PreOP Assessment - Quiz 1 Flashcards
What Is Anesthesia
Reversible, drug-induced depression of Central Nervous system resulting of loss of response & perception of external stimuli
Type of Anesthesia
General
Regional
MAC
Anesthetic States
Unconsciousness
Amnesia
Analgesia
Immobility
Goals of Anesthesia
- Optimize: Patient care, satisfaction, comfort, convenience
- Minimize Perioperative Mortality & Morbidity
- Minimize delays/cancels
- Determine post op plan
- Evaluate health status
- Optimize preexisting conditions
- Formulate anesthetic plan
- Communicate issue
- Educate Patient
Slow PreOp Eval
Perform Early
Take Your Time
Cover Everything
Build Relationship
Fast PreOp Eval
Perform when you can
Time Crunch
Cover Important
Build Relationship
Superfast PreOp Eval
Trauma/Emergency
Get what you can
Preanesthetic Assessment Clinic
- One stop shop - medical history & physical exam
- done well before surgery day
- at least 1 wk before surgery for complex patients
- Teach - what meds to take day of surgery, preps, NPO
- Coordinate meeting with other consultants
- Complete other pre-op diagnostics
Chart Review
- History - Medical, Surgical, Social, Anesthesia (MH, PONV)
- Meds/Herbals
- Labs
- Chemistry - Renal Patients, DM, HTN
- Coags - when indicated - spinal/epidural, hx of pt. on anticoags
- Tests - stress, echo
Hematocrit Percentage that is well tolerated in healthy patient
25-30%
Acceptable HGB for patients without system disease
HGB of 7g/dl
- Can cause ischemia in CAD patients
- Eval each patient individually for etiology & duration of anemia
Patient Interview
- Always Name/DOB/Procedure/Allergies/Airway/NPO time
- This might be it in emergencies
- Head-Toe run through of problems
- Confirm what you already know
- Establish relationship
Purpose of PreOp Assessment
- Build Relationship
- Modify plan to adjust for risks associated with comorbidities
- A line, CVC
- Fluid Warmer, Type & Screen
- LMA vs ETT
- Regional vs. General vs. MAC
- Glidoscope/Fiberoptic
- Management - Induction/Maintenance/Emergence
Musculoskeletal Assessment
- Obesity - OSA, Cardiac, DM
- Diseases
- Ankylosing Spondylitis
- RA
- Muscular Dystrophy
Neurologic History
- Significant Pathologies
- stroke, MS, Parkinsons
- seizure - increase MAC value, may need higher doses due to inducing CYP450 enzymes
- GCS
Cardiovascular History
- Pre-existing cardiac issues
- Disease severity/stability
- Risk associated with procedure
- HTN
- Ischemic Heart Disease/LV Dysfunction
- Valve Disease
- Arrhythmias, Pacer/AICD
CV Assessment - 1 MET
Poor Functional Capacity
- Self care
- Eating, dressing, using toilet
- Walking indoors, round the house
- Walking 1-2 blocks
CV Assessment - 4 METs
Good Functional Capacity
- Light housework - dusting, washing dishes
- Climbing stairs w/o stopping
- Brisk walking
- Running short distance
- Heavy House work - scrubbing, moving furniture
- Moderate Fun Stuff - golf, dancing, tennis, throwing ball
CV Assessment - 10+ METs
Excellent Functional Capacity
- Strenuous Sports - bball, jump rope, soccer, swimming, weights
What is METs Assessment
Metabolic Equivalents to Excercise Tolerance
Way to quantify amount of exertion a patient can tolerate.
We want at least 4 METS
HTN History
- Sys > 140 or Dia > 90
- If associated with LVH - greater risk for MI/CVA’
- Diuretic Use - Hypovolemia, Electrolyte Imbalance
- The pts’ BP tend to drop more with induction
- Preload with IVF to minimize this
- Maintain pt within 20% of baseline BP
- Altered autoregulation
Ischemic Heart Disease History
- Unstable angina places pt at risk for MI w/ stress of surgery & anesthesia
- Stents - ask about plavix, coumadin, other anticoags/antiplatelets
Perio-Operative Risk of Infarction
- Overall Population: 0.3%
- Past MI - 6%
- <30 Days prior - 33%
- 1-2 Months prior - 19%
- 3-6 Months prior - 15%
- < 3 months - 30%
If reinfaction occurs, mortalitiy is** **50%
Left Ventricular Dysfunction History
Defined as EF < 50%
Greater Morbidity
EF < 35% = greater incidence of postop HF & Death
Heart Valve History
Aortic Stenosis - Greatest risk for Non-Cardiac surgery MI
- Angina - 5 Years
- Syncope - 2 Years
- CHF - 1 Year
- 14x increase of perioperative sudden death
- If symptoms are severe, elective surgery should be delayed until cardiac consult.
Pacer/AICD History
- Interrogate before and after surgery
- Cautery can misread as arrhythmias so we turn off sensing, and put them into demand mode with magnet (have one)
- Pacers can mask ischemia symptoms
Anesthetic Managment of Patients with Cardiac History
- Avoid extremes of HR & BP
- HR main component of myocardial oxygen demand
- Expect to use A-Line & second IV to intervene quickly
- TEE or Swan if needed
- Always have patient continue scheduled beta blocker
- If pt missed dose, make sure we give it
- Reduce risk of perio-operative ischemia
- SCIP
Cardiac Dignostic Testing
12 Lead ECG
Stress ECG
Stress Myocardial Perfusion Imaging (MPI)
Stress Echo, TEE
PeriOperative Pulmonary Complications
Major cause of morbidity & mortality r/t surgery and anesthesia
- 5-10% Incidence in major non-cardiac surgery
- Atelectasis
- Aspiration Pneumonia
- Bronchospasms
- Respiratory Failure needing mechanical ventilation
- Pneumonia
- Bronchitis
- Hypoxemia
- Acute COPD
Predictors of Pulmonary Complication in Surgery
- Surgical Site
- Thoracic, Aortic, Upper Abdominal, Neck, Neurosurgery
- Lenth of Surgery > 2-3 hours = higher risk
- General Anesthetics
How does General Anesthetics increase Pulmonary Complications
- Altered breathing cycle
- V/Q mismatch
- Dead space ventilation
- Decreased FRC
- Microscopic Affects
- Inhibition of Mucociliary Clearance
- Increased alveolar-capillary permeability
- Inhibition of surfactant
- Blunted ventilatory response to hypoxia and hypercarbia
Pulmonary History - Asthma
- Assess cause/severity/frequency/frequency of inhaler use
- How responsive pt is to inhaler
- Every been hospitalized from asthma attack?
- Have patient take inhaler before taking them to surgery
- Can also give IV steroid
- Reactive airway (bronchospasm) - change induction/emergernce, ventilation plan
Pulmonary History - Smoking
- 6x increase in pulmonary complications
- Nicotine
- Increase HR, Oxygen Demand, BP, Peripheral vascular resistance
- Carbon monoxide binds to HGB stronger than O2
- Non smoking for 12-48 hours really reduces this
- Reactive airway and make more secretions
- Lower incidence of PONV, but increased aspiration risk
Pulmonary History - OSA
- Small doses of meds can cause apnea without pain relief
- monitor pulse-ox 24 hours after anesthetic
- Bring CPAP for PostOp
- Decrease narcotics - sensitive to resp effects
- No deep Exubations
Questioning OSA Risk
STOP
- Snoring Loudly?
- Tired during day?
- Oberved - anyone see you stop breathing while sleep?
- Pressure Problems - only any BP meds?
BANG
- BMI > 35
- Age > 50
- Neck circumfrerence > 40 cm
- Gender - Male
High Risk > 3
Low Risk < 3
Mendelson Syndrome
Another name for chemical pneumonitis
- Aspirate Gastric Volume > 25 mL
- pH < 2.5
- Particulate aspirate > clear aspirate
NPO Guidelines
- Clear Liquids
- Meds can be taken PO with up to 150 mL of water in the hour before anesthesia
- Applies to healthy patients, elective surgery - no gaurantees of gastric emptying
- Breast milk until 4 hours before
- No formula, non human milk, or light meal for at least 6 horus before surgery
- No gum/candy after Midnight
Endocrine History - DM
- Most common endocrine disorder - 8.3%
- 90-95% DM 2
- 5-10% DM 1
- Increased Risk of
- Automnomic neuropathy, gastroparesis, difficult airway, CAD, HTN, CHF, MI, Renal Fail, Stiff Joint
How to manage diabetes perioperatively?
- Hold oral diabetic med morning of surgery (48 hours for metformin)
- Take 1/4 - 1/2 insulin
- ALWAYS check BG for total joints during precedure regardless if diabetic or not
Endocrine History - Hyperthyroidism
- Hypermetabolic State - sympathetic overactivity
- PreOp Goals
-
Euthyroid State - antithyroid drugs for 6-8 weeks
- Followed by Iodine for 1-2 wks
-
Consider intraoperative beta blockers (only propranolol)
- BB reduce peripheral conversion of T4 to T3
- Control sympathetic system
-
Euthyroid State - antithyroid drugs for 6-8 weeks
What are the recommendations to delay surgery for Hypothyroidism
None
Endocrine History - Adrenal
-
Cushing Syndrome - long term steroid use
- may need stress dose steroids for the procedure
- Addison’s disease - Adrenocortical difficiency
What kind of disorders have some higher incidence of malignant hyperthermia?
Musculoskeletal Disorders
Alcohol History
- Acute intoxication
- Lowers anesthetic requirements
- Hypo/Hyperthermia
- Withdrawal - Increased anesthetic requirements
Recreational Drug History
- Stimulants
- Palpitations, True Angina, Labile BP, Lower threshold for serious arrhythmia, convulsions
- Cocaine - do not use beta blockers
- Unopposed alpha stimulation d/t beta blocker further decreases coronary flow
- Use calcium channel blockers
Allergy History
- Antiobiotics - Anaphylaxis
- Induction Agents
- Propofol - egg allergy
- Rocuronium - most common cause of intraop allergic reaction
- Shellfish & Seafood
- Cross reaction with IV contrast dye & Protamine
History of Difficult Anesthesia
- Anyone in your family had serious reaction to anesthesia?
- MH is familial
- Atypical Pseudocholinersterase - takes longer for succinylcholine to wear off
- Difficult intubation, significant PONV
ASA Class I
No organic, physiological, biochemical or psychiatric disturbance
Healthy Patient
ASA Class II
Mild to moderate Systemic Disturbance
Heart disease that slightly limits physical activity, essential HTN, DM, chronic bronchitis, anemia, obesity, age extremes
ASA Class III
Severe Systemic Disease that Limits Activity
Heart/Chronic pulmonary disease, poorly controll essential HTN, DM with vascular complications, angia pectoris, Hx of MI
ASA Class IV
Severe systemic disease that is constantly life threatening
CHF, persisent angina, advanced pulmonary, renal, hepatic dysfunction
ASA Class V
Moribund patient, undergoin surgery as a resuscitative effort, despite minimal chance of survival
Uncontrolled hemorrhage from AAA, PE, head injury with increased ICP
ASA Class VI
Declared brain dead, harvesting organs
ASA Class IE
Emergency surgery required
EX:
Healthy 30 y/o female needs D&C for moderate persistent hemorrhage
ASA Standard II
Informed Consent
- CRNA shall obtain/verify that an informed consent has been obtained by qualified provider
- Discuss options and risks
- Document consent obtained
- Aspects of care outside realm of common experience
- Intubation, ICU, invasive monitoring, regional techniques, blood products
- Alternative Plans
Failure to obtain consent is considered _________, and the act of performing a procedure without proper consent is __________
Breach of Duty, Battery
- No consent needed for emergencies - covered under doctrine of implied consent
What should an Anesthesia Consult Note have?
Medico-Legal Document In Permanent Hospital Record
- Date/Time of Interview
- Planned Procedure
- Description of Extraordinary Circumstances
- Allergies, Medications, Labs
- Disease Processes/Treatments
- ASA Status
ASA Standard III
Formulate a Patient-Specific Plan for anesthesia care
Plan should be based on comprehensive patient assessment, problem analysis, anticipated surgical/therapeutic procedure, patient & surgeon preferences, and current anesthesia principles
What equipment are required for ALL anesthetics
SOAPM
- *S**uction
- *O**xygen
- *A**irway equipment
- *P**ositive Pressure Ventilation
- Pharmacy
- *M**onitors, medications
Factors that Influence Anesthesia Plan
- Patient, Surgeon, Anesthesia Preference
- Site of Surgery
- Body Position need for Surgery
- Elective vs Emergency Surgery
- Co-Existing Disease
- Duration of Surgery
- Pt. Age
- Suspected Difficult Airway
- Suspected increased gastric contents at induction
General Anesthesia
Inhalation
Intravenous - TIVA
Combination
What do patients lose any time they lose consciousness and cant respond purposefully?
The ability to protect their airway
MAC
Monitored Anesthesia Care
- Should be able to respond if stimulated
- Should maintain airway reflexes - protect airway
- Sedation could progress quickly to General
Sodium Bicitrate
Increase gastric pH
Robinul
Decrease amount of secretions
Principles of Benzos
Used to Facilitate Induction and Help with anxiety/memory
Anxiolysis
Anterograde Amnesia
Sedation
Anticonvulsant
Spinal Cord-Mediated Skeletal Muscle Relaxation
How do Benzos Work?
Enhances the affinity of the receptors for GABA (Principle Inhibitory Neurotransmitter)
GABA causes Chloride influx hyperpolarizing neurons, reducing sponteaneous action potential firing –> CNS Inhibition
Versed
- 1-5 mg IV
- 2.5-5 mg IM
- Onset: 30-60 secs. IV, 15-30 min PO
- Peak: 3-5 minutes IV
- Duration: 15-80 min
- Rapid onset & peak, while having shorter DOA when compared to other Benzos
- PK: rapid absorption and quickly passes BBB - lipid soluble
How is Versed Metabolized
By Hepatic Cytochrome P450 (CYP3A4) enzymes to active/inactivate metabolites
- This is slowed by presence of drugs that inhibit CYP450, resulting in profound effects of midazolam greater than expected.
