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192 8-Principles of Endoscopy

•an endoscope, light source, and irrigating fluid

irrigation fluids include sterile water, glycine, or normal saline. If electrocautery use is

anticipated, a solution free•of electrolytes should be used

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Video-endoscopic units, comprising a light source, camera for the endoscope, image processor and recorder, and monitor, are

usually arranged on a mobile tower, are transmitted to the image processor by a

camera attached to the eyepiece and displayed on a viewing monitor

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Cystourethroscopy is used to directly visualize the anterior urethra, posterior urethra, and

•the bladder.

of the most commonindications for cystourethroscopy is the evaluation of microscopicand gross hematuria. Other indications for cystourethroscopyinclude evaluation of voiding symptoms, surveillance of urothelialcarcinoma, foreign body removal, and assisting in difficult placement

•of a catheter.

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Endoscope sizes are expressed using the French (Fr)scale and refer to the outer circumference in millimeters.Pediatric endoscopes are generally 8 to 12 Fr whereasadult scopes range from 16 to 25 Fr .

The size of the endoscope selected will depend on the specific procedure performed,the need for additional working instruments,and the degree of irrigant flow that will be required, butin general the smallest diameter endoscope that willaccomplish the goals of the procedure is selected to minimizegenitourinary tract trauma.

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•UPPER URINARY TRACT ENDOSCOPY•Indications•Ureteroscopy is a standard urologic technique that

providesdirect visualization of the upper urinary tract, facilitating both diagnostic and therapeutic interventions

• Ureteroscopy is most•commonly used for the treatment of nephrolithiasis

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•Ancillary Equipment•Wires. Guidewires used during retrograde instrumentation•serve to provide access to a particular area of the urinary tract and•serve as a guide to pass catheters, stents, and sheaths .

•Guidewire properties vary with•respect to length, diameter, composition, tip design, surface•coating, and shaft rigidity. Guidewire diameters and lengths range•from 0.018 to 0.038 inch and 145 to 280 cm, respectively .

•The•ideal guidewire should have a flexible lubricous tip allowing for•easy atraumatic passage through a tortuous, obstructed ureter•while providing sufficient rigidity of the shaft for the passage of•catheters and instruments.

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Care should be taken to use only as much irrigation needed to provide a clear visual field.

•Utilizing the minimum amount of irrigation necessary to•provide a clear view during ureteroscopy minimizes stone•migration, bleeding from hydrodistention, and

pyelolymphatic•or pyelovenous backflow.

l The holmium:YAG laser is the gold standard for ureteroscopicintracorporeal lithotripsy.

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•Complications of ureteroscopic•basketing range widely in severity and include

ureteral•avulsion, intussusception, abrasion,

perforation, postoperative•stricture formation, and basket breakage or•entrapment

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PREPARATION FOR SURGERY

•Patient Factors That Increase the Risk of Infection

•Advanced age•Anatomic anomalies•Poor nutritional status

•Smoking•Chronic corticosteroid use

•Immunodeficiency•Chronic indwelling hardware

•Infected endogenous/exogenous material•Distant coexistent infection

•Prolonged hospitalization

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Skin Preparation

Sterile skin preparation is fundamental in the prevention of SSI for any procedure.

Currently, the most commonly used skin antiseptics are alcohol, povidone-iodine, or chlorhexidine based.

Whichever antiseptic is chosen, the solution should be applied in concentric circles from the center of the surgical site and be allowed to dry before incision .

A recent review from the did not find sufficient evidence to recommend one skin preparation over another .

Furthermore, although the CDC clearly recommends preoperative showering/bathing to reduce SSI, there is no evidence that bathing with an antiseptic solution reduces the rate ofinfection .

Regarding hair removal, the CDC recommends that if hair removal is performed, it shouldbe performed immediately before the surgical procedure and performed with clippers (rather than shaving .

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•PATIENT ENVIRONMENT•Patient Temperature

There are two primary reasons for hypothermia to develop in the operating room.

Anesthetic agents induce peripheral vasodilation redistributing heat from the core (trunk, head) with resultant drop in immediate core temperature after induction .

Throughout the rest of the procedure, radiation and conductive heat loss

account for most of the heat loss during a surgical procedure. Normothermia is defined as core temperature between

36° C and 38° C, and even hypothermia of 1° C to 2° C results in adverse effect .

mild hypothermia (decrease of 1°C) resulted in a 16% increase in estimated blood loss and 22% increase in transfusion requirements

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The increased bleeding risk is thought to result from a hypothermia-associated decrease in clotting cascade enzymatic function and platelet aggregation.

Even more significant is the increase in the risk of surgical site infections (SSI) associated with mild hypothermia (34° C to 36° C).

Hypothermia was associated with a three times increased riskof wound infection and a 2.6-day increase in hospitalization.

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Strategies to improvement maintenance of :normothermia including

regular use of warming blankets, warmed intravenous fluids,

warmed irrigation fluids (especially during TURP and other prolonged endoscopic procedures) ,warmed/humidified CO2 gas during laparoscopy,and increase in ambient operating room temperature.

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Skin PreparationSterile skin preparation is fundamental in the prevention of SSI for any procedure .

Currently, the most commonly used skin antiseptics are alcohol, povidone-iodine, or chlorhexidine based.

Whichever antiseptic is chosen, the solution should be applied inconcentric circles from the center of the surgical site and be

allowed to dry before incision .

A recent review from the Cochrane database did not find sufficient evidence to recommend one skin preparation over another.

there is no evidence that bathing with an antiseptic solution reduces the rate ofinfection.

Regarding hair removal, the CDC recommends that if hair removal is performed, it shouldbe performed immediately before the surgical procedure and performedwith clippers (rather than shaving) (Mangram et al, 1999)

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Patient Safety :Three causes of immediately preventable injuries are

retractor-associated injuries, thermal injuriesand patient position–related injuries.

1-increased rate of neuropathy (especially femoral nerve) following laparotomy with self-retaining retractors versus without self-

retaining retractors .

Careful attention to be certain that the lateral blades donot directly compress the psoas muscle and only cradle the rectusabdominal muscles will ensure avoidance of femoral neuropathy

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2-In both endoscopic and laparoscopic surgery, high-wattage light sources are used to illuminate the operative field.

While illuminated, the ends of the light cords can result in burns when in direct contact with the patient (even through draping) .

These light sources should be turned off at alltimes when not in use.