Urology And Gynecologic Flashcards
(85 cards)
1
Q
Is Max Pruss at high risk for OSA based on his STOP-Bang score? Ie I what qualifiess a high risk Stopbang
A
Yes
2
Q
What is GFR?
A
Rate of fluid filtration through glomeruli
3
Q
Why can creatinine clearance approximate GFR?
A
Creatinine is minimally secreted or reabsorbed
4
Q
What can be used to estimate GFR more precisely than creatinine clearance?
A
Inulin clearance
5
Q
What is the formula for creatinine clearance?
A
cr cl = ([urine cr] x V)/([serum cr][1440 min/day])
6
Q
What is the definition of a MET?
A
The amount of oxygen consumed by a 40-year-old 70 kg man while sitting at rest = 3.5 ml O2/kg/min
7
Q
What is the definition of Hct?
A
Volume of RBCs/ Volume of Blood x 100
8
Q
What is the DDx of macroglossia?
A
- Pseudomacroglossia
- Congenital
- Tumor or infection
- True Macroglossia
- Acquired
9
Q
DDx of polycythemia?
A
- Decreased plasma volume (dehydration)
- Increased RBC volume (mass)
- Primary -normal EPO
- Secondary-EPO elevated
-altitude
-OSA
-Smoking
10
Q
What is the definition of PAH?
A
sPAP > 30 mm Hg or mPAP > 20 mm Hg
11
Q
What percentage of patients with ESRD have PAH?
A
40%
12
Q
What is the major adverse sequelae associated with PAH?
A
RH Failure
13
Q
How does the presence of PAH alter anesthetic design?
A
- Preoperative treatment with pulmonary vasodilator
- Intraoperative monitoring with arterial line and TEE
- Avoid hypercarbia, hypoxia, hypothermia
*Low TV and peep to minimize intrathoracic pressures
14
Q
What is the mechanism of action of ACE inhibitors in renal artery stenosis?
A
Decrease efferent arteriole pressure
15
Q
What is the DDx of lactic acidosis?
A
- Type A (tissue hypoxia)
- Type B (cellular dysfunction)
16
Q
What is FE Na?
A
Fraction of sodium filtered by kidney that is excreted in the urine
If FeNa< 1 then it is pre-renal
17
Q
Is CIN usually reversible?
A
Yes
18
Q
Does acetylcysteine provide effective prophylaxis for CIN?
A
Probably NOT
19
Q
What is the underlying pathophysiology of CIN?
A
Medullary ischemia due to increased blood viscosity + intra-renal vasoconstriction
Tubular cell cytotoxicity
20
Q
What is the time course of CIN development?
A
24-48 hours post-contrast
21
Q
What is the typical peak time for serum creatinine in CIN?
A
3-5 days thereafter
22
Q
What is the role of hydrostatics in renal physiology?
A
Influences GFR and renal blood flow
23
Q
What are examples of exercises corresponding to > 4 METs?
A
- 2 FOS without stopping
- Walking uphill > 2 blocks
- Scrubbing floors
24
Q
What is the recommended preoperative hydration strategy?
A
Aggressive PO hydration; consider IV hydration immediately before CTA
25
What is the relationship between serum creatinine and GFR?
Nonlinear; small changes in low values reflect sizable changes in GFR
26
What is the incidence of pulmonary hypertension in obesity?
c. 5%
27
What is the definition of AKI?
Clinical syndrome defined as a functional or structural kidney abnormality that results in a > 0.3 mg/dL increase in serum creatinine from baseline within the prior 7 days OR oliguria defined as urine output < 0.5 ml/kg/hour for a defined length of time.
## Footnote
The magnitude of rise in serum creatinine and the length of time for oliguria define the AKI stage [KDIGO definition].
28
What are the major risk factors for postoperative AKI?
* CKI
* CHF
* AoXC
* DM
* HTN
* Emergency surgery
* Intraperitoneal surgery
* Ascites
29
What three factors are assumed to stay relatively constant when comparing GFR using serum creatinine?
* Secretion of creatinine into tubules
* Dietary intake
* Muscle mass
30
Does Max have AKI? What stage?
Yes; KDIGO stage 2: increase in serum cr = 2.9/1.4 = 2.1x baseline in prior 7 days (if his severe intraoperative oliguria persisted: stage 3)
31
What is the broad differential diagnosis (DDx) of AKI?
* Pre-renal AKI [60-70%]
* Intra-renal AKI [25-40%]
* Post-renal AKI [5-10%]
32
What is the definition of a pre-renal condition?
Decreased RBF
33
Ddx of prerenal AKI?
* Low MAP (low CO and/or low SVR)
* Elevated RVP (CHF and/or increased IAP) vascular pressure
* Elevated RVR- renal vascular resistance
RBF = RPP/RVR and RPP = MAP – RVP where RVR = renal vascular R
and RVP = renal venous pressure (Ohm’s Law)
34
What are common methods of establishing intravascular volume status?
* History of volume loss
* Orthostatic VS
* PE (skin turgor; mucous membranes)
* Urine output: fluid challenge
* Labs (UA, urine chemistries, Hct, BNP)
35
What is the utility of FE urea in the setting of AKI?
Helps differentiate between prerenal and intrinsic renal causes when urine Na and FE Na are not diagnostic due to diuretics.
36
What is ATN?
AKI associated with death of tubular epithelial cells characterized by “brown, muddy” tubular cell casts in the urine. May be ischemic and/or toxic in etiology.
37
What are common causes of perioperative ATN?
* Hypotension (ischemic)
* AoXC Surgery (ischemic)
* Sepsis (ischemic and toxic)
* Drugs (toxic)
* Rhabdomyolysis (ischemic and toxic)
38
What is the DDx of postrenal causes of AKI?
* Ureteral Obstruction
* Bladder Outlet Obstruction
* Urethral Obstruction
* Prostate Disease
* Bladder Disease
* Drugs
39
What are the implications of laparoscopies on renal blood flow?
May need higher MAPs to maintain RPP during prolonged laparoscopies due to increased RVP, direct compression of renal arterioles, and RAAS activation.
40
What indicates a diagnosis of rhabdomyolysis?
Presence of elevated creatine kinase (CK) and urine myoglobin.
41
What causes of intrarenal AKI initially show prerenal urinary indices?
* CIN
* Rhabdomyolysis
* GN (often)
* Hepatorenal Syndrome
42
What are the potential causes of hypotension leading to ischemic ATN during AoXC surgery?
* Decreased RAP
* Increased RVR (RAAS activation)
* Hypovolemic hypotension
* Post XC hypotension
* Cardiogenic hypotension
43
What does an ABG of 68/36/7.26/16 indicate?
HAGMA with inadequate respiratory compensation.
44
What is the broad differential diagnosis of intrarenal AKI?
* Glomerular Disease
* Acute Tubular Necrosis (ATN)
* Toxins
* Acute Interstitial Nephritis (AIN)
* Vascular Disease
* Vasculitis
* Occlusive Disease
* Thrombosis
* Embolism
45
What are the common methods for measuring renal function?
* Plasma flow measurement using PAH
* GFR measurement using inulin clearance
46
How can you confirm the diagnosis of Rhabdomyolysis?
Oliguric AKI with pre-renal picture (FE Na < 1), CK (> 15-20K U/L), and urine myoglobin
47
What metabolic/electrolyte abnormalities are often seen with Rhabdomyolysis?
* Lactic acidemia
* Hyperkalemia
* Hypocalcemia
* Hyperphosphatemia
* Hyperuricemia
48
What is the pathogenesis of AKI in Rhabdomyolysis?
Multifactorial: renal artery vasoconstriction (ischemic), direct tubular injury (toxic), tubular obstruction
49
What is the treatment for Rhabdomyolysis?
* Correct electrolyte/acid-base disturbances
* Aggressive IV hydration
* Forced diuresis: mannitol/loop diuretics (controversial)
* Urine alkalinization (controversial)
50
What are the indications for RRT in AKI?**
* Refractory volume overload
* Severe hyperkalemia
* Severe metabolic acidosis
* Uremic organ dysfunction
* Methanol or ethylene glycol intoxication
51
What is ATN?
Intrarenal AKI related to death of tubular epithelial cells characterized by 'brown, muddy' tubular cell casts in the urine
52
What conditions commonly cause ATN?
* Hypotension (ischemic)
* AoXC (ischemic)
* Rhabdomyolysis (ischemic and toxic)
* Sepsis (ischemic and toxic)
* Drugs (toxic)
53
What are the risk factors for perioperative Rhabdomyolysis?
* High BMI
* Hypotension
* Prolonged surgery (> 5 hours)
* Peripheral vascular disease
* Prolonged lithotomy or steep Tburg positions
54
What are common lab findings that indicate the need for dialysis?
* Serum [K+]
* Volume overload
* Uremic platelet dysfunction
55
What is the expected rise in serum [K+] from the use of succinylcholine?
0.5 - 1.0 mEq/L
56
What is the peak effect of IV regular insulin with respect to serum [K+]?
30-60 min
57
What is the likely cause of Max’s coagulopathy?
Uremic platelet dysfunction
Coagulopathy in the setting of AKI and platelet dysfunction
Treat with:
dialysis, DDAVP (0.3 ug/kg IV), cryoprecipitate, or platelets (1 u platelet apharesis = 6
random units)
58
How can you treat uremic platelet dysfunction?
* DDAVP 0.3 ug/kg IV
* Cryoprecipitate 10 u
* Platelets 1 apheresis pack
59
What is the moral of the story regarding aortic aneurysms?
They both are sensitive to loss of integrity.
60
What is the calculated Aa gradient for Amelia Earhart?
50% FiO2
Patm= 615
PaCO2-34
157 mm Hg
PAO2 = FiO2 [Patm – PH2O] – PaCO2/R
● PAO2 = .5 [615 – 47] – 34/.8 = 284 – 43 = 241 mm Hg since Denver
● So Aa gradient = 241 – 84 = 157 mm Hg
61
What is the expected normal Aa gradient for Amelia Earhart?
29 Torr
62
What does an elevated osmolal gap indicate?
> 10 mosmol/kg
Presence of osmotically active compounds not measured or calculated (glycine)
63
What syndrome is associated with the absorption of 1.5% glycine?
TURP syndrome
64
What causes dilutional hyponatremia in this patient? (Hysteroscopy)
Absorption of glycine when fluid pressure exceeds venous pressure
65
What is the osmolality of 1.5% glycine?
Approximately 200 mosm/L
66
What is the likely intravascular volume status of Amelia Earhart? Turp syndrome
Hypervolemic due to absorption of IV glycine solution
67
How is glycine metabolized in patients with functional livers?
Predominantly to NH4+ + CO2
68
Why is the patient excreting significant sodium?
SIADH due to perioperative surgical stress and glycine stimulating ADH release
69
What is Amelia Earhart's sodium deficit?
1,647 mEq
● TBW = .6 (102 kg) = 61 L
● So, deficit = (135 – 108) mEq/L x 61 L = 1,647 mEq
● This represents c. 3 L of 3% saline (513 mEq/
70
What is the correction strategy for symptomatic hyponatremia?
Use 3% saline but consider loop diuretic first
71
What is the goal for sodium increase during treatment?
Increase of [Na+] of 4-6 mEq/L in first 6 hours, but not > 12 mEq/L in first 24 hours
72
What other problem is associated with glycine intoxication?
Hyperammonemia leading to encephalopathy
73
Why is glycine intoxication associated with cerebral edema?
Selective diffusion of glycine into the brain draws water into brain tissue
74
What problems can occur during hysteroscopic surgeries?
* Hyponatremia * Volume overload * Uterine perforation * CO2 embolization * Hypothermia * Coagulopathy
75
How is uterine perforation managed?
Diagnosis via laparoscopy; management depends on the likelihood of event and nature of presentation
76
What technology has made TURP syndrome rare?
Bipolar electrocautery
77
Ddx of macroglossia
Pseudomacroglossia- displacement of tongue forward
-congenital or tumor/infection
True macroglossia (big tongue)
-congenital
-acquired-amyloid/hypothyroid//acromegaly
78
Describe the relationship between GFR and serum creatinine
small changes in low values of serum
creatinine reflect sizable changes in GFR
79
How can someone have tight 3 vessel disease and have a “non-ischemic” MPI?
Uniformly poor uptake (diffuse ischemia) of radioisotope will
mimic uniform significant uptake (no ischemia). Therefore, if
you have a high index of suspicion, CTA or cath (Swerdlow).
80
How do COX inhibitors decrease RBF?
Ibuprofen/celebrex
Afferent arteriole vasoconstriction
81
What medication POSSIBLY protects against CIN
Statins
82
3 criteria in Contrast induced-AKI
>0.5 mg/dl or >25% increase in sCr
Occurs within 24-48hrs and peaks in 3-5 days
Other possibilities have been ruled out
83
Ddx of intrarenal AKI
Glomerular disease
ATN
AIN
Vascular disease
84
Causes of intrarenal injury that commonly present with Na indices
characteristic of prerenal injury are:
CIN
Rhabdo
CN
HRS
85
Indications for RRT in setting of AKI
● Refractory volume overload
● Severe hyperkalemia
● Severe metabolic acidosis
● Uremic organ dysfunction
● Methanol or ethylene glycol intoxication
