gu part 1 audio

Anesthesia for genitourological surgery: Part 1: 

Anesthesia for genitourological surgery: Part 1 University of New England Master of Science in Nurse Anesthesia Program Professor: Maribeth Massie, CRNA, MS, PhD(c)

Patient population: 

Patient population Elderly Coexisting diseases, especially renal dysfunction Acute renal failure Chronic renal failure Diabetes mellitus Endocrine abnormalities

General considerations: 

General considerations Elderly: positioning important Susceptible to hypothermia Diminished requirement for most anesthetics Regional technique may be preferred Decreased mental status changes postop Awake patient able to alert to early S/S of complications Decreased blood loss and incidence of thromboembolic events

Preoperative assessment: 

Preoperative assessment Do you have any problems with your kidneys? Do you urinate frequently at night when you lie down? Do your ever experience difficulty with urination? Do you have renal failure? Do you receive hemodialysis or peritoneal dialysis? Where is your dialysis shunt? When was the last time you had dialysis treatment? Do you still urinate? Usually dehydrated after dialysis – watch with induction! Prone to CHF, increase K+ levels, platelet dysfx , low HCT

Preoperative assessment: 

Preoperative assessment Preserve renal function in pts with renal insufficiency Avoid frequent hemodynamic alterations – low CO, low renal blood flow Acute renal failure is most likely to occur in pts who have renal insufficiency before surgery – greater if pt is >60years of age, and has left ventricular dysfunction Intense preoperative, intraoperative , and postoperative fluid management for pts with nephrotic syndrome and diminished tubular function

Preoperative assessment: 

Preoperative assessment Consider chemotherapeutic agents and their associated side effects if patient receiving before surgery Bleomycin : commonly used with testicular CA; pulmonary complications Doxorubicin: commonly used with bladder CA; cardiotoxic effects Methotrexate : commonly used with bladder CA; hepatic toxicity, neurotoxicity, renal injury Cisplatinum : neurotoxicity and renal injury

Preoperative assessment: 

Preoperative assessment Consider procedures that require radiocontrast agents – proper hydration before procedure to prevent ARF Uremia – the end result of renal tubular failure CV - cardiac failure Neuromuscular – neuropathy Metabolic / endocrinologic – electrolyte changes, acidosis Hematologic – anemia, coagulation and platelet dysfx Lowered immune system

Clinical risk factors that predict renal dysfunction: 

Clinical risk factors that predict renal dysfunction

General considerations: 

General considerations Lithotomy position Prone to nerve injuries Common peroneal nerve: if lateral thigh rests on strap support, results in loss of dorsiflexion of foot Saphenous nerve: if legs rest on medially placed strap supports, results in numbness along medial calf Obturator and femoral nerves: due to excessive flexion of thigh

Lithotomy position: 

Lithotomy position Leg stirrups/supports (Bier-Hoff, Allen) Candy cane strap stirrups

Lithotomy position cont’d: 

Lithotomy position cont’d Physiologic changes FRC decreases, predisposing to atelectasis , hypoxia Trendelenberg furthers these changes Elevation of legs increases venous return Lowering of legs at end of procedure decreases venous return hypotension ALWAYS TAKE BP AFTER LEGS LOWERED

Common procedures: 

Common procedures Cystoscopy Most common urologic procedure Done outpatient Short (15-20 minutes) Indications: hematuria, recurrent UTI’s, obstruction, removal of bladder tumor, treatment of ureteral strictures, catheterization, bladder biopsy, extraction of bladder stones, diagnosis of prostatic hypertrophy

Cystoscopy cont’d: 

Cystoscopy cont’d Choice of anesthetic Determined by amount of stimulation encountered Minor procedures: local with 2% Lidocaine jelly Procedures that dilate the urethra or cause bladder distention: require regional with T10 sensory level (or GA) Procedures that instrument urethra (catheterization): require T6 sensory level (or GA)

Cystoscopy cont’d: 

Cystoscopy cont’d GA: mask, LMA, GETA Regional: spinal preferred 2* setup time c/t epidural; does not abolish obturator reflex (only muscle relaxation does): E xternal rotation and adduction of thigh (muscle contraction) 2* stimulation of obturator nerve by electrocautery through lateral bladder wall

Extracorpeal Shock Wave Lithotripsy (ESWL): 

Extracorpeal Shock Wave Lithotripsy (ESWL) Indications: disintegration of calculi in kidneys, bladder or upper 2/3 of ureters (above iliac crest) Treatments: Flexible and rigid ureteroscopy Stone extraction Stent placement Intracorporeal lithotripsy Laser: Nd:YAG laser Electrohydraulic

ESWL: 

ESWL Extracorporeal Shockwave Lithotripsy (ESWL) Noninvasive method to disintegrate urinary calculi using sound waves directed towards kidney stones Requires analgesia, immobility, support of vital functions Older machines: Special room with immersion tub filled with demineralized water Patient placed in hydraulic chair and immersed in heated water bath Shock waves generated by underwater capacitor Newer machines: patient lies supine on soft cushion or water mattress and allows MAC or straight local Another version looks like a CT/MRI table with an opening for the lithotripter Tissue has the same acoustic density as water so the waves travel through the tissue without causing damage 11/28/2011 16

ESWL WATER IMMERSION: 

ESWL WATER IMMERSION

ESWL Lithotriper Table: 

ESWL Lithotriper Table

ESWL cont’d: 

ESWL cont’d May insert ureteral stents before procedure to aid passage of fragments Patients with cardiac arrhythmia's and/or pacemaker are prone to developing arrhythmia's from shock waves; must synchronize shock waves to R wave on EKG

ESWL cont’d: 

ESWL cont’d Monitoring: standard, nasal cannula or mask O2 Immersion in water bath can cause vasodilatation  hypotension; arterial BP rises as venous blood is redistributed centrally from hydrostatic pressure of water Watch for CHF 2* increased venous pressure and reduced FRC (30-60%)  hypoxia

ESWL: 

ESWL Physiological Concerns CV: dysrhythmias , increased CVP, decreased BP, tachycardia, vasodilatation, vagal responses Don’t slow heart rate too much since wave pulses are triggered by EKG  procedure lasts longer Synchronization of R waves decreases incidence of arrhythmias: 20 sec after R wave Asynchronous delivery safe in patients without cardiac disease Resp : hypoxemia, V/Q mismatch 2* reduction in FRC from hydrostatic forces against chest 11/28/2011 21

ESWL cont’d: 

ESWL cont’d Regional anesthesia: epidural to T6 sensory level (renal innervation from T10-L2) with light sedation May need to supplement block with Fentanyl 50-100 mcg via epidural Insert smallest amount air possible with LOR technique since large amounts of air can dissipate shock waves and promote injury to neural tissue Infuse 1000-1500 ml LR/ Plyte prior to epidural

ESWL cont’d: 

ESWL cont’d Disadvantage of regional Inability to control diaphragmatic movement Could move stone in and out of wave and prolong procedure Ask patient to breathe rapid but shallow General: allows control of diaphragmatic movement Fluid management: after initial bolus, additional 1-2 L given plus Lasix 10-20 mg to flush debris and blood clots

Contraindications to ESWL: 

Contraindications to ESWL Aortic aneurysm Lumbar orthopedic implants Pregnancy Coagulation disorders Morbid obesity Hemangioma in vertebral canal ?Cardiac disease 11/28/2011 24

Contraindications to ESWL: 

Contraindications to ESWL ?Pacemaker  potential issues: Temporary single beat inhibition with each shock Erratic or cessation of pacemaker function if ESWL transducer placed near pacemaker

Transurethral resection of prostate (TURP): 

Transurethral resection of prostate (TURP) Indications: benign prostatic hypertrophy (BPH), hematuria , recurrent UTI’s, prostate cancer, bladder stones/contracture 30-60% coexisting CV/pulmonary disease .5-6% mortality rate due to MI, pulmonary edema, renal failure T&S necessary 2* potential bleeding T&C for glands > 30-40 mL Length of case: 45-60 minutes

BPH can lead to symptomatic bladder outlet obstruction: 

BPH can lead to symptomatic bladder outlet obstruction

Anatomy of prostate: 

Anatomy of prostate