A Taiwanese woman in her 70s with pre-existing chronic kidney disease was rushed to hospital last week after her family’s well-intentioned cold remedy—daily servings of pork rib soup and chicken essence—sent her potassium levels soaring to nearly double the safe limit, causing a dangerous heart rhythm disorder. Doctors at a local medical center diagnosed the patient with junctional bradycardia and hyperkalemia, requiring immediate dialysis to stabilize her condition.
The Harmful ‘Care’
According to Taiwan-based nephrologist Dr. Lin Hsuan-Jen, who shared the case on his professional Facebook page, the woman had fallen ill during a cold snap. Her family, eager to help her recover, prepared a bowl of slow-cooked pork rib soup with every meal and gave her chicken essence afterward. Within days, the patient grew increasingly lethargic, began complaining of dizziness, and could no longer walk steadily. Alarmed, her relatives called an ambulance.
Emergency tests revealed a potassium level of 8.4 mmol/L—well above the normal range of 3.5 to 4.5 mmol/L. An electrocardiogram showed junctional bradycardia, a condition where the heart’s natural pacemaker fails and backup cells take over, producing a slow, inefficient heartbeat. “This is a classic sign of severe hyperkalemia,” Dr. Lin explained. “The electrical signals in the heart become blocked, and the organ can’t pump blood effectively. If left untreated, it can be fatal.”
Understanding the Danger: Hyperkalemia and Heart Rhythm
Potassium is essential for nerve and muscle function, including the heart’s electrical system. In healthy individuals, excess potassium is filtered by the kidneys and excreted in urine. But for patients with chronic kidney disease—particularly stage 3 or above—this process is impaired. When they consume high-potassium foods, the mineral accumulates in the blood, disrupting the heart’s conduction pathways.
Dr. Lin described the heart’s electrical wiring as a circuit: normal signals start at the sinoatrial node, travel to the atria, then through the atrioventricular node to the ventricles. High potassium jams this signal, forcing the heart to rely on slower, abnormal pacemaker cells. The result is junctional bradycardia, which can cause symptoms from mild weakness and dizziness to cardiac arrest.
Dietary Guidelines for Kidney Patients
The incident underscores a critical message for renal patients and their caregivers: not all nourishing foods are safe. Broths, soups, and supplements that are traditionally considered restorative can be dangerously high in potassium.
Dietitian Mo Ying-Shan from Hong Kong Sanatorium & Hospital advises that kidney patients can still enjoy soups, but must choose ingredients carefully. She recommends avoiding:
- Slow-cooked (老火) soups – prolonged boiling leaches potassium, phosphorus, and protein from meat and vegetables into the broth.
- Bone broths and meat extracts – pork rib soup, chicken essence, and concentrated stock are potent potassium sources.
- High-potassium vegetables – leafy greens like spinach, kale, and Swiss chard; also root vegetables like potatoes and sweet potatoes (unless double-boiled and drained).
Instead, patients can opt for lighter, short-cooked soups with low-potassium ingredients.
Low-Potassium Soup Recipes for Safe Comfort
The dietitian offers four simple, kidney-friendly soup options that provide warmth and flavor without the risk:
1. Chayote and Red Date Soup (佛手瓜蜜棗湯)
- 2 chayote, peeled and cubed
- 1 carrot, peeled and cubed
- 3 red dates (蜜棗)
- 150g lean pork or blanched chicken breast (optional)
- 1.5 liters water
- Simmer for 1 hour; season lightly with salt if desired.
2. Carrot, Apple, and Longan Soup (紅蘿蔔蘋果圓肉湯)
- 1 carrot, cubed
- 1 apple, cored and cubed (skin on)
- 5–10g dried longan flesh (桂圓肉)
- 2 red dates (optional)
- 1.5 liters water
- Boil then simmer 40–50 minutes; no salt needed.
3. Mustard Greens Soup (芥菜膽湯)
- 300g mustard greens (芥菜膽), washed and chopped
- 2 slices ginger
- 50g lean pork slices or tofu
- 1 liter water
- Cook 10 minutes after adding greens; keep seasoning minimal.
4. Corn and Egg White Soup (粟米蛋花湯)
- 1 fresh corn cob, kernels removed (or canned corn, drained)
- 1 egg white, beaten
- 800 ml water
- Cornstarch slurry for thickening (optional)
- Simmer corn kernels 15 minutes, thicken, then slowly pour in egg white while stirring; salt to taste.
Broader Impact and Next Steps
This case highlights a common but preventable danger for the growing population of chronic kidney disease patients worldwide. Dr. Lin urges families to consult a renal dietitian before preparing “tonic” foods. “What seems like comfort can be a toxin,” he warns. For patients, regular monitoring of blood potassium levels is essential, especially during illness when hydration and appetite change.
Hong Kong readers with kidney concerns can seek guidance from hospital renal nutrition services or refer to resources from the Hong Kong Kidney Foundation. A simple change—like replacing bone broth with a low-potassium vegetable soup—could mean the difference between recovery and an emergency room visit.