Intraoperative assessment (mod 6) Flashcards
General Approach to Emergency problems in the surgical setting. (10)
- hint modified CAB approach
- Assess heart and rhythm (feel for the pulse)
- Evaluate adequate/unobstructed airway
- Evaluate adequate ventilation
- Assess pts BP and perfusion
- Assess the Pts volume status
- Temperature
- obvious abnormalities
- Establish additional monitors where appropriate
- Investigate electrolyte/factors status
- Formulate action plan
What do you assess during a heart and rhythm check in an emergency?
Feel for the Radial or Carotid Pulse
- Used to rule out cardiac arrest
- Severe bradycardia should be assumed to be secondary to hypoxemia until proven otherwise
Signs of obstructed airway? (7)
- No chest rise despite effort
- Stridor
- Intercostal/substernal indrawing
- Tracheal tugging (Peds)
- Accessory muscle use
- Decreased/Absent air entry on auscultation
- Decreasing oxygen saturations
What airway elements should be assessed in a emergency when a patient is not intubated?
Assess whether obstruction prevents patient from breathing
- Head-tilt, chin lift, jaw thrust and removal of foreign bodies
- Insertion of oral or nasal airway can assist you to overcome the obstruction
- Maneuvers to resolve a partial/complete airway obstruction take precedence over other interventions
What airway elements should be assessed in a emergency when a patient is intubated?
Ensure ETT is in the trachea and depth is at an appropriate level (etCO2, direct laryngoscopy)
- ventilate and observe chest rise
- EtCO2 and SpO2
- Auscultation of breath sounds
How do you evaluate if the patient is adequately being ventilated?
Observe chest rise and vital signs including EtCO2
- Auscultate
- Ventilator waveforms and data
- ABG/VBG
What are some concerns with aggressive manual ventilation?
Can result in increased mean airway pressure which = impaired venous return and = a decreased systematic blood pressure
- gastric distension
- Regurgitation and aspiration
What could hypotension if left untreated result in?
Decreased organ perfusion
What could inadequate perfusion of the brain result in?
Anxiety, confusion, unconsciousness
What could inadequate perfusion of the heart result in?
Dysrhythmias, ischemia, and/or infarct
What could inadequate renal perfusion result in?
Decreased urine output
What could cause hypothermia to occur intraoperatively?
Temperature loss due to processes of evaporation, conduction, radiation, and convection
What happens to the patients vitals when they are hypothermic?
Increase in HR and BP
- Oxygen consumption increases up to 5-6 times
- After a while, the body will fail to compensate leading to decreased BP and HR
During the perioperative period, what could cause patient temperature to increase?
Drugs like atropine or admin of blood products. Other cause would be:
- Fever/sepsis
- Active warming efforts by team
- underlying disease states such as thyrotoxicosis or malignant hyperthermia
What secondary tests could you assess from the patient?
- CBC
- INR
- aPTT
- ABG
- CXR
- ECG
- Glucose
- Electrolytes
- BUN/Creatinine levels
What is perioperative hypotension?
Mean arterial pressure [MAP] < 60 mmHg….usually caused by:
- Cardiac dysfunctions
- Decreased SVR
- Impaired venous return
- Decreased contractility
- beta blockers and calcium channel blockers could also lower BP by lowering cardiac output
Treatments for Perioperative Hypotension?
- Decrease anesthetic depth
- Support contractility (Inotropes)
- Treat dysrhythmia (Anti-arrhythmics)
- Treat Ischemia (Vasodilators, B blockers)
How do beta blockers treat ischemia?
They cause vasodilation
- By decreasing sympathetic activity, beta-blockers also cause vasodilation, leading to a reduction in peripheral vascular resistance.
What factors would decrease SVR perioperatively?
- Anesthetic agents
- Cardiac medications (ACE inhibitors, Milirone, A1 antagonists)
- Sepsis
- Allergic reaction
- Profound hypoxia
What are treatment options for decreased SVR caused during the perioperative period?
- Decrease anesthetic depth
- Decrease epidural infusion rate
- Vasopressor support
- Volume expansion
Factors that would cause impaired venous return during the perioperative period?
- NPO status
- Vomiting
- NG drainage/bowel prep
- Diarrhea
- Diuresis
Factors that would cause venous pooling during the perioperative phase?
- Gracie uterus
- Surgical retraction
- Insufflation compartment syndrome pressure
Factors that would cause elevated central venous pressure and intrathoracic pressure during the perioperative phase?
- High PEEP
- Hyperinflation
- Air trapping
- Tension pneumothorax
- Cardiac tamponade
- PE
Treatment options for impaired venous return caused during the perioperative period?
Relieve mechanical obstruction (reduce PEEP, heparin)
- volume expansion
What factors could cause new hypertension to occur after an existing hypertension is resolved?
- Noxious stimuli (tracheal intubation or pain)
- Hypercapnia/hypoxemia
- Fluid overload
Management for hypertension caused by: Pain?
Increased analgesia, general anesthesia
Management for hypertension caused by: Intubation
Sedation, analgesia to dull sympathetic response and induction
Management for hypertension caused by: fluid overload
Diuresis
Management for hypertension caused by: Hypercapnia
Increase minute ventilation
Management for hypertension caused by: Hypoxemia
Increase oxygenation
Why would coughs be considered a potential negative event during anesthesia?
Anesthesia prevents coughing, but the clearance of secretions still needs to occur (via suction of pharynx) in order to reduce chance of aspiration
Why does breath holding occur during anesthesia?
Usually noted during inhalation induction only, it is temporary and will disappear as anesthesia depends
What is Aspiration pneumonia?
Pneumonia associated with aspiration of food and gastric contents (Anaerobic bacterial infection)
- Can be missed due to the inflammatory reaction requiring 12-24 hours to peak
- Aspiration pneumonia patients are at increased risk of ARDS
3 distinctive forms of aspiration pneumonia?
- Toxic injury to the lung (chemical pneumonitis)
- Obstruction (by fluids or foreign bodies)
- Infection
How does aspiration lead to ARDS?
Aspiration of food (distinct from stomach acid) can lead to the formation of obilterative bronchitis (popcorn lung) and granuloma formation, as well as ARDS
Why could Nerve Injury occur during general anesthesia?
Increased risk of injury through stretch and compression
- pt lacks awareness of environment and lacks protective muscle tone
What nerves are at an increased risk of injury during general anesthesia?
- Brachial plexus
- Ulnar
- Radial
- Peroneal
- Facial Nerves
what are signs of Malignant Hyperthermia during general anesthesia?
Sudden onset of hypermetabolism after induction using halogenated agents
What is the underlying mechanism that could cause Malignant Hyperthermia?
Abnormal Ryanodine Receptors
- They release calcium from the sarcoplasmic resulting in uncontrolled muscle contractions and increased aerobic and anaerobic metabolism —> Resulting in a steep increase in lactic acid —> metabolic acidosis
- As resultant muscle membranes breakdown, potassium is released from muscle cells leading to hyperkalamia
Early signs of Malignant Hyperthermia?
- Masseter muscle rigidity
- Tachycardia
- Hypercarbia
- Tachypnea when muscle relaxation is not present\
- Hyperthermia is a late sign with core temperature increasing as much a 1 degree Celsius every 5 minutes.
What vitals/lab data/primary assessments could you as signs to identify Malignant Hyperthermia?
- Sympathetic activity?
- Increased O2 consumption
- Metabolic acidosis
- Cyanosis
- Increased sympathetic activity; Increased HR,BP; Arrhythmias; muscle damage
What is Malignant Hyperthermia Protocol? (8)
- Discontinue volatile anesthetic and succinylcholine
- Hyperventilate patient w/100% O2
- Sodium bicarb (1-2 meq/kg)
- Dantrolene admin 2.5 mg/kg IV
- Institute cooling measures
- Inotrope and antidysrhythmics prn
- Monitor urine output, potassium, calcium, ABG, etCO2, clotting studies
- Invasive monitoring w/arterial and central lines
What is Dantrolene?
Primary drug used to treat malignant hyperthermia
- Ryanodine receptor antagonist
- A post sympathy muscle relaxant; inhibits calcium release from sarcoplasmic reticulum
What is the drug dose for Dantrolene admin?
2.5 mg/kg IV
For Malignant Hyperthermia, are there any contraindications for Dantrolene
No contraindications, but it is worth noting there is no reversal agent for Dantrolene
