Recently, parents often ask me if their children are suffering from urinary stones and if it is life-threatening. The reason is that their child “consumed Sanlu brand formula”.
This kind of panic is actually unnecessary, because after all, children with stones are very few, and most stones can be excreted by themselves. Happily, the Ministry of Health and the Chinese Medical Association organized experts on September 12, 2008 to develop a treatment plan for urinary stones in infants and children associated with the consumption of contaminated Sanlu brand infant formula.
The program provides guidance on clinical manifestations, diagnostic points, differential diagnosis, treatment, follow-up and other aspects for the proper treatment and rescue of related children. The following is the full text of the program.
I. Clinical manifestations
(a) Unexplained crying, especially during urination, which may be accompanied by vomiting.
(ii) Hematuria under the naked eye or microscope.
(iii) Acute obstructive renal failure, manifested as oliguria or anuria.
(iv) Stones may be excreted in the urine, such as male infants with stones obstructing the urethra may manifest as painful urination and difficulty in urination.
(v) There may be hypertension, edema, and percussion pain in the kidney area.
II. Diagnostic points
(A) History of feeding Sanlu infant formula.
(B) One or more of the above clinical manifestations.
(C) Laboratory tests: routine urine (visual or microscopic hematuria), blood biochemistry, liver and kidney function, urinary calcium/urinary creatinine (generally normal), urinary red blood cell morphology (non-glomerular-derived hematuria), parathyroid hormone measurement (generally normal).
(iv) Imaging: Urological ultrasound is preferred. If necessary, CT scan of the abdomen and intravenous urography (contraindicated in the absence of urine or renal failure), and renal nuclide scan is feasible to evaluate fractional renal function.
Ultrasound features of urinary stones in infants and children due to consumption of contaminated Sanlu brand infant formula.
General features: both kidneys are enlarged; parenchymal echogenicity is enhanced, and the parenchyma is mostly of normal thickness; the renal pelvis and calyces are mildly dilated, and the calyces are rounded; if the obstruction is located in the ureteral lumen, the ureter is dilated above the obstruction point; in some cases, the perinephric fat pad and the soft tissue around the ureter are edematous; with the development of the disease, the pelvic wall and ureteral wall may appear secondary edematous thickening changes; in a few patients, a small amount of ascites can be detected.
Features of stones: most of the stones involve bilateral collecting system and bilateral ureters; ureteral stones are mostly located at the pelvic-ureteral junction, ureter across the iliac artery segment and ureteral-vesical junction; stones have a crumb-like accumulation and involve a large area with a faint posterior shadow, most of them are different from calcium oxalate stones, and the posterior edge of stones can be detected; urinary tract obstruction due to stones is more complete.
Differential diagnosis
(a) Differentiation of hematuria: pay attention to exclude glomerular-derived hematuria.
(B) Differentiation of stones: stones are usually X-ray negative stones, which are not visible on urinary X-ray, and can be differentiated from positive stones such as calcium oxalate and phosphate, which are not X-ray positive.
(C) Identification of acute renal failure, paying attention to the exclusion of pre-renal and renal renal failure.
IV. Treatment
(a) Immediately stop using Sanlu brand infant formula.
(B) Conservative medical treatment: rehydration, alkalinization of urine to promote the discharge of stones; correction of water, electrolytes and acid-base balance disorders. During the course of conservative treatment, urinary routine, blood biochemistry and renal function should be closely checked, and ultrasound should be repeated (especially pay attention to the degree of expansion of renal pelvis and ureter and changes in stone shape and location). As the stones are loose or sand-like, they are more likely to be expelled on their own.
(iii) Treatment of combined acute renal failure: Firstly, life-threatening conditions such as hyperkalemia should be corrected, such as the application of sodium bicarbonate and insulin, and if conditions are available, blood purification, peritoneal dialysis and other methods should be taken as early as possible, and surgical intervention should be performed to relieve stone obstruction if necessary.
(iv) Surgical treatment: If the stone morphology and location do not change by conservative medical treatment, and the hydronephrosis and renal damage are aggravated, or if renal failure does not allow hemodialysis or peritoneal dialysis, the obstruction can be removed surgically. Cystoscopic retrograde ureteral cannula drainage, percutaneous nephrostomy drainage, surgical excision and stone extraction, percutaneous nephrolithotomy, etc. are available. Because the stones are loose, uric acid is the main component, and the patient is an infant, extracorporeal shock wave lithotripsy has greater limitations and should be considered carefully.
After treatment, stone obstruction is relieved, general condition is improved, renal function is normalized, and urination can be discharged. Follow-up after discharge: urinary routine; urological ultrasound; renal function test; intravenous pyelogram if necessary.
Remind the child’s parents to note: breast milk is the best food for infants and children, and breastfeeding helps prevent kidney stones in infants.
Breastfeeding not only helps the infant, but is also beneficial to the mother, it can reduce the incidence of breast cancer.