful weaning, the duration of ICU stay, and in-ICU mortality. RESULTS: Among 382 randomized patients, 380 (mean age, 69 years; 272 men [71.6%]; 379 [99.7%] with endotracheal intubation) completed the study. For the acetazolamide group (n = 187), compared with the placebo group (n = 193), no significant between-group differences were found for median duration of mechanical ventilation (-16.0 hours; 95% CI, -36.5 to 4.0 hours; P = .17), duration of weaning off mechanical ventilation (-0.9 hours; 95% CI, -4.3 to 1.3 hours; P = .36), daily changes of minute-ventilation (-0.0 L/min; 95% CI, -0.2 to 0.2 L/min; P = .72), or partial carbon-dioxide pressure in arterial blood (-0.3 mm Hg; 95% CI, -0.8 to 0.2 mm Hg; P = .25), although daily changes of serum bicarbonate (between-group difference, -0.8 mEq/L; 95% CI, -1.2 to -0.5 mEq/L; P < .001) and number of days with metabolic alkalosis (between-group difference, -1; 95% CI, -2 to -1 days; P < .001) decreased significantly more in the acetazolamide group. Other secondary outcomes also did not differ significantly between groups. CONCLUSIONS AND RELEVANCE: Among patients with COPD receiving invasive mechanical ventilation, the use of acetazolamide, compared with placebo, did not result in a statistically significant reduction in the duration of invasive mechanical ventilation. However, the magnitude of the difference was clinically important, and it is possible that the study was underpowered to establish statistical significance. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01627639.

Acid-base disorders: learning the basics.

Nutrition support practitioners should be confident in their ability to recognize and treat various metabolic and respiratory disorders encountered in daily practice. A clinician's comprehension of the underlying physiologic processes and/or exogenous causes that occur during acid-base disorders is essential when making therapeutic decisions regarding fluids, parenteral nutrition, and electrolyte management. This invited review will discuss basic metabolic and respiratory disorders while briefly addressing mixed acid-base disorders.

Normalizing CO2 in chronic hyperventilation by means of a novel breathing mask: a pilot study.

INTRODUCTION: Chronic idiopathic hyperventilation (CIH) is a form of dysfunctional breathing that has proven hard to treat effectively. OBJECTIVES: To perform a preliminary test of the hypothesis that by periodically inducing normocapnia over several weeks, it would be possible to raise the normal resting level of CO2 and achieve a reduction of symptoms. METHODS: Six CIH patients were treated 2 h a day for 4 weeks with a novel breathing mask. The mask was used to induce normocapnia in these chronically hypocapnic patients. Capillary blood gases and acid/base parameters [capillary CO2 tension (PcapCO2 ), pH, and standard base excess (SBE)] were measured at baseline and once each week at least 3 h after mask use, as well as spirometric values, breath-holding tolerance and hyperventilation symptoms as per the Nijmegen Questionnaire (NQ). RESULTS: The mask treatment resulted in a significant increase of resting PcapCO2 (+0.45 kPa, P = 0.028), a moderate increase in SBE (+1.4 mEq/L, P = 0.035) and a small reduction in daily symptoms (-3.8 NQ units, P = 0.046). The effect was most pronounced in the first 2 weeks of treatment. CONCLUSION: By inducing normocapnia with the breathing mask 2 h a day for 4 weeks, the normal resting CO2 and acid/base levels in chronically hyperventilating patients were partially corrected, and symptoms were reduced.

[Alkalosis]. / Zasadowica.

An elevation of arterial blood pH called alkalosis remains an underestimated condition in hospitalized patients. Serious alkalosis can be associated with high risk of death. The disorder can be caused by increased concentration of bicarbonate (metabolic alkalosis) or decreased concentration of carbon dioxide (respiratory alkalosis). In most cases of metabolic alkalosis it is generated by vomiting or diuretic use, whereas respiratory alkalosis is provoked by hyperventilation associated with respiratory or neurological disorder. Maintenance of metabolic alkalosis is possible only in patients with impaired renal base excretion which is most often produced by hypochloremia. In both respiratory and metabolic alkaloses treatment depends on the underlying factor. In hyperventilation syndrome is based on behavioral therapy. In most cases of metabolic alkalosis the administration of sodium and potassium chloride forms a substantial part of therapy.

Acid-base and electrolyte abnormalities during renal support for acute kidney injury: recognition and management.

Acute kidney injury (AKI) is associated with electrolyte and acid-base disturbances such as hyperkalemia, metabolic acidosis, hypocalcemia and hyperphosphatemia. The initiation of dialysis in AKI can efficiently treat these complications. The choice of dialysis modality can be made based on their operational characteristics to tailor the therapy according to the clinical scenario. Each dialysis modality can also trigger significant electrolyte and acid-base disorders, such as hypokalemia, hypophosphatemia and metabolic alkalosis, which may direct changes in fluid delivery and composition. Continuous techniques may be particularly useful in these situations as they allow more time for correction and to maintain balance. This review provides an overview of the electrolyte and acid-base disturbances occurring in AKI and after the initiation of dialysis and discusses therapeutic options in this setting.

Evaluation and treatment of respiratory alkalosis.

Respiratory alkalosis is the most frequent acid-base disturbance encountered in clinical practice. This is particularly true in critically ill patients, for whom the degree of hypocapnia directly correlates with adverse outcomes. Although this acid-base disturbance often is considered benign, evidence suggests that the alkalemia of primary hypocapnia can cause clinically significant decreases in tissue oxygen delivery. Mild respiratory alkalosis often serves as a marker of an underlying disease and may not require therapeutic intervention. In contrast, severe respiratory alkalosis should be approached with a sense of urgency and be aggressively corrected.

Diagnosis and treatment of simple acid-base disorders.

The ability to diagnose and treat acid-base disorders is an important component in the practice of the nutrition support clinician. A complete understanding of the basic principles of metabolic and respiratory disorders allows the practitioner to formulate educated decisions regarding fluids, parenteral nutrition salts, and the management of electrolytes. This review will discuss the diagnosis and treatment of common metabolic and respiratory disorders encountered in nutrition support practice.

Distúrbios do equilíbrio ácido-básico na prática clínica / Disorders of basic acid balance in clinical practice

Na prática médica, o distúrbio do equilíbrio ácido-básico possui grande relevância. Muitas funções metabólicas e fisiológicas dependem do pH. Alterações no pH em geral, decorrem de patologias concomitantes (EX: sepse, insuficiência renal, pneumonia, etc...) e, dependendo do grau de alteração, representam um risco eminente de vida ao paciente,O equilíbrio ácido – básico é um assunto de importância para todas as especialidades. Porém, seu entendimento prático é revestido de diversos graus de dificuldade.

[Diagnosis and treatment of disordered acid-base balance]. / Diagnostik und Therapie von Störungen des Säure-Basen-Haushalts. Warum Patienten sauer werden.

Differential diagnosis in disordered acid-base homeostasis is usually possible by measuring the pH, pCO2, pO2 and bicarbonate concentration, and enables differentiation between respiratory alkalosis and acidosis, and metabolic alkalosis and acidosis. Compensatory counter-regulation (respiratory or renal) can make correct assessment of the primary disorder problematic. Treatment of the underlying disease, in particular the provision of adequate oxygenation in respiratory disorders is of the essence. In chronic forms of metabolic acidosis, for example in chronic renal insufficiency and elderly patients, bicarbonate substitution should be initiated in order to prevent the negative effects on various organ systems. Sodium bicarbonate formulations that can be assimilated from the small bowel are especially tolerable and suitable.

Respiratory acid-base disorders.

Respiratory acid-base disorders, although infrequently diagnosed in veterinary medicine, can cause or contribute to adverse clinical outcomes. Recognition of the mechanisms and causes of respiratory acidosis and alkalosis can prompt clinical detection of the acid-base derangement, allowing for appropriate intervention.

Respiratory alkalosis and associated electrolytes in long-term ventilator dependent persons with tetraplegia.

STUDY DESIGN: A pilot case control study of the acid-base and electrolyte status in 30 long-term ventilator-dependent (LTVD) and 30 self ventilating persons with tetraplegia. OBJECTIVES: To assess the extent of respiratory alkalosis and screen for associated hypokalaemia, hypomagnesaemia and/or hypophosphataemia. SETTING: Medically stable persons with tetraplegia under the long-term care of the Southport Spinal Injuries Centre, England. METHODS: Blood gases and electrolytes were sampled from 30 control patients with tetraplegia and from 30 patients having been LTVD for more than 12 months. RESULTS: All the blood gas measurements in the LTVD group lay outside both the reference range and the 95% confidence intervals (CI) of the control group: pH 7.46 (0.06); PCO(2) 3.46 (1.1) kPa; bicarbonate 18.3 (3.8) and base excess -3.2 (2.8) mmol/l; PO(2) 13.8 (2.8) kPa (means and standard deviations). The serum potassium, magnesium, phosphate, and sodium means lay within the reference ranges but the potassium, phosphate and calcium were at or below the 95% CI of the control values. One patient on part-time ventilatory support having less bicarbonate compensation had low serum electrolytes during ventilation. CONCLUSION: There was no evidence of biochemical jeopardy from long-term mechanical hyperventilation although acutely administered hyperventilation has the potential to cause falls in serum potassium, magnesium and phosphate and so caution should be exercised in part-time ventilated persons. The full range of electrolytes should be assayed during stabilisation in LTVD and periodically thereafter. Hyperventilation helps to maintain good oxygenation in LTVD persons with paralysis and normal lungs. SPONSORSHIP: None.