What are the guidelines for anesthesia management in a patient undergoing surgery, considering their medical history, current health status, and potential risks?

Anesthesiology Guidelines for Perioperative Management

Cardiovascular Risk Management in Non-Cardiac Surgery

Blood Pressure Management

Maintain mean arterial pressure >60 mmHg and avoid decreases >20% from baseline for cumulative durations >30 minutes, as these thresholds are associated with increased risk of myocardial infarction, stroke, and death. 1

• Intra-arterial blood pressure monitoring should be established before induction of anesthesia in elderly or high-risk patients to diagnose and prevent significant hypotension 1
• Beat-to-beat monitoring reduces hypotensive episodes that occur between non-invasive measurements 1

Glucose Control

Post-operative hyperglycemia must be prevented by targeting glucose levels <10.0 mmol/L (180 mg/dL) using intravenous insulin therapy in adults after high-risk surgery requiring ICU admission (Class I, Level B). 1

• Screen for elevated HbA1c before major surgery in high-risk patients 1
• Do NOT target post-operative glucose <6.1 mmol/L (110 mg/dL) as this is associated with harm (Class III, Level A) 1
• Intra-operative hyperglycemia prevention with insulin may be considered but is not mandatory 1

Anesthesia Technique Selection

When epidurals or spinals completely replace general anesthesia (not when used to supplement), there is a 29% decrease in mortality risk and 55% reduction in pneumonia. 1

• Neuraxial anesthesia does not reduce myocardial infarction risk 1
• Regional anesthesia is preferred over general anesthesia when feasible, though airway management planning remains mandatory 1

Anesthesia for Cardiac Surgery (CABG)

Anesthetic management directed toward early postoperative extubation and accelerated recovery is recommended for low- to medium-risk patients undergoing uncomplicated CABG (Class I, Level B). 1

• Volatile anesthetics with opioid supplementation are standard in the United States 1
• High-dose opioid techniques should be avoided as they may increase hypotension risk 1
• Nondepolarizing neuromuscular blockers with intermediate duration are preferred over pancuronium to facilitate early extubation 1

Special Populations

Elderly Patients (>75 years)

Use depth of anesthesia monitoring (BIS or entropy) to guide dosing, as elderly patients require 30-50% lower doses of anesthetic agents and are prone to relative overdose with prolonged hypotension. 1

• Check hemoglobin concentration and eGFR preoperatively in all patients >75 years 1
• Avoid rapid bolus administration; use slow titration 1
• Consider intra-arterial monitoring before induction 1
• Implement forced air warming and fluid warming throughout the perioperative period 1

Obese Patients

Obesity alone does not mandate high-dependency postoperative care; base level-2 or level-3 care decisions on: pre-existing comorbidities, OS-MRS score 4-5, surgical procedure type, and untreated OSA with parenteral opioid requirements. 1

• Neck circumference >60 cm predicts 35% probability of difficult laryngoscopy 1
• Remove or clip facial hair preoperatively to facilitate bag-mask ventilation 1
• Regional anesthesia is preferred when possible, though failure rates are higher 1
• Use extra-long spinal/epidural needles and consider ultrasound guidance 1
• Patients with OS-MRS score 4-5 require an experienced anesthesiologist 1

Pediatric Patients

Maintenance infusion rates of 200-300 mcg/kg/min propofol are typically required initially, with younger children requiring higher rates (125-150 mcg/kg/min) than older children. 2

• Sedation is a continuum in pediatrics; patients move easily from light to deep sedation with potential loss of protective reflexes 3
• A dedicated individual (not the proceduralist) should monitor deeply sedated pediatric patients 3
• Reactions including agitation, involuntary movements, and combativeness may occur; consider flumazenil reversal 3

Medication Administration Protocols

Midazolam

Titrate slowly with multiple small doses, allowing 3-5 minutes between doses to achieve peak CNS effect and minimize oversedation risk. 3

• Intramuscular dose for ASA I-II adults <60 years: 0.07-0.08 mg/kg (approximately 5 mg) 3
• Reduce dose to 2-3 mg (0.02-0.05 mg/kg) for patients ≥60 years 3
• Immediate availability of flumazenil, oxygen, resuscitative drugs, and airway equipment is mandatory 3
• Continuous monitoring with pulse oximetry is required 3

Propofol

For cardiac anesthesia, avoid rapid bolus induction; use slow rate of approximately 20 mg every 10 seconds until induction (0.5-1.5 mg/kg total). 2

• Maintenance infusion rates should not be <100 mcg/kg/min when propofol is the primary agent 2
• Administer anticholinergic agents when increases in vagal tone are anticipated, as propofol reduces heart rate 2
• In elderly/debilitated patients, rapid bolus doses increase cardiorespiratory depression including hypotension and apnea 2

COVID-19 Pandemic Considerations

Wear N95 or FFP2 respirators, head cap, gown with apron, gloves, and face shield when performing airway procedures, regardless of COVID status. 1

• Evaluate benefit/risk ratio using patient factors (ASA class, obesity, age >65 or <1 year), pathology, and procedure type 1
• Use standardized questionnaires to screen for SARS-CoV-2 symptoms before any surgery 1
• Provide written information about COVID-19 risks and document in medical records 1

Anaphylaxis Management

Latex Allergy

If latex allergy is diagnosed preoperatively, complete avoidance is mandatory; schedule patient first on the list and prepare operating theatre the night before. 1

• High-risk groups: patients with spina bifida, multiple childhood surgeries, healthcare workers, and those with fruit allergies (banana, chestnut, avocado) 1
• Preoperative testing (skin prick or specific IgE) has 75-90% sensitivity; skin testing may be more sensitive 1
• Premedication with antihistamines or steroids is not useful 1

Mast Cell Tryptase

• Measure tryptase at time of reaction, 1-2 hours post-reaction, and 24 hours later to confirm anaphylaxis 1
• Mature β-tryptase is released during anaphylaxis; α-tryptase is constitutively secreted 1

Preoperative Testing

Patients in usual health undergoing cataract surgery do not require preoperative testing; three randomized trials showed preoperative medical evaluation does not reduce complications. 4

• Directed testing only: hemoglobin if anemia suspected, eGFR if renal disease, glucose if diabetes requiring management 4
• For elderly patients undergoing major surgery, check hemoglobin and renal function 4