emergencies in renal failure and dialysis patients tintinalli chapter 93
TRANSCRIPT
Emergencies in Renal Failure and Dialysis Patients
Tintinalli chapter 93
• ESRD: irreversible loss of renal function, accumulation of toxins and loss of internal homeostasis.
• Uremia: clinical syndrome resulting from ESRD.
Epidemiology
• 1999=89,252 new cases/424,179 patients being tx for ESRD
• Causes: DM=#1, HTN=#2• Therapy: dialysis=70%
– transplants=30%
• ESRD deaths: 50% cardiac causes. – 10-25% infectious
• Survival rates for 1,2,5 yrs= 79, 65, 34 % respectively
Pathophysiology of Uremia
• Excretory Failure: causes >70 chemicals to elevate. Urea= major breakdown of proteins. Limit protein intake
• Biosynthetic Failure: loss of hormones 1,25(OH)3 vit D3 and erythropoietin. – 85% of erythropoietin produced by kidney.– Vit. D3 deficiency= secondary
hyperparathyroidism, renal bone disease.
Pathophysiology of Uremia
• Regulatory Failure: over secretion of hormones , disruption of normal feedback mechanisms
Clinical Features of Uremia
• Neurologic complications:
• Subdural hematoma: 3.5% of ESRD, HTN, head trauma, bleeding dyscrasias, anticoagulants, ultrafiltration.
• Uremic Encephalopathy: nonspecific centreal neurologic symptoms, responds to dialysis.
• Neurologic complications: • Dialysis Dementia: like uremic
encephalopathy but progressive and fatal, seen after 2 years on dialysis
• Peripheral neuropathy: >50% of HD patients. “glove and stocking pattern”, improves after transplant
• Autonomic dysfunction: common; dizzy, impotence, bowel dysfunction.
• Cardiovascular complications: prevalence is greater in ESRD
• d/t pre-existing conditions, uremia, toxins, high lipids, homocystine, hyperparathyroidism, dialysis related conditions
• General population• CAD: 12%• LV hypert. 20%• CHF 5%
• ESRD• 40%• 75%• 40%
• Creatine protein Kinase &MB, Troponin I and T…….NOT significantly elevated in patients undergoing regular dialysis, have been shown to be specific markers in these patients.
• HTN: 80-90% of ESRD starting dialysis. d/t volume, vasopressor effects of kidney, RAS system. Tx initially w/ volume control
• CHF: HTN #1 cause in ESRD.
• Uremic cardiomyopathy: dx of exclusion when other causes of CHF ruled out.
• Pulmonary Edema: fluid overload, MI.– Tx w/ O2, nitrates, ACE inhib, morphine,
diuretics. Can also use phlebotomy, dialysis.
• Cardiac Tamponade: rarely w/ classic presentation of low BP, muffled sounds and JVD.– Echocardiography, pericardiocentisis
• Pericarditis/ Uremic Pericarditis:
• Uremic more common=75%
• Fluid overload, abnl platelet function, ↑ fibrinolytic and inflammatory cell activity
• Friction Rubs= louder, palpable, persist after metabolic abnormality resolved
• BUN always>60 mg/dl
• Absent EKG changes
• Dialysis related percarditis: recurrent, most common type during dialysis. More common adhesions and fluid loculations
• ESRD w/ pericarditis= 8%
• Tx w/ dialysis
• Avg survival without dialysis= 1 month
• Hematologic Complications:
• Anemia: low erythropoietin, blood loss from dialysis, ↓ RBC survival times– Normocytic, normochromic– Hct stabilizes @ 15-20 without tx.– Tx=erythropoietin
• Bleeding diathesis: ↑ risk of GI bleed, subdural.– Can try tx with desmopressin
• Immunologic deficiency: leukocyte chemotaxis and phagocytosis decreased in uremic state. – Dialysis does not help immune function.
• GI complications:
• Anorexia, nausea, vomiting=common in uremia
• Increased GI bleeding
• Chronic constipation
• Ascites from portal HTN, polycystic liver ds., fluid overload.
• Renal Bone Disease:
• Systemic calcification; ↓ GFR=↑ serum phosphate levels. – Pseudogout, metastatic calcification of
tissues, vessels. – Tx=low Ca dialysate and phosphate-binding
gels
• Hyperparathyroidism (Osteitis Fibrosa Cystica); – ↓ ionized Ca=↑ PTH= high bone turnover,
weak bones. – Tx=phosphate binding gels, Vit D3
replacement, subtotal parathyroidectomy
• Osteomalacia; defect in bone calcification
• d/t Vit.D3 deficiency and aluminum intoxication
• Weakened bones, muscle pains, weakness
• Low PTH, ow to normal alkaline phosphate levels, ↑ serum aluminum
• Tx= desferrioxamine
• Β2-Microglobulin amyloidosis:
• Pts >50 yrs old, on dialysis >10 yrs
• Amyloid deposits in GI tract, bones, joints.
• Complications; GI perfs, bone fx’s, carpal tunnel, rotator cuff tears.
• Pts w/ amyloidosis have ↑ mortality rates
Hemodialysis
• Uses ultrafiltration and clearance to replace nephron.
• Solute removal depends on filter pore size and concentration gradient
• Heparin 1000-2000 units typically used
• Sessions take @ 3-4 hrs.
Vascular Access Complications
• Types of Access:
• 1. A-V fistula
• 2. Vascular graft: higher complication rates, shorter functional lifes.
• 3. Tunnel-cuffed catheters; Hickman, Quinton
• Thrombosis and Stenosis of Access:
• Most common complication
• Loss of bruit and thrill
• Stenosis / thrombosis: not Emergencies= tx w/in 24 hours.
• Vascular Access Infections:
• 2-5% of fistulas, 10% of grafts
• Often signs of sepsis, fever, Hypotension, ↑ WBC
• Erythema, swelling, discharge at site often missing.
• Staph Aureus #1, gram neg #2
• Vanc is drug of choice, usually add Gent.
• Hemorrhage:
• d/t aneurysm, anastomosis rupture or over anticoagulation.
• Direct pressure
• Protamine 10-20 mg or 0.01 mg/unit hep.
• Consult surgery or nephrology
• Vascular access aneurysms:
• Repeated punctures
• Bulging in wall
• Rarely rupture
• True aneurysms very rare; 4% of fistulas
• Vascular access pseudoaneurysm:
• Subcutaneous extravasation of blood
• Present w/ bleeding & infection at site
• Vascular insufficiency: distal to access
• “steal syndrome”
• Preferential shunting of blood to low pressure venous side
• s/s exercise pain, non-healing ulcers, cool pulseless digits
• Dx w/ doppler or angiography
• High-output heart failure:
• When 20% of cardiac output diverted through access
• Branham sign: drop in HR after temporary access occlusion
• Doppler to measure access flow rate
• Surgical banding of access is Tx.
Complications During Hemodialysis
• 1. Hypotension:
• Most frequent, 10-20% of treatments
• Dialysis can remove up to 2 L/hr.
• Cardiac compensation limited d/t ↓ diastolic function common in ESRD
• Abnormalities in vascular tone; sepsis, anit HTN meds, ↑ nitric oxide
• Early hypotension: pre-existing hypovolemia
• Peridialysis losses; starts HD below dry weight; d/t sepsis, GI bleed, vomiting, diarrhea, decreased salt/water intake
• Intradialytic blood loss from tubing/dialyzer leads
• Hypotension at end of dialysis: excessive removal, cardiac or pericardial disease.
• Intradialytic hypotension:
• N/V/anxiety, ortho hypotension, tachycardia, dizzy, syncope.
• Tx.; stop HD, Trendelenburg. Salt, broth by mouth, NS 100-200 cc. IV.
• If these fail look for other causes than excessive fluid removal
• 2. Dialysis disequilibrium:
• End of dialysis
• N/V, HTN...progress to coma, seizure and death
• d/t cerebral edema after large solute clearance in HD
• Tx. Stop HD, administer Mannitol IV.
• 3. Air Embolism:
• s/s: dyspnea, chest tightness, unconscious, full cardiac arrest. Cyanosis, churning sound in heart from bubbles
• Clamp venous blood line, place supine
• Other Tx’s: percutaneous aspiration from R ventricle, IV steroids, full heparinization, hyperbaric O2 treatment
• 4. Electrolyte abnormalities:
• ↑ Ca, ↑Mg
• N/V, HA, burning skin, weakness, lethargy HTN
• 5. Hypoglycemia
Evaluation of HD Patients
• Dialysis schedule
• Dry weight
• Length of dialysis
• Inspect access site; erythema, swelling, tender, discharge.
• Peripheral edema, HJR, JVD not always CHF
• Murmurs; high flow d/t anemia?
Peritoneal Dialysis
• Peritoneal membrane= blood-dialysate interface
• Can be done acutely, chronically(continuous)=4 times/day, or multiple exchanges at night while sleeping.
Complications
• Peritonitis #1
• Mortality 2.5-12.5 %
• Fever, abd pain, rebound tender
• Dialysate fluid for cell count, Gram stain, culture
• Staph epidermidis 40%, S. aureus 10%, Strep species 15-20%, gram neg bacteria 15-20%, anaerobic bacteria 5%, fungi 5%.
• Empiric antibiotic therapy• Add to dialysate• Parenteral administration not needed• Rapid exchanges of fluid lavage to wash
out inflammatory cells• First gen Ceph• Vanc if pen allergic• Can add Gent
• Infections around PD catheter site:
• Pain, erythema, swelling, discharge.
• S. aureus, Pseudomonas aeruginosa
• Empiric w/ first generation Ceph or Cipro
• Outpatient therapy with f/u at CAPD center next day
• Abdominal wall hernia
• 10-15%
• Highest rate of incarcerating
• Immediate surgical repair
Overview Evaluating PD Patient
• Type and frequency of dialysis
• Date of last episode of peritonitis
• Frequency of relapse infections
• Baseline weight
• Focus on abdomen and catheter tunnel
Questions:
• 1. T/F Peripheral Neuropathy, “stocking and glove pattern”, is rarely seen in ESRD pts on dialysis.
• 2. T/F ESRD patients carry the same cardiovascular risk as general population.
• 3. T/F Troponins are commonly significantly elevated in patients on regular dialysis and cannot be trusted as cardiac marker.
• 4. #1 cause of dialysis access site infections…– A. klebsiella– B. staph aureus– C. strep species– D. E. coli
• 5. #1 complication during dialysis sessions is ….– A. hypotension– B. fever– C. CHF– D. cough
Answers: false (seen in 50%), false(inc risk), false, B, A.