Transcript Emergencies in Renal Failure and Dialysis Patients

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
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General population
CAD:
12%
LV hypert.
20%
CHF
5%
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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
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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
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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
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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
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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
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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
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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%.
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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
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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
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Abdominal wall hernia
10-15%
Highest rate of incarcerating
Immediate surgical repair
Overview Evaluating PD Patient
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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.