Renal and Hematology Flashcards
What is the main consideration when caring for a patient with a pre-existing AV fistula??
don’t place a BP cuff or IV on the same side
When will dialysis be required?
severe metabolic acidosis hyperkalemia drug toxicity fluid overload metabolic encephalopathy coagulopathy refractory GI symptoms pericarditis *when GFR falls 10-15% below normal
Why should dialysis occur the day before or day of surgery?
to correct potassium and to dry the patient out for the OR
What is the ideal potassium for the OR in a renal patient?
potassium
What kind of drugs are cleared out by dialysis?
low molecular weight, water soluble, and non-protein bound drugs
What are the cardiac effects that are evident in a renal patient?
increased cardiac output - to compensate for low O2 carrying capacity
HTN - r/t RAA actvation
LV hypertrophy
CHF with pulm edema - after compensation has failed
calcium deposits - on heart valves and in conduction system
arrhythmias - r/t electrolyte imbalances
uremic pericarditis - secondary to inadequate dialysis
accelerated CAD and PVD
What are some important pre-op considerations regarding fluid balance in a renal patient?
check a body weight
get VS with orthostatics
check atrial filling pressures if necessary
choose drugs that won’t aggravate hypotension
LR isn’t advised because it contains K+
hydrate with small volumes of fluid (NS)
How is the respiratory system affected in a renal patient?
increased minute ventilation to compensate for metabolic acidosis
increased pulmonary water leading to interstitial edema
widened alveolar/arterial gradient
“butterfly wings” on CXR r/t to increased membrane permeability
Why wouldn’t you want to use nitric oxide on a renal patient with pulmonary compromise?
increases their chances of pleural effusions, despite normal pulmonary capillary pressures.
*so you would want to use 100% O2
How is the endocrine system affected in a renal patient?
peripheral resistance to insulin = poor glucose tolerance
hyperparathyroid = prone to fractures
abnormal lipid metabolism = prone to atherosclerosis
high circulating hormones = increased GH, PTH, insulin, glucagon, etc.
What are some GI complications of a renal patient?
GI hemorrhage
anorexia
N/V
delayed gastric emptying and hypersecretion of gastric acid
high incidence of transfusion related hepatitis
ascites possible with dialysis
Why do you want to minimize blood transfusions in a renal patient?
multiple transfusions create antibodies to the blood that can make them a difficult candidate for a kidney transplant
Why might an RSI be considered in a renal patient?
if there is a high degree of suspicion that the patient has delayed gastric emptying and oversecretion of gastric acid
When are some pre-op considerations when administering drugs to a renal patient?
altered effects of most drugs due to anemia, decreased serum proteins, electrolyte abnormalities, fluid retention, abnormal cell membrane permeability
So… reduce doses of drugs that are bound to protein!
What are some drugs that are contraindicated in renal failure? Why?
gallamine, phenobarbitol, and LMWH
*because they are eliminated by the renal system unchanged!
Why wouldn’t you want to give succinylcholine to a renal patient?
because it can precipitate hyperkalemia?
What are some ways that you can assess fluid status in a renal patient?
VS, mucous membranes, orthostatics, edema, rales
How are electrolytes altered in renal failure?
low bicarb, sodium, chloride, albumin, calcium
high potassium, magnesium, glucose
metabolic acidosis with high anion gap
What are the symptoms of uremic encephalopathy?
asterixis myoclonus lethargy confusion seizures coma
What are the neurologic consequences of renal disease?
uremic encephalopathy
autonomic neuropathy (hypotension and tachycardia)
peripheral neuropathy
disequilbrium syndrome s/p dialysis
What is disequilibrium syndrome?
transient CNS disturbance following dialysis where there is a rapid increase in ECF osmolality as compared to ICF osmolality
presents as dementia
Why are patients anemic when they patient have renal disease?
anemia with normal HGb of 6-8: decreased EPO decreased RBC life span hemodilution r/t fluid overload excess PTH replaces bone marrow with fibrous tissue
Why can renal patients generally tolerate persistent anemia?
because they have increased 2,3 DPG and metabolic acidosis favor a shift to the R on the oxy-Hgb dissociation curve, which allows for better oxygen delivery to the tissues
How is clotting affected in a renal patient?
decreased # and function of platelets
abnormal vWF
Why is aseptic technique required in a renal patient?
they are at increased risk of infections r/t WBC dysfunction.
*infection is a common cause of death in renal patients
What are the cardiovascular effects that occur in renal patients?
increased CO to compensate for anemia HTN r/t salt and water retention LV hypertrophy CHF with pulm edema r/t fluid overload calcium deposits on the heart valves arrhythmias r/t electrolyte imbalances uremic pericarditis r/t inadequate dialysis accelerated CAD and PAD
How would you assess fluid and electrolyte balance altered in a renal patient?
vital signs
body weight
atrial filling pressures
*did they have dialysis?!?
What are important considerations when deciding on fluid replacement for a renal patient?
want them dry when they’re coming to the OR (dialyze 1st)
would want to choose normal saline and hang on a micro drip to avoid hyperglycemia and hyperkalemia that would be associated with LR and D5.
also choose drugs that wouldn’t aggravate hypotension during induction
How is the pulmonary system effected in a renal patient?
MV increases to compensate for metabolic acidosis
increased risk of pulmonary edema r/t fluid overload
butterfly wings on CXR r/t increased capillary permeability –> high risk for pleural effusions
What are the three main components of any physical assessment?
airway
cardiac
pulmonary
What are some diagnostic tests that will assess glomerular function?
BUN
creatinine clearance
plasma creatinine
What are some diagnostic tests that assess renal tubular function?
urine specific gravity
urine osmolarity
Why might BUN be altered, in the absence of kidney disease?
high GI protein intake
febrile illness
GI bleeds
What are the limitations of a BUN?
can be elevated in cases other than renal dysfunction
not a sensitive indicator b/c urea production could be high
How do creatinine levels change in an elderly patient?
they remain relatively normal because there isn’t a lot of muscle mass to break down
however, high levels will indicate renal dysfunction
What is a normal creatinine clearance?
100-120 mL/min
What levels of creatinine clearance would indicate ESRD?
CrCl
What are some treatments for hyperkalemia in a renal patient?
calcium gluconate - immediate onset, short effect
sodium bicarb - fast onset, short effect
glucose + insulin - fast onset, moderate effect
dialysis - more long term solution
ion exchange resin
When would you give a blood transfusion to a renal patient?
transfuse only when absolutely indicated for a Hgb
Why would you want you avoid a spinal/epidural in a renal patient?
because they have a high risk of spinal hemorrhage or clotting
What does bleeding time tell you about?
tells you about the function of the platelets.
What are some other tests that you can order that would tell you about clotting function?
bleeding time *best one PT/INR PTT activated clotting time thrombin time fibrinogen
How can you treat bleeding in a renal patient?
desmopressin or cryopecipitate
prepare to administer blood products with a blood warmer
Why should a renal patient have an EKG?
hyper or hypo K+ common LV hypertrophy ischemia conduction blocks hypocalcemia
Why would you want to get an echocardiogram on a renal patient?
evaluate ventricular ejection fraction
evaluate LV hypertrophy
wall motion abnormalities
possibility of pericardial fluid
What are some general hematology questions you can ask your patient?
have you ever had anemia or leukemia?
have you ever had a bleeding problem?
have you ever received a blood transfusion?
do you take any meds like NSAIDS, ASA, COX2-inhibitor, herbal meds like garlic or ginseng? how often and when did you last take them?
has anyone in your family ever had a serious bleeding problem?
How can you calculate the arterial oxygen content in the blood?
1.39 x Hgb x SaO2 + PaO2 x .003
What factors will shift the oxy-hgb curve to the L? what is the effect?
cold
increased pH
decreased PaCO2
*O2 will remain tightly bough to Hgb
What factors will shift the oxy-hgb curve to the R? what is the effect?
increased temp
increased PaCO2
decreased pH
How do chronically anemic patients compensate for their decreased O2 carrying capability?
decrease SVR
increase 2,3 DPG
increase CO
increase plasma volume
redistribute blood to organs with a high extraction ratio
increase the extraction ratio in vascular beds
What factors will determine if your Hgb/HCT levels are adequate?
duration? (acute vs chronic) cause intravascular fluid volume status urgency of the surgery anticipated blood loss presence of co-existing disease such as CV, resp, renal or hepatic
How can you determine when you should transfuse an anemic patient?
will need to transfuse when the rate of O2 consumption is higher than what the RBCs can deliver
What is the ASAs recommendation for blood transfusion criteria?
transfuse based on the risks of complications of inadequate O2 delivery
What is one of the best treatments for anemia?
treat the underlying disease because anemia often secondary to another chronic condition
What are the key points that the CRNA should remember when attempting to treat acute blood loss?
you need to replace the volume! pressors won’t fix the problem!
What are the perioperative concerns and considerations when caring for a patient with hemolytic anemia?
increased risk of hypoxia
increased risk of infection if they’ve have a splenectomy
EPO should be prescribed 3 days before
acute drops in Hgb should be treated with a blood transfusion
What are the common complications of sickle cell anemia?
stroke HF and pulmonary HTN MI hepatic and splenic sequestration renal failure
What are the priority differences between heterozygous and homozygous phenotypes for sickle cell disease?
heterozygous - are not anemic, do not require transfusions
homozygous - anemia is present but well tolerated r/t compensatory mechanisms and R shift of oxy-hgb curve
What are three situations that you MUST AVOID in a sickle cell disease patient?
hypoxia
hypovolemia
stasis
What are some diagnostic tests you should review before caring for a patient with sickle cell disease?
BUN/Cre to check renal involvement baseline SaO2 baseline Hgb/Hct ABG and echo to check for heart failure CXR to eval for pulmonary HTN
What are some measures that the CRNA can take to minimize the risk of crisis in a sickle cell patient?
consider pre-op transfusion if hgb warrants for a major surgery
avoid respiratory depression, which could causes acidosis and crisis
hydrate well 12 hours before the case
maintain normothermia
maintain oxygenation
careful positioning to avoid stasis
pain management critical to prevent crisis
What are the periop risks of providing anesthesia to a patient with thalassemia?
- high output CHF common
- overgrowth of the maxillary bone may cause difficult intubation
- iron loading may cause diabetes, adrenal insufficiency, liver dysfunction, hypothyroid/parathyroid, arrhythmias and heart failure
- hypersplenism may cause thrombocytopenia and increase infection
What are the pre-op considerations when caring for a patient with thalassemia?
cranial deformities may make intubation difficult
cardiac arrhythmias are possible
coagulopathies may make regional anesthesia dangerous
consider checking electrolytes
consider invasive monitoring to evaluate the degree of heart failure
What are some common periop risks and concerns when dealing with a patient who has aplastic anemia?
infection
hemorrhage
LV dysfunction r/t high output cardiac state
sepsis
concurrent congenital abnormalities
difficulty cross-matching blood products r/t frequent transfusions
labile response to hemodynamic changes
What are the most important factors to review in caring for a patient with aplastic anemia?
CBC - infection present?? platelets low?? need a transfusion??
hx of transfusions?? how often??
what meds are you on?? any steroids?? do they need a stress dose??
should they get a pre-op antibiotic because of infection risk??
is reverse isolation warranted??
Why would you want to avoid nasal intubation in a patient with aplastic anemia?
decreased blood counts and platelets… super high risk of hemorrhage
What kind of monitoring might be indicated in a patient with aplastic anemia?
urine output
a-line for BP and frequent lab draws
CVP monitoring for overall fluid status
what is the main problem in a patient who has porphyria?
an abnormal feedback loop exists in the pathway to make porphyrins, causing an increase in the precursors to heme
What are some triggers for porphyrias?
drugs, diet, steroid hormones
What are the symptoms of a porphyria attack?
severe abd pain GI disturbances ANS instability electrolyte changes CNS disturbances life threatening muscle weakness
Which drugs are unsafe to give to a patient with porphyria?
barbituates etomidate diazepam sulfonamides phenytoin alcohol nifedipine ketorolac
Which drugs are safe to give to a patient with porphyria?
propofol insulin glucocorticoids opioids PCN atropine aspirin acetaminophen ketamine
Hemophilia A?
factor 7 is abnormal = abnormal PTT
treat with factor 7 infusion and desmopressin
Hemophilia B
factor 9 is deficient = abnormal PTT
treat by giving factor 9
von Willebrand’s disease
vWF and factor 8 are deficient = prolonged bleeding time
treat with cryoprecipitate and desmopressin
