Management of surgical procedures common in men. Part 1: genitourinary procedures

Management of surgical procedures common in men. Part 1: genitourinary procedures

Original article Management of surgical procedures common in men. Part 1: genitourinary procedures Keywords Genitourinary TURP Radical prostatectomy ...

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Original article

Management of surgical procedures common in men. Part 1: genitourinary procedures Keywords Genitourinary TURP Radical prostatectomy TURBT Cystoscopy ESWL

Gerardo E. Ortega, Shan A. Couvillion and Laura S. Bonanno Abstract Common genitourinary surgical procedures in the male population have seen a dramatic rise in frequency as the percentage of men aged greater than 50 years old increases in the United States. Accompanying the advanced age of many men undergoing these procedures is the presence of one or more co-existent medical conditions. This article explores the surgical and anesthetic implications of transurethral resection of the prostate (TURP), radical prostatectomy (RP), transurethral resection of a bladder tumor (TURBT), cystoscopy, and extracorporeal shock wave lithotripsy (ESWL) and the considerations necessary when one or more coexistent illnesses are present. Each procedure will be considered from the surgical, anesthetic, pre-operative and postoperative perspective. ß 2010 WPMH GmbH. Published by Elsevier Ireland Ltd.

Introduction

Gerardo E. Ortega, MN, CRNA Louisiana State University Health Sciences Center School of Nursing Shan A. Couvillion, MN, CRNA Louisiana State University Health Sciences Center School of Nursing Laura S. Bonanno, DNP, CRNA Louisiana State University Health Sciences Center, School of Nursing E-mail: [email protected]

Online 10 November 2010

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Advances in both surgical and anesthetic techniques in the past several decades have improved both patient safety and the level of pain experienced by patients undergoing surgical procedures. The surgical time required for many procedures has been shortened. The increase in the number of men over the age of 50 in the United States parallels the increase in the number of genitourinary surgical procedures performed annually. The percentage of the male population older than 65 years was 12.3% in 2003 and this percentage is predicted to increase to 20% by the year 2030 [1]. It is not uncommon for men over the age of 50 to have one or more co-morbidities. The most common genitourinary surgical procedures performed in men are transurethral resection of the prostate (TURP), radical prostatectomy (RP: robotic/ laparoscopic versus open), transurethral resection of a bladder tumor (TURBT), cystoscopy and extracorporeal shock wave lithotripsy (ESWL) (Table 1). The purpose of this article

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is to outline the pre-operative, intra-operative, and postoperative surgical and anesthetic management of genitourinary surgical procedures in men. According to the Integrated Health Care Information Solutions (IHCIS) database, an enlarged prostate ranks 4th and prostate cancer ranks 10th among the 10 most prevalent disorders/diagnoses in men over 50 years of age [2]. There were 168,000 prostatectomies performed in the United States in 2006, based on a National Health Statistics report published in 2008 [3]. Cancer of the prostate is the most common cancer in men and is the second leading cause of cancer-related mortality for men in the US and Canada [2]. Bladder cancer is the 4th most common cancer in men [4]. According to the American Cancer Society, a prostate-specific antigen (PSA) level between 4 and 10 ng/dl indicates a 25% chance of the presence of prostate cancer and a PSA value greater than 10 increases the chance of having prostate cancer to 50% and above [5].

ß 2010 WPMH GmbH. Published by Elsevier Ireland Ltd.

Original article Table 1 Statistics by procedure. Age Gender ratio, M:F Incidence/year Mortality

TURP

Radical prostatectomy

TURBT

Cystoscopy

ESWL

>50 N/A 151,000 <1%

>40 N/A 17,000 <1%

15–85 1:1 68,000 <1%

15–85 1:1 83,000 Minimal

>40 1:2 600,000 1.5–5%

Source: Jaffe et al. [6]. M, male; F, female.

Transurethral resection of the prostate

is required to maintain visibility, distend the operative site, and to aid in the removal of dissected tissue and blood [9].

Benign prostatic hypertrophy (BPH) is a condition in which the enlarged prostate gland prevents the flow of urine from the bladder. TURP is usually the treatment of choice, and is considered the ‘‘gold standard’’ in the surgical management of patients with BPH [7]. TURP is indicated in patients whose prostate gland volume measures less than 50 gm. A prostate gland has a normal volume of less than 30 gm and a prostate gland measuring greater than 50 gm would require RP. The majority of men presenting for TURP are over 60 years of age. Consequently, pre-existing co-morbidities are common and can include coronary artery disease (CAD), congestive heart failure (CHF), hypertension (HTN), peripheral vascular disease (PVD), cerebrovascular disease, renal insufficiency, and chronic obstructive pulmonary disease (COPD). Patients in this age group have a high incidence (30–60%) of both cardiovascular and pulmonary compromise [8].

Surgical technique The surgical procedure is performed with the patient in the lithotomy position. A resectoscope is inserted through a modified cystoscope into the bladder and the tissue protruding into the prostatic urethra is resected. Continuous irrigation of the bladder and prostatic urethra

Anesthetic options Regional or general anesthesia can be safely administered for TURP. The choice of anesthetic technique depends on the individual patient’s co-existing diseases (Table 2), as well as patient preference (Table 3). If spinal or epidural anesthesia is chosen, a T10 dermatome anesthetic level (or lack of sensation at the level of the 10th thoracic vertebrae, corresponding with the level of the umbilicus) is required to alleviate the pain associated with bladder distention. When compared with general anesthesia, regional anesthesia is less likely to mask signs and symptoms of TURP syndrome and reduces the incidence of postoperative complications, including deep vein thrombosis (DVT) and bladder perforation [8]. Regional anesthesia is also optimal for patients with cardiovascular compromise who might not tolerate the cardiac depressant effects of the inhaled anesthetics used in general anesthesia. Regional anesthesia must be accompanied by some form of sedation for those patients who wish to be unaware during their procedure. General anesthesia is administered by delivering an inhalation agent through a patent airway by either laryngeal mask airway (LMA) or endotracheal tube (ETT) [8].

Table 2 Pre-operative diagnostic procedures

TURP RP TURBT Cystoscopy ESWL

Basic

Complete

Prostate

Chest

Type &

metabolic

blood

specific

X-ray

cross

panel

count

antigen

x x x x x

x x x x x

x x

(*) (*) (*) (*) (*)

(+) (+)

EKG

(8) (8) (8) (8) (8)

Pulmonary

Arterial

function

blood

tests

gas

x x x

x x X

(+), prostate measuring > 40 gm; (*), as indicated w/ concurrent lung disease; (8), as indicated w/ concurrent cardiac disease. Source: Jaffe et al. [6].

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Original article Table 3 Anesthetic techniques Anesthetic option

TURP

Radical

Robotic

prostatectomy

prostatectomy

General anesthesia Spinal anesthesia Epidural anesthesia Combined technique: spinal/epidural & general anesthesia MAC

x x x

x x x x

x

TURBT

Cystoscopy

ESWL

x x x

x x x

x x x

x

x

Source: Jaffe et al. [6].

Pre-operative management The most common pre-operative diagnoses requiring TURP are BPH and prostate cancer [6]. A comprehensive pre-operative assessment is vital and should focus on the detection and management of the patient’s physical condition and pre-existing co-morbidities in order to tailor an anesthetic plan. TURP carries a 0.2– 6% mortality rate, according to the American Association of Anesthesiologists, and the leading causes of death related to TURP include myocardial infarction, pulmonary edema, and renal failure [8]. Mental status and cognitive functioning should be thoroughly assessed to compare with any potential intra- or postoperative findings.

Intra-operative management Intra-operative complications include bleeding, bladder perforation, hypothermia, septicemia, disseminated intravascular coagulation (DIC), common peroneal nerve injury related to positioning, and TURP syndrome. TURP syndrome is the collection of symptoms caused by excessive irrigant absorption into the venous sinuses of the prostate leading to dilutional hyponatremia and hypo-osmolality. It can present intra- or postoperatively. Symptoms of TURP syndrome include fluid overload (which can exacerbate CHF and cause pulmonary edema), hemolysis, seizure, arrhythmias, and cyanosis. Solute toxicities may also occur and can include hyperglycinemia/hyperammonemia when glycine is used, hyperglycemia when sorbitol is used, and intravascular volume expansion when mannitol is used. Symptoms of TURP syndrome in the awake patient include headache, restlessness, confusion, and dyspnea [8].

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The recent introduction of laser technology for endoscopic resection of prostatic tissue has nearly eliminated the risk of TURP syndrome. The advantages of the new laser technology include a decrease in the amount of irrigant required, decreased bladder pressures, improved hemostasis, fewer blood transfusions, and shorter hospital stays. Laser procedures allow for the use of saline as an irrigant, provide for profound reduction in fluid absorption and reduced local tissue swelling, and may offer specific advantages for elderly or debilitated patients. The new techniques also provide advantages over traditional TURP for patients with cardiopulmonary disease by showing an insignificant change in hematocrit and serum sodium post-procedure, suggesting the risk of excessive intravascular volume related to irrigant absorption is minimal [10].

Postoperative management Blood pressure, heart rate, respiration, and oxygen saturation are monitored postoperatively. Pain should be treated according to the patient’s history and assessment. The evaluation of mental status is the best tool for detecting the early signs of TURP syndrome and bladder perforation. Patients are monitored for elevated temperature, bacteremia, sepsis, and hypothermia. Postoperative shivering associated with hypothermia is particularly worrisome as shivering can dislodge clots and promote or worsen postoperative bleeding [8]. Patients with bladder perforation will often complain of nausea, diaphoresis, retropubic or lower abdominal pain, and shoulder pain. In patients exhibiting signs of TURP syndrome, serum osmolality, chest X-ray, and EKG should immediately be obtained. In patients with an

Original article elevated temperature of greater than 38.6 8C blood cultures are indicated [6].

been established with either regional or general anesthesia [9].

Radical prostatectomy

Surgical techniques

The most common diagnoses for RP are BPH (with a prostate gland measuring 50 gm or more) and cancer of the prostate. RP is recommended for localized cancer that has not spread outside the prostate gland itself. Men with clinically localized prostate cancer and with a life expectancy greater than 10 years tend to undergo RP. Those greater than 70 years of age, and with life expectancy less than 10 years, usually opt for radiation therapy or ‘‘watchful waiting’’. Watchful waiting, also referred to as active surveillance, involves close monitoring of patients utilizing prostate specific antigen (PSA) serologies and digital rectal examination (DRE) at 6 month intervals. An annual transrectal ultrasound-guided biopsy is generally indicated as well [9].

RP is the surgical removal of the prostate gland and local lymph nodes via a retropubic/perineal or robotic approach [12]. The patient is placed in the supine position with slight hyperextension at the waist in order to distance the symphysis pubis from the umbilicus. The prostate gland is removed with the seminal vesicles, ejaculatory ducts, and a portion of the bladder neck.

Anesthetic options – perineal approach to RP Regional or general anesthesia, or a combined technique, may be used for this procedure. If regional anesthesia is used a sensory block level of T8 to T10 is adequate. Patients typically do not tolerate regional anesthesia without heavy sedation due to positioning during this procedure. Advantages of regional anesthesia include lower intra-operative blood loss, reduced incidence of postoperative DVT, and faster return of bowel function. A combined technique of regional anesthetics and intravenous sedation provides greater patient comfort, improved airway management, faster onset, and a more controllable duration of action [9].

Anesthetic options – retropubic approach to RP As with radical perineal prostatectomy, regional anesthesia with sedation or general anesthesia may be used. Epidural anesthesia is the preferred technique for all patients undergoing this procedure as epidural anesthesia is devoid of the need for ventilator support and virtually eliminates pulmonary complications [11]. There is a decrease in intra-operative blood loss, better control of postoperative pain, and the patient has a higher level of activity following surgery. No difference in patient mortality has

Pre-operative management The majority of patients presenting for RP are older than 55 and many have existing co-morbidities similar to those found in the patient population presenting for TURP. These co-morbid conditions often include CAD, CHF, PVD, cerebrovascular disease, COPD, and renal impairment [11]. As with patients presenting for TURP, patients presenting for RP should have a thorough pre-operative assessment including appropriate lab studies and diagnostic tests consistent with those recommended for TURP and by body system. Furthermore, each patient should be optimized with regard to any abnormal findings prior to surgery. Patients should also have a type and cross for a minimum of two units of packed red blood cells as moderate blood loss is not uncommon during RP [6].

Intra-operative management A nerve sparing technique is often used in an attempt to preserve sexual function. Significant blood loss (800–1200 ml) is generally associated with this procedure. Factors influencing blood loss include positioning, pelvic anatomy, and the size of the prostate gland. Arterial and central venous pressure monitoring are recommended for ongoing assessment of blood pressure and intravascular volume status [8]. Potential complications associated with RP include venous air embolism when the patient is placed in trendelenburg as the surgical site is above the level of the heart. Extended time in the trendelenburg position, combined with administration of large amounts of fluid, can precipitate upper airway edema necessitating a delay in extubation until airway edema subsides. Fluid administration must be carefully titrated by the anesthesia provider to ensure

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Original article adequate replacement without the risk of intravascular overload.

Postoperative management Complications for radical perineal or retropubic prostatectomy include DVT and peroneal nerve injury (secondary to lithotomy positioning). The most common complaint following these procedures is urgency to urinate. Additional complaints include abdominal fullness and pain. Pain should be aggressively treated with analgesics. Epidural infusion of dilute local anesthetics/opiates or patient-controlled analgesia (PCA) is recommended [6]. Most patients are discharged after 2 nights of hospitalization depending on the patient’s medical history and postoperative status. Thromboembolic events and infection may occur postoperatively and the procedure carries a mortality rate of about 0.2% [13].

Robotic prostatectomy Robotic prostatectomy is very similar to the laparoscopic prostatectomy with the major difference being that the computerized electromechanical controls give the surgeon much more precision and stability for the dissection of critical structures. The robotic console has tridimensional vision, which provides depth of field and helps with regard to orientation and surgical precision. In the hands of an experienced surgeon the procedure can be performed in approximately 2 hours, excluding patient positioning and anesthesia related pre- and post- operative time. Thus, the procedure will most often be 3 to 4 hours long [14]. Although this procedure is referred to as minimally invasive it can be considered maximally invasive physiologically. It is imperative for the surgeon and the anesthesia provider to understand the complications and the unique challenges of this procedure.

Surgical techniques The patient will be placed in the lithotomy position and steep trendelenburg with arms tucked in at the sides [14]. Lithotomy positioning causes major physiological alterations that include a decrease in functional residual capacity of the lungs, which predisposes the patient to atelectasis and hypoxia.

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Anesthetic options For laparoscopic or robotic prostatectomy general anesthesia is the technique of choice because of the length of the procedure and the extreme trendelenburg position with the need for abdominal distention. Endotracheal intubation, combined with muscle relaxation, provides a secure airway with controlled ventilation during pneumoperitoneum to facilitate the surgical procedure. Pulmonary implications of laparoscopy include management of decreased lung compliance and increased arterial carbon dioxide content from carbon dioxide absorption during pneumoperitoneum. In general, major cardiovascular complications during pneumoperitoneum are dysrhythmias and carbon dioxide embolism. Direct arterial pressure monitoring is recommended to facilitate management of blood pressure and measurement of blood gas values. Steep trendelenburg positioning produces physiologic changes in the cardiopulmonary and cerebrovascular systems in proportion to the degree of head down tilt [9]. If the surgery lasts only a few hours and there are no signs of facial and buccal edema the patient can be safely extubated. If the surgery is prolonged and there are signs of upper body and facial edema it is advisable to keep the patient intubated until the edema subsides [14]. The use of nitrous oxide during anesthesia is avoided by most clinicians during laparoscopic procedures to prevent bowel distention and expansion of residual intraoperative gas.

Pre-operative management The most common pre-operative diagnoses of patients undergoing robotic prostatectomy, as with RP, include BPH and prostate cancer. Care must be taken to ensure optimization of the patients’ co-existing diseases, such as cerebral aneurysm, diabetes mellitus, HTN, COPD and any history of myocardial infarctions or stroke. Pre-operative testing would mirror those diagnostic and laboratory tests suggested for TURP. Previous abdominal surgery is not a contraindication, but history of stroke or cerebral aneurysm is a relative contraindication for this procedure. Due to the possibility of severe hemorrhage during this procedure, which would be difficult to control, a discontinuation of anticoagulant and antiplatelet agents must take place 7 days prior to surgery [14].

Original article Intra-operative management Problems associated with robotic prostatectomy are the result of the steep trendelenburg positioning, abdominal insufflation with carbon dioxide to produce pneumoperitoneum, spatial restrictions, unexpected visceral injury and/or blood loss. Complications mentioned for radical perineal prostatectomy due to the steep trendelenburg position are also a possibility for robotic prostatectomy. Additionally, the insufflation present may further complicate ventilation and potentially cause the development of pulmonary interstitial edema. Insufflation is also associated with reduced blood flow to abdominal organs, increased systemic blood pressure, and bradycardia (which can be severe). Most hemodynamic changes are transient and return to baseline gradually over a 20–30 minute period [1]. Other possible complications include hypercarbia, venous carbon dioxide embolus, subcutaneous emphysema, and development of a pneumothorax and/or pneumomediastinum. Robotic prostatectomies have longer operative times but less blood loss and improved wound healing when compared with open radical retropubic prostatectomy. The results from eight non-randomized reports have suggested that complications, continence rates, positive surgical margins, and operative time were similar for robotic assisted and open radical prostatectomy. However, length of hospital stay and catheterization time were shorter after robotic RP [15].

Postoperative management As with other open procedures the most common postoperative complaint is urgency to urinate. Pain and the feeling of abdominal fullness are also frequent postoperative sensations after robotic prostatectomy. Aggressive analgesic therapy for pain is recommended and complete blood counts should be continued every 4 hours for 24 hours postoperatively or until blood loss is diminished and the laboratory values have stabilized [6].

Transurethral resection of bladder tumor Superficial transitional cell carcinoma accounts for 90% of all bladder cancers. Most patients undergo endoscopic transurethral

resection of bladder tumor (TURBT) for the diagnosis and treatment of this cancer. Transurethral resection of visible lesions is the standard initial treatment for superficial bladder cancer and is often followed by adjuvant intravesical therapy such as chemotherapy or immunotherapy. Cigarette smoking is currently the single most important risk factor contributing to the development of bladder cancer [4].

Surgical techniques The patient is placed in the lithotomy position and care must be taken to avoid the risk of peroneal nerve compression inherent with all procedures in the lithotomy position. A resectoscope (a lit tube) is inserted through the urethra into the bladder. A solution is infused to maintain visibility and the tumor, or tissue to be examined, is cut away using an electric current. Transurethral resection removes the tumor and allows for pathologic analysis of the resected specimen, establishing the diagnosis and providing important information about the tumor grade and depth of bladder invasion. Other surgical and non-pharmacological treatment approaches include laser treatment and photodynamic therapy, which are therapeutic but less commonly used as initial therapy because they do not supply grading and staging information [16].

Anesthetic options TURBT can be performed using either regional or general anesthesia. When using regional anesthesia either spinal or continuous lumbar epidural anesthesia is acceptable, noting that a T10 anesthetic level is required to block pain involved with bladder distention. The choice of anesthetic technique is based on the length of the procedure, the patient’s age, presence of coexisting disease, and the preference of the patient. If the bladder tumor lies near the obturator nerve, the electrocautery may cause the thigh muscle to contract resulting in inadvertent bladder perforation regardless of the anesthetic technique. In this situation general anesthesia with the addition of muscle relaxant is the preferred technique of most anesthesia providers [9].

Pre-operative management The most common diagnoses for which TURBT is utilized are bladder tumor and hemorrhagic

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Original article cystitis. Bladder tumors are often seen in elderly patients who present for cystoscopy or TURP. Pre-operative evaluation should parallel that for TURP with the laboratory and diagnostic tests being suggested by the patient’s co-existing medical conditions. The same implications for the cardiac and respiratory systems exist as have been mentioned in relation to lithotomy positioning for robotic prostatectomy.

Intra-operative management The ideal irrigant for TURBT is water, which provides a clear field of vision, but absorption of water into the central circulation leads to intravascular hemolysis and hyponatremia. The use of isotonic fluids such as glycine reduces the risk of dilutional hypontaremia and hemolysis [17]. Complications of TURBT are not uncommon, but usually have a low morbidity and are frequently unreported. The most common complication reported is bleeding and the occurrence is 0.9–13%. Bladder perforation is the second most frequent complication with a presumed incidence of 1.3–5% and it usually occurs during difficult resections [18]. When perforation of the bladder occurs, intra- or extraperitoneal extravasation of the irrigant solution can occur. The conscious patient (receiving regional anesthesia) will complain of sudden severe abdominal pain that is often associated with referred pain from the diaphragm to the shoulder. Other symptoms may include pallor, sweating, abdominal rigidity, nausea, and vomiting [7]. Other complications associated with TURBT include infection, damage to the ureteric orifices, obturator nerve simulation, and peripheral neuropathy [17].

Postoperative management Pain should be treated according to the patient’s history and assessment. Evaluation of mental status is the best method for detection of early signs of bladder perforation and should be assessed frequently. Temperature should be assessed regularly as hyperthermia is frequently associated postoperatively with bacteremia. Hypothermia is often accompanied by shivering which can promote both the dislodgement of clots and postoperative bleeding [8]. Patients who complain of nausea, retropubic pain, lower abdominal pain,

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shoulder pain, or who are diaphoretic should be considered high risk for bladder perforation. Patients with elevated temperature should have blood cultures obtained [6].

Cystoscopy Cystoscopy is a procedure that affords examination and treatment of the internal structures of the lower urinary system. It is the ‘‘most commonly performed urological procedure’’ [8] and allows for direct visualization of the anterior and posterior urethra, bladder neck, bladder, and ureters [9]. Cystoscopy is most often performed to diagnose and/or treat conditions that include recurrent urinary tract infections (UTIs), hematuria, urinary obstruction, urinary frequency, renal calculi, urinary tract growths or tumors, or following abnormal results from a urinalysis.

Surgical technique Patients are usually positioned in the lithotomy position. Since the legs are lifted and lowered simultaneously, caution must be used as the same implications regarding changes in venous return that are present for TURBT also apply here. The legs are padded and positioned properly to avoid damage to the common peroneal nerves lateral to the thighs and to the saphenous nerves medially. After induction of anesthesia and patient positioning the cystoscope is placed into the urethral orifice following sterile preparation. Connections at the distal end of the cystoscope allow for a light source and an irrigant source (again used to extend the bladder and aid in visualization). If it is necessary to enter either or both ureters (for stone extraction, stent placement, or to bypass obstruction) a ureteral catheter can also be placed through the cystoscope for this purpose. During cystoscopy urine output is difficult to measure prior to removal of the cystoscope and placement of a foley catheter because of the volume of irrigant solution used.

Anesthetic options Either regional or general anesthesia can be used for cystoscopic procedures. The anesthetic choice will be dependent on the type

Original article and length of procedure, age of the patient, coexisting illness, and patient preference. General anesthesia might be a better technique in procedures with a shorter surgical time to avoid the need to wait for a regional block post-procedure to take effect. Patients who desire to be completely unaware during their procedure will benefit from a general anesthetic. One study found that ‘‘Midazolam anesthesia during cystoscopy is well tolerated and is associated with no or minimal discomfort’’ [19] when used in combination with topical local anesthetics. In patients unable to tolerate general anesthesia because of coexistent disease processes regional anesthesia is used. A sacral block is used for urethral procedures with a T9–T10 epidural or spinal level for procedures involving the bladder, and as high as T8 for procedures involving the ureters [6]. A LMA is commonly used to administer general anesthesia for cystocopy, barring contraindications such as obesity, gastro-esophageal reflux disease, or diabetes mellitus. LMAs are airway devices that lie in the oropharyngeal area and do not require laryngoscopy for placement. Placing the patient in lithotomy position will decrease functional residual capacity (FRC), which will be exacerbated if the trendelenburg positioning is used simultaneously. Thus, patients with respiratory compromise, decreased respiratory capacity, or a contraindication to the use of a LMA, might require general endotracheal anesthesia to ensure adequate mechanical ventilation during the procedure.

finding is increased temperature. Otherwise, postoperative care would include routine monitoring of vital signs in a post-anesthesia care unit until the patient is able to urinate, has stable vital signs, and, if regional anesthetics were administered, can demonstrate termination of action of the local anesthetics.

Pre-operative management As with the previously mentioned procedures, it is not uncommon for patients presenting for procedures to the genitourinary system to be elderly and/or have co-existing medical conditions. Obtaining a comprehensive pre-operative assessment helps ensure that a patient’s coexisting disease processes are considered when tailoring an anesthetic plan. Pre-operative testing should include those studies recommended for TURP as applicable for the patient.

The procedure is performed with the patient in the supine position on a lithotripter table. ESWL uses radiography to concentrate repetitions of sound waves toward the stone in order to shatter the stone into fragments small enough to be eliminated through the ureters, bladder, and urethra. Body tissues are sufficiently dense to be unaffected by the sound waves as they travel toward the stone. Upon impact with the stone the ‘‘change in acoustic impedance at the tissue–stone interface creates shear and tear forces on the stone’’ [8].

Postoperative management

Anesthetic options

In addition to the transient hypotension related to leg positioning mentioned above, there is a rare, but potential risk of bladder perforation. Another potential postoperative

Monitored anesthesia care (MAC) is the anesthetic technique most frequently used for ESWL, though regional or general anesthesia is also appropriate. MAC anesthesia is the

Extracorporeal shock wave lithotripsy Modern treatments for kidney stones generally involve minimally invasive or non-invasive procedures. Stones located either in the bladder, or low in the ureters, are generally treated using a cystoscopic procedure. Stones located in the kidneys or the proximal 2/3 of the ureter are often treated with extracorporeal shock wave lithotripsy (ESWL). The patient assists in positioning the operative kidney on a water filled pillow adjacent to the sound wave generator. Monitors are attached and anesthesia is induced. The location of the stone is verified with the use of an X-ray source under the table and an image intensifier that is positioned above the table. Once the stone is precisely located production of the sound waves can begin with the focus being on the stone(s). Treatments consist of an average of 1,500– 2,000 shocks and the procedure generally lasts 45 minutes to 1 hour. Being extracorporeal, or ‘‘outside the body’’, the procedure is completely non-invasive.

Surgical technique

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Original article administration of intravenous sedation and analgesia titrated to allow the patient to maintain spontaneous ventilation while providing amnesia and pain control. A T6 sensory level is required to alleviate the pain associated when ESWL is performed under regional anesthesia. An LMA can be used for general anesthesia if there are no contra-indications. General anesthesia is often preferred by patients, allows for control of ventilation, and is associated with a decreased incidence of patient movement. Patient movement during this procedure can displace the sound wave alignment. Additionally, general anesthesia offers the advantage of more rapid recovery from anesthesia than a regional technique.

Pre-operative management Absolute contraindications to ESWL include: the inability to safely position the patient with the intestinal and lung tissues outside the trajectory of the sound wave pathway; an untreated infection; pregnancy; coagulopathy; and any obstruction to urine flow below the level of the stone. Relative contra-indications to ESWL include the presence of either ‘‘orthopedic prostheses or an aortic aneurysm’’ [8] in the area near where the wave generator will be placed. Since all body systems are reviewed, it is important to note that ESWL can heighten the incidence of cardiac arrhythmias, especially in patients with a history of arrhythmias. In these patients, the generator can be synchronized to deliver waves immediately following the ‘‘R’’ wave on the electrocardiogram to decrease the likelihood of eliciting cardiac arrhythmias during the procedure. Patients who have an implanted pacemaker or automated internal cardiac defibrillator are at risk of device damage caused by the waves emitted by the generator. Pre-operative diagnostics should follow the guidelines mentioned earlier for any co-existing illnesses present.

Intra-operative management Vigilant EKG monitoring during ESWL is essential to check for the occurrence of procedure related arrhythmias. Liberal fluid administration (1–2 l) is recommended intra-operatively, if not contra-indicated due to cardiac disease, to promote increased urine output which aids in the removal of stone debris and any blood clots which may be present.

Postoperative management Transient bleeding post-procedure is not uncommon and is related both to renal parenchymal damage due to the treatment and to stone fragments irritating the lining of the kidney and ureter as they pass through the urinary tract. Bruising, mild swelling, and mild flank pain are sometimes found at the site of contact with the shock wave generator. Complications attributable to ESWL include pacemaker complications in that specific patient group (minimal) [20]. Additionally, a collection of stone fragments may accumulate in the ureter causing an obstruction that requires cystoscopic placement of a ureteral stent to relieve the obstruction.

Conclusions TURP, radical prostatectomy, TURBT, cystoscopy, and ESWL are common surgical procedures of the genitourinary system in men. Advances in techniques and equipment have improved patient safety in these procedures. A variety of anesthetic techniques are available, which help to ensure that despite various coexisting diseases in patients presenting for genitourinary surgery, there will be a safe anesthetic option.

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