anesthesia for turp, turbt and nephrectomy

ANESTHESIA FOR TURP, TURBT AND NEPHRECTOMY

MODERATED BY-DR GIRISHPRESENTED BY-DR CHITTRA

ANESTHESIA FOR TURP AND TURBT

WHAT IS TURP!!!!!!TURP is resecting prostatic tissue with an electrically powered cutting-coagulating metal loop performed by inserting a resectoscope through the urethra As much prostatic tissue as possible is resected, but the prostatic capsule is usually preservedAn irrigating solution flows into surgical site to distend bladder and to bathe surgical site washing away blood and debris removed by wire loop

ANATOMY

The prostate is a fibromuscular glandular organ that surrounds the prostatic urethra It is about 1.25 in. (3 cm) long and lies between the neck of the bladder above and the urogenital diaphragm below

The prostate is divided into five lobes The anterior lobe lies in front of the urethra and is devoid of glandular tissue The median lobe is situated between the urethra and the ejaculatory duct

The posterior lobe is situated behind the urethra and below the ejaculatory ducts and also contains glandular tissue The right and left lateral lobes lie on either side of the urethra and are separated from one another by a shallow vertical groove on the posterior surface of the prostate

ARTERIAL SUPPLYBranches of the inferior vesical and middle rectal arteries

VENOUS SUPPLY Veins form the prostatic venous plexus,

which lies outside the capsule of the prostate

LYMPHATIC DRAINAGEInternal iliac nodes

NERVE SUPPLYInferior hypogastric plexuses

The average age of patients currently undergoing TURP is approximately 69 years,and the average amount of prostate tissue resected is 22 g Risk factors associated with increased morbidity

prostate glands larger than 45 g operative time longer than 90 min acute urinary retention as presenting symptom

AGE RELATED PHYSIOLOGICALCHANGES

CENTRAL NERVOUS SYSTEMDecreased fxnl neuronal tissue Sluggish or impaired reflex responsesReduced ability to generate body tempReduction in the area of the epidural

space Increased permeability of dura Decreased volume of cerebrospinal fluid

PERIPHERAL NERVOUS SYSTEM Diameter and number of myelinated fibers in

dorsal and ventral nerve roots are decreased Decrease in inter–Schwann cell distance

conduction velocityCARDIOVASCULAR SYSTEMDecreased contractility, increased myocardial

stiffness , ventricular filling pressures, and decreased β-adrenergic sensitivity

Impaired baroreceptor function

RESPIRATORY SYSTEMDecreased alveolar surface area,diffusion

capacity,lung elasticity,mechanical ventilation reserve

Ventilatory responses to hypoxia, hypercapnia, and mechanical stress are impaired secondary to reduced central nervous system activity

RENAL FUNCTIONRenal blood flow decrease about 10% per

decadeProgressive decline in creatinine clearance

with age

Renal capacity to conserve sodium is decreased

At risk for dehydration and sodium depletion

Prolongation of plasma half life of drugs

PREOP EVALUATION AND PREPARATION

Routine history and physical examinationSpecial attention to CVS and respiratory

systemBecause of their age these patients have

relatively high (30–60%) prevalence of both cardiovascular and pulmonary disorders

Beta-blockers suppress the compensatory tachycardic response to hypotension associated with SAB or haemorrhage

Alpha blockers-The combined hypotensive effects of these drugs may precipitate severe hypotension after SAB

Aspirin-stopped minimum 7 days before surgery

Warfarin- If the INR is greater than 1.4 the procedure should be postponed until the INR is acceptable

Clotting studiesBlood should be available and

crossmatched

POSITIONING OF PATIENT Hips are flexed 80 to 100 degrees from trunk,

and legs are abducted 30 to 45 degrees from the midline

Knees are flexed until the lower legs are parallel to torso and legs are held by supports or stirrups

The foot section of the operating room table is lowered

Positioning the arms on armrests far from the table hinge point is recommended at all times when patients are in the lithotomy position

Initiation of the lithotomy position requires coordinated positioning of the lower extremities by two assistants to avoid torsion of the lumbar spine

Both legs should be raised together flexing the hips and knees simultaneously

The lower extremities should be padded to prevent compression against the stirrups

Injury to the common peroneal nerve, resulting in loss of dorsiflexion of the foot may result if the lateral thigh rests on the strap support

If legs are allowed to rest on medially placed strap supports, compression of the saphenous nerve can result in numbness along the medial calf

Excessive flexion of thigh against the groin can injure obturator nerve and femoral nerve

Extreme flexion at thigh can also stretch the sciatic nerve

PHYSIOLOGICAL ALTERATIONS Preload increases, causing a transient increase in

cardiac output may exacerbate congestive heart failure. cerebral venous and intracranial pressure may increase diaphragm becomes cephalad, reducing lung

compliance ,FRC and predisposing patient to atelactasis and hypoxia

If obesity or a large abdominal mass is present abdominal pressure may increase significantly enough to obstruct venous return to the heart

Normal lordotic curvature of the lumbar spine is lost in the lithotomy position, potentially aggravating any previous lower back pain

ANESTHETIC TECHNIQUESREGIONAL ANESTHESIASpinal anesthesia is the most frequently used

anesthetic for TURP and is believed to be the technique of choice

Satisfactory anesthesia for TURP involves achieving an anesthetic block level that interrupts sensory transmission from the prostate and bladder neck

Regional anesthesia resulting in a sensory level to T10 is required to eliminate the discomfort caused by bladder distention

Spinal anesthesia provides adequate anesthesia for the patient and good relaxation of the pelvic floor and the perineum Signs and symptoms of water intoxication and fluid overload can be recognized early because the patient is awake.Accidental bladder perforation also is recognized easily if the spinal level is limited to T10 because the patient would experience abdominal or shoulder pain.

Subarachnoid anesthesia is generally preferred over continuous epidural anesthesia

It is technically easier to perform in elderly patients and the duration of surgery is generally not very long

o CAUDAL ANESTHESIA has been used effectively in high-risk patients undergoing laser prostatectomy

o Hemodynamic stability is the main advantage with this technique.

GENERAL ANESTHESIAo Who require ventilatory or hemodynamic

supporto Have a contraindication to regional

anesthesiao or refuse regional anesthesia.

INTRAOP MONITORING

ECGBlood pressureTemperaturePulse oximetryEnd tidal CO2CVP Line

ADVANTAGES OF REGIONAL ANESTHESIA

Amount of blood loss is reduced Less chances of DVTmonitoring the patient's mental status

intraoperatively Bladder perforation is recognized earlier

in a conscious patientdecreased requirement for analgesics in

the immediate postoperative period

COMPLICATIONS OF TURPABSORPTION OF IRRIGATION

FLUID/TURP SYNDROME Height of irrigating fluid > 60cm above

operating field Time of resection >1hr 10 to 30 mL of fluid is

absorbed per minute of resection time Vascularity of diseased prostate {(Preop Na÷post op Na)× ECF}-ECF

Dilutional hyponatraemia-Encephalopathy and seizures may develop when the sodium concentration falls below 120mmol/l

Fluid overload- causes pulmonary oedema and cardiac failure

Glycine toxicity- causes depression of the level of consciousness and visual impairment at toxic levels

SIGN AND SYMPTOMS Tachycardia Nausea and vomiting Confusion / disorientation Hypertension (fluid overload) then

hypotension Transient blindness Angina Dyspnoea and hypoxia Cardiovascular collapse and arrhythmias Convulsions ,coma

If the patient is under general anaesthesia all of the symptoms and some of the signs are masked and only unexplained tachycardia and hypotension may be present.

Increase risk of TURP syndrome Pre-existing hyponatraemia or pulmonary

oedema Prostate size larger than 60-100g Inexperienced or slow surgeon Procedures longer than 1 hour Hydrostatic pressure > 60cm H20 Use of large volumes of hypotonic

intravenous fluids like 5% dextrose

MANAGEMENTABC Algorithmterminate surgery as soon as bleeding

points have been coagulated stop IV fluids and commence fluid

restriction frusemide 40mg IVHypertonic saline solutions 1.8%, 3% or 5% should be used to increase the serum

sodium level by about 1 mmol/l/hour, not exceding an increase of 20mmol/l in the first 48 hours of therapy

Convulsions should be acutely treated with a benzodiazepine or small doses of thiopentone

In presence of intractable seizures, the sodium level may be corrected more rapidly at a rate of up to 8-10mmol/l/hour for the first 4 hours of therapy

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IRRIGATION FLUIDS

IDEAL….. Non-electrolytic Non-toxic Transparent Non-metabolizable Rapidly excreatable Inexpensive Isosmolar and non- hemolytic

GLYCINE Glycine-1.2% 175 mosm/kg Glycine-1.5% 220 mosm/kg Metabolizes to ammonia ,water and

glycolic acid Hyperammonemia and water intoxication

can lead to cerebral edema and seizuresSORBITOL 3.5% 165mosm/kg Metabolizes to CO2,H2O and glucose

MANNITOL 5% 275mosm/kg Dehydration and hyperosmolalityCYTAL Sorbitol 2.7%, and mannitol 0.54%GLUCOSE 2.5% 139mosm/kg Leaves surgical site and instruments very

sticky Elevated serum glucose levels

UREA 1% 167mosm/kg Permeable to intracellular and extracellular Nausea,vomiting,headache,tachycardia,dimi

nished vision,convulsions and coma Osmotic diuretic effectSALINE AND RL SOLUTION These electrolyte solutions are highly ionized

and facilitate the dispersion of high-frequency current from a monopolar resectoscope

GLYCINE TOXICITY Glycine is a major inhibitory transmitter

acting in the spinal cord and brainstem Retinal toxicity and blindness Might be associated with myocardial

depression and hemodynamic changes associated with TURP syndrome

AMMONIA TOXICITY CNS toxicity may occur as a result of

oxidative biotransformation of glycine to ammonia

Deterioration of CNS function is said to occur when ammonia levels are greater than 150 M

BLADDER PERFORATION If extraperitoneal pain in the periumbilical, inguinal

or suprapubic regions and irregular return of irrigating fluid

If intraperitoneal pain may be generalized in the

upper part of the abdomen or referred from the diaphragm to precordial region or shoulder

HYPOTHERMIA Heat loss as a result of irrigation and

significant absorption of fluid may lead to a decrease in the patient's body temperature and cause shivering

Warmed irrigating solutions are efficacious in reducing heat loss and the resultant shivering

BLOOD LOSSA hypertrophied prostate is highly vascular Blood is washed into the draining bucket and mixed with ample quantities of irrigant fluidEstimation of blood loss is inaccurate and extremely difficult Blood loss based on resection time- 2 to 5 mL/min size of the prostate in grams -20 to 50 mL/gpatient's vital signs should be monitored to assess better for the blood loss and need for transfusion

OBTURATOR REFLEXo The obturator nerve runs near the prostate and

can be electrically stimulated during transurethral prostate surgery, causing a violent thrusting of the leg

o This reflex can possibly lead to inadvertent intraoperative surgical complications

o The problem of unintentional obturator nerve stimulation can be corrected under general anesthesia by paralyzing the patient

o The obturator reflex most often occurs while resecting bladder tumors on the lateral walls of the bladder

o LA injection into sensitive area

ANESTHESIA FOR NEPHRECTOMY

ANATOMICAL DETAILSThe right kidney lies slightly lower than the

left kidney During respiration, both kidneys move

downward in a vertical direction by as much as 1 inch

On the medial concave border of each kidney there is a structure called the hilum

The hilum transmits, from front backward, the renal vein, two branches of renal artery and ureter

ARTERIAL SUPPLY

The renal artery arises from aorta at the level of the second lumbar vertebra

Each renal artery usually divides into five segmental arteries that enter the hilum of the kidney

Lobar arteries –interlobar-arcuate-interlobular-afferent glomerular

VENOUS SUPPLY

Renal vein emerges from the hilum in front of the renal artery and drains into the inferior vena cava.

NERVE SUPPLYSympathetic nerves to the kidney originate as

preganglionic fibers from the T8 to L1 and converge at the celiac plexus and aorticorenal ganglia

Parasympathetic input is from the vagus nerve Effective neural block of these segments is

necessary to provide adequate analgesia or anesthesia.

PREOP ASSESMENT AND EVALUATION

Routine history and examinationRenal function tests and BPSerum electrolytesAll baseline investigationsBlood should be arranged

ANESTHESIAGeneral anesthesia

POSIOTIONING OF PATIENT

The patient's head must be kept in a neutral position to prevent excessive lateral rotation of the neck and stretch injuries to the brachial plexus

The dependent ear should be checked to avoid folding and undue pressure

Eyes should be securely taped before repositioning if the patient is asleep

The dependent eye must be checked frequently for external compression

an axillary roll is frequently placed just caudal to the dependent axilla

never be placed in the axilla

weight of thorax is borne by the chest wall caudal to the axilla and avoid compression of the axillary contents

pulse should be monitored in the dependent arm consistently

When a kidney rest is used, it must be properly placed under the dependent iliac crest to prevent compression of the inferior vena cava

Padding is generally placed between the knees with the dependent leg flexed to minimize excessive pressure on bony prominences and any stretch on low extremity nerves

Combination of lateral weight of the mediastinum and disproportionate cephalad pressure of abdominal contents on the dependent lung favors overventilation of the nondependent lung

Also pulmonary blood flow to underventilated, dependent lung increases owing to the effect of gravity

Consequently, ventilation-perfusion matching worsens potentially affecting gas exchange and ventilation.

RADICAL NEPHRECTOMY FOR TUMORS

ANESTHETIC IMPLICATIONS85%-90% are for renal cell cancer 5%-10% extension to the IVC and right atrium Large-bore IV access, A-line, IJV line Hypercalcemia, increased prolactin, erythropoietin, glucocorticoidsAssociated comorbidities

extent of the lesion must be defined preoperativelyCVP catheter inserted through left IJV or external jugular vein so as not to place it beyond the superior vena cavaCardiopulmonary bypass is often required in these cases to prevent tumor embolization, and necessary with tumor thrombus extension into the upper portion of the hepatic vena cavadecrease in venous return also predisposes the patient to hypotension during induction of anesthesia

All approaches are painful-epidurals are useful but need to cover up T7/8 for loin incisionNSAIDS are useful if renal fxn is good postoperatively

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