A brief anaesthetic management of various outdoor urological procedures.

2. Urolithiasis
ᵹAlthough stone disease is one of the most common afflictions of
modern society, it has been described since antiquity. With
Westernization of global culture, however, the site of stone formation
has migrated from the lower to the upper urinary tract and the disease
once limited to men is increasingly gender blind.
ᵹWith the lifetime prevalence of stone disease estimated at 1% to
15%, varying according to age, gender, race, and geographic location, it
is one of the most common diagnosis a patient presents in a Urology
OPD other than stricture and prostatism.
ᵹRevolutionary advances in the minimally invasive and noninvasive
management of stone disease over the past 2 decades have greatly
facilitated the ease with which stones are removed. However, surgical
treatments do little to alter the course of the disease.

3. URILITHIASIS
Forced
Diuresis
Alkalisation
of urine
Tamsulosine
with
hydration
Extra
Corporeal
Shockwave
Lithotripsy
Percutenous
Nephro-
lithopexy
Uretro-
Reno scopic
Lithotripsy
Cysto-
litholapexy
Pyelo/Neph
ro/Cysto/Ur
ethro-
lithotomy
Nephrecto
my
Endoscopic
removal

4. HIPPOCRATIC OATH :
“I Will not cut, even for the stone, but leave such
procedures for the practitioners of the craft”

5. ESWL
ᵹEngineers of Dornier Labs, Germany observed that during high
speed flight, shock waves generated by collision with raindrops
caused pitting on the metal surfaces of supersonic aircraft.
ᵹDr. Christian Chaussey and colleagues at Munich, succeeded in
using this principle to treat kidney stones by developing a lithotripsy
machine.
ᵹIt was Feb, 7th 1980 that this machine
was first used successfully for the cause,
and as always, improvements followed
suit.

6. All lithotripters share similar technologic principles in having
three main components:
(1) an energy source,
(2) a system to focus the shock wave; and
(3) fluoroscopy or ultrasound to visualize and localize the
stone in focus.

7. Three different generator types (energy sources) for Shockwave
lithotripsy can be distinguished:-
Electro hydraulic:- First generation lithotriper
Shockwave is generated by an
underwater spark discharge,
which is reflected by an ellipsoid.
Consists of a water bath and a
metal gantry chair.
Posed anaesthetic challenges due to
immersion in water.
Now nearly obsolete.
The second and third-generation lithotripters have evolved
mainly in the direction of multipurpose use, eliminating the
water bath and producing a pain-free lithotripter.

8. ESWL
Electromagnetic:- The shockwave is generated by an electromagnetic
coil, which moves a membrane.
-An acoustic lens system reflects and focuses the shockwave.
-The resulting shock wave is constant.
-The energy is focused to a smaller focal point with higher peak
energy.
Piezoelectric:- Shockwave generated by mechanical deformation of a
piezoelectric crystal.
-The crystals are aligned along spherical dish, which allows the focusing.
-It induces low pain and can be used without any analgosedation.
- The disadvantage is the large diameter of the source and the limited
total energy in the focus.

9. Shock wave generator
Waves travel through water
Body-water interface
Similar impedence
No energy dissipation
Entry surface of stone
Sudden change in impedence
Release compressive energy
Exit surface of the stone
Another impedence change
Shock wave energy released as a blast.
Repeat cycles cause the stone to disintegrate.

10. Classical description
- Patient immersed up to the clavicles, and
- An electrode placed at the base of the tub in an ellipse
- The electric energy creates a spark across the gap
causes
- Generation of a loud noise,
intense heat, and explosive
vaporization of water.
- The sudden expansion of air
bubbles created sets up a
pressure wave (shock wave)
- Focused onto F2 focus
- Exponential reduction in
energy of wave beyond F2.

11. Submersion variety of ESWL

12. Newer lithotripers
ᵹNewer devices generate shock waves within a “shock tube”
coupled to the body surface with a water cushion.
This eliminates the water bath and all problems associated
with patient immersion in water.
ᵹThey also have decreased power, causing less pain.
ᵹBut by decreasing power, efficiency of stone fragmentation is
reduced. Thus the prevalence of retreatment is higher.
ᵹNewer lithotripters use multifunctional tables that allow other
procedures, such as cystoscopy and stent placement, to be
accomplished without moving the patient off the table.

13. Newer Version of ESWL

15. Effects of respiration:-
For shock waves to be most effective, the stone should remain in the
F2 focus during treatment.
Because of movements during respiration..
The stone is likely to move in and out of focus.
To increase the efficacy of the treatment advised techniques are,
- decreased tidal volumes with increased respiratory rates, and
- high-frequency jet ventilation
However, studies in sedated patients with intercostal blocks and local
infiltration anesthesia have documented that stone movement with
spontaneous respiration is mainly restricted to the F2 focal zone
during ESWL.

16. Pain:- The pathogenesis of pain is considered to be multifactorial.
- Both cutenous and visceral nociceptors are involved.
Visceral nociceptors may include periosteal, pleural, peritoneal, and/or
musculoskeletal pain receptors
ᵹVariables associated with pain :
the type of lithotriptor,
size and site of stone burden,
location of the shockwave front,
size of focal zone
shockwave peak pressure,
area of shockwave entry at the skin

17. Physiologic Changes During Immersion Lithotripsy
Cardiovascular changes
-Increase in central blood volume
-Increase in central venous pressure (about 10-14 cm H2O) and
-Increased pulmonary artery pressure.
Weber and colleagues observed that increases in central venous pressure
and pulmonary arterial pressure were directly correlated with the depth
of immersion.
A decrease in cardiac output and an increase in systemic vascular
resistance during immersion lithotripsy under general anesthesia has
been documented, mainly due to the sitting position.

18. Respiratory changes
FRC and vital capacity are reduced by 20% to 30%,
Pulmonary blood flow has been shown to increase, and
tight abdominal straps and the hydrostatic pressure of water on the
thorax impart a characteristic shallow, rapid breathing pattern.
Ventilation-perfusion mismatch and hypoxemia are more likely.
Renal changes
Diuresis, natriuresis, and kaliuresis.
A decrease in antidiuretic hormone and renal prostaglandins occurs.
ᵹThe temperature of the bath water can cause profound changes in
the patient's temperature. This heat transfer is augmented further by
the vasodilation produced by general or epidural anesthesia.
Hypothermia and hyperthermia have been reported.

19. Changes on Immersion during Lithotripsy
Cardiovascular
Increased Central blood volume
Increased Central venous pressure
Increased Pulmonary artery pressure
Respiratory
Increased Pulmonary blood flow
Decreased Vital capacity
Decreased Functional residual capacity
Decreased Tidal volume
Increased Respiratory rate

20. ᵹFor effective stone disintegration, shock waves should reach the stone
unimpeded. Nephrostomy dressings be removed and Epidural and
nephrostomy catheters be taped clear of the blast path.
ᵹAlthough shock waves pass through most tissues relatively
unimpeded, they do cause tissue injury
- Skin bruising and
- Flank ecchymoses are common at the entry site.
- Painful hematoma in the flank muscles may occur.
- Hematuria is almost always present and results from shock wave–
induced endothelial injury to the kidney and ureter.
ᵹAdequate hydration is necessary to prevent clot retention.

21. ᵹLung tissue is especially susceptible to injury by shock waves.
Air trapped in alveoli presents the classic water (tissue)-air interface to the
shock wave and causes dissipation of energy with alveolar rupture and
hemoptysis.
Styrofoam sheet or Styrofoam board be placed under the back in children
to shield the lung bases from shock waves during ESWL.
ᵹMechanical stress on the conduction system exerted by the shock waves
may lead to arrhythmia, although rarely now-a-days.
ᵹBrachial plexus injuries have also occurred from improper positioning of
patients in the lithotripter chair.

22. Anaesthetic Management
Anesthetic regimens used successfully for lithotripsy
include
General anesthesia,
Epidural anesthesia,
Spinal anesthesia,
Flank infiltration with or without intercostal
blocks, Analgesia-sedation, including patient-
controlled analgesia.

23. ᵹGeneral Anesthesia:-
Advantages:-
-Rapid onset
-Control of patient movement.
-Ventilation parameters can be controlled decrease
stone movement with respiration, which translates into more effective
stone targeting and fragmentation.
Disadvantage:-
- Morbidity and potential mortality associated with GA
- Longer hospital stay, so expensive
Therefore, GA may be preferred in
- Children,
- Extremely anxious individuals,
- Anticipated lengthy treatment (bilateral
ESWL, concomitant renal and ureteral stones, or calculi composed of
cystine, or brushite).

24. ᵹNeuraxial blockage:-
Epidural anesthesia
Advantage: An awake patient can help with transfers, reducing the
likelihood of injury.
Saline , or only the smallest amount of air necessary should be
injected, for LOR :-
Air in the epidural space provides an interface and causes
dissipation of shock wave energy and local tissue injury.
Neurologic injury has never been seen.
However, increased procedural difficulty and slow onset of
action are the reasons against its use.

25. Spinal anesthesia
Rapid onset, simplicity and routineness of use.
Intrathecal sufentanil is a safer and an effective alternative to
lidocaine, resulting in
- early ambulation and discharge,
- ability to void,
most likely due to preservation of motor and sensory function.
However, its use results in undesirable pruritis .
The incidence of hypotension (the patient is in a sitting
position for treatment) is higher, however. In one series, the incidence of
hypotension with general, epidural, and spinal anesthesia was
13%, 18%, and 27%. Further, recovery is prolonged due to residual
sympathetic blockade.

26. Local anaesthesia
Adequate anesthesia when combined with intravenous sedation and
avoids hypotension.
When given 1-2 min before the procedure in the target area, it
results in better pain control with lesser supplementary analgesia
requirement, thus reducing side effects of the other drugs.
Prilocaine has been used in the form of subcutaneous
infiltration during ESWL. In comparison to lidocaine, it has a
- rapid onset of action,
- equal efficacy, and duration of effect
- with lesser toxic effects due to rapid metabolism.
Patient Controlled Analgesia may be used as well. It is said that PCA
provides a better compliance of treatment to the urosurgeons.

27. The EMLA cream : Used as an occlusive dressing
It can penetrate to a depth of 4 mm after 60 mins of application.
It reportedly reduces opioid requirement by 23% during ESWL
performed with newer lithotriptors.
However, its own analgesic effect is inefficient.
Recently, the use of dimethyl sulfoxide (DMSO) in
combination with lidocaine has been reported to provide better pain
control during ESWL as compared to EMLA cream, due to
- local anesthetic effect along with
- diuretic,
- anti-inflammatory,
- muscle relaxant, and
- hydroxyl radical scavenger effects of DMSO.

28. ᵹMonitored Anaesthesia Care: -
The anesthesiologist is in control of the patient's vital signs and is
available to administer anesthetics and provide other medical care as
appropriate.
ᵹThe fentanyl-propofol combination has been proven as an effective
IV analgesic option.
Adverse effects:
- centrally mediated respiratory depression along with
decrease in oxygen saturation,
- nausea, vomiting, drowsiness, and hypersensitivity
reactions.
Therefore, regular oxygen saturation measurement is
necessary, especially when this drug is used along with sedatives in
ESWL.

29. - Both remifentanil and sufentanil have been found to be of equal
efficacy with regards to analgesia, and patient's and surgeon's satisfaction
during ESWL.
Remifentanil has a short elimination half-life and a rapid analgesic
action.
- Lesser respiratory depression, nausea, and vomiting.
- It can be safely used in clinically significant hepatic or renal diseases.
- During MAC, this drug can be used as intermittent bolus doses or as a
continuous IV infusion as total intravenous anesthesia (TIVA) or as a
combination of the two.
However, all techniques of MAC require active patient monitoring during
and after the procedure for the potential adverse effects of opioid
usage, especially respiratory depression, postoperative
nausea, vomiting, and dizziness.

30. The ideal analgesia, which offers pain-free treatment, minimal
side effects, and adequate cost-effectiveness, remains to be established.
Combination therapy (oral NSAID and occlusive dressing of
EMLA, DMSO with lidocaine) offers an effective alternative mode for
achieving analgesia with minimal morbidity. This therapy avoids the
need for general anesthesia, injectable analgesics, and opioids along
with their side effects
However, any titrated, and well controlled
anaesthetic approach will always be better than A “Hit-and-
Trial” analgesia by the Urosurgeons.

32. ᵹThomas Hillier in 1865 : first therapeutic
percutaneous nephrostomy
ᵹHillier: repeatedly aspirated the hydronephrotic
kidney of a young boy for symptom relief.
ᵹGoodwin and colleagues 1955: published their landmark report on
therapeutic percutaneous nephrostomy.
ᵹFernström and Johansson (1976): Percutaneous removal of renal
calculi.

33. TECHNIQUE
Access Removal
ᵹAccess: Fluoroscopic or ultrasonic control required.
ᵹGenerally through a lateral calyx, one of the lower polar calyces
in most instances.
ᵹApproach through the upper polar calyces is useful for access to
the pelvis and UPJ, but the risk of pleural injury is significantly
increased.

34. An 18--gauge needle is placed through the flank into the kidney
A guide wire of .035 or .038 size is passed through the needle.
The tract is enlarged by passing serial or telescopic Teflon or
metal dilators co-axially over the guide wire.
Amplatz sheath is passed over the last dilator,
The nephroscope is passed through
the sheath to visualize the inside of the
collecting system.

35. Stone Removal
Small stones can be removed intact with forceps or basket.
For Larger ones, Lithotripsy is required
Stone removal continues until the patient
is free of stone or until it is necessary to
stop the procedure.
Common reasons for this include
progressive bleeding and
extravasation of irrigating fluid.
Ultrasonic
Pneumatic
Electro-hydraulic

36. ᵹ. If the patient is not free of stone at the termination of the
procedure, the nephroscope can safely be reinserted through the
same tract after 48 hours.
ᵹAt the end of the procedure, a nephrostomy tube is placed
through the tract into the collecting system, large enough to
maintain an adequate tract to permit blood and clots to drain
readily.

37. -: Anaesthesia Considerations:-
ᵹPractically all varieties of anaesthesia techniques have been
successfully used ranging from General anaesthesia to local
infiltration with sedation.
ᵹPatient position: Usually prone position. In anesthetized
patients, it has advantages over the supine position with regard to
lung volumes and oxygenation without adverse effects on
mechanics, including obese and pediatric patients.
ᵹGA offers an advantage that the respiratory movements of the
patient may be synchronized with the procedure, so easing out
the surgeons job.

38. -: Anaesthesia Considerations:-
Regional Anesthesia: -
- The first description of PCNL with regional anesthesia was reported in
1988; The authors described 112 patients who underwent percutaneous
renal surgery with epidural anesthesia. Hemodynamic and respiratory
parameters were satisfactory in 88% of the cases.
- In 1991, Saied and colleagues found that an interpleural block produced
a totally pain-free operation and necessitated less frequent
administration in the postoperative period.
- General anesthesia can be a challenging in some situations such as
PCNL for staghorn calculi, because of the possibility of fluid absorption
and electrolyte imbalance. Therefore, regional anesthesia may be a good
alternative.

39. -: Anaesthesia Considerations:-
- In 2005, Singh and coworkers reported tubeless PCNL under
regional anesthesia. They considered that by omission of the
percutaneous nephrostomy tube and adopting regional (spinal
low-dose anesthesia, low-dose bupivacaine plus fentanyl) in place
of general anesthesia in selected patients, one may further reduce
the morbidity without compromising effectiveness and safety.
- Salonia and colleagues found that epidural anesthesia allowed
good muscle relaxation and a successful surgical outcome in these
patients. Moreover, it resulted in less intra-operative blood
loss, less postoperative pain, and a faster postoperative recovery
than general anesthesia.

40. Fluid management is important.
ᵹDuring nephroscopy procedures, continuous irrigation of fluid
through the endoscope is necessary to prevent blood and debris
from obscuring the surgeon's vision.
If a significant discrepancy exists between the amount of
irrigating fluid infused and output from the patient, then
clinical evaluation of the patient for extravasation of irrigation
fluid into the retroperitoneal, intraperitoneal, intravascular, or
pleural spaces is warranted.
ᵹIntravenous absorption of irrigation fluid can create a situation
similar to that seen with TUR syndrome, in which electrolyte
abnormalities and fluid overload can occur.

41. Cystoscopy
Cystoscopy
directed
procedures
Urethroscopy
TURP
Optical Internal
Urethrotomy
Stricture
dilatation
TUR Bx
TURBT
Bladder Neck
Incision

42. ᵹCarried out as Ambulatory cases.
ᵹBenefits of Ambulatory Surgery
- Patient preference, especially children and the elderly
- Lack of dependence on the availability of hospital beds
- Greater flexibility in scheduling operations
- Low morbidity and mortality
- Lower incidence of infection
- Lower incidence of respiratory complications
- Higher volume of patients (greater efficiency)
- Shorter surgical waiting lists
- Lower overall procedural costs
- Less preoperative testing and postoperative medication

43. Pre-Operative management
Minimize patient anxiety by using both pharmacologic (e.g., benzodiazepines)
and nonpharmacologic (e.g., relaxation therapies) approaches.
Patients should be encouraged to continue all their chronic medications up to
the time that they arrive at the surgery center. Oral medications can be taken
with a small amount of water up to 30 minutes before surgery.
NPO guidelines
Prolonged fasting does not guarantee an empty stomach at the time of
induction.
Due to short half-life of clear fluids in the stomach (10-20 minutes), residual
gastric volume after 2 hours is less in patients ingesting small amounts of clear
fluids than in fasted patients.
Furthermore, the ingestion of 150 mL of either coffee or orange juice 2 to 3
hours before induction of anesthesia had no significant effect on residual
gastric volume or pH even in obese adults.
Thus, arbitrary restrictions prohibiting outpatients from drinking
fluids on the day of surgery are completely unwarranted.

44. Basic Anesthetic Techniques
Quality, safety, efficiency, and the cost of drugs and equipment are all
important considerations in choosing an anesthetic technique for ambulatory
surgery.
The ideal outpatient anesthetic should:-
‐ Have a rapid and smooth onset of action,
‐Produce intraoperative amnesia and analgesia,
‐provide optimal surgical conditions and adequate muscle relaxation with a
short recovery period and
‐ no adverse effects in the postdischarge period.

45. General Anaesthesia
ᵹThe ability to deliver a safe and cost-effective general anesthetic with minimal
side effects and rapid recovery is critical in a busy outpatient surgery unit.
ᵹDespite a higher incidence of side effects than local or regional
anesthesia, general anesthesia remains the most widely used anesthetic
technique for ambulatory surgery.
ᵹTracheal intubation causes a more frequent incidence of postoperative
airway-related complaints, including sore throat, croup, and hoarseness than a
facemask or laryngeal mask airway (LMA). Most outpatients undergoing
superficial procedures under general anesthesia do not require tracheal
intubation unless they are at an increased risk for aspiration.
ᵹWhen compared with a facemask and oral airway, patients with an LMA had
fewer desaturation episodes, fewer intraoperative airway manipulations, and
fewer difficulties in maintaining a patent airway.

46. ᵹPreMedication :- A Combination of a short acting benzodiazepine with an
anticholinergic is usually preferred. An additional agent for preemptive
analgesia may be added as per doctors preference.
ᵹFor induction, the available options are
- Barbiturates
- Benzodiazepines
- Etomidate
- Ketamine
- Propofol
- Inhaled agents.
Propofol is the most favored agent. It has quick onset of induction, superior
and fast recovery, minimal post operative side effects, no PONV and no
residual effects.
Inhaled agents are as good choices. Changes in the depth of anesthesia can
be achieved readily because of the rapid uptake and elimination of these
anesthetics. The rapid elimination of anesthetic vapors also provides for fast
recovery and potentially earlier discharge from the outpatient facility.

49. Labat’s Classical Approach

51. Contraindications to Outpatient Surgery
1. Potentially life-threatening chronic illnesses (e.g., brittle
diabetes, unstable angina, symptomatic asthma)
2. Morbid obesity complicated by symptomatic cardiorespiratory
problems (e.g., angina, asthma)
3. Multiple chronic centrally active drug therapies (e.g., use of
monoamine oxidase inhibitors) and/or active cocaine abuse
4. Ex-premature infants less than 60 weeks’ postconceptual age
requiring general endotracheal anesthesia
5. No responsible adult at home to care for the patient on the
evening after surgery

52. ᵹMiller’s Anaesthesia, 7th edition
ᵹEndourology and stone disease.
Results and Complications of Spinal Anesthesia inPercutaneous
Nephrolithotomy by Sadrollah Mehrabi, Kambiz Karimzadeh Shirazi..
ᵹJournal of Endourology, Volume 23, Number 11, November 2009.
Percutaneous Nephrolithotomy Under General Versus Combined
Spinal-Epidural Anesthesia
ᵹClinical anaesthesia by Barash, Cullen and Stoelting.
ᵹhttp://www.nysora.com/peripheral_nerve_blocks/nerve_stimulator_t
echniques/3095-obturator-nerve-block.html
ᵹhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2684259/
(Indian Journal Of Urology - Analgesia for pain control during
extracorporeal shock wave lithotripsy: Current status)