Renal/Coagulation Flashcards

1
Q

What are basic questions to ask for renal history?

A
  • Have you ever had any kidney problem?
  • Have you ever had kidney failure, dialysis, or more than two kidney infections?
  • Have you ever had kidney stones?
  • Are you undergoing dialysis for kidney problems?
  • Have you had changes in bowel or bladder function in the last year?
  • Has your appetite for food changed in the last year? (Voluntary avoidance of foods having a high protein content is a subtle sign of renal disease.)
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2
Q

In what situations will dialysis be required?

A
  • Oliguria
  • Fluid overload
  • Hyperkalemia
  • Severe acidosis
  • Metabolic encephalopathy
  • Pericarditis
  • Coagulopathy
  • Refractory GI symptoms
  • Drug toxicity

CHEAPFDOG

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3
Q

What kind of access can be used for hemodialysis?

A
  • AV fistula = cephalic vein anastomosed to radial artery

- Jugular or femoral vein for emergency access

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4
Q

What are some considerations with pre-operative dialysis?

A
  • Optimization, optimization, optimization!
  • Dialysis should occur day of surgery or day before surgery
  • Review dialysis flowsheet if available
  • Amount of fluid “taken off”
  • Pre and post dialysis weights compare with day of surgery weight
  • Note POST dialysis chemistry! Serum K < 5.5 mEq/L
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5
Q

What should the potassium level be after dialysis?

A

Less than 5.5 mEq/L

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6
Q

What drugs are readily cleared by dialysis?

A
  • Low molecular weight
  • Water soluble
  • Non-protein bound
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7
Q

When should most drugs be delivered in regards to dialysis?

A

After dialysis

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8
Q

What are some neurological problems that can result from renal failure?

A
  • Uremic encephalopathy
  • Autonomic neuropathy
  • Peripheral neuropathy
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9
Q

What are the symptoms of uremic encephalopathy?

A
  • Asterixis
  • Myoclonus
  • Lethargy
  • Confusion
  • Seizures
  • Coma

CCLAMS

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10
Q

What are some neurological problems that can occur after dialysis?

A
  • Disequilibrium syndrome-transient CNS disturbance after rapid decrease in ECF osmolality compared with ICF osmolality
  • Dementia
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11
Q

What are some hematological changes expected with renal failure?

A
  • Anemia
  • Impaired platelets-decreased platelet factor 3 activity and decreased adhesiveness and aggregation
  • Impaired WBC function
  • Release of defective von Willebrand factor
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12
Q

What are some causes of anemia in renal failure?

A
  • Decreased erythropoietin production
  • Decreased RBC production & cell life span
  • GI blood loss, hemodilution, bone marrow suppression
  • Excess PTH replaces bone marrow with fibrous tissue
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13
Q

What are some ways renal patients compensate for anemia?

A
  • Increased 2,3-DPG

- Metabolic acidosis which favors rightward shift

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14
Q

What precautions with regards to aseptic technique should be taken for renal patients?

A
  • Infection is a common cause of death
  • Care with ETT-prone to pulmonary infection
  • IVs, line insertion
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15
Q

What are some cardiac changes seen in renal failure patients?

A
  • Increased cardiac output (compensation for low O2 carrying capacity)
  • HTN (Na retention, RAS activation)
  • Left ventricular hypertrophy
  • CHR with pulmonary edema
  • Deposition of calcium in the conduction system and on the heart valves
  • Arrhythmias due to electrolyte imbalances
  • Uremic pericarditis- can be asymptomatic, chest pain, tamponade, usually secondary to inadequate dialysis
  • Accelerated CAD and PVD
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16
Q

What can be used to assess fluid balance in renal patients?

A
  • Body weight
  • Orthostatic hypotension (BP)
  • Tachycardia (HR)
  • Atrial filling pressures
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17
Q

What pulmonary changes do you see in a patient with renal failure?

A
  • Minute ventilation increased to compensate for metabolic acidosis
  • Increase pulmonary extravascular water=interstitial edema=widened alveolar/arterial O2 gradient
  • Butterfly wings on chest xray secondary to increased permeability of alveolar capillary membrane
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18
Q

What endocrine changes do you see in a patient with renal failure?

A
  • Peripheral resistance to insulin = poor glucose tolerance
  • Hyperparathyroidism = prone to fractures
  • Abnormal lipid metabolism = accelerated atherosclerosis
  • Kidneys do not degrade hormones and proteins normally = increased circulating PTH, insulin, glucagon, GH, LH, PL
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19
Q

What are some GI/liver changes you will see in the renal failure patient?

A
  • 10-30% of patients will develop GI Hemorrhage
  • Anorexia
  • Nausea and Vomiting
  • Hypersecretion of gastric acid + delayed gastric emptying (autonomic neuropathy)
  • High incidence of Hep B and C in these pts (multiple transfusions, etc.)
  • Ascites with dialysis
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20
Q

Why is drug metabolism altered in patients with renal failure?

A
  • Anemia
  • Decreased serum protein
  • Electrolyte abnormalities
  • Fluid retention
  • Abnormal cell membrane activity
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21
Q

What drugs are contraindicated in patients with kidney failure

A
Drugs that are eliminated by the kidneys unchanged are contraindicated.
Examples:
-Gallamine
-Phenobarbital
-LMWH
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22
Q

How can you assess fluid status?

A
  • Vital signs
  • Mucus membranes
  • Orthostatics
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23
Q

What blood tests would you want for a patient with renal failure?

A
  • Chemistry panel
  • BUN
  • Cr
  • Creatinine Clearance
  • Urine specific gravity
  • Urine osmolarity
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24
Q

What blood tests assess GFR?

A
  • BUN (10-20 mg/dl)
  • Cr (0.7-1.5 mg/dl)
  • Creatinine Clearance (110-150 ml/min)
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25
Q

What blood tests assess renal tubular function?

A
  • Urine specific gravity (1.003-1.03)

- Urine osmolarity (38-140 mOsm/L)

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26
Q

What BUN level is indicative of a decreased GFR?

A

> 50 mg/dl

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27
Q

Besides GFR what else does BUN depend on?

A

BUN also depends on the production of urea so it is not a sensitive index

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28
Q

What can be causes of abnormal BUN despite a normal GFR?

A
  • High protein diet
  • GI bleed
  • Febrile illness
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29
Q

What is the most common cause of increased BUN?

A

CHF secondary to the reabsorption of BUN

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30
Q

How long of a lag time is there after a change in GFR before changes in creatinine are seen?

A

8-17 hours

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31
Q

What changes to GFR correspond to a 50% increase in plasma creatinine?

A

A 50% decrease.

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32
Q

What is the source of creatinine?

A

Skeletal muscle.

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33
Q

What is the most accurate test of creatinine clearance?

A

A 24 hour collection is most accurate but a 2 hour test can also be helpful.

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34
Q

What is the normal creatinine clearance?

A

100-120 ml/min

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35
Q

What lab abnormalities are common with renal failure?

A
  • Hyponatremia
  • Hyperkalemia
  • Metabolic acidosis with high anion gap
  • Hypermagnesemia
  • Hypocalcemia
  • Hypoalbuminemia
  • Hyperglycemia
36
Q

What are some treatments for hyperkalemia?

A
  • Calcium gluconate
  • Sodium bicarbonate
  • Glucose and insulin
  • Dialysis
  • Ion exchange resin
37
Q

What is the normal bleeding time and what coagulation factors effect it?

A

3-10 minutes

Platelet function

38
Q

What is the normal platelet count and what effects it?

A

150,000-400,000 cells/mm^3

Vascular integrity

39
Q

What is normal prothrombin time and what factors effect it?

A

10-12 seconds

I, II, V, VII, X

40
Q

What is the normal INR and what factors effect it?

A

0.8-1.2

I, II, V, VII, X

41
Q

What is the normal PTT and what factors effect it?

A

25-35 seconds

I, II, V, VIII, IX, X, XI, XII

42
Q

What is the normal activated clotting time and what factors effect it?

A

90-120 seconds

I,II, V, VIII, IX, X, XI, XII

43
Q

What is the normal thrombin time and what factors effect it?

A

9-11 seconds

I,II

44
Q

What is the normal fibrinogen level and what factor effects it?

A

160-350 mg/dl

I

45
Q

What is the best screening test to test for coagulation abnormalities in the renal failure patient?

A

Bleeding time- patient may have increased bleeding despite normal PT, PTT

46
Q

What is the treatment for coagulation abnormalities in renal failure patients?

A
  • Desmopressin 0.3-0.4 mg/kg over 39 minutes
  • Cryoprecipitate 10 unites IV over 30 minutes
  • Blood warmer ready
47
Q

What pulmonary tests should be performed for patients in renal failure?

A
  • CXR

- ABG

48
Q

What can a CXR determine for patients in renal failure?

A
  • Fluid status
  • Presence of HTN related CV disease
  • Pericardial effusion
  • Uremic pneumonitis
49
Q

What can an ABG determine for patients in renal failure?

A
  • Hypoxia

- Acid/base status especially if dyspnea noted on exam

50
Q

What cardiac tests should be considered for a patient in renal failure?

A
  • ECG

- Echocardiogram

51
Q

What can an ECG indicate?

A
  • Hyper or hypokalemia
  • Hypocalcemia
  • Ischemia
  • Conduction blocks
  • LVH
52
Q

What can an echocardiogram indicate?

A
  • Ventricular EF
  • Hypertrophy
  • Wall motion abnormalities
  • Pericardial cluid
53
Q

What are some basic questions you can ask regarding the hematologic system?

A
  • Have you ever had a blood problem such as anemia or leukemia
  • Have you ever had a problem with blood clotting or a serious bleeding problem?
  • Have you received a blood transfusion since 1979?
  • Do you use any medications such as aspirin or vitamins such as vitamin E or supplements such as ginseng or garlic known to affect blood clotting? How much? How often? -When did you last use such?
  • Has a family member or blood relative ever had a serious bleeding problem?
  • Have you ever had prolonged or unusual bleeding from cuts, nosebleeds, minor bruises, tooth extractions, or surgery?
  • Have you ever had excessive bleeding that required blood transfusion?
54
Q

What are some pre-op considerations for a patient with anemia?

A

.

55
Q

How do you calculate the arterial oxygen content?

A

(Hgb x 1.39) x SaO2 + PaO2* 0.003

56
Q

What shifts the oxygen hemoglobin disassociation curve to the left?

A
  • Low PaCO2
  • Low temperature
  • High pH
57
Q

What shifts the oxygen hemoglobin disassociation curve to the right?

A
  • High PaCO2
  • High temperature
  • Low pH
58
Q

What are some compensations that occur in chronic anemia for reduced oxygen carrying capacity?

A
  • ↓ SVR
  • ↑ 2,3-DPG- major compensatory mechanism till 7 g/dl (Alters O2 binding- Right shift->↓Hgb affinity for O2)
  • ↑ CO
  • ↑ plasma Volume
  • Redistribution of blood flow to organs with higher extraction ratio
  • ↑Extraction ratio in vascular beds
59
Q

What hemoglobin is representative of anemia according to the WHO?

A

Males: < 13
Females: < 12

60
Q

What are some factors considered in developing minimum acceptable Hb and Hct?

A
  • Duration of anemia
  • Etiology
  • Intravascular fluid volume
  • Urgency of surgery
  • Anticipated blood loss during surgery
  • Co-existing disease
61
Q

What is the goal of transfusion therapy?

A

To increase oxygen-carrying capacity or to correct the coagulation disorder

62
Q

How long does it take Hgb and Hct levels to reflect blood loss?

A

3 days to reach plateau

63
Q

What are some perioperative risks and concerns with hemolytic anemia?

A
  • ↑ risk of tissue hypoxia
  • Previous splenectomy may ↑ risk of perioperative infection
  • Erythopoietin is often prescribed for 3 days preoperatively
  • Acute drops in Hb below < 8 g/dl and chronic reductions to below 6 g/ dl should be considered for transfusion
64
Q

What is the difference between sickle cell trait vs disease?

A

Trait: 8% African Americans are Heterozygous carriers (hgb genotype AS- 40% of their Hgb is S)

Disease: RBCs homozygous for Hgb S contain 70-98% Hgb type S

65
Q

What are some perioperative complications that can occur with patients with sickle cell disease?

A

30% overall complication rate

  • Stroke
  • Heart failure and Pulmonary HTN
  • MI
  • Hepatic or splenic sequestration
  • Renal failure
66
Q

What should be done preoperatively for the patient with sickle cell disease?

A
  • Procedures intermediate to high risk conservative transfusions preoperatively to Hgb10 g/dl = Hct of 30%
  • Low risk procedures- no benefit
  • Emergency surgery- High risk for postop complications-optimal transfusion support
  • Venous access may be difficult to obtain
  • Preoperative hydration for 12 hours prior to surgery
  • Premed-Avoid respiratory depression = acidosis
67
Q

What should be avoided in sickle cell disease?

A
  • Hyopxemia
  • Hypovolemia
  • Stasis
68
Q

What measures can be taken to avoid vaso-occlusive crisis in sickle cell patients?

A
  • Maintain normothermia = cold patient vasoconstricts = sickling
  • Hydration- avoid dehydration hemoconcentration = ↑ sickling
  • Maintain oxygenation
  • Acidosis promotes sickling
  • Positioning prevent stasis
69
Q

What are some perioperative risks for thalassemia patients?

A
  • High-output CHF common with severe anemia
  • Compensatory RBC production = craniofacial deformity and overgrowth of the maxillae increase challenge of DVL
  • Complications of iron loading from chronic transfusions
  • -Diabetes (Blood glucose monitoring)
  • -Adrenal insufficiency (↓ response to vasopressors)
  • -Liver dysfunction & Coagulation abnormalities
  • -Hypothyroidism & hypoparathyroidism
  • -Arrhythmias (cardiac hemochromatosis) (ECG)
  • -Heart failure (cardiac hemochromatosis) (ECHO)
  • Hypersplenism can result in thrombocytopenia and ↑ risk of infection
70
Q

What are some pre-operative considerations for patients with thalassemia?

A
  • Potential difficult airway 2° to maxillary deformities
  • Cardiac arrhythmias of HF
  • Coagulopathy (? Regional Anesthesia)
71
Q

What kind of monitoring should be used for patients with thalassemia?

A
  • Routine
  • +/- invasive monitors  presence and severity of HF
  • Electrolytes
72
Q

What are some important pre-op considerations for patients with Aplastic Anemia?

A
  • CBC results are important- neutrophil, RBC and platelet counts can be extremely low and they may need a pre-op transfusion
  • Know their medications- they may be on steroids and need a steroid “stress” dose
  • Airway hemorrhage a possibility with intubation
  • Reverse isolation
  • Neutropenia and severe co-existing congenital heart disease- may need prophylactic antibiotics
73
Q

What are some perioperative risks and concerns for patients with aplastic anemia?

A
  • Infection
  • Hemorrhage (GI and intracranial)
  • LV dysfunction secondary to high output state and fluid overload
  • Sepsis
  • Co-existing congenital abnormalities such as Fanconi anemia
  • Difficulty cross-matching blood products after multiple transfusions
74
Q

What kind of intraoperative monitoring is needed for patients with aplastic anemia?

A
  • Invasive monitoring (A-line, CVP, PA)

- UO

75
Q

What are some considerations during induction for patients with aplastic anemia?

A
  • Avoid nasal intubation- use extreme caution with friable oral and pharyngeal mucosal surfaces
  • Labile hemodynamic response to induction
  • +/- regional anesthesia—depends on coagulation status
76
Q

What are porphyrias?

A

Porphyrias are a group of inborn erros of metabolism–overproduction of porphyrins.

77
Q

What is the function of porphyrins?

A

They are essential for many vital processes including O2 transport and storage. Heme is a porphyrin

78
Q

What can activate porphyrias?

A
  • Diet
  • Drugs
  • Steroid hormones
79
Q

How do drugs trigger a porphyria attack?

A

By inducting ALA synthetase or interfering with negative feedback control in the final common pathway.

80
Q

What are the symptoms of a porphyria attack?

A
  • Severe abdominal pain/GI distrurbance
  • ANS instability
  • Electrolyte disturbances
  • CNS disturbances
  • Life threatening muscle weakness
81
Q

What drugs are unsafe for patients with porphyrias?

A

-Barbiturates
-Sulfonamide antibiotics
-Alcohol
-Diazepam
-Phenytoin
-Etomidate??
Probably avoid:
-Nefedipine
-Ketorolac

82
Q

What drugs are safe for patients with porphyrias?

A
  • Opioid analgesics
  • Propofol
  • Ketamine (probably safe)
  • Aspirin
  • Acetaminophen
  • PCN
  • Glucocorticoids
  • Insulin
  • Atropine
83
Q

What are some hereditary coagulation disorders and what should be done for these patients pre-operatively?

A
  • Hemophilia A
  • Hemophilia B
  • Van Willebrand’s syndrome
  • You should consult a hematologist
84
Q

What factor is absent or defective in hemophilia A and what lab test does this change?

A

Factor VIII, PTT

85
Q

What factor is absent or defective in hemophilia B and what lab test does this change?

A

Factor IX, PTT

86
Q

What factor is absent or defective in Von Willebrand’s and what lab test does this change?

A

vWF and VIII, prolonged bleeding time