Anaesthesia and nephrectomy

PREOPERATIVE:

Hepatic cell dysfunction or Stauffer

syndrome: abnormal LFTs, decreased

WBC count, fever, areas of hepatic

necrosis; no evidence of metastases;

reversible following removal of

primary tumour

• Smoking - ?COPD - CXR
• Obese - airway/ventilation

• Creatinine and urea
• Uremia- Pericarditis; bleeding;delayed gastric emptying
• ?Post op renal fx - consider MAG3
• Proteinuria - Hypoalbuminemia
• Electrolyte disturbances
• Acid-Base
• Antiacid premed/Maxalon

Fluid therapy:

• Pt may be dehydrated from dialysis/prolonged fasting
• Replace fluid deficit preop (Replacement fluid)
• Clear fluids up to 2h preop po

Decreased GFR

INTRAOPERATIVE

Anaesthesia and nephrectomy

Hematopoietic disturbances: anemia,polycythemia, raised ESR, thrombocytosis

LINES AND MONITORS

ECG

64yo male presenting with left sided renal mass and heamaturia for 6/12

Hx: Controlled Hypertension

• HCTZ 12.5mg dly
• Enalapril 5mg dly

Hemodynamic alterations: systolic

HTN (due to AV shunting), peripheral

edema (due to caval obstruction)

• FBC
• Type and screen/crossmatch
• Optimise Hb (watch out for precipitating CF in compensated anaemia); and fluid status; input output

CVP line

Booked on tomorrows list for "Open nephrectomy"

ECG/CXR/UKE/FBC ordered and pending

RENAL CELL CARCINOMA (RCC)

Etiology

• cause unknown
• originates from proximal convoluted tubule epithelial cells in clear cell subtype (most common)
• hereditary forms seen with von Hippel-Lindau syndrome and hereditary papillary renal carcinoma

Epidemiology

• 8th most common malignancy (accounts for 3% of all newly diagnosed cancers)
• 85% of primary malignant tumours in kidney
• male:female = 3:2
• peak incidence at 50-60 yr of age

Pathology

• histological subtypes: clear cell (75-85%), papillary (10-15%), chromophobic (5-10%), collecting duct sarcomatoid elements in any subtype is a poor prognostic factor

Risk Factors

• top 3 risk factors: smoking, HTN, obesity
• miscellaneous: horseshoe kidney, acquired renal cystic disease

Gas analyser

Capnograph

Increased onset of PVD; IHD;CCF --> optimise HTN (ECG; consider stress test and Echo)

Endocrinopathies: hypercalcemia

(increased vitamin D hydroxylation),

erythrocytosis (increased

erythropoietin), HTN (increased

renin), production of other hormones

(prolactin, gonadotropins, TSH,

insulin, and cortisol)

Peripheral and autonomic neuropathies may be present --> full stomach

Temp

SURGICAL CONSIDERASIONS

INDICATIONS FOR NEPHRECTOMY:

• Surgical treatment varies with the pathology.
• Simple nephrectomy -- non-neoplastic disease (e.g. trauma, non-functioning kidney with chronic infection)
• Radical nephrectomy - neoplastic disease.

Radical nephrectomy - Gerota's fascia, perinephric fat, lymphatics, and the ipsilateral adrenal gland.

The vast majority (+/-90%) of solid renal masses are RCC; the remainder comprising mainly of transitional cell carcinoma or Wilm's tumour (in children).

Pulse oximeter

Urine catheter

• The incision varies depending on the kidney location, tumour characteristics, body habitus, and surgeon's preference.
• Most commonly - flank, thoraco-abdominal, and trans-abdominal (chevron or anterior subcostal).
• Most kidneys can be removed safely via a transperitoneal subcostal approach.

• Radical nephrectomy - laparoscopic technique in tumours which measure no more than 10 cm in diameter. Results appear to demonstrate similar survival, recurrence, and renal impairment rates regardless of technique or surgical approach.

• Partial nephrectomy is performed in those patients with tumours smaller than 7 cm in diameter, those at risk of future significant renal impairment, tumours in a peripheral position (e.g. at one pole), those with bilateral tumours, and those with a solitary kidney.
• They can be performed using advanced laparoscopic techniques which require a great deal of technical skill. This may result in increased warm ischaemic times and as such, open partial nephrectomy may be preferable in certain circumstances (e.g. solitary kidney).
• Conversion to open --synchronous tumour or extension into the renal vein is discovered during surgery.

IBP +

Pulse contour

device

POST OPERATIVE

Large bore IV

theatre preparation and position

• Can be delivered with level 1 surgical ward care for a standard radical nephrectomy (open or laparoscopic).
• Low threshold for arranging a higher level of care for individuals with significant co-morbidities and those planned to have continuous thoracic epidural analgesia in the immediate postoperative period.

• Laparoscopic nephrectomy -reduced analgesic requirements and reduced length of stay. Further developments - including hand-assisted procedures and robotic technology.
• In all such operations, particular attention needs to be paid to the cardiovascular and respiratory systems, given the need for pneumoperitoneum and the use of steep Trendelenburg.
• A laparoscopic approach may not be appropriate - severe ischaemic or valvular heart disease, given the haemodynamic instability or in patients with increased ICP
• However, an attempt at laparoscopy combined with a low threshold for conversion to open surgery may be a reasoned approach.

• Prevention of hypothermia - (active warming)forced-air warmer, heated mattress, and warmed i.v. fluids.
• Venous thormboprophylaxis -graduated stocking, low molecular weight heparin therapy, pneumatic calf compression devices
• No routine antibiotics - only high risk pts (CRF/Immunocompromised/current infection)

THANK YOU

• Commonly performed in the lateral position with varying degrees of tilt and flexion at the waist.
• Increased risk of pressure sores, nerve damage, venous pooling, corneal abrasion, and venous congestion.
• Lateral positioning and/or Trendelenburg - reduce FRC, increase V/Q mismatch, development of atelectasis.
• Laparoscopic approach, - pneumoperitoneum, aggravate respiratory function but may also have a deleterious effect on the venous return and cardiac output, particularly if intra-abdominal pressures increase above 20 mm Hg.
• Laparoscopic surgery may not be well tolerated in patients with significant systolic dysfunction or those with co-existing coronary artery disease with ventricular hypertrophy.

ANALGESIA

• Good analgesia is essential -coughing and early mobilisation and reduce the incidence of post-operative respiratory complications. Multimodal approach

• Epidural analgesia is usually used unless contra-indicated.(coagulopathy or thrombocytopenia, or recent haemodialysis with anticoagulation).
• Thoracic epidural catheter is usually used, and a block to about T8 is required for good analgesia.
• Continuous infusions of a mixture of low dose local anaesthetic and opioid provide the best pain relief, although intermittent boluses can also be used.
• Epidural catheters should be left indwelling for the minimum time possible, but may be used for up to 5 days
• Prevent ileus

• Subcostal catheter - bolus doses or infusions of local anaesthetic agents.
• PCA- Fentanyl is a suitable drug for those with renal failure as it is largely metabolised in the liver. Morphine can be used with caution, and a reduction in both the dose and time interval between doses should be made for those with impaired renal function (usually a 0.5mg bolus dose with a 10 minute lock-out period).

• Laparoscopic surgery - reduced blood loss, less tissue trauma, less postoperative pain and shorter hospital stays. Epidural analgesia should not be necessary, although local anaesthetic infiltration of the wounds at the end of surgery is helpful.
• Patient controlled analgesia may be used, although opioid requirements are often low.
• Nonsteroidal anti-inflammatory drugs are relatively contra-indicated because of their nephrotoxic potential.
• Paracetamol - safe to use in renal impairment.
• Oral opioids may be used for moderate pain.
• Thromboprophylaxis should be used for all patients until they are mobilising well.

FLUID MANAGEMENT

• Normal maintenance fluid
• Intra-operatively, evaporative losses from an open abdomen (10-30 mL/kg/h) and third space losses to bowel, omentum and retroperitoneum must be taken into account.
• Some blood loss is normal, and haemorrhage may occur at any time. Therefore fluid requirements intra-operatively are usually high.

• Crystalloids - maintenance.
• Colloid and packed red blood - haemorrhage.
• Pre-existing chronic anaemia - will tolerate less blood loss than those with higher haemoglobin levels.
• Other blood products such as fresh frozen plasma, cryoprecipitate and platelets may be required in the face of massive blood loss.
• Cell salvage can be used despite early concerns of it theoretically being associated with an increased risk of tumour recurrence.
• Current literature - appears a safe practice to adopt.
• Leucocyte depleting filter as routine.
• Urine output - guide to fluid replacement. (But drops with anaesthesia)
• Postoperatively a urine output of 0.5-1.0 mL/kg/h (normal renal function).

RENAL PROTECTION

• Great care must be taken to avoid risk factors .
• Surgery is the biggest risk factor
• Hypotension, dehydration, sepsis and nephrotoxic drugs.

• Various methods have been used to try to protect kidney function in patients undergoing surgery:
• Administration of dopamine, diuretics, calcium channel blockers, angiotensin converting enzyme inhibitors and hydration fluids.
• Recent Cochrane database review -no evidence that any of these interventions protect the kidneys