Causes and Clinical Features of Metabolic Alkalosis

Clinical Manifestations: Neurological Symptoms

Metabolic alkalosis occurs due to an elevation in serum bicarbonate levels, leading to an increase in blood pH. This condition can result from various causes, including excessive loss of hydrogen ions, increased bicarbonate retention, or abnormal metabolic function.

Causes of Metabolic Alkalosis

• Gastrointestinal loss: Excessive vomiting or nasogastric suction leads to depletion of hydrochloric acid, increasing serum bicarbonate.
• Renal dysfunction: Hyperaldosteronism and diuretic use enhance bicarbonate retention.
• Exogenous bicarbonate administration: Overconsumption of alkalizing agents raises systemic pH.

Neurological Symptoms

Metabolic alkalosis affects neurological function due to alterations in ion gradients across neurons, leading to various symptoms:

• Confusion: Impaired cognitive function and disorientation.
• Muscle twitching: Neuromuscular excitability due to electrolyte imbalance.
• Tetany: Prolonged muscle contraction caused by calcium shifts.
• Seizures: Severe alkalosis may lead to convulsions due to increased neuronal excitability.
• Paresthesia: Tingling sensations in extremities due to impaired ion exchange.

Diagnosis and Management

Metabolic alkalosis is diagnosed via arterial blood gas analysis, revealing elevated bicarbonate and compensatory hypoventilation. Management includes addressing the underlying cause, electrolyte correction, and, in severe cases, acidifying agents.