Metabolic and respiratory alkalosis: Clinical (To be retired)


00:00 / 00:00



Metabolic and respiratory alkalosis: Clinical (To be retired)

Medical and surgical emergencies

Cardiology, cardiac surgery and vascular surgery

Advanced cardiac life support (ACLS): Clinical (To be retired)

Supraventricular arrhythmias: Pathology review

Ventricular arrhythmias: Pathology review

Heart blocks: Pathology review

Coronary artery disease: Clinical (To be retired)

Heart failure: Clinical (To be retired)

Syncope: Clinical (To be retired)

Pericardial disease: Clinical (To be retired)

Valvular heart disease: Clinical (To be retired)

Chest trauma: Clinical (To be retired)

Shock: Clinical (To be retired)

Peripheral vascular disease: Clinical (To be retired)

Leg ulcers: Clinical (To be retired)

Aortic aneurysms and dissections: Clinical (To be retired)

Cholinomimetics: Direct agonists

Cholinomimetics: Indirect agonists (anticholinesterases)

Muscarinic antagonists

Sympathomimetics: Direct agonists

Sympatholytics: Alpha-2 agonists

Adrenergic antagonists: Presynaptic

Adrenergic antagonists: Alpha blockers

Adrenergic antagonists: Beta blockers

ACE inhibitors, ARBs and direct renin inhibitors

Loop diuretics

Thiazide and thiazide-like diuretics

Calcium channel blockers

cGMP mediated smooth muscle vasodilators

Class I antiarrhythmics: Sodium channel blockers

Class II antiarrhythmics: Beta blockers

Class III antiarrhythmics: Potassium channel blockers

Class IV antiarrhythmics: Calcium channel blockers and others

Positive inotropic medications

Antiplatelet medications

Dermatology and plastic surgery

Blistering skin disorders: Clinical (To be retired)

Bites and stings: Clinical (To be retired)

Burns: Clinical (To be retired)

Endocrinology and ENT (Otolaryngology)

Diabetes mellitus: Clinical (To be retired)

Hyperthyroidism: Clinical (To be retired)

Hypothyroidism and thyroiditis: Clinical (To be retired)

Parathyroid conditions and calcium imbalance: Clinical (To be retired)

Adrenal insufficiency: Clinical (To be retired)

Neck trauma: Clinical (To be retired)


Mineralocorticoids and mineralocorticoid antagonists


Gastroenterology and general surgery

Abdominal pain: Clinical (To be retired)

Appendicitis: Clinical (To be retired)

Gastrointestinal bleeding: Clinical (To be retired)

Peptic ulcers and stomach cancer: Clinical (To be retired)

Inflammatory bowel disease: Clinical (To be retired)

Diverticular disease: Clinical (To be retired)

Gallbladder disorders: Clinical (To be retired)

Pancreatitis: Clinical (To be retired)

Cirrhosis: Clinical (To be retired)

Hernias: Clinical (To be retired)

Bowel obstruction: Clinical (To be retired)

Abdominal trauma: Clinical (To be retired)

Laxatives and cathartics


Acid reducing medications

Hematology and oncology

Blood products and transfusion: Clinical (To be retired)

Venous thromboembolism: Clinical (To be retired)

Anticoagulants: Heparin

Anticoagulants: Warfarin

Anticoagulants: Direct factor inhibitors

Antiplatelet medications


Infectious diseases

Fever of unknown origin: Clinical (To be retired)

Infective endocarditis: Clinical (To be retired)

Pneumonia: Clinical (To be retired)

Tuberculosis: Pathology review

Diarrhea: Clinical (To be retired)

Urinary tract infections: Clinical (To be retired)

Meningitis, encephalitis and brain abscesses: Clinical (To be retired)

Bites and stings: Clinical (To be retired)

Skin and soft tissue infections: Clinical (To be retired)

Protein synthesis inhibitors: Aminoglycosides

Antimetabolites: Sulfonamides and trimethoprim

Antituberculosis medications

Miscellaneous cell wall synthesis inhibitors

Protein synthesis inhibitors: Tetracyclines

Cell wall synthesis inhibitors: Penicillins

Miscellaneous protein synthesis inhibitors

Cell wall synthesis inhibitors: Cephalosporins

DNA synthesis inhibitors: Metronidazole

DNA synthesis inhibitors: Fluoroquinolones

Herpesvirus medications



Miscellaneous antifungal medications

Anthelmintic medications


Anti-mite and louse medications

Nephrology and urology

Hypernatremia: Clinical (To be retired)

Hyponatremia: Clinical (To be retired)

Hyperkalemia: Clinical (To be retired)

Hypokalemia: Clinical (To be retired)

Metabolic and respiratory acidosis: Clinical (To be retired)

Metabolic and respiratory alkalosis: Clinical (To be retired)

Toxidromes: Clinical (To be retired)

Medication overdoses and toxicities: Pathology review

Environmental and chemical toxicities: Pathology review

Acute kidney injury: Clinical (To be retired)

Kidney stones: Clinical (To be retired)

Adrenergic antagonists: Alpha blockers

Neurology and neurosurgery

Stroke: Clinical (To be retired)

Seizures: Clinical (To be retired)

Headaches: Clinical (To be retired)

Traumatic brain injury: Clinical (To be retired)

Neck trauma: Clinical (To be retired)

Lower back pain: Clinical (To be retired)

Spinal cord disorders: Pathology review

Anticonvulsants and anxiolytics: Barbiturates

Anticonvulsants and anxiolytics: Benzodiazepines

Nonbenzodiazepine anticonvulsants

Migraine medications

Osmotic diuretics

Antiplatelet medications


Opioid agonists, mixed agonist-antagonists and partial agonists

Opioid antagonists

Pulmonology and thoracic surgery

Asthma: Clinical (To be retired)

Chronic obstructive pulmonary disease (COPD): Clinical (To be retired)

Venous thromboembolism: Clinical (To be retired)

Acute respiratory distress syndrome: Clinical (To be retired)

Pleural effusion: Clinical (To be retired)

Pneumothorax: Clinical (To be retired)

Chest trauma: Clinical (To be retired)

Bronchodilators: Beta 2-agonists and muscarinic antagonists

Pulmonary corticosteroids and mast cell inhibitors

Rheumatology and orthopedic surgery

Joint pain: Clinical (To be retired)

Anatomy clinical correlates: Clavicle and shoulder

Anatomy clinical correlates: Axilla

Anatomy clinical correlates: Arm, elbow and forearm

Anatomy clinical correlates: Wrist and hand

Anatomy clinical correlates: Median, ulnar and radial nerves

Anatomy clinical correlates: Bones, joints and muscles of the back

Anatomy clinical correlates: Hip, gluteal region and thigh

Anatomy clinical correlates: Knee

Anatomy clinical correlates: Leg and ankle

Anatomy clinical correlates: Foot

Acetaminophen (Paracetamol)

Non-steroidal anti-inflammatory drugs


Opioid agonists, mixed agonist-antagonists and partial agonists

Antigout medications


Metabolic and respiratory alkalosis: Clinical (To be retired)

USMLE® Step 2 questions

0 / 6 complete


USMLE® Step 2 style questions USMLE

of complete

A 3-week-old infant is brought to the emergency department because of projectile vomiting after feeding. She has vomited like this for three days, but her mother says the infant has a good appetite despite losing weight. The mother remembers that there may have been a similar problem with the baby's paternal uncle, who needed surgery when he was an infant. Her temperature is 37.0°C (98.6°F), pulse is 140/min, respirations are 45/min, and blood pressure is 70/45 mm Hg. The abdomen is non-tender and non-distended, but a small mass can be palpated below the costal margin. Which of the following findings is most likely a characteristic sign of this condition?


Content Reviewers

Rishi Desai, MD, MPH


Elizabeth Nixon-Shapiro, MSMI, CMI

Kaia Chessen, MScBMC

Anca-Elena Stefan, MD

In metabolic alkalosis, the blood pH is above 7.45, and it’s due to a bicarbonate or HCO3 concentration in the blood over 27 mEq/L.

Individuals with metabolic alkalosis can be asymptomatic or can cause hypoventilation, due to respiratory compensation.

Associated symptoms are related to the underlying cause.

For example, if there’s a history of vomiting, nasogastric suction, laxative abuse or use of loop or thiazide diuretics, then there may be symptoms of dehydration.

The diagnosis is usually based on an ABG, and in addition to a pH above 7.45, and HCO3 levels above 27 mEq/L, if there’s respiratory compensation, the pCO2 is usually above 45 mm Hg.

Generally, for every 1 mEq/L elevation in HCO3 above the normal level of 27 mEq/L, pCO2 increases by about 0.7 mm Hg above the normal level of 45 mm Hg, but pCO2 doesn’t usually rise above 55 mm Hg, regardless of HCO3 levels.

Let’s take an example and say that HCO3 level is 30 mEq/L - so it’s 3 mEq/L above the baseline.

This means that our pCO2 should be 45- which is the baseline for pCO2- plus 3 times 0.7, which equals 47.1 mm Hg.

In addition, electrolytes are also done to see if there’s any imbalances, like hypokalemia.

Now, if the cause of metabolic alkalosis isn’t obvious from the history, then a spot urine chloride is measured.

If the urine chloride is below 20 mEq/L, that suggests volume depletion from a variety of causes like vomiting which leads to loss of hydrochloric acid, so the treatment is really aimed at addressing the underlying cause of vomiting.

A related cause is aggressive nasogastric suction, so the treatment is stopping or slowing the removal of gastric secretions.

Another cause is loop or thiazide diuretics which block hydrogen ion and chloride ion reabsorption in the kidney.

Chloride is a negatively charged ion, so loss of chloride leads to increased reabsorption of bicarbonate to compensate for the loss.

The loss of chloride causes the urine chloride to go above 20 mEq/L, and a lot of hydrogen is lost-leading to metabolic alkalosis.


  1. "Clinical manifestations and evaluation of metabolic alkalosis" undefined (undefined)
  2. "Simple and mixed acid-base disorders" undefined (undefined)
  3. "Hyperventilation syndrome in adults" undefined (undefined)

Copyright © 2023 Elsevier, except certain content provided by third parties

Cookies are used by this site.

USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.