Peri-Operative Care

Question 1

What are the pre-operative checks that need to be performed in a patient?

Answer 1

Pre-operative checks can be summarised by the mnemonic OP CHECS

• Operative fitness:cardiorespiratory comorbidities
• Pills
• Consent
• History
  
  • MI, asthma, HTN, jaundice
  • Complications of anaesthesia: DVT, anaphylaxis
• Ease of intubation: neck arthritis, dentures, loose teeth
• Clexane: DVT prophylaxis
• Site: correct and marked

Question 2

What drugs need special consideration pre-surgery?

Answer 2

• See thromboprophylaxis. In summary, stop warfarin and swap to LMWH on admission.
• Anti-epileptic drugs can be given as usual. Post-operatively continue IV or via NGT if unable to tolerate orally.
• Oral contraceptive pill / hormone replacement therapy should be stopped 4 weeks before major surgery / leg surgery.
• Beta blockers can continue as usual.
• Oral hypoglycaemics should be stopped
• Antiplatelets such as aspirin should also be stopped.
• We try to avoid altering beta-blocker and calcium-channel blocker drugs preoperatively as it can cause intraoperative complications (obviously if a patient is profoundly bradycardic or hypotensive then they should be omitted, but stopping the diuretic should resolve the hypotension here anyway).
• Lithium should be omitted the day before surgery.

Question 3

How long are surgery patients kept NBM?

Answer 3

Prior to surgery patients are kept nill by mouth for at least 6 hours for solids and at least 2 hours for water.

Question 4

Describe the use of bowel-preparations before surgery

Answer 4

Bowel preparations may be needed in left-sided procedures, but not usually needed in right-sided procedures. This is usually:

• Picolax: pico sulfate and Mg citrate
• Klean-Prep: macrogol

Question 5

Describe the use of prophylactic antibiotics before surgery

Answer 5

Prophylactic antibiotics are usually used for GI surgery and joint replacements. They are given 15-60 minutes before surgery:

• For biliary or GI surgery regimen is usually cefuroxime and metronidazole.
• For vascular: co-amoxiclav
• For MRSA +ve: vancomycin.

Question 6

Describe the special consideration patients with Diabetes require pre-surgery

Answer 6

In terms of pre-operative blood glucose concentration are happy with a blood glucose of between 4-12 mmol/L as long as there is no ketosis.

Patients with diabetes are at increased risk of post-operative complications such as infection.

If the patient is insulin-dependent, the surgeons and anaesthetists must be informed if they are put onto the surgical list. Usually their long-acting insulin is given at 80% of usual dose and the short-acting insulin is omitted and the patient is commenced on a sliding scale. Bloods are checked hours, and actrapid insulin is adjusted accordingly. The sliding scale is continued until the patient can tolerate food.

Non insulin-dependent diabetes (NIDDM) patients are treated as IDDM if they have poor fasting control (>10 mM), otherwise oral hypoglycaemics are discontinued until first post-op meal.

Question 7

What are patients on steroids at increased risk of after surgery?

Answer 7

Patients on steroids are at increased risk of:

• Infection
• Poor wound healing
• Adrenal crisis

Question 8

Describe the special consideration needed for patients usually taking steroids, before surgery

Answer 8

To prevent an Addisonian crisis, there is a need to increase steroid dose peri-operatively to cope with stress:

• Hydrocortisone 50-100mg IV pre-operatively, then continued for 3 days post-operatively for major surgery.
• The same for minor surgery apart for hydrocortisone is only continued for 24 hours post-operatively.

Question 9

What surgical patients are at increased risk of DVT?

Answer 9

The following surgical patients are at increased risk of deep vein thrombosis:

• Surgery greater than 90 minutes at any site

or

• Surgery greater than 60 minutes if the procedure involves the lower limbs or pelvis

or

• Any additional VTE risk factor such as:
  
  • Acute admissions with inflammatory process involving the abdominal cavity
  • Expected significant reduction in mobility
  • Age over 60 years
  • Known malignancy
  • Thrombophilia
  • Previous thrombosis
  • BMI >30
  • Taking hormone replacement therapy or the contraceptive pill
  • Varicose veins with phlebitis

Question 10

Describe the management of VTE risk in surgical patients

Answer 10

All patients should (unless contraindicated) be engaged with mechanical thromboprophylaxis involves:

• Early ambulation after surgery is cheap and is effective
• Compression stockings (contra-indicated in peripheral arterial disease)
• Intermittent pneumatic compression devices
• Foot impulse devices

If the patient is already on pharmacologic thromboprophylaxis, they may be allowed to continue. Warfarin is stopped 5-days pre-op as it is difficult to control. If indicated, patients are begun on low molecular weight heparin such as dalteparin:

• From admission/pre-op clinic until 12/24 hours before surgery
• Prophylaxis started again 6-12 hours post wound-closure and continued at home for up to 1 month.
• Warfarin can be started the next day after surgery, this may be alongside LMWH if patient has high thromboembolic risk.

Exact times vary between trusts and procedures.

In emergency scenarios where patients on warfarin have not been stopped, discontinue warfarin as soon as possible and commence on vitamin K infusion.

Question 11

What are the causes of post-operative pyrexia?

Answer 11

Early causes of post-op pyrexia (0-5 days) include:

• Blood transfusion
• Cellulitis
• Urinary tract infection
• Physiological systemic inflammatory reaction (usually within a day following the operation) - the patient is usually otherwise quite well.
• Pulmonary atelectasis - this if often listed but the evidence base to support this link is limited

Late causes (>5 days) include:

• Venous thromboembolism
• Pneumonia
• Wound infection
• Anastomotic leak
• Collection