Preoperative Assessment and Preparation

Prioperative Assessment and Preparation

BY DR SALEHA JABALI

Anesthesiologists’ Role

• Anesthesiologists have increasingly taken on a leadership role in
  • preoperative evaluation and preparation, well in advance of the scheduled procedure which may be up to 3 months with frequent visits and follow-up with anesthesia clinic till optimization (Complex surgery, more elderly patient)
• A rapid transformation in practice from hospital admission of patients the night
  • before surgical procedures to admission on the morning of surgery

Goals and Benefits of Preanesthesia Evaluation

• Ensure that the patient can safely tolerate anesthesia for the planned surgery and mitigate perioperative risks such as
  • pulmonary or cardiovascular complications

Current Known Medical Problems

• Past medical issues
• Previous surgeries, anesthesia types, and anesthesia-related complications

A detailed notation of diseases or symptoms such as hypertension, diabetes mellitus, ischemic heart disease, shortness of breath, or chest pain, their associated severity, stability, associated activity limitations, exacerbations (current or recent), prior treatments, and planned interventions should be clearly documented. All related diagnostic test results and interventions should be reviewed. The patient’s responses to these initial questions may elicit further inquiry to establish a complete history.

Medical History Guidelines

• List any allergies to medications and other substances (e.g., latex, radiographic dye)
• Tobacco, alcohol, or illicit drug use must be documented
• A personal or family history of pseud cholinesterase deficiency and malignant hyperthermia
• A standardized general review of all organ systems should then be performed.
  • For example, patients should be asked whether they ever had problems with their heart, lungs, kidneys, liver, and nervous system.
  • In addition, they should be asked about any history of cancer, anemia.

MET (Functional Capacity Assessment)

• Assessment of the patient’s cardiopulmonary fitness or functional capacity is an integral component of the preoperative clinical examination. Estimate a patient’s risk for major postoperative morbidity or mortality, and to determine whether further preoperative testing is required.
• One metabolic equivalent of task (MET) is the amount of oxygen consumed while sitting at rest, and is equivalent to an oxygen consumption of 3.5 mL/min/kg body weight.

Special Issues in Preoperative Evaluation

Malignant Hyperthermia (MH)

• A known history or suggestive history (e.g., hyperthermia or rigidity during anesthesia) of malignant hyperthermia in a patient or family member must be clearly documented in the preoperative assessment.
• Team must be informed so MH protocol must be ready.
• Patients are asymptomatic until they are exposed to triggering agents (Volatile & SUX).
• Certain neuromuscular diseases are associated with elevated risks of MH, including some muscular dystrophies (i.e., Duchenne, Becker, myotonic).

Smokers and Second-Hand Smoke Exposure

• It increases risks for a range of postoperative complications, including:
  • Mortality
  • Cardiac complications
  • Pulmonary complications
  • Acute stroke
  • Surgical site infections
• A child is a passive smoker if anyone at home is smoking, which will increase:
  • Respiratory complications

Special Group of Patients

Older Adults

• Geriatric-specific risk factors such as functional and cognitive impairment
  • are associated with poor postoperative outcomes

Pediatric

• History of prematurity, low birth weight, and neonatal intensive care admission
• Gestational age (GA) less than 37 weeks is a premature infant and at high risk for respiratory complications (RDS) and other organ dysfunction
• Post general anesthesia apnea till age 60 weeks post-conceptional age (GA + age after birth)
• May present with syndromes or congenital anomalies
• Less than 2 years old have high vagotonic effect over sympathetic system and child is heart rate cardiac output dependent, so bradycardia is a risk

Hypertension (HTN)

• To identify any secondary causes of hypertension, presence of other
  • cardiovascular risk factors (e.g., smoking, diabetes mellitus), and evidence of end-organ damage (ECG, Creatinine concentration)
• Risk of cardiovascular complication is generally not evident for systolic
  • blood pressure values less than 180 mm Hg or diastolic blood pressure values less than 110 mm Hg
• Long-term antihypertensive treatment should be continued up to the day of
  • surgery, with the possible exception of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs). If given within 24 hours before surgery, it is consistently associated with increased risks of intraoperative hypotension.

Patient on Anticoagulant

• Risk of intraoperative bleeding
  • It is a contraindication for neuraxial block
• Antiplatelet agent
  • Must be held for 7-10 days
  • Except Mini Aspirin is safe
• Antithrombotic agent
  • Heparin LMWH = at least 12-24 h hold
  • Unfractionated heparin = 2-4 h hold and check coagulation status
  • Warfarin = 4-5 day hold and INR must be normal