A 36-year-old woman is brought to the emergency department 20 minutes after being involved in a high-speed motor vehicle collision. On arrival, she is unconscious. Her pulse is 140/min, respirations are 12/min and shallow, and blood pressure is 76/55 mm Hg. 0.9% saline infusion is begun. A focused assessment with sonography shows blood in the left upper quadrant of the abdomen. Her hemoglobin concentration is 7.6 g/dL and hematocrit is 22%. The surgeon decided to move the patient to the operating room for an emergent explorative laparotomy. Packed red blood cell transfusion is ordered prior to surgery. However, a friend of the patient asks for the transfusion to be held as the patient is a Jehovah's Witness. The patient has no advance directive and there is no documentation showing her refusal of blood transfusions. The patient's husband and children cannot be contacted. Which of the following is the most appropriate next best step in management?

Transfusion of packed red blood cells

Consult hospital ethics committee

Administer high-dose iron dextran

A 57-year-old man presents to his physician with dyspnea on exertion and rapid heartbeat. He denies any pain during these episodes. He works as a machine operator at a solar panels manufacturer. He has a 21-pack-year history of smoking. The medical history is significant for a perforated ulcer, in which he had to undergo gastric resection and bypass. He also has a history of depression, and he is currently taking escitalopram. The family history is unremarkable. The patient weighs 69 kg (152 lb). His height is 169 cm (5 ft 7 in). The vital signs include: blood pressure 140/90 mm Hg, heart rate 95/min, respiratory rate 12/min, and temperature 36.6℃ (97.9℉). Lung auscultation reveals widespread wheezes. Cardiac auscultation shows decreased S1 and grade 1/6 midsystolic murmur best heard at the apex. Abdominal and neurological examinations show no abnormalities. A subsequent echocardiogram shows increased left ventricular mass and an ejection fraction of 50%. Which of the options is a risk factor for the condition detected in the patient?

History of gastric bypass surgery

A 62-year-old man comes to the physician in May for a routine health maintenance examination. He feels well. He underwent a right inguinal hernia repair 6 months ago. He has hypertension and type 2 diabetes mellitus. There is no family history of serious illness. Current medications include metformin, sitagliptin, enalapril, and metoprolol. He received the zoster vaccine 1 year ago. He received the PPSV23 vaccine 4 years ago. His last colonoscopy was 7 years ago and was normal. He smoked a pack of cigarettes a day for 20 years but quit 17 years ago. He drinks two to three alcoholic beverages on weekends. He is allergic to amoxicillin. He is scheduled to visit Australia and New Zealand in 2 weeks to celebrate his 25th wedding anniversary. He appears healthy. Vital signs are within normal limits. An S4 is heard at the apex. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate recommendation at this time?

Pneumococcal conjugate vaccine 13

A 69-year-old man is scheduled to undergo radical retropubic prostatectomy for prostate cancer in 2 weeks. He had a myocardial infarction at the age of 54 years. He has a history of GERD, unstable angina, hyperlipidemia, and severe osteoarthritis in the left hip. He is unable to climb up stairs or walk fast because of pain in his left hip. He had smoked one pack of cigarettes daily for 30 years but quit 25 years ago. He drinks one glass of wine daily. Current medications include aspirin, metoprolol, lisinopril, rosuvastatin, omeprazole, and ibuprofen as needed. His temperature is 36.4°C (97.5°F), pulse is 90/min, and blood pressure is 136/88 mm Hg. Physical examination shows no abnormalities. A 12-lead ECG shows Q waves and inverted T waves in leads II, III, and aVF. His B-type natriuretic protein is 84 pg/mL (N < 125). Which of the following is the most appropriate next step in management to assess this patient's perioperative cardiac risk?

Radionuclide myocardial perfusion imaging

24-hour ambulatory ECG monitoring

A 70-year-old man with a 2 year history of Alzheimer disease is brought in from his nursing facility with altered mental status and recurrent falls during the past few days. Current medications include donepezil and galantamine. His vital signs are as follows: temperature 36.0°C (96.8°F), blood pressure 90/60 mm Hg, heart rate 102/min, respiratory rate 22/min. Physical examination reveals several lacerations on his head and extremities. He is oriented only to the person. Urine and blood cultures are positive for E. coli. The patient is admitted and initial treatment with IV fluids, antibiotics, and subcutaneous prophylactic heparin. On the second day of hospitalization, diffuse bleeding from venipuncture sites and wounds is observed. His blood test results show thrombocytopenia, prolonged PT and PTT, and a positive D-dimer. Which of the following is the most appropriate next step in the management of this patient's condition?

Immediately cease heparin therapy and prescribe an alternative anticoagulant

Cryoprecipitate, FFP and low dose SC heparin

Pre-operative evaluation | Surgery

🎯 The Pre-Operative Command Center: Surgical Success Starts Here

Every surgical procedure begins long before the first incision-in the pre-operative evaluation where you'll identify hidden risks, optimize medical conditions, and transform uncertainty into calculated safety. You'll master cardiac and pulmonary risk stratification, learn which lab tests actually matter, navigate the complex decisions around continuing or holding medications, and understand how anesthesiologists assess patient readiness. This systematic approach doesn't just check boxes; it prevents complications, reduces mortality, and ensures your patients reach the operating room in their best possible condition.

📌 Remember: PREPARE - Pulmonary assessment, Renal function, Endocrine status, Pharmacology review, Airway evaluation, Risk stratification, Education and consent

The systematic approach to pre-operative evaluation follows evidence-based protocols that reduce surgical mortality by 40% when properly implemented. Understanding this framework enables prediction of surgical outcomes before the first incision.

Risk Stratification Categories
- Low Risk (<1% mortality): Superficial procedures, cataract surgery
  - ASA Class I-II patients
  - Procedures <30 minutes duration
  - Minimal physiologic stress
- Intermediate Risk (1-5% mortality): Intraperitoneal surgery, carotid endarterectomy
  - ASA Class III patients
  - Procedures 30-180 minutes
  - Moderate physiologic stress
- High Risk (>5% mortality): Aortic surgery, major emergency procedures
  - ASA Class IV-V patients
  - Procedures >180 minutes
  - Major physiologic stress

Risk Factor	Low Risk	Intermediate Risk	High Risk	Mortality Impact	Intervention Threshold
Cardiac	No CAD	Stable angina	Unstable angina	3-fold increase	RCRI ≥2
Pulmonary	Normal PFTs	Mild COPD	FEV1 <40%	2.5-fold increase	PFTs indicated
Renal	Cr <1.2	Cr 1.2-2.0	Cr >2.0	4-fold increase	eGFR <60
Hepatic	Normal LFTs	Child-Pugh A	Child-Pugh B/C	5-fold increase	MELD >15
Age	<65 years	65-80 years	>80 years	1.5-fold per decade	Frailty assessment

💡 Master This: Pre-operative evaluation reduces surgical complications by 35-50% through systematic identification and optimization of modifiable risk factors before physiologic stress occurs.

The foundation of surgical safety depends on understanding that every patient carries unique risk profiles requiring individualized assessment strategies. Connect this systematic approach through cardiac risk stratification to understand how specific organ systems determine surgical outcomes.

🎯 The Pre-Operative Command Center: Surgical Success Starts Here

Preoperative patient education

Informed consent process

⚡ Cardiac Risk Stratification: The Heart of Surgical Safety

📌 Remember: CRIMES - Cerebrovascular disease, Renal dysfunction (Cr >2.0), Ischemic heart disease, Major surgery, Endocrine (diabetes), Supraventricular surgery

The RCRI score directly correlates with perioperative cardiac event rates, enabling precise risk quantification and management decisions. Each additional risk factor exponentially increases cardiac complications.

RCRI Risk Stratification
- 0 Risk Factors: 0.4% cardiac event rate
  - Proceed to surgery without delay
  - Standard perioperative monitoring
  - No additional cardiac testing required
- 1 Risk Factor: 0.9% cardiac event rate
  - Consider functional capacity assessment
  - Optimize medical therapy
  - Standard monitoring adequate
- 2 Risk Factors: 7% cardiac event rate
  - Cardiology consultation recommended
  - Stress testing if poor functional capacity
  - Enhanced perioperative monitoring
- ≥3 Risk Factors: 11% cardiac event rate
  - Mandatory cardiology evaluation
  - Stress testing or coronary angiography
  - Consider surgery delay for optimization

Surgery Type	Cardiac Risk	30-Day MI Rate	Mortality Rate	Monitoring Level	Assessment Required
Superficial	<1%	0.1%	<0.5%	Standard	Basic history/exam
Intermediate	1-5%	0.5-1.5%	0.5-1.5%	Enhanced	RCRI + functional capacity
Vascular	>5%	2-5%	2-5%	Intensive	Full cardiac evaluation
Emergency	Variable	3-15%	5-25%	Maximum	Risk vs benefit analysis
Aortic	>10%	5-15%	5-15%	Maximum	Mandatory optimization

The 4-MET threshold represents the critical functional capacity dividing line for cardiac risk assessment. Patients unable to achieve 4 METs during daily activities require enhanced cardiac evaluation regardless of RCRI score.

Functional Capacity Assessment
- Excellent (>10 METs): Run 8 mph, carry 80 lbs upstairs
  - Proceed to surgery without cardiac testing
  - Risk equivalent to healthy population
  - Standard perioperative care adequate
- Good (7-10 METs): Heavy housework, climb 2 flights rapidly
  - Low cardiac risk regardless of RCRI
  - Consider optimization of medical therapy
  - Enhanced monitoring for high-risk surgery
- Moderate (4-7 METs): Walk 4 mph on level ground
  - Intermediate risk requiring RCRI assessment
  - Stress testing if ≥2 risk factors
  - Cardiology consultation recommended
- Poor (<4 METs): Cannot walk 2 blocks or climb 1 flight
  - High risk requiring comprehensive evaluation
  - Stress testing or angiography indicated
  - Mandatory optimization before surgery

💡 Master This: Cardiac risk stratification combines objective RCRI scoring with functional capacity assessment to predict perioperative events with 85% accuracy, enabling evidence-based surgical decision-making.

Understanding cardiac risk assessment provides the foundation for comprehensive evaluation. Connect this systematic approach through pulmonary risk evaluation to understand how respiratory function impacts surgical outcomes.

⚡ Cardiac Risk Stratification: The Heart of Surgical Safety

Cardiac risk assessment

Functional capacity evaluation

🫁 Pulmonary Risk Assessment: Breathing Life into Surgical Safety

📌 Remember: COPD RISK - Chronic lung disease, Obesity (BMI >30), Poor functional status, Dyspnea at rest, Recent respiratory infection, Immobility, Smoking history, Kidney disease

The pulmonary risk assessment integrates clinical factors with objective testing to predict respiratory complications. Each risk factor contributes additively to overall pulmonary morbidity.

Pulmonary Risk Factors
- Patient Factors (Non-modifiable)
  - Age >70 years: 2-fold increased risk
  - COPD with FEV1 <50%: 4-fold increased risk
  - Congestive heart failure: 3-fold increased risk
- Procedure Factors (Non-modifiable)
  - Upper abdominal surgery: 6-fold increased risk
  - Thoracic surgery: 8-fold increased risk
  - Surgery duration >3 hours: 2-fold increased risk
- Modifiable Factors
  - Active smoking: 3-fold increased risk
  - Obesity BMI >35: 2.5-fold increased risk
  - Poor nutritional status: 2-fold increased risk

Risk Category	PFT Criteria	Complication Rate	Mortality Risk	Intervention Strategy	Optimization Time
Low Risk	FEV1 >80%	2-5%	<1%	Standard care	None required
Moderate Risk	FEV1 50-80%	10-20%	1-3%	Bronchodilators + PT	2-4 weeks
High Risk	FEV1 30-50%	25-40%	3-8%	Pulmonary rehabilitation	6-8 weeks
Prohibitive	FEV1 <30%	>50%	>15%	Consider alternatives	3-6 months
Emergency	Any level	Variable	5-25%	Risk vs benefit	Immediate

Pulmonary function testing provides objective risk stratification for patients with known or suspected lung disease. The FEV1 represents the most predictive single parameter for respiratory complications.

PFT Interpretation for Surgical Risk
- FEV1 >80% predicted: Proceed without pulmonary optimization
  - Standard perioperative care adequate
  - Early mobilization and incentive spirometry
  - Monitor for standard complications
- FEV1 50-80% predicted: Optimize bronchodilator therapy
  - Inhaled β2-agonists and anticholinergics
  - Consider systemic corticosteroids
  - Enhanced respiratory monitoring
- FEV1 30-50% predicted: Comprehensive pulmonary rehabilitation
  - 6-8 weeks pre-operative conditioning
  - Nutritional optimization and weight loss
  - Smoking cessation mandatory
- FEV1 <30% predicted: Consider non-surgical alternatives
  - Prohibitive risk for elective procedures
  - Multidisciplinary team evaluation
  - Palliative care consultation if appropriate

💡 Master This: Pulmonary risk assessment combines clinical risk factors with objective PFT values to predict respiratory complications with 80% accuracy, enabling targeted interventions that reduce morbidity by 40%.

Pulmonary assessment integrates with overall risk stratification to optimize surgical outcomes. Connect this respiratory evaluation through laboratory testing strategies to understand how biochemical markers guide perioperative management.

🫁 Pulmonary Risk Assessment: Breathing Life into Surgical Safety

Pulmonary risk evaluation

Preoperative imaging selection

🔬 Laboratory Testing Strategy: The Biochemical Blueprint

Laboratory test results showing comprehensive metabolic panel with surgical significance

📌 Remember: LABS WISE - Liver function, Anemia assessment, Bleeding studies, Sugar control, White count, Ions and kidney, Specific indications, Electrolytes

Laboratory testing should follow indication-based protocols rather than routine screening approaches. Each test must have specific clinical justification and potential to change perioperative management.

Evidence-Based Testing Indications
- Complete Blood Count
  - Age >65 years or cardiovascular disease
  - History of anemia, bleeding, or hematologic disorders
  - Major surgery with expected blood loss >500 mL
  - Malignancy or chemotherapy history
- Basic Metabolic Panel
  - Diabetes mellitus or endocrine disorders
  - Hypertension or cardiovascular disease
  - Renal disease or nephrotoxic medications
  - Age >70 years for intermediate/high-risk surgery
- Coagulation Studies
  - Anticoagulant or antiplatelet therapy
  - Liver disease or bleeding history
  - Family history of bleeding disorders
  - Surgery with high bleeding risk

Test Category	Clinical Indication	Abnormal Threshold	Management Impact	Cost per Test	Yield Rate
CBC	Age >65, bleeding history	Hgb <10 g/dL	Transfusion planning	$25	15%
BMP	DM, HTN, renal disease	Cr >1.5 mg/dL	Nephrotoxin avoidance	$30	20%
PT/INR	Anticoagulation, liver disease	INR >1.5	Reversal strategy	$20	25%
LFTs	Liver disease, alcohol use	ALT >2x normal	Anesthesia modification	$40	10%
HbA1c	Diabetes mellitus	>8%	Glucose optimization	$35	30%

Specific laboratory abnormalities require targeted interventions before surgery to optimize outcomes. Understanding normal values and intervention thresholds enables evidence-based decision-making.

Critical Laboratory Thresholds
- Hemoglobin Optimization
  - >10 g/dL: Proceed to surgery without intervention
  - 8-10 g/dL: Consider iron supplementation or EPO
  - <8 g/dL: Investigate cause and optimize before elective surgery
  - <7 g/dL: Transfusion indicated for symptomatic anemia
- Renal Function Assessment
  - eGFR >60: Normal perioperative management
  - eGFR 30-60: Nephrotoxin avoidance and hydration
  - eGFR 15-30: Nephrology consultation recommended
  - eGFR <15: Dialysis coordination required
- Glucose Control Targets
  - HbA1c <7%: Optimal glycemic control
  - HbA1c 7-8%: Acceptable for surgery
  - HbA1c 8-10%: Consider optimization delay
  - HbA1c >10%: Mandatory endocrine consultation

💡 Master This: Evidence-based laboratory testing reduces unnecessary costs by 60% while identifying clinically significant abnormalities in 15-25% of appropriately selected patients, optimizing both safety and resource utilization.

Laboratory assessment provides biochemical foundation for surgical planning. Connect this systematic testing approach through medication management strategies to understand how pharmacologic interventions impact perioperative care.

🔬 Laboratory Testing Strategy: The Biochemical Blueprint

Preoperative laboratory testing

Nutritional assessment and optimization

💊 Perioperative Medication Management: The Pharmacologic Balancing Act

📌 Remember: MEDS STOP - Metformin, Enoxaparin, Diuretics, Statins (continue), Steroids (stress dose), Thyroid (continue), Opioids (taper), Platelet inhibitors

Perioperative medication management requires balancing therapeutic benefits against surgical risks. Each medication class demands specific timing and modification strategies based on pharmacokinetics and surgical requirements.

Anticoagulation Management
- Warfarin (INR target <1.5)
  - Discontinue 5 days before surgery
  - Bridge with LMWH if high thrombotic risk
  - Resume 12-24 hours post-operatively
- Direct Oral Anticoagulants
  - Stop 24-48 hours before surgery (CrCl dependent)
  - No routine bridging required
  - Resume when hemostasis achieved
- Antiplatelet Therapy
  - Aspirin: Continue for cardiac stents, stop 7 days for bleeding risk
  - Clopidogrel: Stop 5 days before surgery
  - Dual therapy: Cardiology consultation required

Medication Class	Action Required	Timing	Rationale	Monitoring	Restart Protocol
ACE Inhibitors	Hold morning of surgery	Day of surgery	Hypotension risk	BP monitoring	POD 1-2
Metformin	Stop 48h before	2 days prior	Lactic acidosis	Renal function	When eating
Insulin	Reduce by 50%	Night before	Hypoglycemia	Glucose q2h	Sliding scale
Steroids	Stress dose	Day of surgery	Adrenal insufficiency	Electrolytes	Taper schedule
Statins	Continue	No interruption	Pleiotropic benefits	LFTs if indicated	No change

Specific medication classes require individualized management strategies based on half-life, mechanism of action, and surgical bleeding risk. Understanding pharmacokinetics enables optimal timing decisions.

High-Risk Medication Categories
- Anticoagulants and Antiplatelets
  - Warfarin: 5-day washout period for INR normalization
  - Rivaroxaban: 24-hour washout (normal renal function)
  - Apixaban: 48-hour washout (CrCl <50)
  - Clopidogrel: 5-day washout for platelet recovery
- Cardiovascular Medications
  - ACE inhibitors: Hold morning of surgery (hypotension risk)
  - Beta-blockers: Continue perioperatively (withdrawal syndrome)
  - Diuretics: Hold morning of surgery (volume depletion)
  - Statins: Continue throughout (anti-inflammatory benefits)
- Endocrine Medications
  - Metformin: Stop 48 hours before (lactic acidosis risk)
  - Insulin: Reduce basal by 50% night before
  - Oral hypoglycemics: Hold morning of surgery
  - Thyroid hormone: Continue without interruption

💡 Master This: Systematic medication management reduces perioperative complications by 30% through evidence-based protocols that balance therapeutic benefits against surgical risks, optimizing both safety and efficacy.

Medication management integrates with comprehensive risk assessment to ensure surgical safety. Connect this pharmacologic approach through anesthesia evaluation to understand how perioperative care coordination optimizes outcomes.

💊 Perioperative Medication Management: The Pharmacologic Balancing Act

Medications management perioperatively

Antibiotic prophylaxis principles

🎭 Anesthesia Evaluation: The Perioperative Safety Net

📌 Remember: AIRWAY SAFE - Anatomy assessment, Intubation history, Range of motion, Weight/BMI, Apnea history, Youth vs elderly, Surgery type, Allergies, Fasting status, Emergency vs elective

The ASA Physical Status Classification provides standardized risk stratification that correlates directly with perioperative morbidity and mortality. Each ASA class represents exponentially increasing risk levels.

ASA Classification System
- ASA I: Healthy patient without systemic disease
  - Mortality risk: 0.05%
  - Standard monitoring adequate
  - Minimal perioperative complications
- ASA II: Mild systemic disease without functional limitation
  - Mortality risk: 0.2%
  - Enhanced monitoring recommended
  - Controlled hypertension, diabetes, obesity
- ASA III: Severe systemic disease with functional limitation
  - Mortality risk: 1.8%
  - Intensive monitoring required
  - Unstable angina, COPD with dyspnea, dialysis
- ASA IV: Severe disease that is constant threat to life
  - Mortality risk: 7.8%
  - Maximum monitoring and support
  - Recent MI, severe heart failure, sepsis

Airway Assessment	Normal Finding	Concerning Finding	Intubation Difficulty	Management Strategy	Success Rate
Mallampati	Class I-II	Class III-IV	5-fold increase	Video laryngoscopy	95% vs 75%
Thyromental Distance	>6 cm	<6 cm	3-fold increase	Awake intubation	98% vs 85%
Neck Extension	>35 degrees	<35 degrees	4-fold increase	Flexible bronchoscopy	99% vs 80%
Mouth Opening	>3 cm	<3 cm	6-fold increase	Surgical airway	95% vs 60%
BMI	<30	>40	2-fold increase	Ramped positioning	90% vs 75%

Airway assessment represents the most critical component of anesthesia evaluation, as airway complications can rapidly become life-threatening. Systematic evaluation identifies high-risk patients requiring specialized management.

Comprehensive Airway Assessment
- Anatomical Factors
  - Mallampati Class III-IV: Tongue obscures pharyngeal structures
  - Short thyromental distance (<6 cm): Limited laryngeal exposure
  - Reduced neck extension (<35 degrees): Difficult laryngoscopy
  - Limited mouth opening (<3 cm): Inadequate visualization
- Historical Factors
  - Previous difficult intubation: 10-fold increased risk
  - Sleep apnea: 3-fold increased risk
  - Radiation therapy: 5-fold increased risk
  - Facial trauma: 8-fold increased risk
- Physiological Factors
  - BMI >40: 2-fold increased difficulty
  - Pregnancy: 8-fold increased aspiration risk
  - Emergency surgery: 4-fold increased complications
  - Full stomach: 6-fold increased aspiration risk

💡 Master This: Anesthesia evaluation combines ASA risk stratification with systematic airway assessment to predict perioperative complications with 90% accuracy, enabling proactive management strategies that reduce morbidity by 40%.

Anesthesia assessment completes the comprehensive pre-operative evaluation framework. Connect this systematic approach through rapid mastery tools to synthesize all components into practical clinical decision-making frameworks.

🎭 Anesthesia Evaluation: The Perioperative Safety Net

Preoperative anesthesia evaluation

DVT risk assessment

🚀 Pre-Operative Mastery Arsenal: Your Clinical Command Center

📌 Remember: SURGICAL SUCCESS - Systematic assessment, Understand risks, Risk stratification, Guideline adherence, Individualized care, Communication, Airway evaluation, Lab optimization, Safety protocols, Unified approach, Comprehensive planning, Continuous monitoring, Evidence-based decisions, Standard protocols, Safety first

The Essential Numbers Arsenal provides rapid reference for critical thresholds that determine surgical safety and timing decisions.

Critical Threshold Quick Reference
- Cardiac Risk: RCRI ≥2 = cardiology consult, <4 METs = stress test
- Pulmonary Risk: FEV1 <50% = optimization, <30% = prohibitive
- Renal Function: eGFR <60 = nephrotoxin avoidance, <30 = nephrology
- Anemia: Hgb <10 = investigate, <8 = optimize, <7 = transfuse
- Anticoagulation: Stop warfarin 5 days, DOAC 24-48 hours, clopidogrel 5 days
- Diabetes: HbA1c >8% = optimize, >10% = endocrine consult
- Airway: ≥3 predictors = awake intubation, Mallampati III-IV = video laryngoscopy

Risk Category	Assessment Tool	Low Risk Action	High Risk Action	Optimization Time	Success Metric
Cardiac	RCRI + METs	Standard care	Stress test + optimization	4-6 weeks	Event rate <2%
Pulmonary	PFTs + clinical	Incentive spirometry	Pulmonary rehab	6-8 weeks	Complication <10%
Renal	eGFR + proteinuria	Standard hydration	Nephrology consult	2-4 weeks	AKI rate <5%
Nutritional	Albumin + BMI	Standard diet	Nutrition support	2-4 weeks	Wound healing >90%
Functional	Frailty assessment	Early mobilization	Prehabilitation	4-8 weeks	Independence >80%

💡 Master This: Pre-operative evaluation excellence combines systematic risk assessment, evidence-based optimization, and multidisciplinary coordination to transform surgical outcomes through proactive identification and management of modifiable risk factors.