Diagnostic Testing: Urine Studies and Genetics

Welcome to PICU Doc on Call, the podcast where we break down real-life cases from the pediatric intensive care unit and share practical insights for clinicians everywhere! I’m Dr. Monica Gray, and I’m joined by my co-host, Dr. Pradip Kamat.

Today, we’re diving into a fascinating case: a 13-year-old boy who suddenly developed muscle weakness and was found to have severe hypokalemia. After some detective work, he was diagnosed with familial hypokalemic periodic paralysis, a rare but important condition to recognize in the PICU.

We’ll discuss the genetic underpinnings, classic clinical features, and common triggers associated with this disorder. Additionally, we’ll guide you through the differential diagnosis, key management strategies, such as potassium supplementation, and explain why genetic testing is so crucial. We’ll also cover essential considerations for anesthesia and cardiac monitoring in these patients.

Whether you’re a pediatric intensivist or just interested in acute neuromuscular care, stick around for some practical pearls you can use on your next shift!

Show Highlights:

• Clinical case discussion of a 13-year-old male patient with muscle weakness and hypokalemia
• Diagnosis and management of familial hypokalemic periodic paralysis
• Genetic basis and mutations associated with hypokalemic periodic paralysis (CACNA1S and SCN4A)
• Physiological mechanisms underlying hypokalemic periodic paralysis
• Common clinical presentations and triggers for episodes of muscle weakness
• Differential diagnoses for muscle weakness and hypokalemia in pediatric patients
• Laboratory investigations to confirm hypokalemic periodic paralysis
• Treatment options for hypokalemic periodic paralysis, including potassium supplementation and prophylactic medications
• Importance of avoiding triggers and coordinating care with anesthesia

References:

• Fuhrman & Zimmerman - Textbook of Pediatric Critical Care Chapter 68: Weimer M et al. Acute neuromuscular disease and disorders page 840
• Rogers Textbook of Pediatric Intensive Care Medicine: Management of Sodium and Potassium Disorders. Pages 1876- 1883
• Reference 1: Weber F, Lehmann-Horn F. Hypokalemic Periodic Paralysis. 2002 Apr 30 [Updated 2018 Jul 26]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2025. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1338/
• Reference 2: Channelopathies. Clin Exp Pediatr. 2014;57(1):1-18.   Published online January 31, 2014**DOI: https://doi.org/10.3345/kjp.2014.57.1.1**
• Reference 3: Statland JM, Fontaine B, Hanna MG, Johnson NE, Kissel JT, Sansone VA, Shieh PB, Tawil RN, Trivedi J, Cannon SC, Griggs RC. Review of the Diagnosis and Treatment of Periodic Paralysis. Muscle Nerve. 2018 Apr;57(4):522-530.