LITHOTRIPSY

1. Anaesthetic choices for
lithotripsy
Dr Nida Fatima
Department of Anaesthesia and Critical care,
JN Medical college and hospital
AMU aligarh

2. Urolithiasis
• Prevalence of stone disease -1% to 15%.
• Varies- age, gender, race, and geographic
location.
• stone formation - migrated -lower to the
upper urinary tract.
• once limited to men is increasingly gender
blind.

3. UROLITHIASIS
Forced
Diuresis
Alkalisation
of urine
Tamsulosine
with
hydration
Extra
Corporeal
Shockwave
Lithotripsy
Percutenous
Nephro-
lithopexy
Uretro-
Reno scopic
Lithotripsy
Cysto-
litholapexy
Pyelo/Nephro
/Cysto/
Urethro-
lithotomy
Nephrectomy
If non
functional
kidney
Endoscopic
removal

4. • Lithotripsy( Greek) meaning "stone crusher“.
• Techniques:
• Extracorporeal shock wave lithotripsy
• Laser lithotripsy
• Electro-hydraulic lithotripsy
• Mechanical lithotripsy
• Ultrasonic lithotripsy
What is lithotripsy?

5. • Introduction ESWL in 1980.
• 85% of renal calculi - treated
• Externally generated, harmlessly penetrated
shock waves, provide pressure (900-1000 bar)
on a kidney stone to disintegrate it into
smaller granules.
Why lithotripsy?

6. Extracorporeal shock wave lithotripsy
(ESWL)
• Disintegration of urinary stones in the ureter and
kidney.
• High-energy waves (20 kilovolts)- focused on
ureter or kidney.
• Lithotripter uses “R-wave ECG”- trigger for shock
wave - refractory period of the cardiac cycle.

7. When lithotripsy?

8. MANAGEMENT OF RENAL CALCULI by
ESWL
< 2cm in diameter and/or surface area < 500 mm2
Treatment : ESWL mono-therapy
> 2cm in diameter and/or surface area > 500
mm2
Treatment : PCNL +/- ESWL
Combination therapy

10. Lithotripter
• Comprises of:
• spark plug
• Energy reflector
• Energy concentrator
• Fluoroscopy
• ultrasound

11. Spark plug Energy vaporize water
external shock wave
water bath/cushions
Release energy patient’s body
stone
generate
Focussed on
Passed to
hits
Crushed to pieces

13. - The sudden expansion
of air bubbles created
sets up a pressure
wave (shock wave)
- Focused onto F2 focus
- Exponential reduction
energy of wave beyond
F2.

14. EFFECTS OF RESPIRATION
• For shock waves -most effective- stone at 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 :
• decreased tidal volumes ,increased
respiratory rates, high-frequency jet
ventilation .

15. Physiological effects of lithotripsy
• Mechanical stimulation of myocardium and
conduction system…arrhythmias.
• Atrial premature contraction
• Ventricular premature contraction
• Atrial fibrillation
• Supraventricular tachycardia
• Ventricular tachycardia

16. When a patient is placed in a water bath:
Problems
• Cardiac preload is augmented
• Increase in CVP and PCWP
• Compression -peripheral venous system.
• ↑ SV and cardiac output of 30%.
• Hydrostatic pressure on the chest:
↓ FRC by 30% and VC by 20%.
• ↓tidal volume , ↑ work of breathing

17. 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

18. • Newer lithotripters no need of water bath.
• universal table for fluoroscopy.
• energy can be focused more precisely.
• less painful.

19. Renal changes
• Diuresis, natriuresis, and kaliuresis.
• ↓ADH and renal prostaglandins
Temperature changes:
• This heat transfer is augmented -vasodilation
produced by general or epidural anesthesia.
• Hypothermia and hyperthermia have been
reported.

20. • The pathogenesis -multifactorial.
• - Both cutenous and visceral nociceptors
Visceral nociceptors –
• periosteal,
• pleural,
• peritoneal,
• musculoskeletal pain receptors
PAIN

21. Variables associated with pain
• the type of lithotriptor,
• size of focal zone
• shockwave peak pressure,
• size and site of stone burden
• area of shockwave entry at the skin,
• location of the shockwave front

22. Special considerations!!!
• Women of childbearing age need to undergo-
a pregnancy test.
• Abdominal aortic aneurysms with calcium deposits
• orthopedic prostheses - kept out of the path of shock
wave.
• Lung tissue -susceptible to shock wave injury- Hemoptysis
and pulmonary contusion.
• Styrofoam padding.

23. • No incisions
• No surgery
• No lengthy hospital stays
• No lengthy recovery periods
Advantages of lithotripsy

24. • Some discomfort.
• Medicine to prevent infection.
• Passing sand-like particles in
urine
Disadvantages of lithotripsy

25. • Weight > 300 pounds (140 kg)
• Pregnant (absolute NO)
• Bleeding diathiasis (relative)
• Non- functional kidneys
• Pacemaker in-situ
• Contraindicated to anaesthesia or x-rays.
Who should not have lithotripsy?

26. Laser Lithotripsy
• Ureteral stones low in ureter and not amenable to
ESWL.
• laser beam of 504-nm.
• organic green dye.
• Laser beam -absorbed by the stones
• pulsatile energy is released - disintegration of the
stones
pulsed dye laser

27. • The anaesthesia method for ESWL
procedures
Depends upon:
• The level of patient consciousness
• The spontaneous breathing ability
• Need for intensive monitoring
• Anaesthesia recovery time.
Anaesthetic choices for lithotripsy

28. • Patient’s ASA class.
• Model of lithotripter – high-energy
lithotripters may require deeper level of
sedation
• Availability of certified anaesthetist or nurse
anaesthetist.
• Location of lithotripsy treatment

29. General
anesthesia
Analgesia-
sedation
Spinal
anesthesia
Epidural
anesthesia
Flank infiltration
± intercostal
blocks
Monitored
anesthesia care
Conscious
sedation
Anaesthetic choices for lithotripsy

30. Conscious Sedation
• An altered state of consciousness
• Minimizes pain and discomfort - analgesics and
sedatives.
• Patients able to speak and respond.
• A brief period of amnesia may erase the patient’s
memory of the procedure.

31. • Benefits:
• Ease of administration
• Minimal equipment.
• Rapid recovery time.

32. • Drawbacks:
• Diaphragmatic excursion
• Increase treatment time
• Decrease effectiveness of the treatment.
• Unpleasant memories

33. Monitored Anesthesia Care
(MAC Anesthesia)
• Patient protects the airway
• Requires active participation of anaesthesiologist.
• Can induce loss of normal protective reflexes
• Loss of consciousness
• The level varies widely during a single case and
from case to case.

34. • Benefits:
• A deeper level of anaesthesia
• Diaphragmatic excursion is reduced
• Improving treatment times and effectiveness

35. • Drawbacks:
• Must be administered by qualified anesthesia
personnel.
• Diaphragmatic excursion when anaesthesia is
not deep enough
• This can increase treatment time and/or
decrease the effectiveness of the treatment

36. General Anesthesia (GA)
• Drug-induced loss of consciousness
• Cannot be aroused, even by painful stimulation.
• Impaired respiratory and cardiovascular function
• If PPV → Securing airway using:
• Laryngeal Mask Airway
• Endotracheal Intubation

37. Benefit
• Rapid onset
• Control of patient movement.
• Ventilation parameters –controlled.
• Decrease stone movement with respiration,
• Effective stone targeting and fragmentation.

38. Drawback
• Morbidity and potential mortality
• Longer hospital stay,
• Expensive
• Prolonged recovery
• Strict monitoring
• Equipment and personel

39. GA preferable
- Children,
- Extremely anxious individuals,
- Anticipated lengthy treatment
• bilateral ESWL,
• concomitant renal and ureteral stones,
• calculi composed of cystine, or brushite, COM.

40. MAC VS GA
• MAC
• Rapid recovery
• Bypasses PACU
• Fastracking surgery
• G.A
• Prolonged recovery
• Shorter duration of
ESWL procedure
• Less opioids
required

41. Regional Anesthesia
• Easier to provide.
• Controlled loss of sensation.
• Better analgesia.
• Methods for shock wave include:
• Spinal Anesthesia
• Epidural Anesthesia

42. Epidural anesthesia
• Early recovery , good analgesia.
• LOR with saline
• Smallest amount of air if necessary-provides
an interface → dissipation of shock wave
energy and local tissue injury.

43. Spinal anesthesia
• Rapid onset
• Hypotension is higher.
• The incidence of hypotension with general ,
epidural, and spinal anaesthesia was 13%,
18%, and 27%, respectively.

44. Regional anaesthesia
• Drawbacks
• Postdural puncture headache (42%)
• Transient neurological symptom
• Urinary retention
• Pruritis
• Hypotension

45. • Flank infiltration ±
intercostal blocks.
• L.A infiltration of
flank ± intercostal
blocks + intravenous
sedation
→adequate
anesthesia avoids
hypotension.
• Analgesia -sedation
Intravenous analgesia-
sedation in various
combinations has
been used successfully