52
Anaesthetic Management of Minimally invasive Urologic Surgeries Moderator : Dr. Varsha Kothari Presentor : Dr. Abhinav Gupta

Eswl, PCNL, MAC, Urological procedures

Embed Size (px)

DESCRIPTION

A brief anaesthetic management of various outdoor urological procedures.

Citation preview

Page 1: Eswl, PCNL, MAC, Urological procedures

Anaesthetic Management of Minimally invasive Urologic Surgeries

Moderator : Dr. Varsha KothariPresentor : Dr. Abhinav Gupta

Page 2: Eswl, PCNL, MAC, Urological procedures

UrolithiasisᵹAlthough 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.

Page 3: Eswl, PCNL, MAC, Urological procedures

URILITHIASIS

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

Endoscopic removal

Page 4: Eswl, PCNL, MAC, Urological procedures

ESWLHIPPOCRATIC OATH :

“I Will not cut, even for the stone, but leave such procedures for the practitioners of the

craft”

Page 5: Eswl, PCNL, MAC, Urological procedures

ESWLᵹEngineers 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.

ᵹ Dr. 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.

Page 6: Eswl, PCNL, MAC, Urological procedures

ESWL

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.

Page 7: Eswl, PCNL, MAC, Urological procedures

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.

Page 8: Eswl, PCNL, MAC, Urological procedures

ESWLElectromagnetic:- 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.

Page 9: Eswl, PCNL, MAC, Urological procedures

ESWLShock wave generator

Waves travel through waterBody-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.

Page 10: Eswl, PCNL, MAC, Urological procedures

ESWL 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 inenergy of wave beyond F2.

Page 11: Eswl, PCNL, MAC, Urological procedures

Submersion variety of ESWL

Page 12: Eswl, PCNL, MAC, Urological procedures

ESWLNewer 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.

ᵹ But 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.

Page 13: Eswl, PCNL, MAC, Urological procedures

Newer Version of ESWL

Page 14: Eswl, PCNL, MAC, Urological procedures

Anaesthetic considerations

Page 15: Eswl, PCNL, MAC, Urological procedures

ESWLEffects 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.

Page 16: Eswl, PCNL, MAC, Urological procedures

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 zoneshockwave peak pressure, area of shockwave entry at the skin

Page 17: Eswl, PCNL, MAC, Urological procedures

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.

Page 18: Eswl, PCNL, MAC, Urological procedures

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.

Page 19: Eswl, PCNL, MAC, Urological procedures

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

Page 20: Eswl, PCNL, MAC, Urological procedures

ESWL

ᵹ For 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.

ᵹ Although 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.

ᵹ Adequate hydration is necessary to prevent clot retention.

Page 21: Eswl, PCNL, MAC, Urological procedures

ESWLᵹ Lung 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.

ᵹ Mechanical stress on the conduction system exerted by the shock waves may lead to arrhythmia, although rarely now-a-days.

ᵹ Brachial plexus injuries have also occurred from improper positioning ofpatients in the lithotripter chair.

Page 22: Eswl, PCNL, MAC, Urological procedures

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.

Page 23: Eswl, PCNL, MAC, Urological procedures

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 expensiveTherefore, 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).

Page 24: Eswl, PCNL, MAC, Urological procedures

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.

Page 25: Eswl, PCNL, MAC, Urological procedures

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.

Page 26: Eswl, PCNL, MAC, Urological procedures

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.

Page 27: Eswl, PCNL, MAC, Urological procedures

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.

Page 28: Eswl, PCNL, MAC, Urological procedures

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.

ᵹ The 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.

Page 29: Eswl, PCNL, MAC, Urological procedures

- 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.

Page 30: Eswl, PCNL, MAC, Urological procedures

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.

Page 31: Eswl, PCNL, MAC, Urological procedures

PCNL

Page 32: Eswl, PCNL, MAC, Urological procedures

PCNLᵹThomas Hillier in 1865 : first therapeutic percutaneous nephrostomy

ᵹ Hillier: repeatedly aspirated the hydronephrotic kidney of a young boy for symptom relief.

ᵹ Goodwin and colleagues 1955: published their landmark report on therapeutic percutaneous nephrostomy.

ᵹ Fernström and Johansson (1976): Percutaneous removal of renal calculi.

Page 33: Eswl, PCNL, MAC, Urological procedures

PCNLTECHNIQUE

Access Removal

ᵹ Access: 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.

Page 34: Eswl, PCNL, MAC, Urological procedures

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.  

Page 35: Eswl, PCNL, MAC, Urological procedures

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

Page 36: Eswl, PCNL, MAC, Urological procedures

PCNL

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.

Page 37: Eswl, PCNL, MAC, Urological procedures

-: Anaesthesia Considerations:-

ᵹ Practically 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.

Page 38: Eswl, PCNL, MAC, Urological procedures

-: 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.

Page 39: Eswl, PCNL, MAC, Urological procedures

-: 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.

Page 40: Eswl, PCNL, MAC, Urological procedures

Fluid management is important.

ᵹ During 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.

Page 41: Eswl, PCNL, MAC, Urological procedures

Other Minimally invasive Urosurgical procedures

Cystoscopy

Cystoscopy directed

procedures

Urethroscopy

TURP

Optical Internal Urethrotomy

Stricture dilatation

TUR Bx

TURBT

Bladder Neck Incision

Page 42: Eswl, PCNL, MAC, Urological procedures

Minimally invasive proceduresᵹCarried out as Ambulatory cases.

ᵹ Benefits 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

Page 43: Eswl, PCNL, MAC, Urological procedures

Pre-Operative managementMinimize 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 guidelinesProlonged 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.

Page 44: Eswl, PCNL, MAC, Urological procedures

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.

Page 45: Eswl, PCNL, MAC, Urological procedures

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.

Page 46: Eswl, PCNL, MAC, Urological procedures

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.

Page 47: Eswl, PCNL, MAC, Urological procedures

ᵹOpioid analgesia:-

- Opioid compounds are frequently administered during anesthesia to suppress autonomic responses to tracheal intubation and painful (noxious) surgical stimuli. - Opioids can also reduce the dosage requirements for sedative-hypnotic and volatile anesthetic drugs, thereby decreasing recovery times. - Potent opioid analgesics have been shown to decrease the incidence of pain on injection and involuntary motor activity associated with intravenous methohexital, etomidate, and propofol.

Page 48: Eswl, PCNL, MAC, Urological procedures

ᵹMuscle Relaxants:

Muscle relaxants are not often required during these short procedures of urosurgeries. However, direct stimulation of the obturator nerve by the resector as it passes in close proximity to the bladder wall may result in a sudden, violent adductor muscle spasm. This is not only distracting to the surgeon, but also potentially dangerous, increasing the risk of serious complications such as bladder wall perforation, vessel laceration, incomplete tumor resection and obturator hematomas. This is an Indication for the use of Muscle relaxants in endoscopic Uro-surgeries. - Alternatively, An Obturator nerve block may be used for the same.

Page 49: Eswl, PCNL, MAC, Urological procedures

Obturator Nerve Block:-Landmarks needed to be identified:-

Bony landmarks: Anterior and superior iliac spine and pubic tubercle, inguinal ligament.Vascular landmarks: femoral artery, femoral crease Muscular landmarks: tendon of the long abductor muscle

Labat’s Classical Approach

Page 50: Eswl, PCNL, MAC, Urological procedures

Technique:- The nerve may be blocked either as a Plexus block or either as a single nerve block. As single nerve block, the Labat’s classical method may be used. Steps include..- The patient lays supine, with the limb to be blocked at 30º abduction. The pubic tubercle is identified by palpation and a 1.5 cm long line is drawn laterally and caudally. - Using a 22G 8 cm long needle, the skin is penetrated perpendicularly and the needle is advanced until it makes contact with the inferior border of the superior pubic branch at a depth of 2-4 cm. - During the second phase, the needle is slightly withdrawn and then slipped along the anterior pubic wall (another 2-4 cm); following this it is redirected anterior/posterior. - Finally, the needle is withdrawn again and slightly redirected (cephalically and laterally) at an angle of 45º for another 2-3 cm until contractions of the thigh adductor muscles are observed.- 15 mL of 1-2% Lignocaine is injected at the site.- Reduction in adduction strength is the most reliable means of demonstrating successul obturator nerve blockade.

Page 51: Eswl, PCNL, MAC, Urological procedures

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

Page 52: Eswl, PCNL, MAC, Urological procedures

Referencesᵹ Miller’s Anaesthesia, 7th edition

ᵹ Endourology and stone disease. Results and Complications of Spinal Anesthesia inPercutaneous Nephrolithotomy by Sadrollah Mehrabi, Kambiz Karimzadeh

Shirazi..

ᵹ Journal of Endourology, Volume 23, Number 11, November 2009. Percutaneous Nephrolithotomy Under General Versus Combined

Spinal-Epidural Anesthesia

ᵹ Clinical anaesthesia by Barash, Cullen and Stoelting.

ᵹhttp://www.nysora.com/peripheral_nerve_blocks/nerve_stimulator_techniques/3095-obturator-nerve-block.html

ᵹ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2684259/(Indian Journal Of Urology - Analgesia for pain control during

extracorporeal shock wave lithotripsy: Current status)