Recent Advances in Surgery 35 Colin D Johnson, Irving Taylor
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Section 1
1Surgery-in-General

Perioperative Care1

Jyoti Shah
 
INTRODUCTION
There were 6,954,241 surgical operations and procedures carried out in the UK in 2010-11.1 Although the overall risk of death and major complications after surgery is low,2 the majority of deaths (80%) occur in a small group of high-risk patients.3
Surgeons are under growing pressure to increase day case surgery and reduce inpatient hospital stays. The Modernisation Agency High Impact change No. 1 recognises that at least 80% of patients undergoing elective surgery could be treated as day cases and states that this should be the norm for elective surgery. Coupled with factors such as an ageing population, greater co-morbidities and complex surgical procedures, a multidisciplinary team approach is essential to achieve satisfactory results. There is good evidence that patient outcome after major noncardiac surgery can be considerably improved with effective perioperative care.4 But what do we mean by perioperative care? The perioperative period incorporates the patient's entire surgical experience. It starts at the point a patient is listed and thus consented for an operation, and extends into their postoperative recovery. The best outcome can only be achieved with attention to detail at every stage of this journey.

Key Point

Perioperative care incorporates the patient's entire surgical journey and includes pre-, peri- and postoperative care.
 
PREOPERATIVE ASSESSMENT
The fundamental purpose of preoperative evaluation is to obtain information about the patient's medical history and background, formulate an assessment of their surgical risk and minimise cancellations on the day of surgery (Table 1.1). The preoperative visit may also relieve anxiety and answer any questions about the operation and the anaesthetic.5 In a recent publication, 16% of UK hospitals had no preadmission anaesthetic assessment clinic and 17% had no surgical assessment clinic.6
Table 1.1   Benefits of effective preassessment
Ensure patients are fully informed about their proposed operation
Estimate the level of risk from an anaesthetic
Check consent
Identify co-existing illnesses and optimise them
Identify high-risk patients
Undertaken relevant investigations
Reduce patient's anxiety
Reduce cancellations on the day of surgery
Plan discharge
Many of these clinics are nurse-led and are essential for the assessment of a patient before elective surgery. They also provide an opportunity to ensure patients know and understand the procedure scheduled to be carried out, and the risks involved. A full discussion of the consenting process is beyond the scope of this chapter, but readers are reminded that good surgical practice incorporates the following principles:
  1. Describes the procedure, usually in the outpatient setting
  2. Discusses probability of risks and likely complications
  3. Discusses associated risks such as those from an anaesthetic, need for intravenous fluids or catheters, etc.
  4. Describes alternatives to the proposed operation and the likely prognosis if the patient declines surgery. Failure to provide sufficient information can result in a claim in negligence.7

Key Point

Preassessment clinics are essential to screen patients for fitness for an anaesthetic and surgery.
 
IDENTIFYING RISK
There are a number of ways of stratifying risk preoperatively in patients scheduled for surgery. Of these, the American Society of Anaesthesiologists (ASA) grading of physical status (PS) on a scale of 1 to 6 is the simplest and most widely used. It was originally introduced in 1941, and has since undergone modifications such that an additional suffix ‘E’ has been added for patients undergoing emergency surgery (Table 1.2).8
Table 1.2   American Society of Anaesthesiologists (ASA) physical status (PS) classification
ASA PS 1
Normal healthy patients
ASA PS 2
Patients with mild systemic disease
ASA PS 3
Patients with severe systemic disease
ASA PS 4
Patients with severe systemic disease that is a constant threat to life
ASA PS 5
Moribund patients not expected to survive without the operation
ASA PS 6
Patients declared brain-dead whose organs are being removed for donor purposes
E
Patients undergoing emergency surgery
3The ASA grade is a subjective tool that provides an indication of relative risk of surgery to the patient. However, it does not actually quantify the risk as a patient undergoing excision of a skin lesion under local anaesthetic will have the same ASA grade for this as they would with major bowel surgery. Hence, the ASA grade cannot be used as the sole predictor of operative risk. It can also change from when the patient was seen in clinic to the actual time of surgery. Interestingly, it fails to take account of age, weight, malignancy or the results of any laboratory tests, and is based on history alone. It seems to omit risk for patients with moderate disease allowing for only mild and severe.
Although other more complex and time-consuming classifications exist, the ASA grade is relatively robust having stood the test of time, and is used commonly to communicate patient risk between doctors.
 
DETECTING DISEASE
Several investigators have demonstrated the costly overuse of routine investigations for healthy patients undergoing elective surgery. Almost 30 years ago, Kaplan and colleagues reviewed the laboratory screening results of 2,000 patients booked for elective surgery. They found that 60% of these tests were unnecessary and only 0.22% revealed abnormalities that might influence perioperative management.9 Similarly, in a review of 2,570 patients with 5,003 preoperative screening test results, only four patients were believed to have a conceivable benefit from those tests.10 Unnecessary preoperative investigations are associated with problems other than cost and waste. Doctors do not always check the results of requested investigations, and many requests are duplicated. In a study reviewing the results of 7,549 preoperative tests in 1,109 patients who had elective surgery, the authors demonstrated that 47% of these tests were duplicated and unnecessary.11 Additionally, false positive results can lead to unnecessary, costly and potentially harmful treatments, further investigations and cancellation of operations.12
The National Institute of Healthcare and Clinical Excellence (NICE) recommends the following preoperative tests based on surgical severity (Table 1.3).13
  • Full blood count: In patients aged over 60 years and surgical severity 2 or more, all patients with surgical severity 3 or more and severe renal disease
  • Serum electrolytes: Serum creatinine is elevated in 0.2–2.4% of asymptomatic patients.14 NICE recommends routine testing of creatinine in patients aged over 60 years and surgical severity 3 or more, all patients with surgical severity grade 4 and all patients with renal or cardiovascular disease
  • Sickle cell test: All patients of African, Afro-Caribbean, Asian, Middle-Eastern or East-Mediterranean ancestry
  • 4Pregnancy test: All women of child-bearing age (regardless of history)
  • Electrocardiogram (ECG): In a large study of 23,036 patients undergoing 28,457 surgical procedures, the absolute difference in the incidence of cardiovascular death between those with and those without ECG abnormalities was only 0.5%, thereby questioning the benefit of its routine use.15 NICE recommends its use in patients aged over 80 years, those over 60 years of age and surgical severity of 3 or more, and any patient with cardiovascular disease or severe renal disease
  • Chest X-ray (CXR): In a meta-analysis of 21 studies that included review of 14,390 routine preoperative CXR films, 1.3% of films had unexpected abnormalities, causing modification of management in only 0.1%.16 Routine use of CXR is recommended in patients undergoing cardiac or major abdominal surgery, or in patients with respiratory disease.
Table 1.3   Surgical severity13
Surgical severity
Examples of surgical procedures
Grade 1
Diagnostic procedures – endoscopy, laparoscopy, breast biopsy
Grade 2
Inguinal hernia repair, varicose veins, adenotonsillectomy, knee arthroscopy
Grade 3
Total abdominal hysterectomy, transurethral prostatectomy, lumbar discectomy, thyroidectomy
Grade 4
Total joint replacement, vascular reconstruction, colonic resection, radical neck dissection
Evidence, however, points to history and examination performed by trained staff as the most efficient way of detecting disease. In a general medical clinic, the correct diagnosis was established in 56% of patients after taking a good history. Physical examination increased this figure to 73% and routine laboratory investigations only helped to make the diagnosis in 5% of patients whilst significantly increasing cost.17

Key Point

Laboratory tests should not be repeated for elective surgery if the results were normal within 4 months, providing there has been no change to the patient's condition.
 
JEHOVAH’S WITNESSES
The absolute refusal of whole blood and major blood components is a core value of the 140,000 Jehovah's witnesses in the UK. They will usually identify themselves in the preoperative setting and clarify their own decision regarding blood products, often producing a detailed advance directive. A thorough discussion of the risks of surgery is essential when the patient is a competent adult, usually with local representatives from the Jehovah's Witness Hospital Liaison Committee. A specific Department of Health consent form must be completed and the acceptability of various fluids should 5be documented and respected. Whole blood, packed red cells, platelets, white blood cells, plasma and ‘predonation’ of blood for later autotransplantation is not acceptable, whereas fractions of blood products such as albumin, immunoglobulin, vaccines, clotting factors and prothrombin complex concentrates may be.18 Various pre-, intra- and postoperative measures need to be considered to minimise the risk of bleeding.18
 
OBESITY
The prevalence of obesity worldwide is increasing and therefore surgeons are likely to see more obese patients presenting for surgery. Obesity is defined as body mass index (BMI) > 30 kg/m2 (Table 1.4).
Table 1.4   Definition of obesity
Body mass index (BMI) (kg/m2)
Description
< 25
Normal
25–30
Overweight
30–35
Obese
> 35
Morbidly obese
> 55
Supermorbidly obese
Patients with an elevated BMI have a high prevalence of co-morbid conditions (50% hypertension, 25% asthma, 50% arthritis, 30% diabetes), thereby increasing their operative morbidity. This group has an ‘all cause of death’ hazard ratio of upto 3.19 Risk reduction begins with careful case selection for surgery, taking a detailed history focusing on evidence of snoring, daytime somnolence and sleep patterns (these may indicate sleep disordered breathing), assessment of the airway and appropriate investigations. Routine CXRs and ECGs are likely to be of poor quality and therefore of limited use.
Special equipment may be required for obese patients, including large gowns and stockings, blood pressure cuffs that are at least 20% greater than the diameter of the upper arm and operating tables that can accommodate the increased weight. Most operating theatre tables can take weights of approximately 130 kg, and the maximum weight should be labelled on each table, trolley and bed.19
Manual handling of the obese patient should be kept to a minimum and patients should be placed on the operating table prior to induction. The patient should be positioned with caution as areas may ‘overhang’ increasing the risk of contact with metal, slipping down the table in the head up position and pressure sores or nerve injuries. Extra gel pads, bean bags and supports should be available in theatre.
Venous thromboembolism (VTE) is a leading cause of death in obese patients and multi-modal VTE prophylaxis incorporating mechanical and 6pharmacological means is essential. Most hospitals will have evidence-based local protocols for VTE thromboprophylaxis.
 
DIABETES MELLITUS
Diabetes mellitus is the most common endocrine disease that surgeons will be faced with. Patients with Type 1 diabetes are treated with insulin, whereas those with Type 2 diabetes may start with diet and lifestyle modifications, but due to the progressive nature of the disease, are likely to eventually need oral hypoglycaemic agents and/or insulin.20
Patients with diabetes are at increased risk of complications such as hyperglycaemia, hypoglycaemia, diabetic ketoacidosis, postoperative surgical infections and perioperative mortality.21 This risk can be minimised by good preoperative diabetic control as measured by glycated haemoglobin (upper limit 8–9%).
In general, the period of starvation for diabetic patients should be kept to a minimum, and this is best managed by placing them first on an operating list. All hospitals should have local protocols on how to manage diabetic medication, and clinicians should advise patients on individual adjustments whilst preparing for surgery.22 Regular measurement of blood sugar is essential, aiming between 6 mmol/L and 10 mmol/L. In situations where the fasting period is prolonged, diabetic control is poor, or patients cannot resume their next meal, an insulin infusion may be required. This is now called ‘variable rate intravenous insulin infusion’, replacing the previously used term ‘sliding scale’ and uses 0.45% sodium chloride with 5% glucose and either 0.15% or 0.3% potassium chloride as the first choice for fluids.22 Patients should resume their normal diabetic medication as soon as possible, usually when they have started to eat.

Key Point

Fasting times for patients with diabetes should be kept to a minimum and patients should be first on a list.
 
PERIOPERATIVE MANAGEMENT OF MEDICATION
In a study of 1,025 general surgical patients, Kennedy and colleagues reported that 49% of patients were taking medications unrelated to their surgical procedure and that these patients were at higher risk for a postoperative complication.23 Whilst most chronic drugs are omitted on the day of surgery, there is a risk that 33% of them may not be restarted on the first postoperative day.24 For many patients, this is because of ongoing fasting (40%), failure to represcribe (29%), drug withheld on doctor's orders (10%), drug unavailable in pharmacy or not as yet delivered to the ward (1%), or prolonged ileus (3%).24 Of concern, 11.4% of elderly patients who had been taking warfarin continuously for at least 1 year did not resume 7their indicated warfarin therapy within 6 months after it was discontinued for elective in-patient surgery.25
In general, a thorough medication history is essential. Medications that have a withdrawal potential should be continued. Those medications that increase surgical risk should be stopped. Specific examples are listed in Table 1.5.

Key Point

Many medications can be continued perioperatively and can be taken with a sip of water upto 2 hours before surgery.
Table 1.5   Management of specific perioperative medication26
Medication
Comments
Diuretics, angiotensin-converting enzyme (ACE) inhibitors, angiotensin-receptor blockers
Omit on the morning of surgery because of risk of hypovolaemia/hypokalaemia
Beta-blockers, calcium-channel blockers
Continue at usual dose
Nonsteroidal anti-inflammatory drugs (NSAIDs)
May need to stop 1 week before depending on risk of bleeding during surgery
Digoxin
Should be continued and levels monitored if altered renal function
Central nervous system drugs—antiepileptics, antipsychotics, benzodiazepines, lithium, selective serotonin reuptake inhibitors, tricyclic antidepressants
These drugs have a significant potential for withdrawal and should be continued
Levodopa/carbidopa
Continue due to risk of deterioration of Parkinson's symptoms
Antithyroid drugs
Continue as there are no perioperative complications
Contraceptives
For major surgery with a prolonged period of immobilisation, stop 4 weeks before surgery due to increased risk of deep vein thrombosis (DVT). Alternatively, continue contraceptives and give higher intensity DVT prophylaxis
Methotrexate
Can increase the risk of wound infections and dehiscence. Many surgeons therefore withhold this drug for 1–2 weeks
Clopidogrel
Stop 7 days prior to surgery
 
ANTITHROMBOTIC THERAPY
The perioperative management of surgical patients taking warfarin is complicated and is based on an assessment of the risk of thromboembolism versus the risk of bleeding. Some procedures such as simple skin excisions and endoscopic procedures carry a low risk of bleeding, and it is therefore safe to continue anticoagulation. For procedures with a higher risk of bleeding such as neurosurgery, anticoagulation should be fully reversed aiming for an international normalised ratio (INR) of less than 1.3.27
8Warfarin should be stopped 5 days before surgery, and the INR should be measured on the day of surgery. If the INR is greater than 1.5, then 1 mg of vitamin K can reduce the INR to a safe level, but may delay re-warfarinisation. If bridging therapy is required then either unfractionated heparin (UFH) or low molecular weight heparin (LMWH) should be started when the INR falls below the therapeutic range. Hospitals should have local guidelines on bridging regimes.
The last dose of LMWH should be administered 24 hours before surgery, whereas UFH has a short half-life and can be stopped 4 hours before surgery.27 Instructions on when to resume bridging therapy must be communicated in the operation record and warfarin dosing guided using the Fennerty nomogram. In low-risk patients, warfarin can be restarted at the normal dose without the need for loading.
 
SAFE SURGERY
It is disappointing to learn that 45% of medical errors occur in the operating theatre and almost half of these are preventable.28 The use of surgical safety checklists has been shown to decrease death rates from 1.5% to 0.8% and serious complications from 11% to 7%.29
The National Patient Safety Agency (NPSA) has launched an adaptation of the 2008 WHO surgical safety checklist, which is required for every patient undergoing surgery. Five steps to safer surgery involve the following:30
  1. Briefing: Before the start of the list
  2. Sign-in: Before the induction of anaesthesia and includes checking the patient's details and allergies
  3. Timeout: Also known as the stop moment and takes place before the start of surgery
  4. Sign-out: Before staff leave theatre, including steps such as the swab count
  5. Debrief: At the end of the list to learn from incidents or address issues such as equipment failure.
Perceived benefits of the checklist are improved teamwork, improved safety, reduced near misses, smoother flow of procedures and better staff morale. However, the major obstacle to adoption of the checklist is a tendency to view the process as a tick box exercise with lack of clinical engagement.30 Perhaps the greatest challenge to its adoption is a culture change amongst healthcare professionals.

Key Point

Implementation of the World Health Organization (WHO) surgical safety checklist reduces surgical complications and deaths.
 
PREOPERATIVE FASTING
This is defined as the period of time for which patients must refrain from any oral intake of liquids or solids before surgery to minimise the risk of pulmonary aspiration from gastric contents. 9
  • Clear fluids such as water, fruit juices without pulp, carbonated beverages, clear tea and black coffee can be ingested upto 2 hours before surgery.
  • A light meal and nonhuman milk (this behaves similar to solids in gastric emptying time) can be ingested 6 hours preoperatively.
  • A fasting period of 8 hours is required for fried or fatty foods or meat.31
 
PERIOPERATIVE FLUID REPLACEMENT
All too often perioperative fluid replacement is left to the most junior member of the team who many not appreciate the subtleties of intravenous fluid therapy. Inadequate fluid replacement can lead to reduced oxygen delivery to tissues, including those that are injured, but too much fluid replacement can lead to acidosis, coagulation problems, and pulmonary and peripheral oedema. As with any other drug therapy, fluids have beneficial as well as side effects.
For most patients, fluids should be replaced orally with early resumption of food and drink. For patients who remain nil by mouth, fluids will need to be replaced intravenously, although studies have not confirmed whether crystalloids or colloids are superior (Table 1.6).32
Table 1.6   Commonly used crystalloids and colloids32
Crystalloids
Colloids
0.9% saline
Gelofusine
5% dextrose
Hetastarch
0.18% saline + 4% dextrose
Volulyte
Hartmann's solution
Human albumin 4.5%
Sodium bicarbonate 8.4%
Another area that is often poorly considered is that of blood transfusion. There are many documented side effects associated with transfusion in surgical patients, such as increased risk of postoperative infection.32 Hence, current guidelines recommend perioperative transfusion only when haemoglobin levels are below 70 g/L.

Key Point

Many patients do not need intravenous fluid therapy and should be encouraged to eat and drink as soon as possible after surgery.
 
PATIENT POSITIONING
Moving and positioning of the patient requires coordinated manual handling by the theatre team to avoid injury to staff and patients. There are many different surgical positions used to provide the best surgical access, whilst minimising risks to the patient (Table 1.7). 10
Table 1.7   Common surgical positions in theatre
Surgical position
Description
Supine
• Patients lie flat on their backs
• Used for abdominal surgery
Lateral
• Patients lie on their side, often with a pillow between their knees
• Used for hip/renal surgery
Prone
• Patients lie on their stomach with the chest supported to allow movement with respiration
• Used for spinal/neurosurgery
Trendelenburg
• Patients lie flat on their backs with a head down position to allow the abdominal organs to move away from the pelvis
• Used for lower abdominal or gynaecological surgery
Lithotomy
• Patients lie on their backs with their perineum at the edge of the operating table. Legs are often supported in stirrups.
• Used for urological surgery
Lloyd-Davies
• Similar to lithotomy with legs apart and hips flexed
• Used in colorectal and pelvic surgery
For any position, consideration should be given to avoid nerve/joint injuries, friction burns, damage to tissues, and prevention of patient slippage and pressure sores.

Key Point

Safe positioning of the patient requires good communication between the theatre team.
 
SUMMARY
Any patient's surgical journey is divided into three distinct phases, which are encompassed in the term perioperative care. The preoperative phase focuses on discussing the surgery, taking informed consent, and ensuring that resources are available for preassessment clinics. It is within the intraoperative phase that the patient is most vulnerable and totally reliant on the theatre team.

Key Point

  1. Perioperative care incorporates the patient's entire surgical journey and includes pre-, peri- and postoperative care.
  2. Preassessment clinics are essential to screen patients for fitness for an anaesthetic and surgery.
  3. Laboratory tests should not be repeated for elective surgery if the results were normal within 4 months, providing there has been no change to the patient's condition.
  4. Fasting times for patients with diabetes should be kept to a minimum and patients should be first on a list.
  5. Many medications can be continued perioperatively and can be taken with a sip of water upto 2 hours before surgery.
  6. Implementation of the World Health Organization (WHO) surgical safety checklist reduces surgical complications and deaths.
  7. Many patients do not need intravenous fluid therapy and should be encouraged to eat and drink as soon as possible after surgery.
  8. Safe positioning of the patient requires good communication between the theatre team.
It is therefore our priority that the patient comes to no harm with moving and surgical positioning, risk 11of infection, risk of DVT, and risk of hyper- or hypothermia. Postoperatively, our goals include managing the patient's pain, nausea and vomiting, and minimising surgical complications, whilst preparing the patient for prompt surgical discharge. Successful perioperative care, therefore, requires careful team work and communication at all times during this journey.
 
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