T3 - Renal Assessment Flashcards
1
Q
~_____% TBW is water (varies w/ _____, ______, _____ %)
A
- 60%
- gender, age, body fat
Slide 3
2
Q
ECF- fluid outside of cells ( _____ + _______) = < 1/2 volume of TBW
A
ISF +Plasma
Slide 3
3
Q
How is osmolar homeostasis primarily mediated?
A
Osmolality sensors in the anterior hypothalamus
Slide 3
4
Q
What is the path created by the hypothalamus to regulate osmolar homeostasis?
A
- Stimulate thirst
- Cause pituitary release of vasopressin (ADH) (To retain fluid)
- Cardiac atria release ANP (will act on kidney to decrease Na/H2O reasbsorption) (to get rid of fluid)
Slide 3
5
Q
How is volume homeostasis mediated?
A
Mediated by juxtaglomerular apparatus
Slide 3
6
Q
What are the changes caused by the JGA?
A
- JGA senses a decrease in volume
- JGA triggers Renin-Angiotensinogen-Aldosterone system
- RAAS causes Na+/H2O reabsorption
Slide 3
7
Q
What would be concerning when it comes to Na levels and surgery?
A
Acute changes
≤125 or ≥155
Correct prior to elective cases
Slide 4 notes
8
Q
In hypovolemia, what fluid and Na abnormality would you expect?
What could be some causes?
A
- Na and H2O loss
- Diuretics, GI loss, burns, trauma
Slide 4 notes
9
Q
What could cause sodium decrease in a euvolemic state?
A
- Salt restriction
- Endocrine-related: hypothyroid, SIADH (retaining H2O more than Na)
Slide 4
10
Q
What disease processes could cause hyponatremia in a hypervolemic state with a urine Na >20?
A
- ARF/CKD
- Heart failure
Slide 4 notes
11
Q
What percentage of hospitalized patients are considered hyponatremic?
What could be a cause?
A
- 15%
- Over fluid-resuscitation
- ↑ endogenous vasopressin
Slide 4 notes
12
Q
Clinical neurological presentation of hyponatremia: 130-135 mEq/L
A
- Asymptomatic
- Headache
- Nausea
- Vomiting
- Fatigue
- Confusion
- Muscle cramps
- Depressed reflexes
*Bold are individual to this category and are not repeated in the next category
Slide 5
13
Q
Clinical neurological presentation of hyponatremia: 120-130 mEq/L:
A
- Malaise
- Unsteadiness
- Headache
- Nausea
- Vomiting
- Fatigue
- Confusion
- Muscle cramps
*Bold are individual to this category and are not repeated in the other categories
Slide 5
14
Q
Clinical neurological presentation of hyponatremia: <120 mEq/L
A
- Headache
- Restlessness
- Lethargy
- Seizures
- Brain-stem herniation
- Respiratory arrest
- Death
*Bold are individual to this category and are not repeated in the other categories
Slide 5
15
Q
Which are the most severe consequences of hyponatremia:
A
- Seizures
- Comma
- Death
Slide 5
16
Q
What is the single most important for the treatment of hyponatremia?
What are some treatment options?
A
- Treat underlying cause (look at volume status)
- Electrolyte drinks
- Normal saline
- Diuretics
- Hypertonic saline/3% NaCl
Slide 6
17
Q
What should the infusion rate be when treating hyponatremia with 3% NaCl hypertonic solution?
What should the Na correction not exceed?
A
- 80 ml/hr over 15h
- Correction should not exceed 1.5 mEq/L/hr
Slide 6
18
Q
What could happen with rapid correction of hyponatremia?
How fast would you have to correct in order to achieve this adverse effect?
Is this a serious or reversible adverse effect?
A
- Osmotic Demyelination Syndrome
- You’d have to correct >6 mEq/L in 24h
- Serious - often permanent neuro damage
Slide 6
19
Q
Are hyponatremic seizures a medical emergency?
How would you treat this?
A
- Yes! neurological damage could occur
- 3-5 ml/kg of 3% over 20 min until seizures resolve
Slide 6
20
Q
What are some causes of HYPERnatremia?
A
- Diabetes insipidus
- Excessive evaporation
- Poor oral intake (very young, very old, altered mental status)
- Overcorrection of hyponatremia
- GI losses
- Excessive sodium bicarb (treating acidosis)
Slide 7
21
Q
HYPERnatremia diagnostic algorithm
Hypovolemia
S/S:
- Urine Na >20:
- Urina Na <20:
Treatment:
A
PPT notes: Renal or GI loss
S/S: Decreased skin turgor, flat neck veins, dry mucous membranes, orthostatic hypotension, tachycardia, oliguria
Urine Na >20: Renal salt and water loss
- Osmotic diuretic
- Loop diuretic
- Postrenal obstruciton
- Intrinsic recall disease
- Profound glycosuria
Urine Na <20: Extrarenal salt and water loss
- Diarrhea
- GI fistulas
- Sweating
Treatment: Normal saline
Slide 8/9
22
Q
HYPERnatremia diagnostic algorithm
Euvolemia
- Urine Na ______?
Treatment:
A
Urine Na variable
Renal water loss:
- Diabetes insipidus: Central, nephrogenic, gestational
Extrarenal water loss:
- Insensible losses: Respiratory tract; Skin
Treatment: water replacement (po or D5W)
Slide 8
23
Q
HYPERnatremia diagnostic algorithm
Hypervolemia
S/S
Urine Na >20:
Treatment:
A
S/S: Peripheral edema, rales, ascites
Urine Na >20: Sodium gains
- Hyperaldosteronism
- Cushing’s syndrome
- Hypertonic dialysis
- IV NaHCO3
- NaCl tablets
- Hyperalimentation
- Salt water drowning
Treatment: diuretics
Slide 8/9
24
Q
What are common symptoms of HYPERnatremia?
A
LORDTS (Madea’s voice)
- Lethargy
- Orthostasis
- Restlessness
- Death
- Tremor/muscle twitching
- Seizures
25
How would you treat HYPERnatremia in hypovolemic, euvolemic, or hypervolmeic states?
Root cause, Assess volume status (VS, UOP, Turgor, CVP)
- Hypovolemic: normal saline
- Euvolemic: water replacement (po or D5W)
- Hypervolemic: diuretics
Slide 9
26
How fast do you want to reduce Na levels for correction?
Why would you want to correct at this rate?
≤ 0.5 mmol/L/hr and ≤ 10 mmol/L/day
- To avoid cerebral edema, seizures, and neurological damage
27
What is the percentage of the major intracellular fluid (ICF) cation (K+) that is present in the extracellular fluid (ECF)?
Less than 1.5% of the major intracellular fluid cation is present in the extracellular fluid.
28
Does serum potassium (K+) reflect transmembrane K+ regulation or total body K+ more accurately?
Serum potassium (K+) reflects transmembrane K+ regulation more than total body K+.
29
What is the effect of aldosterone on potassium and sodium in the distal nephron?
Aldosterone causes the distal nephron to secrete potassium (K+) and reabsorb sodium (Na+).
30
How does renal failure affect potassium excretion?
In renal failure, potassium excretion declines and excretion shifts towards GI system.
31
When renal potassium excretion declines, where does the excretion shift towards?
When renal potassium excretion declines, excretion shifts towards the gastrointestinal (GI) system.
32
What dietary issue can cause low serum potassium?
Low PO intake
33
By which 2 ways mentioned in the PPT can we lose K+ through the kidneys?
Diuretics use and hyperaldosteronism can cause renal loss of potassium.
34
How can gastrointestinal issues lead to low potassium?
Nausea, vomiting, diarrhea, and malabsorption can cause gastrointestinal loss of potassium.
35
Which conditions lead to an intracellular shift of potassium?
Alkalosis, the use of β-agonists, and insulin administration can cause an intracellular shift of potassium.
36
Which medical condition related to diabetes can cause low serum potassium? How?
Diabetic ketoacidosis (DKA) can lead to low serum potassium due to osmotic diuresis.
37
Which type of blood pressure medication can lead to a decrease in potassium?
Hydrochlorothiazide (HCTZ) found in some blood pressure medications.
38
What unusual dietary source can lead to low potassium levels?
Excessive consumption of licorice.
39
What are general types of symptoms seen in hypokalemia?
Generally cardiac and neuromuscular symptoms.
40
What muscular symptoms can hypokalemia cause?
Muscle weakness and cramps.
41
What is 'Ileus' in the context of hypokalemia?
A disruption of the normal propulsive gastrointestinal motor activity due to hypokalemia.
42
How does hypokalemia affect the heart?
It can cause dysrhythmias and U waves on an EKG.
43
What is the typical rate for IV potassium replacement?
Generally 10-20 mEq/L per hour IV.
44
What is the preferred route of potassium administration for treating hypokalemia?
Potassium orally is preferred over intravenous; central venous catheter (CVC) may be used; treatment may require several days.
45
What is the effect of 10 mEq IV potassium on serum levels?
Each 10 mEq of IV potassium can raise the serum potassium by approximately 0.1 mmol/L.
46
What treatments or actions should be avoided in hypokalemia?
Avoid excessive insulin, β-agonists, bicarbonate, hyperventilation, and diuretics.
47
What are renal-related causes of hyperkalemia?
Renal failure and hypoaldosteronism (causes K+ secretion and excretion)
48
Which type of drugs affecting the renin-angiotensin-aldosterone system (RAAS) can cause hyperkalemia?
Drugs that inhibit RAAS and drugs that inhibit K+ excretion
49
How can neuromuscular blocking agents affect potassium levels?
Depolarizing NMBs like Succinylcholine (Succs) can cause hyperkalemia by increasing serum K+ by 0.5 to 1 mEq/L
*mEq is used interchangibly in monovalent ions just fyi
ChatGPT:
For monovalent ions (those with a charge of +1 or -1), like potassium (K+), sodium (Na+), chloride (Cl-), and bicarbonate (HCO3-), 1 mmol/L is equivalent to 1 mEq/L because their valence is 1.
However, for divalent ions (those with a charge of +2 or -2), like calcium (Ca2+), magnesium (Mg2+), and sulfate (SO4^2-), the situation is different. For these ions, 1 mmol/L is equivalent to 2 mEq/L because their valence is 2. Therefore, when converting concentrations for divalent ions, the concentration in millimoles is multiplied by 2 to get the concentration in milliequivalents.
50
What role does acidosis play in potassium balance?
Both respiratory and metabolic acidosis can lead to hyperkalemia.
51
Which conditions associated with cell damage can lead to hyperkalemia?
Cell death from trauma, use of tourniquets, and massive blood transfusion.
52
What neuromuscular symptoms can occur with hyperkalemia?
Skeletal muscle paralysis and decreased fine motor skills.
53
How does hyperkalemia affect the heart?
It can cause cardiac dysrhythmias.
54
What are the EKG progression signs of hyperkalemia?
* Peaked T waves
* P wave disappearance
* Prolonged QRS complex
* Sine wave formation
* Asystole
55
When should you dialyze a hyperkalemic patient before surgery?
Dialyze within 24 hours prior to surgery.
56
What is the first initial treatment for hyperkalemia and why?
Calcium is given to quickly stabilize the cell membrane.
57
How does hyperventilation affect serum potassium levels?
Increasing the pH by 0.1 can decrease K+ by 0.4-1.5 mmol/L.
58
What is the role of insulin and glucose in treating hyperkalemia?
Insulin 10 units IV + glucose 25g D50 —> lower K+ levels in 10-20 minutes.
59
What is the role of bicarbonate in managing hyperkalemia?
Bicarbonate can help shift potassium into cells by increasing blood pH, reducing serum levels.
60
How does Kayexalate work in treating hyperkalemia?
Kayexalate binds to K in digestive tract and removes potassium from the body, working over hours to days.
61
What should be avoided in the management of hyperkalemia?
- Avoid using Succinylcholine (0.5-1 mEq/L increase)
- Hypoventilation (decreased pH=increased K)
- Lactated Ringer's solution (will also decrease pH=increased K)
- Potassium-containing IV fluids.
62
What is the distribution of calcium in the body?
Only 1% of the body’s calcium is in the extracellular fluid (ECF); 99% is stored in bones.
63
Which form of plasma calcium is physiologically active?
Only ionized plasma calcium (Ca++) is physiologically active, not protein-bound calcium.
64
What are the normal levels of ionized calcium (iCa++) in the blood?
Normal iCa++ levels range from 1.2 to 1.38 mmol/L.
65
How are ionized calcium levels affected by albumin and pH?
- 60% plasma Ca++ is protein bound (mainly to albumin)
- pH changes influence the binding of Ca++ to albumin
Increase in pH/alkalosis=Increased Ca++ binding to albumin, therefore a decrease in plasma Ca++
66
Which hormone increases gastrointestinal absorption, renal reabsorption of calcium, and pulls calcium from bone?
Parathyroid hormone (PTH) increases GI absorption, renal reabsorption, and mobilizes calcium from bone.
67
What role does vitamin D play in calcium regulation?
Vitamin D augments intestinal calcium absorption.
68
How does calcitonin affect calcium levels?
Calcitonin promotes bone resorption, which decreases plasma calcium levels.
69
Aldosterone _________ effects K+
inversely
70
3 major categories of cause of hypokalemia?
Renal loss
GI loss
Transcellular shift
71
Aldosterone causes K+ ________ & ________
secretion & excretion
72
Succinylcholine increases serum K+ by __________
0.5-1 mEq/L
73
Dialysis ALSO initially causes ___________
Hypovolemia
74
pH Δ’s influence the ____________ of Ca++ to albumin
binding
75
___% plasma Ca++ is protein bound (mainly to _________)
- 60
- Albumiin
76
↑pH/Alkalosis leads to ↑Ca++ binding to albumin
Therefore, there will be a ________ in plasma iCa++
decrease
77
What can cause a decrease in parathyroid hormone (PTH) secretion leading to hypocalcemia?
complication of thyroid or parathyroid surgery.
78
How does magnesium deficiency affect calcium levels?
Magnesium deficiency can lead to hypocalcemia as magnesium is required for PTH production
79
What role does vitamin D play in calcium levels?
Low vitamin D or disorders of vitamin D metabolism can lead to hypocalcemia due to reduced calcium absorption from the gut.
80
How does renal failure contribute to hypocalcemia?
Renal failure can cause hypocalcemia due to the kidneys not responding to PTH effectively.
81
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Why can massive blood transfusions lead to hypocalcemia?
The citrate preservative in blood products can bind calcium, leading to hypocalcemia.
82
What are the target sites of PTH action to increase calcium absorption?
PTH acts on:
- The bones to mobilize calcium
- The kidneys to increase calcium reabsorption
- The gastrointestinal system to enhance calcium absorption
83
Why is magnesium important for PTH function?
Magnesium is essential for the production and secretion of PTH.
84
What is the role of Vitamin D in calcium homeostasis?
Vitamin D facilitates gastrointestinal absorption of calcium.
85
When should ionized calcium (iCa++) levels be checked in the context of blood transfusions?
Check iCa++ after transfusing 4 or more units of packed red blood cells (PRBCs), as you may need to administer calcium to counteract the binding effects of citrate in transfused blood.
86
What are neurological symptoms of hypercalcemia?
Confusion and lethargy.
87
How does hypercalcemia affect muscle tone and reflexes?
Causes hypotonia and decreased deep tendon reflexes (↓DTR).
88
What are gastrointestinal symptoms of hypercalcemia?
Abdominal pain and nausea/vomiting (N/V).
89
What is a characteristic EKG change in hypercalcemia?
Short QT interval (QT-I).
90
What chronic condition can result from elevated calcium levels?
hypercalciuria and nephrolithiasis.
91
What sensations are typical in hypocalcemia?
Paresthesias.
92
What behavioral changes might indicate hypocalcemia?
Irritability.
93
How can hypocalcemia affect blood pressure?
Hypocalcemia can cause hypotension (HoTN).
94
What are severe neurological symptoms of hypocalcemia?
Seizures and myocardial depression.
95
What is a characteristic EKG change in hypocalcemia?
Prolonged QT interval (QT-I).
96
What is a life-threatening complication of hypocalcemia post-parathyroidectomy?
Hypocalcemia-induced laryngospasm
97
Extra caution when extubating parathyroidectomy, always have ____________ plan
Larangospasm
98
What dietary issues can lead to hypomagnesemia?
Low dietary intake or poor absorption can cause hypomagnesemia.
99
How can renal function affect magnesium levels?
Renal wasting can lead to hypomagnesemia.
100
What are muscular symptoms of hypomagnesemia?
Muscle weakness or excitation can occur.
101
What are the neurological effects of hypomagnesemia?
**Seizures** may be a symptom of hypomagnesemia.
102
What cardiac dysrhythmia is associated with hypomagnesemia?
Polymorphic V-tach or
Torsades De Pointes
103
Where are the kidneys located?
Retroperitoneal T12-L4
Right is slightly caudal to the left to accommodate liver
104
How common is hypermagnesemia and what are its usual causes?
Hypermagnesemia is very uncommon and is generally due to:
Overtreatment
- Pre-eclampsia/eclampsia
- Pheochromocytoma
105
What symptoms are associated with magnesium levels of 4-5 mEq/L?
Lethargy, nausea/vomiting (N/V), and flushing.
106
What symptoms appear when magnesium levels exceed 6 mEq/L?
Hypotension (HoTN) and decreased deep tendon reflexes (↓DTR).
107
What are the severe symptoms of magnesium levels over 10 mEq/L?
Paralysis, apnea, heart blocks, and cardiac arrest.
108
What are the treatment options for hypermagnesemia?
diuresis
intravenous calcium (to stabilize cell membranes)
dialysis.
109
What is the nephron?
The nephron is the primary structural and functional unit of the kidney. Each kidney contains approximately 1 million nephrons.
110
What are the main components of a nephron?
A nephron consists of the:
* glomerulus, tubular system
* Bowman's capsule
* proximal tubule (PCT)
* loop of Henle
* distal tubule (DCT)
* collecting duct.
111
What percentage of cardiac output does the kidney receive?
The kidneys receive 20% of the cardiac output (COP).
112
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How much blood do the kidneys filter per minute?
The kidneys filter 1 to 1.25 liters of blood per minute (L/min).
113
What is the outer layer of the kidney called and what percentage of renal blood flow (RBF) does it receive?
The outer layer is called the cortex, and it receives the majority of renal blood flow, about 85-90%.
114
What is the inner layer of the kidney called?
The inner layer of the kidney is called the medulla.
115
Which part of the kidney is particularly vulnerable to necrosis due to hypotension?
The Loop of Henle (LOH) in the medulla is particularly vulnerable to developing necrosis in response to hypotension (decreased kidney perfusion).
116
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What do the kidneys regulate in terms of extracellular fluid?
extracellular (EC) volume
osmolarity
composition.
117
How do the kidneys contribute to blood pressure regulation?
via RAAS and atrial natriuretic peptide (ANP).
118
What is the role of the kidneys in excretion?
The kidneys excrete toxins and metabolites from the body.
119
How do the kidneys maintain acid/base balance?
by excreting hydrogen ions and reabsorbing bicarbonate.
120
What hormones are produced by the kidneys?
renin
erythropoietin
calcitriol
prostaglandins.
121
How do the kidneys assist in blood glucose homeostasis?
by producing glucose through gluconeogenesis
filtration and reabsorption of glucose
122
What is the normal range for the glomerular filtration rate (GFR)?
The normal GFR range is 125-140 mL/min.
It is the best measure of renal function over time
heavily influenced by hydration status.
123
What is the creatinine clearance range and how is it performed?
Creatinine clearance measures 110-140 mL/min and is obtained from a 24-hour urine test.
Creatinine is freely filtered and not reabsorbed, making this the most reliable measure of GFR.
124
What is the normal range for serum creatinine and what does it indicate?
0.6-1.3 mg/dL
correlates with muscle mass.
influenced by:
- high protein diet
- supplements
- muscle breakdown.
125
Why is having a baseline serum creatinine important in acute monitoring?
It is important for acute monitoring as serum creatinine (SC) is inversely related to GFR.
In acute cases, a doubling of SC can mean a drop in GFR by 50%.
126
What is the role of the Renin-Angiotensin-Aldosterone system (RAAS)?
RAAS increases sodium and water reabsorption, which helps regulate volume and blood pressure.
127
How does Atrial Natriuretic Peptide (ANP) function in the kidneys?
ANP is secreted from cardiac atria and binds to receptors in the kidney
leading to increased sodium and water excretion to decrease blood volume and pressure.
128
How do the kidneys regulate pH balance?
The kidneys regulate pH balance by the reabsorption and excretion of bicarbonate (HCO3-) and hydrogen ions (H+).
129
What is Erythropoietin's (EPO) role in renal function?
EPO is involved in red blood cell (RBC) production
renal patients often require EPO supplementation due to kidney dysfunction.
130
What role does Calcitriol play in renal function?
Calcitriol is crucial for maintaining serum calcium levels.
131
What is the role of prostaglandins (PGs) in the kidneys?
Prostaglandins act as inflammatory modulators
vasodilatory effects that help maintain renal blood flow.
132
How are the kidneys involved in glucose regulation?
The kidneys contribute to gluconeogenesis and are responsible for the filtration and reabsorption of glucose.
133
What is the normal range for Blood Urea Nitrogen (BUN)?
The normal range for BUN is 10-20 mg/dL.
134
What does a low BUN indicate?
malnutrition or a volume-diluted state.
135
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What could cause a high BUN level?
high protein diet
dehydration
GI bleed
trauma
muscle wasting.
136
What is the normal BUN:Creatinine ratio and what does it signify?
The normal BUN:Creatinine ratio is 10:1
measure of hydration status because BUN is reabsorbed and creatinine is not.
137
What does proteinuria indicate and what is the normal range?
Normal proteinuria is less than 150 mg/dL. More than 750 mg/day could suggest glomerular injury or a urinary tract infection (UTI).
138
What does the specific gravity of urine measure and what is the normal range?
1.001-1.035
compares the weight of 1ml urine to 1ml distilled water
measures the nephron’s ability to concentrate urine.
139
What should be considered when assessing a patient's hydration status?
history and physical exam
orthostatic pressure changes.
140
Which lab changes might you see with dehydration?
Decreased base excess (↓BE)
increased lactate levels
141
What is a late sign of volume loss in renal assessment?
A drop in urine output (UOP) is a late sign of volume loss.
142
What is the normal range for urine output?
Normal UOP is 30 ml/hr or 0.5-1 ml/kg/hr.
143
How is oliguria defined?
UO less than 500 mL/ 24 hours.
144
What does a compressed/collapse IVC indicate?
What other way could you have to patient do to determine fluid responsiveness?
50% collapse = Dehydration
Passive leg raise to determine fluid responsiveness
145
How can ultrasound (US) be used in assessing volume status?
Ultrasound is used to assess the inferior vena cava (IVC) for changes in diameter that correlate with volume status.
Slide 28 - extra info added by ChatGPT
146
What do CVP and RAP indicate in volume monitoring?
Central venous pressure (CVP) and right atrial pressure (RAP) are indicators of right-sided heart pressures and can reflect fluid status.
Slide 28 - extra info added by ChatGPT
147
Why are LAP and PCWP important in renal assessment?
LAP and PAWP —> stimuli for renal vasoconstriction, affecting kidney function.
Slide 28 - extra info added by ChatGPT
148
What does pulmonary artery pressure (PAP) indicate?
Pulmonary artery pressure (PAP) can indicate fluid overload, especially in the context of heart failure.
Slide 28 - extra info added by ChatGPT
149
What does stroke volume variation (SVV) measure?
SVV compares inspiratory vs. expiratory pressure to assess fluid responsiveness, particularly in ventilated patients with sinus rhythm.
Slide 28 - extra info added by ChatGPT
150
Over what time period does acute kidney injury develop?
AKI develops over hours to days.
151
What percentage of hospitalized and ICU patients are affected by AKI?
AKI affects 20% of hospitalized patients and 50% of ICU patients.
152
What are common causes of AKI?
hypotension
hypovolemia
nephrotoxins.
153
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What is azotemia and its significance in AKI?
Azotemia is the buildup of nitrogenous waste products such as urea and creatinine
**hallmark** of AKI
154
What is the mortality rate of AKI with multi-system organ failure (MSOF) requiring dialysis?
mortality rate greater than 50%.
155
Can AKI be reversible and what intervention may be used?
AKI is reversible with timely interventions
managed with Continuous Venovenous Hemodiafiltration (CVVHD) to get through temporary insults.
156
Risk Factors of AKI:
* Pre-existing renal disease
* Advanced age
* CHF
* PVD
* Diabetes
* Sepsis (hypotension)
* Jaundice
* Major operative procedures
* IV Contrast
157
What serum creatinine changes meet the AKI diagnostic criteria?
An increase in serum creatinine by 0.3 mg/dL within 48 hours or an increase by 50% within 7 days.
158
What changes in creatinine clearance indicate AKI?
A decrease in creatinine clearance by 50%.
159
Is oliguria always present in AKI?
Abrupt onset of oliguria is a diagnostic criterion, although it is not always seen in AKI.
160
Can AKI be asymptomatic?
Yes, AKI can be asymptomatic.
161
What general symptoms might a person with AKI experience?
Malaise and hypotension (HoTN) can be symptoms of AKI.
162
What are the volume status symptoms associated with AKI?
Patients may present as hypovolemic or hypervolemic.
163
Prerenal Azotemia Causes:
**Pre-renal= ↓ renal perfusion**
Hemorrhage
GI fluid loss
Trauma
Surgery
Burns
Cardiogenic shock
Sepsis
Aortic clamping
Thromboembolism
164
Renal Azotemia Causes:
**Renal = nephron injury**
Acute glomerulonephritis
Vasculitis
Interstitial nephritis
Acute Tubular Necrosis (ATN)
Contrast dye
Nephrotoxic drugs
Myoglobinuria
165
Postrenal Azotemia Causes:
**Post-renal = outflow obstruction (easiest to treat)**
Nephrolithiasis
Benign Prostatic Hyperplasia (BPH)
Clot retention
Bladder carcinoma
166
What is the prevalence of pre-renal azotemia in AKI cases?
Pre-renal azotemia is the most common form of AKI, accounting for half of hospital-acquired AKI cases.
167
How can anesthesia medications affect renal blood flow?
Anesthesia medications, along with volume and blood loss, can lead to decreased renal blood flow (RBF).
168
What is the typical BUN:Cr ratio in pre-renal AKI?
In pre-renal AKI, the BUN:Creatinine ratio is greater than 20:1.
169
Is pre-renal azotemia reversible?
Yes, pre-renal azotemia is usually reversible as it's often a volume issue.
170
: What is the relationship between pre-renal azotemia and acute tubular necrosis (ATN)?
Pre-renal azotemia is the most common cause of ATN if not reversed, as the condition can progress from pre-renal to renal azotemia.
171
What happens to sodium and water reabsorption in pre-renal azotemia?
In pre-renal azotemia, the body is still reabsorbing sodium and water efficiently.
172
What is renal azotemia?
Renal azotemia is intrinsic renal disease and is a potentially reversible condition along a continuum of renal injury
Renal AKI BUN:Cr decreased from pre-renal AKI (>20)
173
What are the treatments for pre-renal azotemia?
renal blood flow with fluids
mannitol
diuretics
maintaining mean arterial pressure (MAP)
possibly using pressers.
174
Decreased GFR is a _______ of renal azotemia
Decreased GFR is a late symptom
indicating significant impairment in kidney function.
175
How does renal azotemia affect blood urea nitrogen (BUN) levels?
decreased urea reabsorption in the proximal tubule —> decreased BUN.
176
What happens to blood creatinine levels in renal azotemia?
Decreased creatinine filtration leads to increased blood creatinine levels.
177
What is the typical BUN:Creatinine ratio in renal azotemia?
The BUN:Creatinine ratio often falls below 15:1 in cases of renal azotemia.
178
What is the primary cause of post-renal azotemia?
Post-renal azotemia is caused by outflow obstruction of urine from the kidneys.
179
What effect does post-renal azotemia have on nephron tubular pressure?
It leads to increased nephron tubular hydrostatic pressure.
180
Which diagnostic tool is useful for post-renal azotemia?
Renal ultrasonography —> identifying the cause and location of the obstruction.
181
How does the duration of obstruction affect reversibility in post-renal azotemia?
The reversibility of post-renal azotemia is inversely related to the duration of the obstruction.
Increased reversibility = decreased duration
182
What is the treatment for post-renal azotemia?
The treatment involves removing the obstruction if possible.
183
What can prolonged obstruction lead to in post-renal azotemia?
damage in the tubular epithelium.
184
What causes prerenal AKI and what are its features?
volume loss or decreased effective arterial blood volume
due to conditions like cardiorenal or hepatorenal syndrome, and certain drugs.
It's characterized by a
BUN/Cr ratio > 20:1
FeNa (fractional excretion of Na) < 1%
FEurea (Fractional excretion of Urea) < 35%.
Urine [Na] <20
Seditment: Bland and hyaline casts
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185
What causes intrinsic AKI and what are its features?
damage to the glomeruli, tubules, or interstitium.
Causes include ATN, ischemia, toxic substances, and inflammation.
It's characterized by a
BUN/Cr ratio < 20:1
FeNa > 2% for ATN (varies for other causes)
FEurea > 50% for ATN.
Urine [Na] >20
Sediment - ATN=Muddy, brown casts;
AIN= WBC casts+ Neg Ucx;
GN= RBC casts;
Abx/chol. emboli= urine E.O.s;
NSAIDS= lymphocytes
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186
What are the key diagnostic markers for different types of AKI?
Urine sediment in
-prerenal AKI is typically bland with hyaline casts.
-In intrinsic AKI, the urine sediment can show muddy brown casts for ATN and White blood cell casts for acute interstitial nephritis (AIN), among others.
- postrenal AKI urine sediment might contain blood.
187
Neurological complications of AKI
Related to **protein/amino acids buildup** in blood
**Uremic Encephalopathy** (Dialysis improves)
Mobility disorders
Neuropathies
Myopathies
Seizures
Stroke
188
What are the cardiovascular complications associated with AKI?
systemic hypertension,
left ventricular hypertrophy (LVH),
congestive heart failure (CHF),
pulmonary edema,
uremic cardiomyopathy,
arrhythmias
pericarditis with or without effusion.
189
What is the typical progression of cardiovascular complications in AKI?
The typical order of incidence is hypertension (HTN) → LVH → CHF → ischemic heart disease → anemic heart failure → rhythm disturbances → pericarditis with or without effusion → cardiac tamponade → uremic cardiomyopathy.
190
What type of anemia is associated with AKI?
due to decreased
- erythropoietin (EPO) production,
- reduced red blood cell production,
- decreased red blood cell survival.
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How does AKI affect platelet function?
AKI can lead to platelet dysfunction
platelet function assays or thromboelastography (TEG) are valuable for assessing this condition.
192
What role does von Willebrand factor (vWF) play in AKI?
vWF is disrupted by uremia in AKI, which can affect coagulation.
193
What is the role of DDAVP in the management of hematological complications in AKI?
Prophylactic Desmopressin (DDAVP) can increase vWF and Factor VIII levels, which helps improve coagulation in patients with AKI.
194
Why might coagulation factors be affected in AKI?
Uremic conditions in AKI disrupt normal coagulation factor function, necessitating interventions like DDAVP to restore effective coagulation.
195
What electrolyte imbalance is commonly seen in AKI?
Hyperkalemia is a common electrolyte imbalance in AKI due to decreased excretion by the kidneys.
196
What fluid and electrolyte imbalances are associated with AKI?
fluid overload or Na depletion.
197
Albumin is ____ in AKI, Why?
Low
kidneys allow albumin to escape in AKI due to altered glomerular permeability.
198
What type of acid-base imbalance is often seen in AKI?
Metabolic acidosis is common in AKI because the kidneys cannot excrete acid effectively.
199
How does AKI contribute to malnutrition?
losses of nutrients and protein through impaired kidney function.
200
What is the connection between AKI and hyperparathyroidism?
Hyperparathyroidism may develop as the parathyroid glands go into overdrive in an attempt to stimulate the kidneys to reabsorb calcium,
often a **compensatory response** to the kidneys' impaired function in AKI.
201
What initial management steps should be taken for AKI in the context of anesthesia?
Correct fluid, electrolyte, and acid/base status to prevent further renal injury.
202
What type of fluid is preferred for AKI management during anesthesia and why?
**Normal Saline (NS)** is preferred due to the **absence of potassium**, which is important for patients at risk of hyperkalemia.
203
What should be considered when using colloids in AKI?
risk of exacerbating fluid overload and affecting osmolarity.
204
What is the target for mean arterial pressure (MAP) maintenance during anesthesia in AKI?
Maintain MAP at least 20% of baseline to ensure adequate renal blood flow.
205
What role do vasopressors play in managing AKI during anesthesia?
Vasopressors, such as Vasopressin and Alpha-agonists, may be used to maintain MAP and renal perfusion.
206
Why is prophylactic sodium bicarbonate administered during anesthesia in the context of AKI?
decrease the formation of free radicals
prevents acute tubular necrosis (ATN) from progressing to renal failure.
207
How does Vasopressin aid in managing AKI compared to alpha agonists?
Vasopressin preferentially constricts the efferent arteriole, which is more effective than alpha agonists for maintaining renal blood flow.
208
What is the preference regarding dialysis before surgery?
Prefer preoperative dialysis to optimize fluid and electrolyte balance, especially if the patient is already on a dialysis regimen
209
What lab values are particularly important to have before anesthesia in patients with kidney issues?
potassium (K+)
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What equipment should be readily available for patients with kidney issues undergoing anesthesia?
Point-of-care (POC)
211
How should drug dosing be approached in these patients?
tailored to the individual's renal function
avoiding drugs
- with active metabolites
- those that decrease renal blood flow (RBF)
- renal toxins.
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What may be required if the patient is unable to clear drugs on their own?
Post-op dialysis
213
What is CKD?
CKD stands for chronic kidney disease. It's a progressive condition where kidney function declines over time.
214
How does CKD commonly present?
* CKD patients often undergo surgeries for dialysis access
* May require procedures like toe/foot surgeries due to diabetes complications.
* They might also have non-healing wounds and frequent healthcare visits.
215
CKD chart to look at:
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What is the GFR range for Stage 1 CKD?
normal or increased GFR (>90 mL/min/1.73m²).
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What is the GFR range for Stage 2 CKD?
mildly decreased GFR (60-89 mL/min/1.73m²).
218
What is the GFR range for Stage 3 CKD?
moderately decreased GFR (30-59 mL/min/1.73m²).
219
What is the GFR range for Stage 4 CKD?
severely decreased GFR (15-29 mL/min/1.73m²).
220
What is the GFR range for Stage 5 CKD?
kidney failure with a GFR of less than 15 mL/min/1.73m².
221
What happens to GFR with age?
GFR decreases by 10 per decade starting from age 20.
222
What cardiovascular effects are associated with CKD?
systemic hypertension ( both the cause and consequence)
223
What contributes to the development of systemic hypertension in CKD?
- Retention of sodium and water, leading to volume overload leading to the activation of the renin-angiotensin-aldosterone system (RAAS).
224
What are the first-line treatments for hypertension in CKD?
Thiazide diuretics are often the first-line treatment for hypertension in CKD patients.
Additionally, ACE inhibitors (ACE-I) or angiotensin II receptor blockers (ARBs) may be necessary.
225
How do ACE inhibitors (ACE-I) and angiotensin II receptor blockers (ARBs) affect CKD?
ACE-I and ARBs are often used in CKD to:
- Decrease systemic blood pressure and glomerular pressure
- Reduce proteinuria by decreasing glomerular hyperfiltration
- Slow the progression of glomerulosclerosis
226
Why are ACE-I/ARBs typically withheld on the day of surgery for CKD patients?
to **_reduce the risk of profound hypotension_** during anesthesia induction.
227
What interventions may be necessary if ACE-I or ARBs are continued up to the day of surgery in CKD patients?
- Vasopressin
- Norepinephrine
- Epinephrine
may be needed to counteract the potential risk of hypotension.
228
What cardiovascular effects are associated with CKD?
dyslipidemia —> elevated triglycerides (>500 mg/dL) and LDL cholesterol (>100 mg/dL).
229
What is a common risk associated with dyslipidemia in CKD?
predisposed to "silent MI"
- may occur without typical symptoms due to peripheral and autonomic neuropathy, leading to **blunted sensation**
230
Which populations are at high risk for silent MI in CKD?
Women and individuals with diabetes
231
What hematologic effects are associated with CKD?
CKD commonly leads to anemia, which is often responsive to exogenous erythropoietin therapy. The target hemoglobin level for CKD patients is typically around 10 g/dL.
232
What are the considerations for platelet dysfunction in CKD?
CKD patients may experience platelet dysfunction, which can impact their coagulation status.
233
What should be considered before transfusing blood in CKD patients?
Excess hemoglobin can lead to sluggish circulation.
Acidosis and hyperkalemia is also associated with blood transfusions.
234
Indications to consider dialysis:
- Volume overload
- Severe hyperkalemia
- Metabolic acidosis
- Symptomatic uremia
- Failure to clear medications
235
What should be considered regarding dialysis modalities?
Hemodialysis (HD) is more efficient than peritoneal dialysis (PD).
However, PD may be more suitable for patients who can't tolerate fluid shifts, such as those with poor cardiac function.
236
What is the most common side effect of hemodialysis?
Hypotension
237
What is a leading cause of mortality in dialysis patients?
Infection due to their impaired immune system and delayed wound healing.
238
What considerations are important for anesthesia in patients with end-stage renal disease (ESRD)?
Anesthesia in ESRD patients requires:
- Assessing stability
- Monitoring body weight pre/post dialysis (within 24 hours of surgery)
- Evaluating blood pressure control
- Determining whether medications should be continued
- Managing glucose levels and A1C
- Taking aspiration precautions, especially in patients with diabetes and obesity.
239
What precautions should be taken for uremic bleeding in ESRD patients undergoing anesthesia?
- Assessing normal platelet count & function, PT, and PTT
Treatment options may include:
- Cryoprecipitate
- Factor VIII
- von Willebrand factor (vWF)
- Desmopressin, which peaks at 2-4 hours and lasts 6-8 hours
- Tachyphylaxis should also be considered.
240
How are many anesthetic agents eliminated in patients with renal impairment?
Many anesthetic agents are lipid-soluble and are reabsorbed by renal tubular cells, leading to prolonged effects in patients with renal impairment.
241
What type of anesthetic agents are preferred in patients with renal impairment?
use anesthetic agents that are not dependent on renal elimination to avoid potential toxicity and prolonged effects.
242
What characteristics make for the best neuromuscular blocking agents (NMB) in patients with renal impairment?
The best neuromuscular blocking agents (NMB) for patients with renal impairment are those that **_do not rely on renal elimination_**, as they can be safely used without the risk of accumulation and prolonged effects.
243
Which 2 analgesic medications mentioned in the PPT should be avoided in patients with renal impairment?
avoid analgesic medications such as **_morphine and Demerol (meperidine)_** due to the risk of **_accumulation of active metabolites_** and potential toxicity.
244
How are lipid insoluble drugs eliminated in patients with renal impairment?
Some medications are eliminated unchanged in urine, leading to prolonged duration of action (DoA) and increased risk of accumulation in patients with renal impairment.
245
How is renal dosing typically determined for medications?
Renal dosing of medications is usually based on glomerular filtration rate (GFR)
246
Give examples of medications that require renal dosing.
- Thiazide diuretics
- Loop diuretics
- Digoxin
- Many antibiotics
247
Name 2 induction drugs that are primarily eliminated by the kidneys.
Phenobarbital
Thiopental
248
Give 2 examples of muscle relaxants eliminated by the kidneys.
Pancuronium
Vecuronium
249
What are 2 cholinesterase inhibitors that undergo renal excretion?
Edrophonium
Neostigmine
250
Name 5 cardiovascular drugs that are excreted renally.
Atropine
Digoxin
Glycopyrrolate
Hydralazine
Milrinone
251
Name 4 antimicrobials are primarily excreted by the kidneys?
Aminoglycosides
Cephalosporins
Penicillins
Vancomycin
252
What morphine metabolites are excreted in the urine? by how much?
- morphine-3 glucuronide
- morphine-6 glucuronide
- 40%
253
What is normeperedine?
What are the main adverse effects of Normeperidine?
Active metabolite of meperedine
is **_neurotoxicity_**, which can manifest as nervousness, tremors, muscle twitches, and seizures.
254
How does Normeperidine accumulate in the body?
What is its parent drug elimination half-life?
What is normeperedine's elimiation half-life?
Multiple doses of meperidine result in the accumulation of Normeperidine due to its long elimination half-life (15-30 hours)
compared to meperidine (2-4 hours).
255
What is the recommended potassium level for elective surgery?
Potassium should be less than 5.5 mEq/L for elective surgery.
256
What is the recommendation for dialysis patients before elective surgery?
Dialysis patients should undergo dialysis within 24 hours preceding elective surgery.
257
Why is aspiration prophylaxis important, especially in patients with diabetes mellitus (DM)?
Aspiration prophylaxis is crucial, especially in patients with diabetes mellitus (DM), to prevent the risk of aspiration during surgery.
258
How does anesthesia and surgery affect renal blood flow (RBF) and glomerular filtration rate (GFR)?
Anesthesia and surgery decrease renal blood flow (RBF) and glomerular filtration rate (GFR).
259
How does blood loss affect renal blood flow (RBF)?
Blood loss activates baroreceptors, leading to increased sympathetic nervous system (SNS) outflow.
Catecholamines activate α1-receptors, causing afferent arteriole constriction and decreased renal blood flow (RBF).
260
What are the consequences of longer periods of hypotension during surgery?
Longer periods of hypotension, such as during cross-clamping, hemorrhage, or sepsis, lead to decreased renal blood flow (RBF).
261
What clinical signs indicate hypovolemia in the context of hyponatremia?
Decreased skin turgor,
flat neck veins,
dry mucous membranes,
orthostatic hypotension,
tachycardia,
oliguria.
262
With a urinary sodium concentration greater than 20 in a hypovolemic patient, what is the likely cause of hyponatremia?
Renal losses, which can be due to:
- Salt-losing nephritis
- Diuretic excess
- Osmotic diuresis
- Mineralocorticoid deficiency
- Ketonuria
- Renal tubular acidosis
- Metabolic alkalosis
263
What does a urinary sodium concentration less than 20 indicate in a hyponatremic and hypovolemic patient?
Extrarenal losses, such as those from vomiting, diarrhea, third space losses (like burns, pancreatitis, or muscle trauma).
264
What are the clinical signs of euvolemia in hyponatremia?
The absence of signs of volume depletion or volume overload; patients appear clinically normal in terms of volume status.
265
In euvolemic hyponatremia, what does a urinary sodium concentration above 20 suggest?
Causes such as:
- Glucocorticoid deficiency
- Hypothyroidism
- High sympathetic drive
- Drugs
- Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH).
266
For euvolemic hyponatremia with a urinary sodium concentration less than 20, what is the probable cause?
Salt-restricted diet.
267
What are the signs of hypervolemia in a patient with hyponatremia?
Peripheral edema, rales (crackles heard in the lungs), and ascites.
268
In hypervolemic hyponatremia, what does a urinary sodium concentration above 20 indicate?
Renal losses due to conditions like acute renal failure or chronic renal failure.
269
With a urinary sodium concentration less than 20 in a hypervolemic patient, what could be the causes of hyponatremia?
sodium reabsorption due to conditions such as nephrotic syndrome, cardiac failure, or cirrhosis.
270
In the context of hypovolemia and hyponatremia, what does a urinary sodium (UNa) concentration less than 20 mmol/L suggest?
External renal losses due
- vomiting
- diarrhea
- third-space losses (like burns, pancreatitis, or muscle trauma).
271
When assessing a euvolemic patient with hyponatremia, what does a urinary sodium (U_Na) concentration less than 20 mmol/L suggest when paired with symptoms like decreased skin turgor and dry mucous membranes?
It suggests a salt-restricted diet
272
What does a urinary sodium (U_Na) concentration greater than 20 mmol/L indicate in a hypervolemic patient with hyponatremia and signs like peripheral edema and ascites?
Renal losses due to acute renal failure or chronic renal failure.
273
What clinical signs suggest hypovolemia in the context of hypernatremia?
- Decreased skin turgor
- Flat neck veins
- Dry mucous membranes
- Orthostatic hypotension
- Tachycardia
- Oliguria.
274
In a hypovolemic patient with hypernatremia, what does a urinary sodium (U_Na) concentration greater than 20 mmol/L indicate?
Renal salt and water loss due to causes such as
- Osmotic diuretics
- Loop diuretics
- Postrenal obstruction
- Intrinsic renal disease
- Pofound glycosuria
275
For a hypovolemic patient with hypernatremia, what does a urinary sodium (U_Na) concentration less than 20 mmol/L suggest?
Extrarenal salt and water loss, potentially from diarrhea, GI fistulas, burns, or sweating.
276
What does euvolemia in a patient with hypernatremia indicate about their water loss?
It suggests renal water loss due to diabetes insipidus (central, nephrogenic, or gestational)
or
extrarenal water loss from insensible losses through the respiratory tract or skin.
277
What are the signs of hypervolemia in a patient with hypernatremia?
Peripheral edema, rales, and ascites.
278
In a hypervolemic patient with hypernatremia and a urinary sodium (U_Na) concentration greater than 20 mmol/L, what is the likely cause?
Sodium gains due to conditions such as
- Hyperaldosteronism
- Cushing's syndrome
- Hypertonic dialysis
- Intravenous sodium bicarbonate
- Sodium chloride tablets
- Hypertonic saline enemas
- Hypertonic alimentation
- Salt water drowning
279
What are the possible causes of renal salt and water loss leading to hypovolemic hypernatremia with a urinary sodium concentration greater than 20 mmol/L?
- Osmotic diuretic use
- Loop diuretic use
- Postrenal obstruction
- Intrinsic renal disease
- Profound glycosuria
280
What are some causes of extrarenal salt and water loss leading to hypernatremia with a urinary sodium concentration less than 20 mmol/L in a hypovolemic patient?
- Diarrhea
- Gastrointestinal fistulas
- Burns
- Excessive sweating
281
In the context of euvolemia with hypernatremia, what are the causes of renal and extrarenal water loss when the urinary sodium concentration is variable?
Renal water loss can be due to diabetes insipidus (central, nephrogenic, or gestational), and extrarenal water loss can be due to insensible losses from the respiratory tract or skin.
282
What consideration should be given to hemodynamic monitoring in patients with kidney issues?
There should be a low threshold for invasive hemodynamic monitoring to closely track and manage blood pressure and fluid status.
283
Which diuretics are useful in treating hyperkalemia?
Loop Diuretics can be used to increase renal excretion of potassium.
284
What are the symptoms of chronic hyperkalemia?
Chronic hyperkalemia may cause minimal symptoms like **_malaise and gastrointestinal upset_**.
