Nephrology Case Presentation Douglas Stahura DO 17 September 2002.
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Transcript of Nephrology Case Presentation Douglas Stahura DO 17 September 2002.
Learning Objectives
Rhabdomyolysis– Definition– Acute renal failure– Pathophysiology– Clinical presentation– Treatment– Case studies
Case 1
56 y/o CF presented with Acute MI, developed pulseless right lower extremity. Normal renal function.
Case 2
48 y/o CM found “down” after 3 days in his kitchen. Unresponsive, hypotensive, anuric.
Na 185, Glucose 2500, CPK 18,000
Case 3
62 y/o “gentleman” found by police in park unresponsive and smelling of alcohol.
Thin, cachetic, hypotensive. Bun 22, Creatinine = 7.6, CPK=22,000
Case 4
19 y/o AAF presents with weakness and falls. 3rd ED visit in 7 weeks.
K=2.8, CPK=19,000, BUN=55, Creatinine=6.2
Case 5
18 y/o CM presents by squad from local arena where “The Who” reunion tour kicked off. “Festival seating” caused a rush at the gate.
Pt has extensive bruising and crush injuries.
Case 6
Earthquake levels 4 story apartment building trapping 18 people. The injured present to trauma stations from 1 to 30 hours after the collapse.
Case 7
76 y/o AAM presents with nausea and anorexia x2 weeks. Now feels week. Dark urine.
PMH: CAD, DM2, HTN BUN=110, creatinine=8.2, CPK 42,000
Case 9
17 y/o AAF presents from home by EMS in seizure. Further efforts require 90 minutes to gain control of her convulsions.
Case Studies
All the above cases were complicated by acute renal failure induced by endogenous toxicity to myoglobin released by damage to muscle cells – rhabdomyolysis
Definition
Rhabdomyolysis– Muscle necrosis– Release of intracellular constituents of muscle cells
Severity– Asymptomatic enzyme elevation– Life threatening enzyme elevation, electrolyte
disturbances, acute renal failure
Myoglobinuric Acute Renal Failure
Classic description from 1941 when Bywaters described “crush syndrome” in which victims of the London Blitz trapped and crushed in bombed buildings would, despite rescue, die of uremia soon afterwards
Myoglobinuric Acute Renal Failure
Myoglobin – heme containing protein – Freely filtered at the glomerulus
Proximal endocytic reabsorption is overwhelmed
Delivery to distal tubule is increased
Myoglobinuric Acute Renal Failure
Acute Tubular Necrosis (ATN) is provoked– Intrarenal vasoconstriction by scavenging NO– Third spacing of fluids leads to hypovolemia– Obstructing tubular casts, especially in acidic urine– Iron may be directly toxic
Trauma Crush, Burn, Electric shock
Ischemia Vascular occlusion, compression,substance abuse (EtOH, heroin)
Exercise Marathon, convulsions
Metabolic Hypokalemia, Hypophosphatemia
Infection Hyperthermia, virus, bacterial
Drugs Fibrates, HMG CoA reductase inhibitors
Inflammatory Polymyositis
Genetic McArdle’s , PFK-1 deficiency, carnitine palmityl transferase deficiency
Clinical Findings
Muscle pain is variable Urinalysis
– Dipstick strongly positive for blood– Few if any RBC’s on microscopic– Color may be red-brown-black
CPK elevated– General correlation of CPK with ARF (>16,000)
Clinical Findings
Creatinine– Serum levels high out of proportion to BUN
Electrolytes– Potassium, Uric acid, Lactic acid, phosphorous
released by necrotic myocytes– Hypocalcemia due to calcium-phosphate
precipitation
Treatment
Fluid replacement– Saline infusion @ 1.5 L/hr
Forced diuresis +/- urinary alkalinization– Goal is suggested as 300 cc/hr– .45 NS + 10 gm Mannitol + 40 Meq NaHCO3
Treatment
Mannitol– Diuresis maintains high flow rate through tubules – Possible free radical scavenging effect
Alkalinization– May provide theoretical advantage in preventing
conversion of myoglobin to methemoglobin– May cause precipitation of calcium phosphate in
urinary system
Treatment
Role of acute dialysis– Does not remove myoglobin– May be needed to control the severity of
hyperkalemia– CVVHDF may not be able to manage
Case 1
56 y/o CF presented with Acute MI, developed pulseless right lower extremity. Normal renal function.
Pt has occluded aorto-bifem bypass, pulseless, cold, pale-to-blue, painful leg.
Case 2
48 y/o CM found “down” after 3 days in his kitchen. Unresponsive, hypotensive, anuric.
Na 185, Glucose 2500, CPK 18,000 Pt lay on the floor in his kitchen >72 hours in
one position. Has muscle breakdown on right side of head, shoulder, arm, hip leg.
Case 3
62 y/o “gentleman” found by police in park unresponsive and smelling of alcohol.
Thin, cachetic, hypotensive. Bun 22, Creatinine = 7.6, CPK=22,000
Chronic alcoholics have pre-existing hypophosphatemia– Increased renal losses, damage to proximal epi– Decreased GI intake/absorption– Muscle depletion of phosphorous
Case 3
Superimposed second metabolic insult result in hypophosphatemic rhabdo (ATP theory)
Respiratory alkalosis – prolonged intense hyperventilation as seen with EtOH withdrawal– Increase in pH activates glycolysis increasing
phosphorylated compounds within the cell. Serum phosphorous falls precipitously
Case 4
19 y/o AAF presents with weakness and falls. 3rd ED visit in 7 weeks.
K=2.8, CPK=19,000, BUN=55, Creatinine=6.2 Hypokalemic periodic paralysis can be
associated with hypophosphatemia.
Case 5
18 y/o CM presents by squad from local arena where “The Who” reunion tour kicked off. “Festival seating” caused a rush at the gate.
Pt has extensive bruising and crush injuries. Classic crush syndrome, can be associated
with compartment syndrome
Case 6
Earthquake levels 4 story apartment building trapping 18 people. The injured present to trauma stations from 1 to 30 hours after the collapse.
Classic crush syndrome Fluids initiated in the field to replete volume
and force diuresis may be of significant benefit even before a pt is freed, or crushed limb is reperfused.
Case 7
76 y/o AAM presents with nausea and anorexia x2 weeks. Now feels week. Dark urine.
PMH: CAD, DM2, HTN BUN=110, creatinine=8.2, CPK 42,000 Pt has dysmetabolic syndrome Hyperlipidemia treated with statin and fibrate
Case 8
27 y/o Air Force Captain presents on Monday with red discolored urine that started Sunday.
Previously healthy, no meds, no previous urinary complaints (hematuria/proteinuria)
You happen to remember that WPAFB held annual Air Force marathon on Saturday.
Case 9
17 y/o AAF presents from home by EMS in seizure. Further efforts require 90 minutes to gain control of her convulsions.
Intense electrical stimulation of muscles can cause rhabdo