Renal Flashcards

Question

Patients without renal disease can excrete up to ______ mg of protein per day (greater amounts may be present with exercise).

Answer 1

**\> 750** mg/day

Answer 2

* Measure of percentage of filtered Na+ excreted in urine * Useful to distinguish **hypovolemia and renal injury** *(differentiate b/t prerenal and renal causes of azotemia)* * _FE_NA **\> 2%**_ (or **urine Na⁺ concentration \> 40 mEq/L**) reflects ↓ ability of renal tubules to conserve Na+ and is consistent w/ tubular dysfunction * _FE_NA **\< 1%**_ (or **urine Na⁺ excretion \< 20 mEq/L**) occurs when normally functioning tubules are conserving Na+ *and is suggestive of **prerenal azotemia***

Answer 3

* Useful for renal tubular dysfunction and urinary tract disease * Detects presence of: * Protein * Glucose * Acetoacetate * Blood * Leukocytes * Urine pH & solute concentrations (specific gravity) determined * Microscopy used to identify cells, casts, microorganisms, crystals

Answer 4

* Glomerulonephritis * Renal calculi * CA of the GU tract

Answer 5

Acute glomerulonephritis

Answer 6

Pyelonephritis

Answer 7

* Deterioration of renal function- hrs to days * Failure to excrete waste products * Failure to maintain fluid & electrolyte homeostasis

Answer 8

* Increase in serum creatinine **\> 0.3 mg/ dL** in 48 hrs or **\> 50% increase over 7 days** * Acute drop in urine: \< 0.5 mL/kg/h for \> 6 hrs *(oliguria)* * Severe injury: UO \< 100 mL/day * Diagnostic biomarkers & urinalysis

Answer 9

* Generalized malaise * Fluid overload * dyspnea * edema * HTN * Nausea * Confusion * Hematuria * \*\* Caution: encephalopathy, coma, seizures, death

Answer 10

new dialysis OR rise in serum creatinine \>2 mg/dL, 50% increase in serum creatinine

Answer 11

Creatinine rise of: 50% as “risk” 100% “injury” 200% “failure” (**RIFLE** criteria)

Answer 12

1.5X or 0.3 mg/dL creatinine rise w/in 48-hr period OR \> 6hrs of oliguria (modified RIFLE)

Answer 13

↑ in serum creat at least **0.3 mg/dL w/in 48 hrs** OR ↑ in serum creat **1.5X baseline w/in prior 7 days** OR **UOP \< 0.5 mL/kg/h X 6 hrs**

Answer 14

Cr 1.5-1.9X baseline OR Cr increase \>0.3 mg/dL

Answer 15

Cr 2-2.9X baseline

Answer 16

Cr \> 3X baseline OR Cr \> 4 mg/dL OR Initiation of Dialysis

Answer 17

\< 0.5 mL/kg/hr X 6-12 hrs

Answer 18

\< 0.5 mL/kg/hr for \> 12 hrs

Answer 19

\< 0.3 mL/kg/hr for \> 24 hrs OR Anuria \> 12 hrs

Answer 20

* 5%-7% of hospitalized patients * Associated w/ other systemic disease/ clinical conditions/ drugs/ interventional therapy

Answer 21

Hypoperfusion *Hemorrhage, GI fluid loss, Trauma, Surgery, Burns, Cardiogenic shock, Sepsis, Hepatic failure, Aortic or renal artery clamping, Thromboembolism*

Answer 22

Underlying renal causes Ischemia Nephrotoxins *A**cute glomerulonephritis, Vasculitis, Interstitial nephritis** (drug allergy, infiltrative diseases), **Acute tubular necrosis, Ischemia, Nephrotoxic drugs** (aminoglycosides, nonsteroidal anti-inflammatory drugs), **Solvents** (carbon tetrachloride, ethylene glycol), **Heavy metals** (mercury, cisplatin), Radiographic contrast **dyes**, **Myoglobinuria**, **Intratubular crystals** (uric acid, oxalate)*

Answer 23

* Urinary collecting system obstruction * Nephrolithiasis, BPH, Clot retention, Bladder CA*

Answer 24

Condition marked by **abnormally high** serum concentrations of nitrogen-containing compounds such as **BUN & creatinine** and is **hallmark of AKI**, regardless of cause.

Answer 25

* ½ of hospital-acquired cases * **Pre-existing CHF, liver dysfunction, septic shock** * **Reduced RBF d/t ↓ in PP** * **Hypovolemia & blood loss** * Rapidly **reversible** if underlying cause treated * Untreated: = ischemia-induced acute tubular necrosis * Elderly susceptible: hypovolemia/ renovascular disease * Assess volume status, hemodynamics, drug therapy * Blood and urine specimens *(Refer to Stoelting’s 22.5)*

Answer 26

* Categorized according to site of injury * Glomerulus * Renal tubules- ischemia or nephrotoxins * Interstitium * Renal vasculature * Ischemic AKI typically reversible, but… * Irreversible cortical necrosis occurs if severe or prolonged ischemia * **Reperfusion**: influx of inflammatory cells/ cytokines/ oxygen free radicals

Answer 27

* Urinary outflow tracts are obstructed (prostatic hyperplasia, prostate/cervical CA) * May occur at any level of collecting system * Recovery inversely r/t duration of obstruction * Treatment: percutaneous nephrostomy

Answer 28

* Pre-existing renal dx * Advanced age * CHF * PVD * DM * Emergency surgery * Major surgery (aortic aneurysm repair)

Answer 29

* **Inadequate fluid** replacement * **Hypotension** * Delayed treatment of **sepsis** * Nephrotoxic **drugs**

Answer 30

* Confusion * Somnolence * Asterixis * Seizures * Polyneuropathy r/t build up of protein & amino acids

Answer 31

* Systemic **HTN** * **CHF** * Pulmonary **edema** r/t Na⁺ & H₂O retention * **Dysrhythmias** * **Uremic pericarditis** * ****may be asymptomatic or have chest pain and cardiac tamponade * *LVH* * *Inc CO* * *accelerated CAD, PVD*

Answer 32

* **Anemia** *(when creat. clearance falls below 30 mL/min)* * **Coagulopathy** * Hct 20-30% common d/t **hemodilution & ↓ erythropoietin** * ↑ r/f **bleeding** d/t uremia-induced platelet dysfunction * *decreased platelet aggregation and adhesiveness*

Answer 33

* **Hyperk**alemia and **met**abolic **acid**osis * **Hyperphos & hypoca**lc * **Hypoalb**uminemia

Answer 34

* Anorexia, N/V * Ileus * Gastroparesis * GI bleeding

Answer 35

* Respiratory & urinary tracts and sites where breaks in normal anatomic barriers have occurred * Impaired immune response– white cell function are impaired in pts w/ kidney failure

Answer 36

* No specific treatment modalities * Treatment aims: 1. Limit further injury 2. Correct fluid/electrolyte/acid-base derangements 3. Reverse underlying causes of injury (hypovolemia, hypotension, low CO, sepsis) 4. Maintain **MAP \> 65** or (no evidence supporting outcomes w/ supraphysiologic values) 5. Fluid resuscitation (goal-directed therapy) & vasopressor therapy (norepi/vasopressin) 6. **Diuretics not advised** 7. **Alkalinization of urine** w/ sodium bicarb (rhabdo); reduces incidence of contrast-induced nephropathy 8. **Dialysis**- mainstay for severe AKI

Answer 37

Dialysis- mainstay for severe AKI: 1. Volume overload 2. Hyperkalemia 3. Severe metabolic acidosis 4. Symptomatic uremia 5. Overdose w/ dialyzable drug – day of surgery/ day before

Answer 38

* Hospital acquired AKI is poor * Mortality \> 20% * Dialysis- mortality rates \> 50% * Full recovery from AKI- 15% * Retain a degree of stable renal insufficiency- 5% * Continued deterioration throughout life- 5%

Answer 39

* High M&M * **Only life-saving surgery** * Principles that guide anesthetic management: 1. Maintain **adequate systemic BP & CO** 2. **Avoid further renal insults** – hypovolemia, hypoxia, nephrotoxins 3. Invasive **hemodynamic monitoring** – ABGs & Lytes 4. Consider initiation of **post-op dialysis** if in stable condition 5. **Caution w/ diuretics**

Answer 40

Estimated **GFR \<60 mL/min/1.73m² for 3 months or more**

Answer 41

**DM & HTN** responsible for 2/3 of all cases (also glomerulonephritis, polycystic kidney disease)

Answer 42

* Inability to: * Excrete waste * Regulate fluid and electrolyte balance * Secrete hormones

Answer 43

* •U.S. Renal Data System of the NIH (2012)- * 636,000 individuals with ESRD * Prevalence continues- aging population/ increased survival * Incidence varies by race & ethnicity (African American, Native Americans, Hispanics) * Genetic variables + disparities in healthcare access

Answer 44

* Diverse signs, **non-specific** complaints (fatigue, malaise, anorexia) * Diagnosis made during **routine testing** **Serum creatinine** level & **urinary sediment** analysis

Answer 45

* Glomerular HTN * Glomerular hyperfiltration & permeability changes * Glomerulosclerosis

Answer 46

* Reduce systemic & glomerular HTN: * ACEI's & ARBs * Moderate **protein restriction** * **Control BG** * Hyperlipidemia - **statin** therapy advised * **Smoking cessation**

Answer 47

* Patients w/ CKD remain relatively asymptomatic until RF is \< 10% of normal * 3 stages of adaptation: 1. GFR ↓ w/ ↑ in creat & urea 2. Serum K ↑ (normal until GFR approaches 10% of normal) 3. Na⁺ homeostasis and regulation of ECF (volume overload/ volume depletion)

Answer 48

Sodium balance remains fairly intact, but the system can be overwhelmed by abrupt increases or decreases in sodium intake. Increase Na⁺ intake = **volume overload** Decrease Na+ intake = **volume depletion**

Answer 49

* Inability to excrete uremic toxins, secrete, regulate * **BUN _useful_** clinical indicator of severity & response to therapy * **Serum creatinine _poor_** clinical indicator

Answer 50

* N/V, Anorexia * Pruritus * Anemia, Fatigue * Coagulopathy

Answer 51

dietary protein restriction + dialysis

Answer 52

* Secondary hyperparathyroidism & ↓ Vit D production – impairs intestinal absorption of Ca * Hypocalcemia stimulates PTH secretion – leads to bone resorption to restore serum Ca concentrations * As GFR ↓, phosphate clearance ↓ = ↑ serum phosphate/ ↓ Ca

Answer 53

* **Restrict dietary phosphate** * + oral **Ca and Vit D supplements** * + **antacids** *to bind phos in GI tract* (avoid mag & aluminum) * If medical therapies fail- **subtotal parathyroidectomy**

Answer 54

* Likely responsible for symptoms of _fatigue,_ weakness, low exercise tolerance * Normochromic & normocytic d/t decreased erythropoietin * **Excess parathyroid** hormone *(by replacing bone marrow with fibrous tissue)*

Answer 55

* Erythropoietin or darbepoetin * Avoid blood transfusions * Iron

Answer 56

* ↑ tendency to **bleed** & **persistent anemia** *(despite normal platelet count and normal PT/PTT)* * **Bleeding time**: best correlates w/ tendency to bleed * Hemorrhagic episodes: significant source of morbidity

Answer 57

* **Desmopressin**: ↑ factor 8-vWF complex (present w/in 2-4 hrs & lasts 6-8 hrs) * Conjugated estrogens (onset approx. 6 hrs & lasts 14-21 days) * **Erythropoietin**: enhances platelet aggregation & ↑ platelet counts

Answer 58

* Initial symptoms may be mild * impaired abstract thinking, insomnia, irritability * As dz progresses- significant changes: * seizures, obtundations, uremic encephalopathy, coma * Advanced RF: * BLE symmetric mixed motor and sensory **polyneuropathy** & weakness

Answer 59

HD may be helpful

Answer 60

* **Systemic HTN**- contributes to CHF, CAD, CVD * Uncontrolled HTN speeds dz progression * Pathogenesis- retention of Na & water + RAAS activation = intravascular volume expansion * **Dyslipidemias** * **Silent MI** * Uremic pericarditis

Answer 61

* Dialysis- d/t hypervolemia & uremic pericarditis * Increase dosage of **antihypertensives** * Tamponade- prompt drainage of effusion

Answer 62

* **BP control:** **ACEI & ARBs** (1^st line), diuretics, Ca channel blockers, aldosterone antagonists * **Nutrition** * **Protein restriction** (0.6 g/kg/day) * **Phos** **restriction** 600–800 mg/ day * **Sodium restriction** (\< 1500-2000 mg/day) * Advanced dz- **alkali salts** * **Vitamin D** * Long-term: euglycemia * **Anemia**: Benefits vs risks * Erythropoietin (target Hb range 10-11.5 g/ dL) * **Renal Replacement Therapy** * Advised when GFR 10 mL/min/1.73 m2 * Effective dialysis = greater survival

Answer 63

* _Preop Eval_ * **Renal function stable**? --trends in serum creat. * Blood **volume** status before & after dialysis * **VS** * **BG** management * **BP** (ACE-I and ARBs often withheld day of surgery) * **Serum K should not exceed 5.5 mEq/ L day of surgery** * **Anemia** * **Coagulopathy** * Gastric **aspiration prophylaxis** (dose adjustment) * **Dialysis** w/in 24 hrs preceding elective surgery

Answer 64

* Safe w/ most IV induction drugs – concern is accumulation of **_active metabolites_** * ESRD pts- respond as if they are **hypovolemic** * Uremia & antihypertensives – result in hypotension * Attenuated SNS activity impairs compensatory peripheral vasoconstriction (exaggerated hypotension) * Exaggerated CNS effects – uremia induced * **May induce w/ succinylcholine if K is \<5.5**

Answer 65

* Balanced approach – VA's or TIVA, MR's, opioids * VA's: good control of HTN & decrease dose of MR's, but depress CO * Sevo sometimes avoided (fluoride nephrotoxicity/ compound A), but no evidence of increased risk * **Muscle relaxants** – slow excretion of vec, roc/cisatra independent of renal function * **↓ initial dose** and base subsequent doses on TOF * **Opioids:** * ****morphine & meperidine --\> **morphine-6-glucoronide & normeperidine** (neurotoxic compounds) that rely on renal clearance. Hydromorphone active metabolite (**hydromorphone-3-glucoronide**) may accumulate in CKD.

Answer 66

* May benefit from preop hydration (500 mL) if… * Do not require HD or W/out renal dz undergoing surgery w/ high incidence of post-op RF * **Caution – LR or K-containing fluids** * UOP – 0.5 mL/kg/h * **Diuretics not advised** in absence of fluid replacement * HD dependent – narrow margin of safety

Answer 67

Monitoring * _Avoid_: * Venipuncture in nondominant arm & upper part of dominant arm * Radial and ulnar cannulation (same may be said of brachial and axillary) * _Considerations_: * Femoral cannulation: r/f infection * DP or PT arteries: inconvenient/difficult to access * Arterial pressure & ABG will not be accurate if on same extremity as AV fistula * Venous pressure monitoring: may be helpful, CVC access may be difficult * TEE * Dialysis catheters may be used. Use aseptic techniqu, aspirate heparin, heparin after d/c of use

Answer 68

* **Positioning** – prone to bruising, sloughing/ protect vulnerable nerves * **Protect fistulas** * NO BP cuff on arm w/ fistula * If possible, maintain intra-op access to arm w/ fistula

Answer 69

Regional Anesthesia * Neuraxial may be considered * Considerations: * **Sympathetic block T4-T10**- may improve renal function vs platelet dysfunction, residual heparin, Must maintain adequate intravascular fluid volume * **Brachial plexus block** – assess for presence of uremic neuropathies * **Metabolic acidosis** - may decrease seizure threshold in response to LAs

Answer 70

* Reversal – Renal excretion 50% of clearance of **neostigmine**, prolonged effect * “Recurarization” is unlikely * **Sugammadex: not recommended in low creatinine clearance** (\< 30 mL/min) or **RRT**

Answer 71

* **Skeletal muscle weakness**: from residual neuromuscular blockade or… antibiotics, acidosis, electrolyte imbalance * **Caution** w/ parenteral **opioids** – **respiratory depression** * **Avoid NSAIDs** * Continuous **ECG** monitoring * Supplemental **O2** * Check electro**lytes, BUN/creat, HCT** * **Bleeding**- uremic coagulopathy

Answer 72

* Reserved for pts w/ **ESRD on long-term RRT** * Common causes of ESRD: * Systemic HTN * DM * Glomerulonephritis * Cadaver donor – can be preserved for 48 hrs * **Preop - match HLA antigens and ABO** blood groups * **Immunosuppressive** therapy instituted

Answer 73

* RA and GA successful – GA more common * Minimize decrease in CO – promote renal perfusion * **High-normal BP** is required * **Cisatracurium** is often drug of choice * **CVP** is useful * **Mannitol** (osmotic diuretic) * **Albumin** administration is helpful * **Release** of vascular **clamps** – be aware of hypotension & cv arrest

Answer 74

* Advantages – **No ETT & muscle relaxants** * Advantage negated if need to supplement RA with IV anesthetics * BP control may be more difficult * Controversial in presence of **abnormal coagulation**

Answer 75

* Acute immunologic rejection – almost immediate * Delayed signs of graft rejection – fever, local tenderness, decreased UOP * Treatment: * High dose corticosteroids & antilymphocyte globulin * Monoclonal antibodies * Tacrolimus * Mycophenolate mofetil * Dialysis may be required * Opportunistic infections

Answer 76

Anesthesia Considerations * Often **elderly** * Co-existing **CV dz** * Co-existing **DM** * Consider side **effects of immunosuppressant drugs** * ****HTN, low seizure threshold, anemia, thrombocytopenia * Consider drugs excreted by kidneys * Avoid drugs that are nephrotoxic or dependent on renal clearance * Minimize decreases in RBF

Answer 77

Phenobarbital Thiopental

Answer 78

Gallamine Metocurine Pancuronium Vecuronium

Answer 79

Edrophonium Neostigmine

Answer 80

Atropine Digoxin Glycopyrrolate Hydralazine Milrinone

Answer 81

Aminoglycosides Cephalosporins Penicillins Sulfonamides Vancomycin

Answer 82

Codeine Meperidine Morphine

Answer 83

10-11.5 g/dL