Nephrolithiasis

Rule out an infected obstruction - Fever, chills, or hemodynamic instability with an obstructing stone means an infected, obstructed system. That is an emergency decompression on a septic patient, not an elective lithotripsy.

Check renal function before dosing - Basic or comprehensive metabolic panel plus urinalysis. An obstructing stone can drive creatinine up acutely, and recurrent stone formers carry a higher rate of chronic kidney disease and end-stage renal failure.

Expect the metabolic comorbidities - Stone disease tracks with hypertension, diabetes, obesity, and cardiovascular disease, so work up the heart and the glucose accordingly.

Shock wave lithotripsy is more stimulating than it looks - Fragmenting the stone hurts. Get the patient deep before the machine starts. GLMA, a propofol MAC, or conscious sedation with small doses of midazolam and fentanyl plus EMLA over the shock site all work.

Dysrhythmias during ESWL - The shock wave can trigger dysrhythmias, including R-on-T. Keep the ECG where you can see it.

ESWL contraindications - Pregnancy and high bleeding risk are absolute. Pacemaker or ICD, untreated UTI, distal obstruction, renal artery or aortic calcification, and morbid obesity are relative.

Set the room up first - The lithotripter is loud enough that hearing protection is used for patient and staff, and the machine often sits far from the ventilator, so plan circuit and line extensions before you start.

PCNL means prone and fluoroscopy - GETT, prone or lateral. Keep the neck neutral, IVs out of the antecubital fossa because the arms flex, eyes and ears checked repeatedly for pressure, and lead aprons and thyroid shields available for the C-arm.

Cord-injured patients coming for stone surgery - Paraplegic and quadriplegic patients can hyperreflex during percutaneous nephrolithotomy. Watch for flushing, headache, and nasal stuffiness.

Postoperative pain and hematuria - Post-ESWL pain is moderate, and hematuria with skin petechiae or bruising is expected. NSAIDs are the workhorse for stone pain because they cut ureteral smooth-muscle spasm.

Nephrolithiasis is the formation of crystal concretions — kidney stones — in the urinary tract, and it is the most common condition affecting the urinary system, hitting roughly 12% of the population worldwide. Stones form when urine becomes supersaturated with calcium, phosphate, oxalate, uric acid, or cystine, usually against a background of low urine volume; the solutes precipitate, nucleate, and grow. About 80% are calcium stones, most of them calcium oxalate or calcium phosphate; the rest are uric acid, struvite, or cystine.

A stone sitting in the kidney is silent. Pain starts once it enters the ureter, where peristalsis of the smooth muscle against the stone produces colicky flank pain radiating to the groin, nausea, vomiting, and hematuria. What matters perioperatively is what an unpassed stone does: obstruction with hydronephrosis and acute renal failure, or infection behind the obstruction that progresses to pyelonephritis and shock and needs emergency decompression.