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(BQ) Part 2 book “Care of people with diabetes” has contens: Management during surgical and investigative procedures, conditions associated with diabetes, diabetes and sexual and reproductive health; women, pregnancy, and gestational diabetes; diabetes education; managing diabetes at the end of life,… and other contents.
Chapter Management During Surgical and Investigative Procedures SURGICAL PROCEDURES Key points • Surgery induces the counter-regulatory response that can increase the blood glucose 6–8 times higher than normal in people with and without diabetes Optimal control before, during, and after surgery reduces morbidity and mortality and length of stay • Preventing hyperglycaemia reduces the risk of adverse outcomes in people with diabetes • Morning procedures are desirable • Insulin should never be omitted in people with Type diabetes • Complications should be stabilised before, during, and after surgery • Cease oral glucose lowering medicines 24–36 hours before the procedure depending on the particular medicine and their duration of action; but note some experts recommend continuing oral agents until the day of surgery if the blood glucose is high • Ascertain whether the person is using any complementary therapies especially herbal medicines with a high risk of interacting with conventional medicines and/or causing bleeding • An insulin-glucose infusion is the most effective way to manage hyperglycaemia in the operative period Rationale Diabetes is associated with an increased need for surgical procedures and invasive investigations and higher morbidity than non-diabetics Anaesthesia and surgery are associated with a complex metabolic and neuroendocrine response that involves the Care of People with Diabetes: A Manual of Nursing Practice, Fourth Edition Trisha Dunning © 2014 John Wiley & Sons, Ltd Published 2014 by John Wiley & Sons, Ltd 278 Care of People with Diabetes release of counter-regulatory hormones and glucagon leading to insulin resistance, gluconeogenesis, hyperglycaemia and neutrophil dysfunction, which impairs wound healing The stress response also occurs in people without diabetes but is more pronounced and difficult to manage in people with diabetes due to the underlying metabolic abnormalities Advances in diabetes management, surgical techniques, anaesthetic medicines and intensive care medicine have significantly improved surgical outcomes for people with diabetes Introduction People with diabetes undergo surgery for similar reasons to those without diabetes; however, because of the long-term complications of diabetes they are more likely to require: • cardiac procedures such as: {{ angioplasty or stents {{ bypass surgery • ulcer debridement, amputations (toes, feet); • eye surgery such as cataract removal, repair retinal detachment, vitrectory; • carpal tunnel decompression Surgical-induced stress results in endocrine, metabolic and long-term effects that have implications for the management of people with diabetes undergoing surgery (see Table 9.1) Stress induces hyperglycaemia, which causes osmotic diuresis, increased Table 9.1 Hormonal, metabolic, and long-term effects of surgery Hormonal Metabolic Long-term effects if optimal blood glucose control is not achieved ↑ Secretion ofa epinephrine, norepinephrine, ACTH, cortisol and growth hormone ↓ secretion of insulin due to impaired beta cell responsiveness Insulin resistance Catabolic state and ↑ metabolic rate Hyperglycaemia Insulin resistance ↓ Glucose utilisation and glycogen storage ↑ Gluconeogenesis ↓ Protein catabolism and reduced amino acid and protein synthesis in skeletal muscle ↑ Lipolysis and formation of ketone bodies ↓ Storage of fatty acids in the liver Osmotic diuresis with electrolyte loss and compromised circulating volume ↑ Risk of cerebrovascular accident, myocardial arrhythmias infarction electrolyte disorders ↑ Blood pressure and heart rate ↓ Peristalsis Loss of lean body mass – impaired wound healing, ↓ resistance to infection Loss of adipose tissue Deficiency of essential amino acids, vitamins, minerals, and essential fatty acids Surgical complications Longer length of stay a Norepinephrine is mostly augmented during surgery and epinephrine postoperatively Stress stimulates glucagon secretion from the p ancreatic alpha cells and together with growth hormone and cortisol, potentiates the effects of norepinephrine and epinephrine Cortisol increases gluconeogenesis Management During Surgical and Investigative Procedures 279 hepatic glucose output, lipolysis and insulin resistance Unless these metabolic abnormalities are controlled, surgical stress increases the risk of DKA, Hyperosmolar states HHS, and lactic acidosis (see Chapter 7), infection, impaired wound healing, and cerebral ischaemia The risk of HHS is high in procedures such as cardiac bypass surgery and has a high mortality rate (Dagogo-Jack & Alberti 2002) In addition, anaesthesia and surgical stress, as well as medicines, induce gastrointestinal instability that can compound gastric autonomic neuropathy and lead to nausea, vomiting and predispose the individual to dehydration and exacerbate fluid loss via osmotic diuresis and blood loss during surgery As a result, electrolyte changes, particularly in potassium and magnesium, increase the risk of cardiac arrhythmias, ischaemic events, and acute renal failure (Dagogo-Jack & Alberti 2002) The risk is particularly high in people with chronic hyperglycaemia (HbA1c > 8%), existing diabetes complications, older people, and those who are obese, all of which are associated with increased risk of interoperative and postoperative complications (Dickersen 2003) Obesity is associated with functional risks in addition to the metabolic consequences of surgery that need to be considered when positioning the patient The respiratory system is affected and functional residual capacity and expiratory reserve volume may be reduced possibly due to excess weight on the chest wall and/or displacement of the diaphragm Severe obesity can lead to hypoventilation and obstructive sleep apnoea These factors predispose the individual to aspiration pneumonia Various cardiac changes increase the risk of heart failure and inadequate tissue oxygenation In addition, the risk of pressure ulcers is increased due to the weight, and activity level is often compromised increasing the risk of venous stasis and emboli The need for nutritional support may be overlooked in obese individuals and protein deprivation can develop because protein and carbohydrate are used as the main energy sources during surgery rather than fat In addition, energy expenditure is higher, which impacts on wound healing (Mirtallo 2008) Different types of surgery present specific risks as the person’s age: the very young and older people are particularly at risk The specific risks are summarised in Table 9.1 The blood glucose must be controlled to prevent DKA and HHS, promote healing and reduce the risk of infection postoperatively The target blood glucose range in the perioperative period is 5–10 mmol/L (Australian Diabetes Society (ADS) 2012) Hyperglycaemia inhibits white cell function and increases coagulability (Kirschner 1993) The magnitude of the metabolic/hormonal response depends on the severity and duration of the surgical procedure, metabolic control before, during, and after surgery, and the presence of complications such as sepsis, acidosis, hypotension, and hypovolaemia (Marks et al 1998; ADS 2012) Significantly, metabolic disturbances can be present in euglycaemic states (De & Child 2001) Surgery is often performed as a day procedure, often without appropriate consideration of the effects of surgical and the related psychological stress on metabolic control A multidisciplinary approach to planning is important Children with diabetes undergoing surgical procedures Generally, children with Type and Type diabetes needing general anaesthesia should be admitted to hospital and must receive insulin to prevent ketosis even if they are fasting and should be managed with a glucose infusion if they need to fast for more than two hours to prevent hypoglycaemia (Betts et al 2009) Blood glucose must be monitored hourly prior to and every 30 to 60 minutes during surgery to detect hypo- and hyperglycaemia As in adults it is best to perform surgery when metabolic control is optimal and children should be first on the list if possible (Betts et al 2009) An IV insulin-glucose infusion should be commenced two hours prior to surgery 280 Care of People with Diabetes Older people with diabetes and surgical procedures The Geriatric Surgery Expert Panel of the American College of Surgeons recently released a comprehensive guideline for assessing older people prior to surgery (Chow et al 2012) The recommendations are not specific to people with diabetes but diabetesrelated information could be incorporated into the guidelines In addition to conducting a thorough history and physical assessment, the Expert Panel recommended assessing the individual’s: • Cognitive ability and capacity to understand the proposed surgery (give informed consent) • Mental health: undertake a depression screen • Risk of developing delirium postoperatively • Alcohol, tobacco and other substance use • Functional status • Falls history • Frailty Index (score) • Nutritional status • Medicine regimen to determine whether the regimen may need to be adjusted and to assess the level of polypharmacy (Note information about insulin and other GLMs in this chapter) and adherence to their medicine regimen • Expectations of the surgery • Social and family support • Undertake appropriate investigations These include renal function tests haemoglobin, and serum albumin and in some cases, white cell cont, platelet count, coagulation studies, electrolytes and blood glucose and a urinalysis to detect UTI Tests of physical and cognitive function are discussed in Chapter 12 Interestingly, the guidelines not mention CAM use, but as indicated, people with diabetes use CAM and many herbal medicines interact with conventional medicines and increase the risk of adverse events Aims of management (1) To identify underlying problems that could compromise surgery and recovery by undertaking comprehensive presurgical assessment (Dhatariya et al 2012) (2) To achieve normal metabolism by supplying sufficient insulin to counterbalance the increase in stress hormones during fasting, surgery, and postoperatively and avoid the need for prolonged fasting (3) To normalise metabolic control using regimens that minimise the possibility of errors and have the fewest adverse outcomes: target blood glucose range 5–10 mmol/L and is best achieved with an insulin-glucose infusion (ADS 2012) (4) To supply adequate carbohydrate to prevent catabolism, hypoglycaemia, and ketosis (5) To ensure that the patient undergoes surgery in the best possible physical condition (6) To prevent: • hypoglycaemia, children 30 mmHg) Heart rate response on deep breathing (abnormal if increase >10 beats/min) Foot assessment, assess for active and occult infection and signs of neuropathy Renal Nephropathy, which may affect medication excretion Urinary tract infection (UTI), which may be silent and predispose to sepsis Acute renal failure and the need for dialysis UTI if catheterisation is needed Urine culture to detect UTI, which should be treated with the relevant antibiotics Microalbuminuria and creatinine clearance, eGFR Blood electrolytes, correct potassium >5 mmol/L before surgery Respiratory Airway Obese people and smokers are prone to chest infections Obesity may be associated with reduced respiratory reserve and displacement of the diaphragm Reduced tissue oxygenation Soft tissue, ligament, and joint thickening that might involve the neck making it difficult to extend the neck and intubate and predispose the individual to neck injury and post operative pain Counsel to stop smoking Chest physiotherapy Chest X-ray Blood gases Nebulised oxygen pre- and postoperatively if indicated See test for musculoskeletal disease (see page 341–342) Take extra care of the neck Gastrointestinal Autonomic neuropathy leading to gastric stasis delayed gastric emptying, gastric reflux, regurgitation and aspiration on anaesthesia induction Ileus May need to modify nutritional support if required postoperatively and given enterally Assess history of heartburn or reflux and whether the person sleeps in an upright position A H2 antagonist and metclopramide might be indicated preoperatively Erratic food absorption can affect blood glucose levels Eyes Cataracts, glaucoma, and retinopathy can be exacerbated by sudden rise in blood pressure Assess retinopathy stage Neutrophil dysfunction Increased risk of infection Inability to mount an appropriate response to infection Check for possible foci of infection: including feet, teeth, and gums, UTI, Ensure optimal blood glucose control Optimise vascular function Management During Surgical and Investigative Procedures 283 Table 9.2 continued Complication Possible consequences Preoperative evaluation Polypharmacy Risk of medicine interactions with anaesthetic agents and postoperative medicines Risk of lactic acidosis with Metformin Some medicines increase the risk of hyperglycaemia some hypoglycaemia Medicine review Ask about complementary medicines Give the person clear, concise written instructions about how to manage their medicines preoperatively and postoperatively on discharge Musculoskeletal Difficulties with intubation and tube placement Falls risk Assess, for example, prayer sign, Dupuytren’s contracture, trigger finger Foot abnormality including Charcot’s foot Obesity Increased systemic vascular resistance leading to reduced tissue oxygenation and increased risk of lactic acidosis in people on Metformin especially if renal function is compromised and those with surgical wound infections Sleep apnoea and associated daytime sleepiness with associated risk of cardiovascular events Difficulty intubating the person Assumption that the person is well nourished when in fact nutritional deficiencies especially protein are common High prevalence of hypertriglyceridaemia Cardiovascular and respiratory effects, which affect postoperative nutrition support if it is required Non-alcoholic fatty liver Risk of pressure ulcers Assess nutritional status Assess cardiovascular and respiratory status Ask about daytime sleepiness or assess formally, for example, using the ESS Skin condition long acting; however, Chlorpropamide is rarely used nowadays and is no longer available in some countries e.g Australia because of the significant hypoglycaemia risk Metformin is traditionally ceased 24 hours preoperatively but there is little evidence that ceasing Metformin or continuing Metformin in the perioperatic period increases the risk of hyperglycaemia Metformin is associated with a risk of lactic acidosis, although the risk is low; however, surgical procedures, hypotension secondary to blood loss, myocardial ischaemia, sepsis and anaestheic agents can contribute to the development of lactic acidosis, especially in people with renal impairment (Chapter 7) Thus a careful clinical assessment of the risks and benefits of ceasing/continuing Metformin in individual patients is essential Insulin therapy must be initiated before the procedure in people with Type diabetes (5) Encourage patients who smoke to stop (6) Assess: • Metabolic status: blood glucose control, ketones in blood and urine, hydration status, nutritional status, presence of anaemia, diabetic symptoms • Educational level and understanding of diabetes • Family support available postoperatively • Any known allergies or medicine reactions, which should include asking about complementary therapies, particularly herbal medicines, because some herbs predispose the person to haemorrhage and/or interact with anaesthetic agents and should be stopped at least days prior to surgery (see Chapter 19) 284 Care of People with Diabetes • Presence of diabetic complications and other comorbidities, for example, renal, hepatic, cardiac disease (ECG for people >50 years to detect the risk of silent infarction is performed in some units), presence of neuropathy Patients with autonomic neuropathy pose special problems during anesthesia: gastroparesis delays gastric emptying and the stomach can be full despite fasting and increases the possibility of regurgitation and inhalation of vomitus; or the vasoconstrictive response to reduced cardiac output may be absent and they may not recognise hypoglycaemia • Current medication regimen • Presence of infection, check feet and be aware of silent infection such as UTI • Self-care potential and available home support Note: Complications should be managed before the operation where possible (see Table 9.2) Major procedures Major surgery refers to procedures requiring anaesthesia and lasting longer than one hour (Dagogo-Jack & Alberti 2002) Day of the operation Premedication and routine preparation for the scheduled operative procedure should be performed according to the treatment sheet and standard protocols Where insulin is required, for example, Type diabetes, major surgery, and poor control, an IV insulin infusion is the preferred method of delivering the insulin The insulin dose should be balanced with adequate calories to prevent starvation ketosis, for example, saline/dextrose delivered at a rate that matches the insulin dose (Alberti & Gill 1997); see Chapter Fluid replacement should be adequate to maintain intravascular volume; normal saline/dextrose in water is the preferred solution for this purpose Preoperative hyperglycaemia especially if polyuria is present can cause significant fluid deficits and intracellular dehydration Clinical signs of dehydration are: • Thirst and a dry mouth: water loss 2 seconds (normal 10% of body weight (French 2000) Morning procedure (1) Ensure oral medications were ceased on the operative day or earlier in specific circumstances (2) Fast from 12 midnight (3) Ascertain insulin regimen: commence insulin infusion (4) Monitor blood glucose 1–2-hourly If the individual an insulin pump they should continue their usual basal rate (Joslin Diabetes Centre 2009) Afternoon procedure (1) Fast after an early light breakfast (2) Ensure oral medications are ceased (3) Ascertain insulin dose, usually 1/2 to 1/3 of usual dose (best given after IV dextrose has been commenced) Management During Surgical and Investigative Procedures 285 (4) It is preferable for IV therapy to be commenced in the ward to: • prevent hyperglycaemia and dehydration; • reduce the risk of hypoglycaemia This will depend on the surgical and anaesthetic and usual hospital procedure Some anaesthetists prefer to commence the infusion in theatre It is preferable to insert the IV line in theatre in children unless blood glucose is