Respiratory.docx

Airway assessment - Hx - General appearance - NPO status - Airway screening tests = assess difficult airways... but most difficult airways are unanticipated - Mouth opening - Dental assessment anything that's loss chipped or broken can end up in the lung -...

Airway assessment - Hx - General appearance - NPO status - Airway screening tests = assess difficult airways... but most difficult airways are unanticipated - Mouth opening - Dental assessment anything that's loss chipped or broken can end up in the lung - Inter-incisor distance - Mallampati how much space do you have to work with to intubate - Thyromental distance (TMD) - Mandibular mobility (ULBT) - Atlantoocciptal function - LEMON - Hyoid-mental distance - Mandibular protrusion test - Upper lip bite test - Our emergency airway is a cricoidthotomy - Airway AP - Upper respiratory tract - Nose, mouth, pharynx, hypopharynx, larynx, cricoid cartilage - Larynx - **9 cartilages of larynx** - **3 paired** - **3 single** - Lower respiratory tract - Everything beneath the cricoid cartilage - Trachea, bronchi, bronchioles, alveoli - Anesthesia view - Hard palate = made of bone - Soft palate = made of muscle - **Make sure you can recognize structures** - Tonsillar enlargement and adenoid hypertrophy - Congenital abnormalaities - Pierre-Robin - Underdevelopment and recessed chin - Goldenhar's syndrome - Hemifacial macrosomia - Mandibular hypoplasia - Cervical spine abnormality - Veterbrae may be incomplete, fused, or missing - Klippel-Feil - Fusion of 2+ cervical vertebrae - Short/no neck - Treacher-Collins - Mandibular hypoplasia and micrognathia - Choanal atresia -- nasal passage blocked by either bone or soft tissue - Cleft palate - Facial bone hypoplasia - Down syndrome - Micrognathia (small jaw) - Macroglossia (enlarged tongue) - Narrow palate - Large and thick lip - Flattened nose - Small ears - Cervical spine abnormalities - Small subglottic diameter - OSA - Dental abnormalities - Mucopolysaccharidosis - Turner syndrome - Only affects females - Reduced neck mobility - Neck webbing - High arched palate - Mandibular hypoplasia - Short stature - Delayed puberty - TMJ contracture - Short trachea - Acquired conditions - Obesity - **Be familiar with BMI and how to calculate it and what normal is** - GLP-1 agonists and anesthesia - Slow gastric motility - ASA suggests withholding the medication before elective surgery - Obstructive sleep apnea - Increased risk for difficult or failed intubation - STOP-BANG questionnaire used to assess pts risk for OSA - Polysomnography is the gold standard for diagnosis - High risk if yes to 3 or more questions - Low risk if yes to less than 3 questions - In peds -- can be caused by enlarged tonsils or adenoids - Anesthetic considerations - Consider regional techniques when possible - Utilize non-opioid adjunct - Use shorter acting medications - Inspire = implanted stimulated device - TMJ -- also causes trismus - Infections - Ludwig's angina -- can cause trismus (can't open mouth) - Oral and retropharyngeal abscesses - Epiglottis -- thumb sign on x-ray = epiglottis looks like a thumb - Croup - Laryngeal papillomatosis - Angioedema - Benign masses - Rheumatoid arthritis - Many airway abnormalities - Ankylosing spondylitis = abnormal stiffening and fusion of airway - Airway tumors - Radiation therapy - Face/neck/airway trauma - Acromegaly -- caused be excess secretion of growth hormone - Macroglossia - Prognathism - Vocal cord swelling - Enlarged face, hands, nose, and lips - Gigantism = difference between acromegaly is gigantism when it occurs before development of long bones - Mouth opening - Normal value \>5 cm (at least 3 fingers) - Dental assessment - We typically remove dentures - Mallampati = assess mouth opening, size o tongue, size of oropharynx, and visual of posterior oropharyngeal structures - Class I-VI -- class I is best - PUSH acronym in apex anesthesia - Grade 1: Faucial Pillars, Uvula, Soft palate, Hard palate: PUSH - Grade 2: Uvula, Soft palate, Hard palate: USH - Grade 3: Soft palate, Hard palate: SH - Grade 4: Hard palate only: H - **Mallampati pics will be tested** - Should be performed with pt in sitting position - Thyromental distance = measurement of anterior mandibular space - Thyroid cartilage to chin - Normal is 6 cm - Mandibular protrusion test - Upper lip bite test (ULBT) - Sternomental distance = sternal cartilage to chin - Atlanto-occipital joint extension - Prayer sign - Assess joint mobility -- mobility of joints in hand indicate mobility of structures in the airway - Palm print - Assess joint mobility -- mobility of joints in hand indicate mobility of structures in the airway - 3-3-2 Rule - LEMON assessment - Look - Evaluate 3-3-2 rule - Mallampati - Obstruction - Neck mobility - MRI, CT, and ultrasound can be used to evaluate the airway - Can use POCUS to ID airway structures -- think ID cric for emergencies - Predictors of difficult mask ventilation -- pick one to memorize - Ramping to align airway for direct laryngoscopy - Cormack and Lehane Grading System - Difficulty with BVM - Poor mask seal due to beards or NG - Airway obstruction - Obesity - Age \>55 - No teeth - Stiff lungs - Sleep apnea or snoring - Difficulty with intubation - Difficulty on external assessment - 3-3-2 - Mallampati score 3 or 4 - Obstruction of upper airway - Obesity with increased neck circumference - Scarring, radiation, or masses on neck - Neck mobility impaired by disease of immobilization - Operator experience - Difficulty with supraglottic airway - Restricted mouth opening - Obstruction of upper airway - Distortion of upper airway - Stiff lungs - Difficulty with cricothyrotomy - Distortion of neck anatomy (e.g. hematoma, infection, tumor, scarring, etc) - Obesity - Short neck - Impediments causing limited access to neck - Surgery causing limited access to anatomic landmarks - Functional anatomy of airway - Airway tissues are highly vascular and innervated - Upper airway gas flow - Airflow is directly proportional to the pressure gradient and inversely proportional to the resistance - **Resistance = 8xlength x (viscosity/pi) x radius\^4** - **Look into how changes to radius affects resistance** - Laminar flow -- function of viscosity of gas - Turbulent flow -- function of density of gas - Reynold's number - \2000= turbulent - Functions of the upper airway - Condit for inhalation and exhalation of air - Nasopharynx and posterior pharynx warm and humidify inspired gases - Mucous membranes hydrate tissues, trap particles - Turbulent airflow potentiates trapping on inhaled particulate matter - Tracheal and bronchial structure - Trachea originates at the cricoid cartilage - Longer in men than women - Terminates at the bifurcation aka carina - Right mainstem is wider and more vertical than the left - **Right upper lobe bronchus gives off 3 segmental bronchi** - Tracheal bronchial generations - At level of bronchiole, airways lose all generations - First 15-16 generations serve the purpose of ventilating/moving air - Last 8 generations are for respiration/gas exchange - Alveolus = where the respiratory and vascular connect - Each acinus (berry-shaped cluster of cells) includes multiple alveolar ducts with alveoli - Alveolar cells - type 1 squamous epithelial -- allow gas movement - type 2 surfactant -- produce surfactant to decrease surface tension so even small alveoli open easy - alveolar macrophages -- phagocytize foreign materials - Pre-op assessment - Goal = plan implementations to improve outcomes - Functional assessments = respiratory mechanics, gas exchange, cardiopulmonary interaction - Quality of life - Exercise tolerance - Pulmonary function testing when indicated - Lung volumes and capacities - **Spirometry can give all volumes except FRC, TLC, RV** - **This is because you can't measure RV i.e. what's left over after ERV** - Respiratory mechanics - Preop tests correlate with post-thoracotomy outcomes - FEV1 - FVC - Max minute ventilation - RV/TLC - Diffusing capacity for CO (DLCO) - DLCO -- best test for determining the surface area for gas exchange - CO more attracted to Hgb than oxygen - Maximum oxygen consumption - VO2max is the most useful predictor of post-thoracotomy outcome - 6 min walk test correlates with VO2max - No single test can serve as a good pre-op assessment, but you should assess the following - Lung mechanics - Parenchymal function - Cardiopulmonary interaction - Acute upper respiratory infection (URI) - Sx non-productive cough, sneezing, rhinorrhea - Bacterial infections usually have more severe sx - Dx is based on clinical signs and sx - Children with URI are at increased risk of transient hypoxemia and laryngospasm - Factors include copious secretions, prematurity, second-hand smoke exposure, reactive airway disease, endotracheal intubation, airway procedures - Fever, purulent rhinitis, productive cough, and rhonchi are signs of considerable risk of adverse events - Airway hyper-reactivity may take 6+ weeks to resolve - PPV could drive infection lower into pulmonary tree - Mask or LMA is preferred over ETS - Ensure adequate hydration, reduce secretions, avoid manipulation of airway - Asthma = chronic inflammatory disease characterized by obstruction of the airways and is reversible with treatment/spontaneously - What differentiates from COPD is reversibility - Pts with mild, well-controlled asthma are at no increased perioperative risk - Medications = B2 agonists, steroids, antibiotics - Routine testing not indicated preoperatively unless a severe exacerbation is occurring - ET intubation with light anesthesia will likely provoke wheezing and increased airway resistance - COPD = persistent obstruction of airflow with occasional partial reversibility - Severity based on FEV1/FVC ratio = resistance to outflow - FEV1 reduced due to obstruction - FVC increased -- pathologic change due to air trapping so reduced airflow, lost elasticity, and overexpansion - Often the result of smoking, pollutants, chronic infections, long-standing asthma, A1 antitrypsin deficiency - Destruction of tissue surface area that is responsible for gas exchange -- DLCO is reduced - Chest x-ray indicated if infection or bullous disease - Obtain baseline SPO2 - Pulmonary HTN - RBB, peaked p waves, Right axis deviation - Restrictive disease -- characterized by reduced lung capacity - Pulmonary causes = idiopathic interstitial pneumonia, lung resection, pulmonary fibrosis, interstitial lung disease d/t connective tissue disease - Extrapulmonary - Chest wall abnormalities - Muscle or neuromuscular dysfunction - Pleural disease - Chest x-rays and PFTs may be valuable for diagnosis or assessing worsening of disease - FEV1/FVC is normal because both are reduced - Obesity -- most common restrictive disease - Associated with decrease in all lung volumes due to weight of the abdominal contents of chest wall - Decrease in FRC increases the tendency to desat during anesthesia - PEEP can eliminate atelectasis in morbidly obese - Interventions -- minimize things that compromise FRC - Elevate head during emergence of anesthesia to assist in FRC increase - OSA = intermittent airway obstruction \>10 secs - Severity based on apnea-hypoapnea index - STOP Bang questionnaire to evaluate preoperatively - CV disease is common - Airway management may be more difficult including mask ventilation, direct laryngoscopy, and ET placement - More sensitive to respiratory depressant effects of opioids - Pulmonary hypertension - Persistent increase of mean PAP\>25 with PAOP\>15 - Moderate to severe disease increases the risk of right-sided heart failure - Dyspnea is the presenting symptom in 60% of patients and symptomatic in 98% of diagnosed patients - Causes intrinsic vasoconstriction or mitral valve stenosis - EKG changes = right heart strain, p pulmonale, p mitrale - Mild disease does not influence anesthetic management but exercise extreme caution in these patients - Don't give drugs that increase pulmonary vascular resistance - Smoking - it's not the nicotine that is bad... it's the other things -- carcinogens, CO (which blocks O2 from binding to Hgb), etc - cessation should occur 3-4 weeks before surgery - Decreases macrophage function - Impairs coronary blood flow - Provokes ischemia - Causes vascular endothelial dysfunction - Provokes HTN - Increases wound infections, respiratory complications, increases length of stay and time in ICU - Risk of pulmonary complications - History or current cigarette use - ASA -- 2+ - Albumin \< 35 g/dL -- poor nutrition - COPD - Procedures on the neck, chest, upper abdomen, aorta, neuro - Surgery 2\>hours - GETA - Poor exercise tolerance - BMI\>30 - Dyspnea = subjective experience of breathing discomfort - Need to determine - Onset - Progression - Precipitating factors - Associated symptoms - Associated conditions - Schamroth sign = clubbing of fingers **Exam 1 respiratory + neuro** **Use study questions as a study guide** **Neuro** **5 nerve roots** **Know sensory and motor evaluation of each nerve e.g. what does the axillary nerve do? What does it sense?** **Know sensory of other 3 nerves mentioned in** **Know assessment for sciatic nerve = step on gas and point toes**