Anesthesia for Urologic Procedures Flashcards
1
Q
What kind of patient populations do you see for urologic procedures?
A
patients may be of any age; most are elderly with coexisting medical illnesses
2
Q
What should you consider anatomically about the ureter openings?
A
they are posterior and inferior on bladder itself
3
Q
What drugs can be administered to find the ureter openings?
A
methylene blue and indigo carmine
4
Q
What nerve lies close to the ureters and can be stimulated during cautery?
A
obturator nerve
5
Q
How do the kidneys get their blood supply?
A
Via the renal arteries that branch off the aorta
6
Q
How much of the CO do the kidneys get?
A
25% or 1200 mL/min
7
Q
What MAP range are the kidneys able to autoregulate?
A
75-160 mmHg
8
Q
What happens in the kidneys if the MAP drops below 60 mmHg?
A
filtration ceases
9
Q
Where do the kidneys lie in the body?
A
retroperitoneal between T12 and L4 vertebrae
10
Q
What level somatic blockade do you need to have if using spinal anesthesia for a urologic procedure?
A
T8-L3
11
Q
What level of somatic blockade do you need for a procedure on the ureters?
A
T10 sensory level
12
Q
How does anesthesia affect renal function?
A
reversible decreases in RBF, GFR, urinary flow, & Na+ excretion occur during regional or general anesthesia
13
Q
What can partially offset the effects of anesthesia on renal function?
A
normal BP and intravascular volume
14
Q
What is the most frequently used position for urologic procedures?
A
lithotomy
15
Q
What should you consider when moving the patient’s legs into lithotomy position?
A
moving them simultaneously
16
Q
What are some of the respiratory physiologic consequences of lithotomy position?
A
decreased FRC, decreased vital capacity, lung volume, and lung compliance which can result in atelectasis and hypoxemia
17
Q
What are some of the cardiophysiologic consequences of lithotomy position?
A
altered venous return, acute increase or decrease in BP which is why you should always check the BP once the legs are raised
18
Q
What nerve is commonly injured in the lithotomy position?
A
peroneal nerve with loss of dorsiflexion due to fibular head compression
19
Q
What are some risk factors for nerve injury in the lithotomy position?
A
duration >4 hours
BMI
20
Q
What other injuries (besides peroneal) can occur with the lithotomy position?
A
sciatic stretch
hand/finger injuries as foot of table is lowered
incidence of back pain (as high as 37%)
21
Q
What are some of the physiolgoic consequences of extreme lithotomy?
A
increased central venous pressure which can result in cerebral edema (especially with a low BP since CPP = MAP - ICP)
facial edema/airway edema
22
Q
What nerve commonly gets injured in the extreme lithotomy position?
A
brachial plexus injury resulting from hyperabducted arm
23
Q
How should you position someone in the lateral flexed position?
A
iliac crest over the table break; kidney rest up
lower leg flexed at knee/upper leg straight
pad between legs and axillary roll
extend table to separate iliac crest and costal margin
watch eye, ear, and neck position
24
Q
What are some of the respiratory effects of the lateral flexed position?
A
- decreased FRC in the dependent lung
- VQ mismatching (greater blood flow in the dependent lung while greater ventilation to the nondependent lung)
- atelectasis in dependent lung and favors hypoxemia
25
What are some of the cardiac effects of the lateral flexed position?
decreased venous return
26
What is the hyperextended dorsal position?
lateral oblique position with table hyperextended, incision goes longitudionally up abdomen and up into thoracic area
27
What nerves can be injured in the hyperextended dorsal position?
```
brachial plexus
peroneal
saphenous
ulnar
back strain
```
28
What complication is the patient at risk for in the hyperextended dorsal position?
VAE due to pelvis being above heart
29
Where is the hyperextended supine position?
iliac crest over break in table and table extended then table tilted head down
30
What are some of the cardiac effects of the hyperextended supine position?
increased central venous volume which can cause airway edema/facial edema
31
What are the 3 common transurethral procedures?
cytoscopy
TURP
TURBT
32
What is the purpose of a cystoscopy?
Diagnosis of urologic problems
Resection of bladder tumors
Access to urinary system for stent placement
33
What types of anesthesia can you use for a cystoscopy?
local
MAC
Regional (T10 umbilicus)
General
34
What can be a heat source to start fires during a cystoscopy?
light on cystoscopy camera generates heat and when placed on drapes has the potential to start a fire
35
What is the common position for cystoscopies?
lithotomy with or without trendelenburg
36
What nerves can be injured during a cystoscopy?
sciatic
common peroneal
brachial plexus
37
What is a TURP procedure and why do we do them?
transurethral resection of prostate for BPH which causes obstructive uropathy
38
What is the size of the prostate gland in order to have a TURP?
prostate gland must be
39
What are the most common causes of death post-op after a TURP?
MI, PE, renal failure
40
What comorbidites do patients undergoing a TURP usually have?
pulmonary, cardiac, and renal disease (up to 60%)
41
What is the estimated surgical time and blood loss for a TURP?
1-2 hours
| 500 mL
42
What happens during the TURP procedure?
Performed with cautery loop resectoscope while bladder is continuously irrigated
43
What is a common complication with a TURP as a result of the continuous bladder irrigation?
excessive absorption of irrigation fluid into the large venous sinuses, cannot determine exact blood loss because of irrigation
44
What is the limit for resection time due to the continuous irrigation used?
45
What is the best way to keep track of how much fluid may have been absorbed?
Keep count of the irrigation bags used
46
What are the characteristics of the irrigation fluid used during a TURP?
non-electrolyte and hypotonic
47
About how many mLs per minute are absorbed during a TURP?
20 mL/min
48
How severe a dilutional syndrome is depends on what?
duration of resection and bag height, the higher the height the more pressure that is exerted on the bag
49
What physiologic disturbances do hypotonic solutions cause?
acute hyponatremia and hypoosmolality
50
What things can fluid overload with dilutional syndrome cause?
congestive heart failure
pulmonary edema
hypotension
51
When does dilutional syndrome occur with a TURP?
during procedure or immediately post-op
52
At what sodium level can you see confusion and restlessness?
120 mEq/L
53
At what sodium level can you see somnolence and nausea?
115 mEq/L
54
At what sodium level can you see seizures and coma?
110 mEq/L
55
How are most dilutional syndromes managed?
fluid restriction and loop diuretics
56
What is the final line of treatment for dilutional syndrome if fluid restriction and diuretics do not work?
administer 3% saline IV at no more than 100 mL/hr until sodium is above 125 mEq. Diurese with lasix and follow serum electrolytes
57
What is glycine toxicity?
caused by glycine put in irrigation fluid used for TURP
58
What is glycine/
inhibitory neurotransmitter in CNS
59
What is a byproduct of glycine metabolism?
ammonia which can also cause altered mental status and confusion
60
Why is glycine added to irrigation fluid
good optical effect and aids in prevention of dilutional syndrome
61
What can hyperglycemia from glycine toxicity lead to?
nausea, malaise, vomiting, confusion, stupid and coma, blindness, seizure
62
How can you treat glycine toxicity?
lasix and supportive therapy
63
What are 2 other complications that can occur during a TURP other than dilutional syndrome and glycine toxicity?
bladder perforation
| severe blood loss/DIC
64
What happens if the surgeon perforates the bladder during a TURP?
irrigation goes into the abdomen causing abdominal pain, nausea, diaphoresis (may be masked by general anesthesia or heavy sedation)
65
What happens if there is severe blood loss during a TURP?
can result from glands 35-45 g or resection time >90 mins
resection may release fibrinolytic enzymes
dilutional thrombocytopenia
66
What is the obturator reflex during a transurethral procedure?
electrocautery stimulation causes an external rotation and adduction of thigh, patient's legs will "box" surgeon, cannot be blocked by spinal anesthetic, only way to block it is with GA and paralysis
67
Can complication can occur for someone who is paralyzed pre-op undergoing a TURP?
autonomic hyperreflexia can occur if spinal cord lesion is above T6-T7, triggered by surgical manipulation, bladder distention; sympathetic hyperactivity from stimulation below cord lesion (will need anesthetic that can prevent this like a spinal)
Causes: severe HTN, bradycardia, and dysrhythmias
68
What anesthesia can you use for a TURP?
general (ETT or LMA)
| spinal/epidural T10 sensory level
69
If doing a spinal for a TURP, what LA and dose should you use?
hyperbaric bupivacaine 10-12 mg
70
Why would it be ideal to do a spinal for a TURP?
to assess their mental status, best monitor for detecting early signs of TURP syndrome or bladder perforation
71
Can you assess blood loss accurately with a TURP?
no because of the continuous bladder irrigation
72
What are 3 major cancer surgeries that can be done on the urologic system?
radical prostatectomy
radical cystectomy
radical nephrectomy
73
What is a radical retropubic prostatectomy (RRP)?
removal of prostate, seminal vesicles, and part of the bladder neck; remaining bladder neck anastomosed to urethra; done with lower, midline, abdominal incision; more "nerve sparing" so only 25% change of impotence; associated with major blood loss; can remove retroperitoneal lymph nodes
74
What position is generally used for a RRP?
hyperextended supine
75
What anesthesia can you do for a RRP?
patients generally cannot tolerate regional anesthesia because of the position, large amount of fluid and trendelenburg can lead to airway edema so general anesthesia preferred
76
What are some of your concerns with a RRP?
massive blood loss (primarily during resection of the prostate and can have EBL of 1000-2000 mL)
venous air embolism
nerve injury from position
77
What is a typical pain score after a RRP?
4-8
78
What are some anesthetic considerations for a RRP?
- ensure cross-matched blood available with fluid/blood warmers
- 2 large peripheral IVs
- patient will do bowel prep and will require rehydration
- arterial line, +/- CVP (CVP depends on comorbidities and if in teaching facility where procedure may take longer)
- Usually general anesthesia +/- epidural or intrathecal narcotics
- surgical time of 3-5 hours
- post-op to ICU
79
What is a radical perineal prostatectomy?
removal of prostate through transverse curvilinear incision
80
What position is used for radical perineal prostatectomy?
extreme lithotomy
81
Is the abdomen entered for a RPP?
No
82
Is a RPP generally nerve-sparing?
No
83
What are some anesthetic considerations for a RPP?
```
same as RRP
extreme lithotomy position
increased central venous pressure
increased peak inspiratory pressure
make sure patient can handle position
```
84
What comorbidity/habit is strongly associated with bladder cancer?
cigarette smoking
85
What two comorbidities is bladder cancer usually associated with?
CAD and COPD
86
What is the 2nd most common cancer of the GU tract?
bladder cancer
87
What is a radical cystectomy?
removal of the bladder with ileal conduit or ileal pouch put in its place
88
What is removed during a radical cystectomy in males?
bladder prostate
seminal vesicles
part of urethra
89
What is removed during a radical cystectomy in females?
```
uterus
cervix
ovaries
part of urethra
anterior vaginal vault
```
90
What are some anesthetic considerations for a radical cystectomy?
ensure cross-matched blood available with fluid/blood warmers (EBL 500-1000 mL)
2 large peripheral IVs (bowel prep requiring rehydration)
arterial line +/- CVP
general anesthesia +/- epidural or intrathecal narcotics (avoid N2O)
pain score 7-9
surgical time >4 hours
post-op to ICU
91
What is a radical nephrectomy done for?
adenocarcinoma of kidney
92
What happens in 5-10% of patients with adenocarcinoma?
tumors extends into the renal vein and inferior vena cava as a thrombus
93
What should you ensure if the patient has an adenocarcinoma with the tumor extending into the renal vein and inferior vena cava?
Ensure that the facility where you are doing the procedure has cardio-pulmonary bypass machine, may need to clamp inferior vena cava to suture and complete the procedure
94
What is a risk factor for adenocarcinoma?
smoking, CAD, COPD
95
What incisions may be used for an adenocarcinoma?
anterior subcostal, flank, midline, or thoracoabdominal incision
96
What complication is possible during a radical nephrectomy with a thoracoabdominal approach?
pneumothorax
97
What are some anesthetic considerations for a radical nephrectomy?
```
massive blood loss (EBL 500-2000 mL)
hypotension with kidney rest up
preservation of remaining kidney function
thrombus in IVC
emsure cross matched blood available
two large PIVs
arterial line +/- CVP
general anesthesia +/- epidural or intrathecal narcotics
post-op to ICU
```
98
What is the surgical time for a radical nephrectomy?
3-5 hours
99
What position is used for a laparoscopic nephrectomy?
flank position as in open nephrectomy
100
What is the technique for a laparoscopic nephrectomy?
3-4 trochars used
pneumoperitoneum of 14-16 mmHg
may have to be hand assisted so will have larger incision so surgeon can stick in their hand to assist
101
What kind of tumors are in majority of testicular cancer cases?
95% germ cell tumors and can be seminomas or nonseminomas
102
What is the initial treatment for testicular cancer?
radical orchiectomy (removal of testicle)
103
How are seminomas treated?
retroperitoneal radiotherapy
104
How are nonseminomas treated?
retroperitoneal lymph node dissection and chemotherapy (Bleomycin, increased risk for pulmonary insufficiency)
105
What are some anesthetic considerations for testicular cancer removals?
may use general or regional anesthesia
standard monitors
minimal blood loss
watch for reflex bradycardia from traction on spermatic cord
consider ilioinguinal/iliohypogastric nerve blocks
106
What is the position for a urethroplasty?
lithotomy
107
What is the incision for a urethroplasty?
perineal
108
What is the surgical time for a urethroplasty?
3 hours
109
What is the EBL for a urethroplasty?
100 mL
110
What is the pain score for a urethroplasty?
3
111
What is the position for a urethrectomy?
lithotomy
112
What is the incision for a urethrectomy?
perineal
113
What is the surgical time for a urethrectomy?
2hours
114
What is the EBL for a urethrectomy?
300 mL
115
What is the pains core for a urethrectomy?
3
116
What is the position for insertion of a sphincter?
lithotomy
117
What is the incision for insertion of a bladder sphincter?
perineal and scrotal
118
What is the surgical time for insertion of a bladder sphincter?
3 hours
119
What is the EBL for insertion of a bladder sphincter?
minimal
120
What is the pain score for insertion of a bladder sphincter?
4
121
What is the position for brachytherapy?
lithotomy
122
What is the incision for brachytherapy?
none
123
What is the surgical time for brachytherapy?
2 hours
124
What is the EBL for brachytherapy?
minimal
125
What is the pain score for brachytherapy?
3
126
Why are circumcisions done?
phimosis (obstruction of urine flow)
| recurrent infection
127
What anesthetic can you do for a circumscision?
any anesthetic of choice
128
What are some implications for a penile prosthesis and anesthetic considerations with it?
```
semi-rigid or inflatable
organic impotence
supine position
can do anesthetic of choice
pain score of 5
```
129
What procedures can be done for urinary incontinence in females?
Stamey procedure
Raz bladder neck suspension
Sling procedures
130
What is the position, surgical time, and anesthetic implications for vaginal procedures for urinary incontinence?
lithotomy position
surgical time about 1 hour
anesthetic of choice
pain score of 5
131
What are some causes of ESRD?
IDDM (31%) caucasians
chronic glomerulonephritis (28%) (hispanics and asians)
polycystic kidney disease (12%)
nephrosclerosis (9%) (Af. am. with HTN and nephrosclerosis)
SLE (3%)
interstitial nephritis (3%)
132
What are contraindications for kidney transplant?
infection
| cancer
133
What are relative contraindications for kidney transplant?
>60 years old
| severe cardiovascular disease
134
What is the 3 year survival rate for cadaveric transplants?
80-90%
135
What should you worry about with a kidney transplant?
- hypo/hypervolemia depending on dialysis-surgery interval
| - hyperkalemia (should be
136
What are some anesthetic considerations for kidney transplants?
- supine position
- preoperative antibiotics (immunosuppressed due to chronic uremia)
- lower quadrant curvilinear incision
- generally use general anesthesia
- avoid Sevoflurane due to Chloride issue
- consider cisatracurium, atracurium, rocuronium, or vecuronium
- morphine clearance is reduced
137
What are some anesthetic considerations regarding the curvilinear incision used for a kidney transplant?
- donor kidney placed extraperitoneally into iliac fossa; renal vessels --> iliac vessels; ureter --> bladder
- heparin prior to temporary clamping of iliacs
- IV mannitol after reperfusion
138
How can you maximize renal blood flow at time of graft reperfusion during kidney transplant?
blood volume expansion (CVP 10-12)
mannitol
furosemide
139
When should you administer immunosuppression during a kidney transplant and what is commonly administered?
administer prior to graft reperfusion
corticosteroids
cyclosporine
azathioprine
140
What should you closely monitor during a kidney transplant
- serum electrolytes (hyperkalemia occasionally reported following arterial vascular clamp release)
- urine output every 30 minutes (watch for brisk urine flow following arterial anastomosis)
- maintain normal to elevated arterial BP and CVP to maximize renal blood flow
141
Why is a percutaneous lithotripsy done?
indicated for large stones that will not pass beyond the renal pelvis, percutaneous sheath placed into renal pelvis, nephroscope inserted and stone is shattered with ultrasonic probe, stones then irrigated out of kidney
142
What position is used for a percutaneous lithotripsy?
prone on cystoscopy table
143
What anesthesia is usually done for a percutaneous lithotripsy?
general anesthesia, patient may be 180 degrees
144
What are some anesthetic considerations for a percutaneous lithotripsy?
watch for severe bleeding
large PIV
potential for kidney injury from high pressure fluid delivery for nephroscope
145
How is a laser lithotripsy done?
performed through uteroscope with patient in lithotomy position, fiber-optic probe is placed against stone which is fragmented with laser light, useful for smaller stones
146
What are the anesthetic considerations for a laser lithotripsy?
same as cystoscopy
| can use regional or general anesthesia
147
What is extracorporeal shock wave lithotripsy?
disrupts kidney stones with high-energy shock waves (calcium oxalate monohydrate, calcium phosphate, and cystine calculi are resistant to fracture with ESWL)
- employed for stones in the renal pelvis or upper two-thirds of ureters (above iliac crest)
148
What are some common elements of all lithotriptors?
- ability to localize stone target (fluoroscopy or US)
- generation of acoustical shock waves
- mechanism for focusing shock waves onto targeted stone
- technique for coupling shock wave generator to the patient
(most lithotriptors brought in on truck so will have to drag anesthesia machine/equipment out there)
149
What is underwater ESWL?
high-voltage spark generated underwater --> water vaporization and cavitation bubble with rapid expansion and then collapse of cavitation bubble which creates a shock wave that is deflected to converge on the stone
150
What is the goal of ESWL?
pulverize calculi to allow urinary excretion over following week
151
How many shocks may be required for a ESWL and about how long can be treatment last?
1000-4000 shocks lasting about 60 minutes
152
What can you do to decrease the surgical time for a ESWL?
increase the heart rate since the shock wave is synchronized 20 ms after R wave and corresponds it to ventricular refractory period
153
What are some absolute contraindications to ESWL?
pregnancy, coagulopathy, intra-abdominal calcific processes (AAA), orthopedic implants in lumbar/pelvic areas
154
What are relative contraindications to ESWL?
morbid obesity and pacemakers/AICD
155
What are first generation lithotriptors?
require immersion in water bath which serves as acoustic coupling substance
156
What are second generation lithotriptors?
membrane over shock wave generator allows patient to remain dry
157
What are third generation lithotriptors?
smaller, lighter, enhanced focal point
| multifunctional devices for urinary tract and biliary tract
158
What anesthetic techniques can be used for lithotriptors?
local, regional, and/or IV sedation
159
What should you remember regarding ventilation for a patient having lithotripsy?
ventilate with small tidal volumes to minimize stone displacement (LMA or intubate)
160
What anesthesia is preferred for immersion-type lithotriptors?
regional anesthesia
161
What level is required for a regional block for a lithotripsy?
T4-6
162
Is epidural or spinal preferred for lithotripsy?
epidural because spinal has high incidence of PDPH and patient will have increased pressure of H2O that causes CSF leakage, epidurals also allow greater control of sensory level
163
What is one disadvantage of regional anesthesia for lithotripsy?
inability tocontrol diaphragmatic movement, can displace stone in excess of 12 mm
164
What does ESWL have a high association with?
dysrhythmias (10-14%) despite synchronization with ECG
PACs and PVCs most frequently noted
patients with pacemakers and history of dysrhythmias
R wave important in shock wave timing (20 ms after R wave)
165
What should you do if the patient is getting immersed for an ESWL?
- cover ECG pads with water-proof dressing (R wave triggered shocks can induce supraventricular or ventricular arrhythmias)
- use clip-type cuff
- pulse ox probe on nose or ear
- closely monitor body temp if immersed
166
What are common pediatric urologic procedures?
circumcision
urethral meatotomy
orchiopexy (undescended testicle)
Wilms' tumor (nephroblastoma) - less common and occurs in small infants
167
What are some anesthetic considerations for pediatric urologic procedures?
general anesthesia (mask, LMA, ETT)
consider caudal analgesia
penile block (no epinephrine)
ilioinguinal nerve block
168
What sensory level is satisfactory for nearly all cystoscopic procedures?
T10
