Renal Flashcards
1
Q
What is special about blood flow through the kidney?
A
afferent arteriole–> glomerulus–> efferent arteriole
2
Q
What is GFR?
A
- Considered the best indicator of renal function
- based on pt size/gender/weigth/age
- GFR can be calculated from timed urine volume measurements
- multiple different formulas exist to calculate
- ranges
- normal 90-120mL/min
- Troubling 60-89mL/min
- decreases with age
- maybe normal in elderly
- abnormal <50 mL/min
- where we start altering our anesthetics
- Failure <15 mL/min
3
Q
What is creatinine clearance?
A
- Specific test for GFR- most reliable assessment tool for renal function (24 hour urine collection)
- measures ability of glomeruli to excrete creatinine
- Normal 95-150 mL/min
- Mild dysfunction 50-80 mL/min
- moderate dysfunction <25 mL/min
- anephric <10mL/min
4
Q
What does a UA measure?
A
- Specific gravity
- measures solutes in urine
- kidneys ability to excrete concentrate/dilute urine
- normal 1.003-1.008 (>1.018 indicates reasonable function)
- Proteinuria
- >150 mg/day- Can be seent with incrase exercise, HTN, DM
- >750 mg/day indicates severe glomerular damage
- more likely to develop AKI
- Microscope
- RBC (Bleeding), WBC (infection), casts (disease of nephron) or crystals (metabolism)
5
Q
What is BUN?
A
Blood urea nitrogen
- Primary source is liver (protein catabolism)
- not a reliable indicator of GFR
- 40-50% passively reabsorbed by renal tubule
- hypovolemia increases this
- normal 10-20 mg/dL
- 20-40 mg/dL: dehydration, high catabolism, decreased GFR
- >50 mg/dL indicates impairment of renal function
- increased BUN with normal serum creatinine suggests non renal cause
6
Q
What is serum creatinine?
A
- Cretinine is a metabolite of cretine (muscle constitue)
- generally reliable in healthy patients
- prodcution and elminiation is relatively constant
- inversely related to GFR
- Normal 0.6-1.2 mg/dL
- lower in elderly/females
- creatinine levels double for every 50% reduciton in GFR
- delayed lab
7
Q
What is BUN: Cr ratio? Normal? Elevater? Low?
A
- Normal 10:1
- low tubular flow rates enhanve urea reabsorption but do not affect creatinine handling
- >15:1
- volume depletion, CHF, cirrhosis, and nephrotic syndrome
- increase in nitrogen, decrease in blood flow, decrease in BP (specifically CHF, cirrhosis)
- volume depletion, CHF, cirrhosis, and nephrotic syndrome
- <10:1
- decreased urea input, increased creatinine produciton and volume expansion
8
Q
What is fractional excretion of sodium?
A
- Useful in differentiating between prerenal and renal causes of failure
- >2% or >40 mEq/L
- ATN/kidney damage
- inability to conserve sodium- because proximal/distal tubule isn’t reabsorbing Na
- intrarenal
- <1 or <20mEq/L
- increased sodium reabsorption- water follows sodium, less Na in urine because it is reabsorbed
- normal funcitoning tubules
- prerenal- hypoperfusion
9
Q
How can anesthesia effect renal function?
A
- Effects are complicated and difficult to evaluate
- type/depht of anesthesia, choice of agent, fluid regimen
- Indirect or direct effects
- most are indirect (hypoperfusion)
- occur with both general and regional anesthesia
- less pronounced with regional
- more localized effect
- with spinals, big sympathomimectomy, vasodilation, drop in BP
- less pronounced with regional
10
Q
Cardiovascular indirect effects on renal system with anesthesia?
A
- Dose dependent decrease in CO and SVR
- Decreased sympathetic tone (epidural/spinal)
- fluid boluses and vasoconstrictors to increase BP
- DO NOT use dopamine, no changes in outcome
11
Q
Pulmonary indirect effects on renal with anesthesia?
A
- Positive pressure ventilation
- the higher hte PIP and PEEP, the greater decrease in RBF and GFR
- increase intrathoracic pressure, decrease return SVR, decrease in RA and RVEDP, increase in SNS–> increase NE/Epi–> vasoconstriction–> decrease blood flow to kidneys
- Increase in SNS activation, RAAS activation, and vasopressin release
- ensure adequate hydration
- the higher hte PIP and PEEP, the greater decrease in RBF and GFR
12
Q
Neuro indirect effect on renal system with anesthesia?
A
- Increased sympathetic tone
- anxiety, pain, light anesthesia, surgical stimuli
13
Q
Endocrine indirect effects on renal system around anesthesia?
A
- Epi, NE, ADH, angiotensin II
- reduce renal blood flow through vasoconstriction
- Aldosterone
- enhances Na reabsorption and water retention
- Prostaglandins (PGE2)
- To blanace vasoconstriction and stress
- in Litchfields online questions, he states prostaglandins vasodilate at kidneys
- pathway includes phospholipase A2 and cyclooxygenase
- avoid
- celebrex, tylenol, toradol
- avoid
- To blanace vasoconstriction and stress
14
Q
Thiopental renal implications?
A
- Reduced plasma protein binding
- increased volume of distribution
- may undergo some metabolism in kidney
- decrease initial dose
- increased sensitivity
- (not 1st choice of drugs) (BLUE ON PPT)
15
Q
Etomidate renal implications?
A
- Highly metabolized to pharmacologically inactive compounds
- <3% of administered dose found unchanged in urine
- shorter elimination half life than thipental
- inhibits 11-b-hydroxylase–> last conversion to cortisl
- NO change in dosing for renal disease
- Green on ppt
16
Q
Ketamine renal implications?
A
- Biotransformed in the liver
- Norketamine is active metabolite (1/5 to 1/3 as potent)
- may contribute to prolonged effects
- <4% unchanged in urine
- NO change in intiial dosing
-
May need to reduce subsequent dosing and infusion rate
- good renal overall!
- Green on ppt- good to give
17
Q
Propofol renal implications?
A
- Clearance exceeds hepatic blood flow (extra hepatic sites)
- metabolites excreted in urine
- renal dysfunction does not alter clearance
-
NO change in dosing
- however, vasodilator so need to watch BP
- Green on ppt
18
Q
Dexmedetomidine renal implications?
A
- Sedation and anxiolysis
- extensive hepatic metabolism (methyl and glucuronide)
- extensive renal excretion of metabolites
- active metabolites
- reduce dosage in patients with renal insufficiency
- d/t sedation
- Blue on ppt!
19
Q
Midazolam renal implications?
A
- Eliminiation 1/2 time, Vd, and clearance not altered
- NOchange in bolus dosing; may need to decrease infusion
- metabolite 1-hydroxymidazolam is about 1/2 as potent as midazolam
- rapidly conjugated to 1-hydroxymidazolam glucuronide and cleared by kidney
- may accumulate in kidney failure
- Blue on ppt!
20
Q
Diazepam renal implications?
A
- Highly lipid soluble and extensively protein bound- altered PB, more free drug in renal)
- renal insufficiency is associated with increased plasma concentrations
- multiple active metabolites
- use with caution in renal failure patients
- prolonged respiratory depression
- RED ON PPT!! DO NOT GIVE
21
Q
Methoxyflurane renal implications?
A
- extensive metabolism- 70% to inorganic fluroid
- avoid in renal failure patients
- fluoride-induced nephrotoxicity
- polyuria, hypernatremia, hyperosmolarity, increased plasma cretine, and inability to concentrate urine
- <40 umol/L- below toxicity
- 50-80 umol/L- subclinical toxicity
- >80umol/L- clinical toxicity
- >50 umol/L as indicator of toxicity
- peak values alone not enough for dx of renal problems
- RED ON PPT!
22
Q
Halothane renal implications?
A
- Decreased RBF, GFR, UOP r/t decrease in BP
- 20% metabolized with metabolites renally excreted
- trifluroacetic acid and bromide
- RED ON PPT!
23
Q
Enflurane renal implications?
A
- Decreased RBF, GFR, and UOP r/t decrease in BP
- 2-5% metabolized with metabolites renally excreted
- fluoride ions
- renal failure following enflurane has been reported
- genetics?
- RED ON PPT!
24
Q
Isoflurane renal implications?
A
- Decrease RBF, GFR, UOP
- Metabolized to trifluoroacetic acid
- prolonged sedation >24 hours have fluoride ions 15-50 umol/L
- no renal impairment!
- GREEN ON PPT
25
Desflurane renal implications?
* Decreases RBF, GFR, and UOP
* minimal metabolism
* no evidence of nephrotoxic effects
* **no renal impairment**
* **GREEN ON PPT!**
26
Sevoflurane renal implications?
* 3-5% biodegradation
* inorganic fluroide ions
* F ions the same or higher than enflurane
* can be \>50 umol/L
* increased NAG (B-N-acetylglucosaminidase)
* indicator of acute proximal renal tubular injury
* BUN and plasma creatinine did not change
* *humans have much more NAG than rats, no damage from sevo in humans*
* CO2 absorbers
* base -catalyzed degradation
* vinyl ether compound called compound A
* renal PCT injury in rates
* barium hydroxide\>soda lime
* **No renal failure notes in low flow or clsoed circuit anesthesia**
* *****most still practice \>2 L flow*
* ***GREEN ON PPT!***
27
Morphine renal implications?
* **RED DO NOT GIVE**
* **Renal metabolism makes significant contributions morphine metabolism**
* no differencein clearance rates even in pt with cirrhosis
* M6G (active/75-85%) and M3G (inactive 5-10%)
* 1-2 % unchanged in urine
* about 90% excreted by kidneys with the rest via biliary excretion
* **accumulation of metabolites may occur in patients with renal failure**
* prolonged respiratory depression \> 7 days reported
28
Meperidine renal implications?
* RED ON PPT!
* **Hepatic metabolism to normeperidine**
* **urinary excretion is principal eliminiation route**
* is pH dependent
* acidification of urine may speed eliminiation
* 1/2 life is about 15 hours, **up to 35 hours in patients with renal failure**
* normeperidine produces CNS stimulation and toxicity can manifest as myoclonus and seizures
* in patients receiving meperidine for \>3 days- delirium may be observed
* espeically in the elderly
29
Fentanyl renal implications?
Sufentanil?
**all safe renal!!-- GREEN ON PPT!**
Fentanyl:
* metabolized to norfentanyl (minimally active)
* \<10% excreted unchanged in urine
* detected for 72 hours
* **prolonged respiratory depression in chronic renal failure patients**
Sufentail:
* \<1% unchanged
* n-dealkylation metabolites are considered active
* maximal renal tubular reabsorption of free drug(why?)
* metabolites excreted equally between renal/biliary
* **prolonged respiratory depression in chronic renal failure patients**
30
Alfentanil? Remifentanil renal implications?
Alfentanil
* Eliminations 1/2 time and plasma clearance not altered
* protein binding is reduced and free drug increases
* \<1% excreted unchange
Remifentanil
* with renal failure
* no changes in PK and PD
* In patients on HD
* reduced clearance and prolonged elimination 1/2l life
* lower infusion rate required
**BOTH GREEN ON PPT!**
31
Hydromorphone renal implications?
* Hepatic metabolite- hydromorphone 3-gluconoride (inactive)
* potential to accumulate in renal failure- neurotoxic (*more theoretical than clinical implications)*
* \<1% free hydromorphone excreted in urine
* caution in renal failure patients
* **Blue on ppt!**
32
Methadone renal implications?
* Metabolite pyrrolidine (inactive)
* 20-50% excreed as methadone
* 10-45% in feces
* safe to use
* **gree on ppt!**
33
Oxycodone renal implications?
* Metabolites noroxycodone (inactive) and oxymorphone (active)
* prolonged from 2.3 hours- 3.9 hours in patients with renal failure
* **reduce dose and increase interval**
* **blue on ppt!**
34
Hydrocodone renal implications?
* metabolizes to hydromorphone
* hydromorphone 3 glucuronide (neurotoxic)
* decreased clearance in patients with renal disease
* reduce dose and increase interval
* **blue on ppt!**
35
Succinylcholine renal implications?
* Hyperkalemia
* 0.5-1 mEq/dL increase in potassium
* renal failure patients are no more susceptible to exaggerated response to succinylcholine than normal patients
* infusion problematic
* succinylmonocholine (metabolite)
* weaker NMB with longer DOA
* **Green on ppt!**
36
Mivacurium renal implications?
* Metabolized by butyrlcholinesterase
* longer DOA and slower rate of recovery in patients with CKD
* Induction dose OK
* DOA may be increase in 10-15 min
* **Green on ppt!**
37
Atracurium and Cisatracurium renal implications?
Atracurium
* hoffman elimination and ester hydrolysis
* OK in renal failure patients
* laudanosine metabolite (30% renal)
* plasma 1/2 life same in both normal and renal failure patients
Cisatracurium
* hofmann elmiination (77% of elimination)
* OK in renal failure patient
* 16% renally eliminated
* 4-5x as potent as atracurium, so less laudanosine metabolites
**Both green on ppt!**
38
Pancuronium renal implications?
* Long acting NM blocking drug
* 40-60% cleared through the kidneys
* avoid
* metabolites are less potent and renally excreted
* **Red on ppt!**
39
Vecuronium renal impliactions?
* Metabolized in liver to 3 diff metabolites
* 3-OH vecuronium has 80% potency of vec
* approximately 40% excreted uncahnged by kidney
* **single dose fine, but multiple doses/infusions may require adjustment**
* **Blue on ppt!**
40
Rocuronium renal implications?
* Primarily eliminated by the liver and excreted in the bile
* NO active metabolites
* approximately 30% excreted unchanged by the kidney
* **single dose fine, but multiple doses/infusions may require adjustment**
* **blue on ppt!**
41
Cholinesterase inhibitors?
* Neostigmine, pyridostigmine, physostigmine and edrophonium
* renal excretion accounts for 50-75% of the drugs
* renal failure decreases plasma clearance as much, if not more than, the long acting neuromuscular blocking drugs
* **Blue on ppt**
42
Sugammadex renal implications?
* 75% of dose is eliminated through the urine
* clearance approaches GFR
* with substantial renal impairment, clearnace of sugammadex/roc was decreased and elimination 1/2 life was increased
* dialysis is inconstant in remove suggammadex
* **DO NOT use if creatinine clearance \<30 mL/hr**
* **blue on ppt!**
43
Surgical direct effects on kidneys?
* Pneumoperitoneum
* increased intraabdominal pressure
* venous compressiona dn decreased CO
* Renal parenchymal compression
* bypass
* aortic cross clamp
* dissection near renal artery
44
What are indirect effects on renal system from surgery?
inflammatory response
45
Acute kidney injury? Occurance? Postop AKI?
* Rapid deterioration of kidney function over hours to days
* Occurs:
* all hospitalized- 5%
* critically ill 8-10%
* Postop AKI
* general 1%
* cardiothoracic and vascular 30%
preoperative AKI increases: hospitalization, mortality, and morbidity
46
Causes of prerenal AKI?
* Absolute decrease ECBV (extracellular blood volume?)
* hemorrhage
* volume depletion
* Relative decrease BV
* CHF
* cirrhosis
* Renal artery
* stenosis
* thrombosis/embolism
* NSAID
* ACE/ARB
* *blocking enzymes in RAAS, can't regulate BP as well, kidney more susceptible to hypotension*
47
Intrarenal AKI causes?
* ATN
* ischemic
* toxic
* exogenous
* abx
* contrast
* chemo
* endogenous
* pigment
* MM
* crystals
* vascular
* malignant hyertension
* vasculities
48
Postrenal causes AKI?
* Bladder outlet obstruction
* bilateral ureteral obstruction
49
Preoperative risk factors for perioperative renal failure?
* Preexisting renal insufficiency
* advanced age
* heart disease (CHF, ischemia)
* smoking
* DM
* LIver failure
* pregnancy-induced hypertension
* ASA physical status 4 or 5
50
Intraoperative facotrs increase risk for renal failure
* emergency, intraperitoneal, intrathoracic, suprainguinal vascular, transplant surgery
* aortic cross clamping
* CPB
* inotrope use
* erythrocyte transfusion
51
Postoperative risk factors for perioperative renal failure?
* erythrocyte transfusion
* vasoconstrictor use
* diuretic use
* antidysrhythmic use
* sepsis
* nephrotoxins (radiocontrast dyes, NSAID, aminoglycoside antibiotic)
52
Diagnosis/classification of renal injury?
* Increase of serum creatinine of 0.3 mg/dL over 48 hours
* increase of serum creatinine \>50% over 7 days
* acute drop of UOP to \<0.5 mL/kg/hr for \>6 hours
* anuria \<100 mL/day- sign of severe injury
53
What are some biomarkers to look at with AKI?
* **Neutrophil gelatinase-associated lipocalin (NGAL)**
* induced by renal tubular cells folowing ischemia/reperfusion injury
* promising
* **Cystatin-C**
* produced by all nucleated cells and is freely filtered, but not absorbed by kidneys
* maybe used as a measure of GFR; more accurate than creatinine estimates
* **IL- 18**
* synthesized in proximal tubular cells and cells that mediate infalmmatory response
* indicate more general inflammation than kidney damage
* kidney injury molecule
* membrane protein expressed in injured proximal tubular epithelial cells
* still being defined
* renal tubular cell enzymes
* alpha gluthion, s-transferase, N-acetyl-B-D-glucosaminidase
Panel is better--\> in general, no single indicator of renal failure
54
AKI phsyiolgical effects?
* **Neurological**: confusion and somnolence to sz
* **CV**: HTN, CHF, pulmonary edema
* **Hematological**: anemia and coag
* **metabolic**: hyperkalemia, hyperphosphatemia, hypocalcemia, metabolic acidosis
* **GI**: N/V, GI bleeding (1/3 of patients)
* **Infection**: impaired immune response; respiratory/urinary tracts
55
AKI management?
* No speicifc treatment modalities for AKI
* Limiting further injury and correcting deragnement
* correct hypovolemia, hypotension and low CO
* maintain MAP\>65 mmHg
* Fluids
* NS/Plasmalyte perferred
* *but NS can bring r/f hyperchloremic metabolic acidosis as well*
* Vasopressors
* NE vs vasopressin vs phenyl vs dopamine
* Protection
* n-acetylcystein or alkalinization of urine
* *can cause anaphylactoid reaction*
56
AKI Prognosis?
* Poor - mortality \>20%
* if dialysis required \>50%
* 15% will fully recover
* 5% will have renal insufficiency and remain stable
* 5% wille xperience continued renal function deterioration
57
AKI in anesthesia?
* Only lifesaving sx should be undertaken
* Premed: H2 blocker/PPI/reglan
* Monitoring
* intraarterial BP for frequent blood draws
* Induction
* RSI with reduced dosages of induction drugs- *delayed gastric emptying*
* succinylcholine if K known
* Maintenance
* volatile anesthetic vs TIVA
* *propofol has very little impact, just need to watch for hypotension*
* Controlled ventilation
58
Indications for dialysis?
* Fluid overload
* hyperkalemia
* severe acidosis
* metabolic encephalopathy
* pericarditis
* coagulopathy
* refractory GI symptoms
* drug toxicity
59
Complication of hemodialysis
* Neurological: disequilibrium syndrome (wide fluid shift)
* Cardiovascular: volume depletion; arrhythmia
* pulmonary : hypoxemia
* GI: ascites
* hematological: anemia, residula anticoagulation
* metabolic: hypokalemia; large protein loss
* skeletal: osteomalacia; myopathy
* infectious: peritonitis
60
What is chronic kidney disease?
* Kidney damage (GFR \<60 mL/MIN) for 3 or more months
* DM &HTN most common cuase
* mutliple diff stages of CKD
* GFR \<25 mL/min require dialysis or transplant
* ethnic variations
* african american, native american and hispanics have higher rates
61
Stages of CKD?
adaptation- large renal reserve
* Stage 1
* Decrease of \>50% of GFR
* changes in excretion of creatinine and urea
* Stage 2
* GFR 10% of normal
* changes in solutes such as potassium
* Stage 3
* variable
* changes in sodium homeostasis and regulation of ECF
62
Complications of CKD?
* Uremic syndrome
* renal osteodystrophy
* anemia
* uremic bleeding
* neuro change
* CV changes
* altered protein binding of drugs
* acidic drugs: less binding
63
Treatment of CKD?
* Treat underlying cuase
* lower BP
* adequate nutrition and protein restriction
* treat anemia
* RRT (*renal replacement therapy)*
* hemodialysis
* peritonela dialysis
64
Preop eval of CKD?
* Goal: preserve renal function and prevent kidney injury
* renal function- is a continuum: trends in lab values more important
* stop nephrotoxic drugs: NSAIDS/Aminoglycosids/contrast agent
* Volume status- dry and wet weights
* drug admin: bolus vs infusion (based on esimated Vd)
* Labs:
* K\<5.5 on DOS
* H/H 10/30
* Coags DDAVP may be required- *helps release von willbrand factor and helpts PLT aggregate*
* HTN therapy- well contorlled; ACE/ARB therapy (hold?)
* DM management: target glucose 110-150 mg/dL
* GI: prophylaxis- all drugs renally secreted
65
Monitors/lines needs with CKD
* Minor/moderate: noninvasive monitors OK (not on fistula arm)
* Complex: aline/cvp/picco/tte or TEE
* where to place?
* avoid radial/ulnar/brahcial/axillary
* use doraslis pedis or femoral
* Lines
* peipheral
* lower arm or dominant hand
* can dialysis catheter be used or anesthesia?
* yes, but highly discouraged and proper care is imporant
* Central
* maybe dififcult to place
66
Induction of CKD patient?
* Speicfic agent not as important as prevention of severe hypotension
* multiple cuase
* smaybe severe
* treatment: replace volume before induciton
* small doses or brief infusion of phenylephrine or NE ok
* RSI
* can use succinylcholine if K \>5.5 and necessary
* no exaggerated release of K in CKD patients
67
Maintenance in patients with CKD?
* Blanaced technique
* combo of volatiles, opioids, and MR
* maintain MAP \>65 (\>75 mmHg with chronic HTN)
* NE or phenlephrine
* **risk increases with MAP \<60 for 20 min of \<50 for 10 min**
* Check position frequently- *neuropathy*
* Fluid mgmt
* 500 mL bag with 60 gtt tubing
* NS vs 1/2 NS vs LR vs plasmalyte
* 5% albumin ok
* blood products for those that require increased oxygen carrying capacity
* UOP
* At least 0.5 cc/kg/hr
* decrease most likely d/t low volume
* use of diuretics or vasodilators is controversial
68
Emergence in CKD patient?
* Muscle relaxation
* recurization possible- continue to monitor
* ECG monitoring
* electrolyte abnormalities
* HTN
* NTG or SNP
* clevidipine or esmolol
* both short acting, by esterases?
69
Neuraxial in CKD?
* Coagulopathy and peripheral neuropathy is a concern
* evaluate coag panel
* monitor closely
* Maintain MAP
* T4-T10 level may improve renal function
70
Regional anesthesia in CKD?
* Doc peripheral neuropathies prior to placement
* improved surgical conditions
* max vasodilation (greater blood flow), abolish vasospasm
* no changes in DOA
71
Preoperative anesthetic consideration of renal endoscopic procedures?
Tumor
* older patients with many diff preexisting conditions
* CAD, CHF, PVD, COPD and renal impairment
Nephrolithiasis
* paraplegics and quadriplegics have chance for stones
* multiple procedures
* contractions may make positioning difficult
72
Intraoperative considerations for renal endoscopic procedures?
* Topical- *not recommended*
* 2% lidocaine jelly with sedation
* Regional
* may require a T8 level for procedures involving the ureters
* does not abolish obturator reflex (external rotation and adduction of thigh)
* Spinal- *Quick onset but will stick around, not good for PACU flor*
* \<1 hour 7.5 gm of 0.75% bupi
* \>1 hours 10-12 mg of 0.75% bupi
* why not lidocaine? (TNS)
* Epidural
* 2% lidocaine with epi
* 15-25 mL
* takes time to set up
73
Anesthetic consideration for renal endoscopic procedures with GA?
* Monitors: standardized
* positioning: supine to lithotomy
* induction: standard
* ETT vs LMA- *need to hold breath to stop stone from moving*
* succinylcholine? *if K \<5.5, ok*
* Maintenace
* VA vs TIVA
* muscle relaxation to obtund the obturator reflex
* Emergence
* no specifics
74
Complications of anesthetics with renal endoscopic procedures?
* Decrease BP when lowering legs
* peroneal nerve injury
* bladder perforation
* shoulder pain
* autonomic hyperreflexia
* spinal cord injury above T10 (T5 severe manifestations)
* severs HTN, bradycardia, dysrhythmias and cardiac arrest
* TXMT: deepen level of anesthesia
* labetalol 5-10 mg IV
* SNP 0.5-5 mcg/kg/min
75
ESWL?
* shock waves focused at calculi in kidney or upper 2/3 of ureter
* 10-20 mm stones or impacted stone
* 1st gen
* high energy unit
* pt immersed in water bath
* 2nd gen
* low energy unit
* uses small water filling coupling device/pad
* tightly focused sound beam
76
Preop considerations for ESWL?
* 1st gen ESWL- cv/resp changes
* 2/3gen minimal hemodynamic changes
* absolute contraindications
* pregnancy, bleeding disorder, or active UTI
* Relative
* presence of abdominal aortic aneurysm or othopedic prosthetic device
* pt with pacemaker or AICD risk for arrhythmias
* shock synchornized to 20 mms after R wave (refracotry period)
* shcok waves can damage the device
77
Intraoperative ESWL considerations?
* Immbolization is very important to limit shock zoen no matter the anesthesia choice
* General
* does not decrease the # of shocks required
* greatest control (espeically ventilation)
* 1st gen- muscle relaxation for movement
* 2/3rd gen- limit stone movement
* Neuraxial
* T6 level required
* 1st gen-
* epidural most common
* use saline (air can dissipate shcock waves and damage tissue
* do not use foam tape (dissipate shock wave energy)
* spinal- less control
* 2nd gen- spinal (opioids only 50 mcg sufentanil)
* 2nd/3rd gen
* TOPICAL- EMLA cream
* Local infiltration +/- sedation
* TAP block +/- intercostal block
* sedation
* midaz/fent
* propofol gtt
* Fluid mgmt
* liberal admin
* surgeon may request small doses of furosemide to increase uop and stone removal
78
Postop ESWL considerations?
* Bleeding
* moderate to severe (self limiting)
* Perforation or rupture of hollow organs
79
What is a TURP?
transurethral resection of prostate
* Vaporization
* electocuatery or laser
* KTP (pvp/greenlight)
* most common
* thermocoagulation
* lase, microwave or radiofrequency
80
Summary of TURP procedure?
* Position: lithotomy or steep trendelenburg
* special instrumentation: laser or da vinci robot
* unique consideration; immobility is a must
* abx: gentamicin 80 mg IV
* Surgical time \<2 hours (longer if using robot)
* EBL 500 mL (2-5mL/min of resection
* Postop: irrigation of foley to clear; serum Na concentration
* morbidity: bleeding or absorption of irrigation fluid
* pain 1-3
81
Preop consideration of TURPs?
* Patient's are generally elderklyl with comorbid conditions
* resp: copd common
* cv: cad/htn common
* neuro: cerebrovascular disease
* renal: renal impairment secondayr to obstruciton
* endocrine: DM]]
* heme: if gland \>80 grams, need T&C
82
Anesthetic consideraiton for use of neuraxial anesthesia with TURPs?
* Require T9-T10 level
* 1.6-2 mL of 0.75% bupi
* 2-3 mL of 0.5% bupi
* adjuncts: dexmedetomidine or fent
* Potential for earlier detection of TURP syndrome
* incidence of post dural puncture headache is very low
83
General anesthesia in TURPs?
* Induction: standard
* Maintenance: balanced (va/nitrous/opioids)
* minimal to mod blood loss (if venous sinuses entered)
* difficult to detect with irrigation fluid
* irrigation 1.5% glycine, NS, or sorbitol./mannitol mixture (rare)
* Emergence: minimal pain; changes in BP with lowering legs
* airway edema with steep trendelenburg
* Complication: bladder perforation, TURP syndrome, blood loss, or vision problems
84
What is the TURP syndrome physiology?
* Continous irrigation fluid-visibility and wate removal (blood/tissue)
* incidence: 0.78-1.4% with 25% mortality if severe
* time frame: 15 min- 24 hours postop
* resection of prostate opens large venous sinuses and large amt of irrigation fluid can be absorbed
* 10-30 mL/min
* 6-8 L in cases that last 2 hours
* can decrease serum sodium 5-8 mEq/L
* **keep height \<60 cm above bed height**
* ***decreases pressure***
* Various types of fluid used
* based on type of equipment used
* 1.2-1.5% glycine (monopolar cautery) - helps prevent electrical current
* physiological saline (bipolar or lasers)
85
Clinical features of TURP sydnrome?
* Fluid overload- HTN/Bradycardia/pulmonary edema
* water toxicity- confusion/restlessness/seizure/lethargy
* hyponatremia- CNS changes/wide QRS/ T wave inversion
* glycine toxicity- N&V/HA/**Transient blindness**/loss of light reflex
* ammonia toxicity- N&V
* Hemolysis- anemia/clammy skin/hyperkalemia
* coagulopathy- severe bleeding/DIC
86
Treatment for TURP syndrome?
* Terminante sx ASAP
* Fluid restriction
* fursoemide 20 mg IV
* Eval: chem, CBC, glucose, ABG, obtain 12 lead EKG
* Start/continue NS infusion
* Na \<120 mEq/L must be treated to goal of 120 mEq/L
* 3% NS for Na \<100 at rate of \<100 mL./hr
* For seizure: midazolam
* CXR for pulm edema
* DIC
* blood products
* CV collapse- ACLS
87
Preop consideration for scrotal procedures?
* Elderly- metastatic prostate ca accompanied by othe rmed conditions
* young- tosions
* emergent operations- needs to occur within 6 hours to prevent irreversible occurence
88
Intraop consideraiton for scrotal procedures
* Sensory level of T10 is required
* Spinal- same as others
* epidural - same as others
89
General anesthesia in scrotal procedures?
same as before
deeper level of anesthesia are usualyl required to obtund autnomic reflexes that result from intense surgical stim
90
Postop anesthesia consideration for scrotal procedures?
* peroneal nerve injuyr
* pain
* toradol
* ilioinguinal/iliohypogastric nerve block
91
What neuroaxial level is required for:
ESWL?
Endoscopic renal procedures?
TURP?
Scrotal?
ESWL= T6 level
Endoscopic= T8
TURP = T9-T10
Scrotal= T10
