Anaesthesia For Urological Surgery

Dr Koay Choo Kok

Consultant Anaesthetist

Department of Anaesthesia

Toa Payoh Hospital

INTRODUCTION:

In the last decade, there have been many exciting changes in the field of urology and anaesthesia. New modes of surgical treatment such as laparoscopy, laser, shock wave lithotripisy, endoscopic stone removal all aim to make surgery less invasive. Trend is also towards shorter day surgery. Introduction of many new anaesthetic drugs and awareness of total patient care from pre﹐perative to post﹐perative period also expand the anaesthetic scope tremendously.

CHOICE OF ANESTHESIA

Patient's desire, surgical requirements, environmental factors, patients' safety are the factors that affect chocie of anaesthesia. Anaesthesia can be delivered in the simplest form of using 2% lignocaine jelly to the urethral macosa to the elaborate combination of Regional Anaesthesia (RA)/peripheral nerve block and General Anaesthesia (GA).

INDICATIONS FOR GENERAL ANAESTHESIA:

GA with the patients breathing spontaneously or ventilation mechanically controlled are generally considered for the following cases: a. Open Renal procedures b. Prolonged surgical time c. Embarrassed procedure d. Noisy theatre ambience (Teaching, conversation in progress) e. The very short and simple procedure where GA is deemed more comfortable than RA. f. Most laparoscopic work.

REGIONAL ANESTHESIA:

(Spinal, Epidural, Caudal) Good knowledge of sensory supply to various parts of urinary tract is a prerequisite of successful regional anaesthesia. In general, the pelvic viscera receives parasympathetic fibers from S2, 3, 4 (via pelvic splanchnic plexus) and sympathetic nerves from the hypogastric plexus (T11, 12). The kidney receives sympathetic nerve supply from T10/L1 and is under vagal parasympathetic control. egs:

Urethral procedures(S2, 3, 4)

Prostate surgery .

The prostate and bladder neck receives sensory supply from S2, 3, 4. However, distension of bladder requires a sensory blockade till T11/12. A spinal anaesthesia will be ideal for TURP.

Endoscopic procedure on ureters.

RA offers satisfactory operating conditions provided a sympathetic block extending as high as T10 is obtained.

Kidney surgery.

Surgery involving the kidneys is difficult to perform under regional anaesthesia alone.

Peripheral Nerve Block.

1. Penile nerve block

The dorsal nerve of penis (a branch of pudendal nerve), supplies the distal 2/3 of the penis. This block is suitable for circumcision or as a supplement to GA or hypospadias repair.

2. Ilioinguinal and iliohypogastric nerve block

This block provides good post-op pain relief following orchidopexy,hydrocoelectomy or inguinal hernia repair. The nerves are blocked through the skin at 1cm medial and 1 cm below the anterior superior iliac spine.

COMPLICATIONS DURING UROLOGICAL SURGERY:

1. Nerve injuries due to lithotomy position. Nerves involved can be common peroneal nerve, saphenous nerve, sciatic nerve, obturation and femoral nerve. 2. Difficult predictability of duration of surgery especially the endoscopic surgery. 3. Bladder perforation: Coughing and straining to be avoided. 4. Hypothermia: Cold irrigation fluid may produce systemic cooling. 5. Bacteraemia: especially in patient with obstructive uropathy and urinary tract infection. 6. Blood loss: which might be difficult to assess. 7. TURP syndrome 8. Coagulopathy: Carcinoma of prostate might release fibrinolytic substance during its resections and it is also associated with chronic renal insufficiency. 9. Latex allergy.