NBRC Study Guide (National Board of Respiratory Care): Essential Exam Prep Questions, Exams of Medicine

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NBRC Study Guide (National Board of Respiratory Care): Essential Exam Prep Questions The four steps for respiratory mgmt - \1. tx *ventilation *first (should problem exist) 2. *oxygenation* 3. *circulation* 4. *perfusion* problems at one step will adversely affect each process that follows it within sequence External respiration vs. Internal respiration - \External = exchange of O2 and CO2 across AC membrane - depends on diffusion capacity of AC membrane & ventilation Internal = exchange of O2 & CO2 across blood and tissue cells - depends on circulation Signs vs. Symptoms - \*Signs = Objective information*; can be seen, measured, heard, or felt - Color, pulse, edema *Symptoms = Subjective information* - Dyspnea, pain, nausea Steps in Assessment: - \1. *Visual examination* - General appearance, sensorum, chest movement, posture, skin color 2. *Bedside exam* - BS, VS, auscultate, percussion, PMH, cap refill 3. *Lab exam * - ABG, CBC, CXR, lytes 4. *Specials* - urinalysis, gram stain, MIP, VC Skin Appearance - color - condition - \- *Normal:* Race specific - *Decrease in color* = ashen, pallor → anemia, blood loss - *Jaundice: *↑ bilirubin levels → liver failure - *Erythema: *Redness of the skin → *hypercarbia, COHb, inflammation* - *Cyanosis: *Bluish → Hypoxia (this is a poor assessment of hypoxia bc it shows up late! Only appears after 5 gram% of Hb is desaturated...) - *diaphroesis:* sweating - *turgor*: slowed response shows dehydration → either through hypernatremia or/and hypovolemia Smoking history - Calculating Pack-year - Verifying if pt is compliant w/smoking cessation program - \Pack Years = *(packs per day) x (# years smoked)* Measure pt's COHb to see if they actually are quitting smoking COHb be levels should ↓ from their baseline to non-smoking normals of < 1% Terms for Describing Sensorium/Neuro (LOC) - Conscious - Confused - Disoriented - Lethargic - Obtunded - Stuporous - Comatose - \- *Conscious*: alert to time, place, and person; responds appropriately -* Confused: *can't think clearly, responds inappropriately -* Disoriented: *disoriented to time/place; starting loss of conscience -* Lethargic: *sleepy, but will wake; still oriented (can be early sign of increased ICP) -* Obtunded:*hard to wake; slowed response but appropriate - *Stuporous: *doesn't awaken completely; only responds to painful stimuli - *Comatose*: unconscious; doesn't respond to any stimuli Glasgow Coma Scale (GCS) - \To measure level of consciousness (LOC) *Eye opening:* spontaneous 4, in response to voice 3, respond to pain 2, none 1 *Verbal response:* oriented 5, confused 4, inappropriate words 3, incomprehensible words 2, none 1 *Motor response:* obeys commands 6, localizes 5, withdraws 4, flexes (decorticate) 3, extends (decerebrate) 2, none 1 • > 13 minor impairment - Bronchial - Vesicular Adventitious (abnormal) Breath sounds: - Diminished - Wheezes & Stridor - Crackles - rhonchi - Pleural friction rub - \NORMAL BS: • *Bronchial* - heard over tracheobronchial tree (tubular) • *Vesicular *- peripheral sites ADVENTITIOUS BS: • *Diminished*: When sound intensity is reduced • *Wheezes*: narrowed LOWER airway • *Stridor*: narrowed UPPER airway - supraglottic swelling = epiglottitis - subglottic swelling = croup • *Crackles* (rales): Secretions/fluid or atelectasis - O2, PPV, lasix (fluid), sxn, DB&C • *Rhonchi*: coarse version of crackles; secretions - sxn & DB&C • *Pleural Friction Rub*: coarse, grating raspy sound Lung Percussion - \Normal lungs = *resonant* - low pitched sound, heard easily Flat, Dull, *decreased resonance *= atelectasis, fluid-filled, pneumonia, or tumor *Hyperresonant, tympanic *= pneumothorax Tactile fremitus - \Vibrations created by the vocal chords echoing through the chest wall -* Increased: *Secretions, consolidation, inflammed -* Decreased: *Hyperinflation, pleural effusion Crepitus - \Palpating bubbles of air under the skin bc air has infiltrated areas where it shouldn't be normally - subcutaneous emphysema - associated with injury, tears, or insults bc the air has to go somewhere, and it gets under the skin Sputum induction & use of Luken's Trap (sterile suction trap) - \- Ultrasonic nebulizer can induce pt to cough up a sputum - IPV (brand: MetaNeb) - Have pt inhale bland aerosol (containing sterile water or NS) or hypertonic saline Trapped in Luken's trap to collect specimen for C&S Describing Sputum - amount - consistency - color & interpretation - \• AMOUNT: *scant, small, moderate, large, copious* • CONSISTENCY:* thin, thick, tenacious* • COLOR & INTERPRETATION: - *Mucoid (white/gray): *Chronic bronchitis - *Yellow: *Bacterial infections -* Green: *Gram negative bacteria; bronchiectasis -* Brown/dark: *Old blood, serious lung infection, smoker - *Bright red: *Hemotysis - *Pink frothy: *Pulmonary edema Acid-fast testing - \Used after a gram stain to detect *mycobacterium TB* Anemia vs. Polycythemia - \*Anemia:* - decreased concentration of Hgb - Give O2 support until transfusion is complete *Polycythemia: * - abnormally increased concentration of Hgb (either bc ↓ plasma volume or ↑ RBCs) Polycythemia & anemia will have normal SpO2! What about ABG???? Hemoglobin (Hb) vs. Hematocrit (HCT) - \Hgb: Female: 12-16 gm% Male: 13-18 gm% HCT: Female: 36-48% Male: 39-55% (gm% = gm/dL of blood = gm/100mL of blood) Leukocytosis vs. Leukopnea - \- *Leukocytosis* = Excessive WBC - *Leukopnea *= Deficient WBC Complete Blood Count (CBC) lab - White Blood Cell (WBC) - Red Blood Cell (RBC) - Platelet count - \WBC = 5,000-10,000 / mm³ WBC= INCREASE bacterial infection ( Recommend antibiotics) WBC= DECREASED Viral infection RBC = 4-6 million/mm³ Platelets = 150,000-400,000 / mm³ Eosinophils - \increase with allergic reactions & asthma - normal = 1-6% Electrolyte lab (BCP): Normals for... Blood Glucose, K⁺, Na⁺, Cl⁻ - \BCP = Blood Chemistry Profile *Blood Glucose (BGL): 70-99 mg/dL* *K⁺: 3.5-4.5 mEq/L* - hypokalemia, hyperkalemia *Na⁺: 135-145 mEq/L* - hyponatremia, hypernatremia *Cl⁻: 95-105 mEq/L* - hypochloremia, hyperchloremia Creatinine - normal values - what is it - abnormal values indicates... - \0.6-1.5 mg/dL • waste product of muscle metabolism • direct relation to amount of muscle mass (∴ men have higher levels) •* best measurement of KIDNEY f(x) *(better test for renal failure than BUN) • ↑ levels show chronic renal insufficiency or obstruction of urinary tract •* ↓ levels may indicate malnutrition* • Abnormal significant pulmonary disease > 20% • Life threatening > 30% Shunt disorders: • cardiac (Tetralogy of Fallot, ASD or VSD)???? why • vessels (patent ductus arteriosus PDA) • pulmonary (pneumothorax, hemothorax, pleural effusion) VD/VT - what is it - equation - normal / abnormal values - \*Deadspace Ventilation *(ventilation s perfusion): Bohr Equation = *(PaCO2 - PeCO2) / PaCO2* *Normal: 20-40% * -*Anatomical Vd = 1 mL/lb of IBW* Acceptable: ≤ 60% for ventilator pts Unacceptable: > 60% Anatomical Deadspace vs. Alveolar Deadspace vs. Mechanical Deadspace - \• *Anatomical Deadspace *= Amount of the inspired VT that does not enter the alveoli • *Alveolar Deadspace *= Amount of alveolar ventilation that has no blood perfusion • *Mechanical Deadspace* = Also amount of VT that doesn't make it to alveoli bc of excess tubing, HME, etc Alveolar Volume (VA) vs. Alveolar Minute Ventilation (V°A) Example: Calculate VA and V°A if pt weighs 130 lbs IBW. There's 20 mL of added mechanical Vd. Pt's Vt is 300 mL with Ftot of 15. - \*Alveolar Volume (VA) = Vt - VDmech - VDanatomic* 300 - 20 - (130) = *150 alveolar flow* • bc 1 lb of IBW = 1 VDanatomical *Alveolar Ventilation (V°A) = VA x RR* 150 x 15 = *2250 mL/min alveolar ventilation* Blood Pressure drugs / Three Pronged Method to tx Heart Failure: - heart - blood/fluid - vessels - \Heart, blood/fluid, vessels are 3 factors that ctrl BP... Three Pronged method to tx heart failure... *Heart:* - Chronotropic drugs (Atropine) to ↑HR - β blockers/β antagonsits (end in "lol") block vasoconstriction & anti-rhythmic - *positive inotropes to ↑ FOC* *Blood/Fluid: *Use *diuretics* (lasix) to ↓ fluids to ↓ preload by removing Na & H2O *Vessels* (vasodilators): - *ACEi *(end in "pril") dilates arteries & veins - *dilate arteries *to ↓ afterload (hydralazine, Ca channel blockers) - *dilate veins *to ↓ preload (nitrates) ECG: Tachycardia - \HR ≥150 BPM If symptoms persist... - Adenosine if narrow QRS - sedate & synchronized cardioversion - β-blocker or Calcium channel blocker - Vagal maneuvers ECG: Bradycardia - \HR < 50 BPM If symptoms persist... - Atropine - Trancutaneous pacing - Dopamine IV - Epinephrine IV ECG: 1st degree heart block - \Long PR intervals tx: Antiarrhythmics - Procainamide - Amiodarone - Sotalol ECG: 2nd degree heart block (Mobitz type 1 / Wenckebach) - \PQ gets longer and longer until QRS is dropped tx: Antiarrhythmics - Procainamide - Amiodarone - Sotalol ECG: 2nd degree heart block (Mobitz type 2) - \Long PR interval of equal length with random QRS dropped tx: Antiarrhythmics - Procainamide - Amiodarone - Sotalol ECG: 3rd degree heart block - \P and QRS waves are completely disjointed; P waves has its own rhythm and so does QRS tx: Antiarrhythmics - Procainamide - Amiodarone - Sotalol ECG: Atrial flutter - \Sawtooth; distinct QRS though ECG: Atrial fibrillation - \P wave quivers randomly; less sawtooth; distinct QRS though ECG: Premature ventricular contractions (PVC) - \Random big lumps - can be unifocal or multifocal tx: Antiarrhythmics - Procainamide - Amiodarone - Sotalol ECG: Ventricular tacycardia (Vtach) - \*Pulse present: *Sedate & synchronized cardiovert @ 100J (for wide & regular) *Pulseless: *Defibrilate, CPR - Epinephrine 1mg, Amiodarone 300 mg then 150 mg ECG: Ventricualr fibrillation (Vfib) - \*ALWAYS PULSELESS* Defibrillate, CPR - Epinephrine 1 mg, Amiodarone 300 mg then 150 mg ECG: Asystole - \Confirm in 2 leads first & check gains - CPR, Epinephrine ECG: Pulseless Electrical Activity (PEA) - PP = Systemic - diastolic (120-80 = 40) Systemic Vascular Resistance (SVR) vs. Pulmonary Vascular resistance (PVR) !!!!!! - \SVR = 80-1600 dynes x sec x cm⁻⁵ PVR = 20-200 dynes x sec x cm⁻⁵ What to do when there's abnormal heart sounds? - \Recommend echocardiogram (echo) Electrophysiology of the heart - \SA node (pacemaker): Atrial depolarization QRS complex: Ventricular depolarization & Atrial Repolarization T wave: Ventricular Repolarization Ischemia vs. Infarction - \*Ischemia = Reduced blood flow to the tissue*, which can lead to pain • EXAMPLE: Myocardial Ischemia (MI) = heart attack - Inverted T-wave - Injury is indicated w/elevated ST segment - Infarction w/significant Q waves - Right axis deviation (RAD) - Occurs in left ventricle ???? only *Infarction = the end point of this ischemia that results in death of tissue *due to absent blood supply Sublingual nitroglycerin - \for chest pain due to coronary artery disease Ways to measure Cardiac Output (CO)? - \1. *Thermodilution* 2. *Green Dye Method* 3.* Fick's Equation* • the only one of the three that CALCULATES Qt • Qt = [VO2 / (CaO2-CvO2)] x 100 • Normal: 4-8 LPM Cardiac index - Equation - Normal - Why important? - \CI = *CO / body surface area* = (SV x HR) / BSA Normal =* 2.5-4.0 L/min/m²* • this is a more accurate measure than CO bc takes into account body size CaO2 vs. CvO2 - \*Arterial oxygen content (CaO2)* • Normal CaO2 = *17-20 vol%* (20) *CaO2= (Hb x 1.34 x SaO2) + (PaO2 x 0.003)* • 1st part of equation: O2 in RBC • 2nd part of equation: O2 in plasma *Venous oxygen content (CvO2)* • Normal CvO2 = *12-16 vol%* (15) • CvO2 and SvO2 values ↓ when Qt ↓ *CvO2= (Hb x 1.34 x SvO2) + (PvO2 x 0.003)* Ca-vO2 - \Arterial minus venous oxygen content *C(a-v)O2 = CaO2 - CvO2* - normal = 4-5 vol% - greater difference when CvO2 is decreasing ∴ indicating a ↓ CO - plays a part in calculating VO2 Oxygen Consumption (VO2) vs. Carbon Dioxide Production (VCO2) - \Oxygen Consumption: *VO2 = Qt x (Ca-vO2)* - *normal = 250 mL/min* - ↑ VO2 = ↑ metabolism or CO Carbon Dioxide Production: - *normal = 200 mL/min* Respiratory quotient (RQ) !!!! - \RQ = VCO2/VO2 Normal: 0.8 ???? Range: 0.67-1.3 Perinatal history - what should be taken - gravidity vs parity vs abortus - \Pregnancy hx, age, smoking & EtoH abuse, nutrition, infection, HTN/toxemia • *Gravidity *= # of times pregnant, regardless of whether made it to term • *Parity *= carried to viable gestational age • *Abortus* = pregnancies lost for any reason Gestational age - normal gestation - preterm, post-term dates - viability of life - \• After 42 weeks = Post-term • *38-42 weeks = Term gestation* • Before 38 weeks = Preterm *Viability of life @ 22-24 wks* (bc Type II cells develop ∴ surfactant begins to be made) L/S Ratio - \Amount of Lecithin (dipalmitoyl phosphatidylcholine) sphingomyelin found in the amniotic fluid / surfactant *2:1 or higher = Mature lungs* (more lecithin) • less than 2:1 shows increased risk of RDS Dubowitz and Ballard method of determining Gestational age - \Assess 7 physical & 6 neurological criteria: Normal maturity rating = 40 < 35 pre-term > 45 post-term APGAR Score - \Airway, pulse, grimace, appearance and response for NEONATES • taken @ 1, 5 min (& 20 min if necessary) • > 7-10 normal: Monitor • 4-6 abnormal: Stimulate, O2, and assist vent • 0-3 emergency: Resuscitate CPR You are assessing the one minute APGAR score for a newborn. She is pink all over and has a pulse of 130. As you dry her off she begins to cry vigorously and kick her legs. Her APGAR score is? 10 - more hazy than PA view, but used when pt is not able to get out of bed • *lateral view:* - excellent view of lung bases •* lateral decubitus view:* (laterally through the chest w/pt *lying down*) - used to see if pleural fluid (white) present Patient lying on the affected side Tracheal deviation - \- If pathology occurs INSIDE the lung: Deviation TOWARD pathology - if pathology occurs OUTSIDE the lung: Deviation AWAY from pathology Position of endotracheal (ETT) or tracheostomy on CXR - \• Below the vocal chords • *3-6 cm above carina* • At the level of the aortic aortic arch • *T2-T4* Head-tilt chin lift vs. Jaw Thrust - \Both methods used to open an airway for CPR But Jaw thrust is used when there's a suspected neck or spinal fracture Oral Pharyngeal Airway (OPA) vs. Nasal Pharyngeal Airway (NPA) - \OPA: - Unconscious patients - Inserted upside down to back of throat then rotated - measured from tip of nose to corner of jaw NPA: - Conscious patients - Changed every 24 hrs. (to prevent epitaxis) - insert with lubricant - measured from tip of nose to tragus + 2cm Sellick maneuver - \Push on cricoid to decrease risk of aspiration & to help visualize the vocal cords when intubating Laryngoscope blade sizes - \Pre-term: 0 Term infant: 1 Pediatric: 2 Adult: 3 Endotracheal tube sizes - \Pre-term infants: 2.5-3.0 Full-term infants: 3.0-3.5 Adult males: 8.0-8.5 Adult females: 7.0-7.5 Evidence of difficult airway - \- Short receding mandible - Enlarged tongue (macroglossia) Magill forceps - \Used for nasal intubation If the light on the laryngoscope doesn't work, what should you do? - \- Tighten bulb (some bulbs are on the handle rather than the blade) - Change blades - Check batteries Endotracheal tube changers ????? is this the actual name - \Airway exchange catheter A small diameter that acts as a stylet Laryngeal mask airway - \A supraglottic airway device - allow for blind insertion - reduces gastric distention - alternative to BVM ventilation Carlen's tube !!!!!!!!! - \Double lumen endotracheal tube Endobronchial tube A tube with two independent lumens used for double ventilation of both lungs Combitube - \A blind insertion airway device to provide an airway for mechanical ventilation ???? why important? King airway !!!! - \Supraglottic airway device that uses two seals that creates a patent seal at the esophagus and pharynx ???? why important? Tube distance & size for... - Oral intubation - Nasal intubation - \Oral intubation: • FEMALE = 7.0-8.0 → 19-23 cm • MALE = 7.5-8.5 → 20-25 cm Nasal intubation = 26-29 (high 20's) Assessment of tube position after intubation - \1. Look for bilateral chest expansion 2. Fogging in the ETT 3. Easy bagging 4. Use EtCO2 colorimetry detector "Easy Cap" turn purple (problem) → yellow (yes) 5. CXR shows ETT 3-6cm above carina or at the aortic knob/notch (best indicator) Cuff pressure - don't exceed what pressure - Minimum Leak Technique (MLT) vs. Minimum Occlusion Technique (MOT) - \Do NOT exceed... *20-25 mmHg* *27-34 cmH2O* *Minimum Occlusion Technique (MOT):* - while listening over suprasternal notch or lateral neck, inflate cuff just until no leak is heard at end-inspiration *Minimum Leak Technique (MLT):* - same as MOT but then remove a little bit of air until leak can be heard - to *prevent TE fistula *or impede blood flow to trachea; but then you *can get micro aspirations *→ which can develop into pneumonia Vacuum pressure for suction - \Adult: 100-150 torr Child: 80-100 torr Infant: 60-80 torr Continuous aspiration of subglottic secretions (CASS) tubes - \Sxn tube incorporated just above the cuff ( ie: Hi-Low Device) TX: lasix Types of noncardiogenic pulmonary edema - \acronym: NOT CARDIAC - Near drowning - O2 toxicity - Transfusion or Trauma - CNS disorder - ARDS, Aspiration, or Altitude sickness - Renal issue or Resuscitation - Drugs - Inhaled toxins - Allergic alveolitis - Contrast or Contusion Atelectasis - CXR - S&S - tx - \CXR: patchy infiltrates, plate-like, crowded pulmonary vessels, scattered S&S: diminished BS, WOB TX: Lung expansion therapy (SMI, IPPB, CPAP, PEEP, lung recruitment maneuver), good lung down for better perfusion - first ↑ PEEP for alveolar recruitment rather than ↑ FiO2 for oxygenation CXR: Alveolar disease ???? elaborate - \Infiltrates, air bronchograms CXR: CHF ???? - \Increased vascular markings Increased heart size Acute Respiratory Distress Syndrome (ARDS) - CXR - S&S - tx - \CXR: ground glass, honeycomb pattern, diffuse bilateral radiopacity S&S: refractory hypoxemia, WOB, tachypnea, tachycardia tx: APRV, ARDS net → low Vt or PIP, high PEEP, high RR, high FiO2, *prone pt*, allow permissive hypercapnia Tuberculosis (TB) - CXR - S&S - tx - diagnosis - \CXR: cavity formation (often in upper lobes) S&S: hemoptysis, ????? tx: antitubercular agent diagnosis: Manatoux test???? Pleural Effusion - CXR - S&S - tx - \CXR: blunting of costophrenic angle, basilar infiltrates w/meniscus, possible mediastinal shift to unaffected side S&S: WOB ???? tx: thoracentesis → chest tubes, antibiotics, steroids Pneumonia - CXR - S&S - tx - \CXR: consolidation & atelectasis S&S: yellow/green sputum, dyspnea tx: antibiotics, good lung down for better V/Q match COPD - normal ABG - tx - breathing techniques - \ABG shows *compensated chronic respiratory acidosis with hypoxemia and elevated HCO3*(example: 7.36,62,58,36) Allow for permissive hypercapnia w/ nasal cannula O2 @ 1-3LPM Breathing techniques: - Pursed lip breathing - Diaphragmatic breathing training Pulmonary Embolism (PE) - CXR - S&S - At risk pts - diagnosis - tx - \CXR: may be normal or atelectasis, rarely see westermark's sign (dilation of pulm arteries close to PE) S&S: sudden refractory hypoxemia & WOB, sudden ↓ in EtCO2 but ↑ PaCO2, tachycardia, hyperpnea, ↑ Vd Pts at risk: Post op, bedridden, DVT Hx, 3rd trimester, venous stasis, obesity, varicose veins, trauma, Afib Diagnosis: CT, pulmonary angiogram, ventilation/perfusion scan, ultrasound Tx: heparin, embolectomy, thrombolytics, support ventilation & oxygenation Thrombolytic agents - \Streptokinase, tissue plasminogen activator (tPA), reteplase, anistreplase, urokinase (ends in "-kinase" or "-plase") Pneumothorax - CXR - S&S - tx - \CXR: visible visceral pleural edge seen as very thin, sharp line (but no lung markings are seen peripheral to this line), tracheal deviation AWAY, radiolucent; vascular markings absent, heart/mediastinum shifts AWAY from injury if tension pneumothorax S&S: dypsnea, tachycardia, hypotension, JVD, pleuritic chest pain, hyperresonant, tx: thoracentesis → chest tube Transillumination - \Done when pneumothorax is suspected If + for pneumo, a light halo will appear around the point of contact Peak Expiratory Flow Rate (PEFR) - Obstructive Disease vs. Restrictive Disease - \*OBSTRUCTIVE *= issues getting air *OUT* due to airways (FACE B-itis) - Foreign body obstruction - Asthma - Cystic fibrosis - Emphysema (& bronchitis → COPD) - Bronchiectasis - Ends in "-itis" for inflammation [Laryngotracheobronchitis (LTB or croup), Epiglotittis, Bronchiolitis (RSV)] *RESTRICTIVE *= issues with lung expansion / unable to take a deep breath - Fluidy & collapse (Pneumonia, Pulmonary edema, Atelectasis, ARDS) - TB - Fungal infections (histoplasmosis, blastomycosis) - PE - Flail Chest - Dealing w/Pleura (Pleuritis, Pneumothorax, Pleural Effusion, Hemothorax, Hemopneumothorax, Empyema) - Kyphosis, scoliosis - Obesity - Neuromuscular conditions (ALS, GB, MG, MS) - Ascites Maximum inspiratory pressure (MIP, NIF, NIP) vs. Maximum Expiratory Pressure (MEP) - \*MIP Normal *= -80 to -120 cmH2O - *Critical Care = 0 to -20 cmH2O* - Used to assess the readiness to wean pt off vent *MEP Normal *= 160 cmH2O - the greatest pressure of expired air achieved after a full inspiration DLCO - function - normal - describe test - \To measure diffusion capacity • Normal = 25 mL/min/mmHg 1. pt takes a big breath of known [CO] 2. hold 10 sec 3. exhales through CO analyzer → missing CO = diffused CO Plethysmography - \measures FRC based on Boyles Law PV = PV • where V = FRC • pt pants lightly → ∆P around pt can be used to calculate FRC 6 Minute walk test (6MWT) vs. Exercise Titration w/Oxygen - \*6MWT: *Simply tests the distance pt walked in 6 min *Exercise Titration w/O2:* - Measuring sats while walking to see if need home O2 - Used for patients with severe COPD Oxygenation index (Oxygen Index) - purpose - equation - normal !!!!! - \Helps determine if patient needs ECMO - ECMO recommended if OI > 40 in infants OI = 100(FIO2 x Mpaw) / PaO2 Normal < 10% PaO2/Fio2 ratio (P/F) - Purpose - Normal - ALI - ARDS - \Clinical indicator of Hypoxemia *• Normal 400-500 torr * *• Moderate dysfunction 300-400 torr* - 5-15% shunt *• ALI 200-300 torr* - 15-20% shunt *• ARDS < 200 torr* - with greater than 20% shunt Alveolar Air Equation P(A-a)O2 - purpose - equation - normal & abnormal values - A-a for age equation - \Helps in diagnosing the source of hypoxemia P(A-a)O2 = [PAO2] - PaO2 P(A-a)O2 = [(Pbatm-PbH2O)FiO2 - (PaCO2 x 1.25)] - PaO2 - Pbatm in KC = 760 torr - PbH2O in KC = 47 torr A-a for age = 10 + 4[(age-20)/10] - *CANNOT be negative!* • *Normal *= < 50 torr on 100% O2 • *V/Q Mismatch *= if gradient > 25 torr on RA but < 50 on 100% • *Shunting Qs/Qt* = if gradient > 25 mmHg on RA and > 50 on 100% ???? • *Diffusion defect* = if gradient same on RA & 100% Partial Pressure of Inspired Oxygen (PiO2) - \PiO2 = (Pb - PbH2O)FiO2 - Pbatm in KC = 760 torr - PbH2O in KC = 47 torr Partial Pressure of Oxygen in the Arteries PaO2 - normal - abnormal values - \80-100 = Normal If PaO2 < 80 with FiO2 > 60% - indicates, shunting, refractory hypoxemia, venous admixture - start to CPAP or ↑ PEEP Partial Pressure of Carbon Dioxide in the Arteries PaCO2 - normal - abnormal values - \35-45 = Normal > 45 means pt is NOT ventilating • initiate ventilation or increase current settings • remove/decrease mechanical deadspace • if PaCO2 is high but pH is compensated, pt is most likely a CO2 retainer w/COPD. That's fine. < 35 means pt is over ventilating • consider other causes of hyperventilation (hypoxemia, metabolic acidosis) Ventilation/perfusion scan - \Two nuclear scan tests to measure breathing (ventilation) and circulation (perfusion) in all areas of the lungs Electroencephalography (EEG) - \- Measures electrical activity of the brain - Evaluation of sleep disorders - diagnoses seizures, coma, brain death (NOT TO BE CONFUSED W/EKG or echocardiogram/echo) Thoracentesis - what is it - most common cause for procedure - CXR findings - procedure (MOVE) - \- needle inserted into chest to remove fluid or air from the space btwn pleura and chest wall - Most common cause for procedure is pleural effusion - CXR findings: Use Lateral decubitus; blunting of costophrenic angles - Procedure: 100-300 mL of pleural fluid is aspirated for diagnostic purposes with a 50 mL syringe ???? 16 gauge needle? Analysis of pleural fluid !!!! (MOVE) - \Transudate fluid (serous fluid) is usually clear; associated with CHF Exudate: Cloudy or opaque; infection would produce yellow or milky fluid; Bloody (hemothorax, erosanguineous) Pleural fluid pH <7.30 is considered significant for an extudate Intracranial pressure (ICP) - normal values - abnormal pressures - therapies to reduce ICP - \Normal value: 5-10 mmHg Compression of capillary bed & compromise microcirculation when ICP >15-20 mmHg RECOMEND TX: • *Hyperventilation: *Target PaCO2= 25-30 torr • *Treat JVD: *HOB elevated ≥30˚; minimize straining or coughing • *Sedation and analgesia: *Narcotics (benzodiazepines) • *Osmotic agents *(to remove fluid from brain): Mannitol, hypertonic saline Cerebral perfusion - normal pressures - \Normal: 70-90 mm Hg Brain natriuretic peptide (BNP) !!!! - \Normal: <100 ???? units Elevated levels indicate CHF Sleep apnea studies (Polysomnography) Central Sleep Apnea vs. Obstructive Sleep Apnea vs. Mixed of both - \*Central: *Apnea due to a loss of ventilation effort • Nasal flow decreases AND respiratory effort decreases (no pleural pressure oscillations) • tx w/Bi-level *Obstructive: *Apnea due to blockage of UA • Nasal flow decreases, but there are still respiratory effort! (there's pleural pressure oscillations) *Mixed: *A combination of central and obstructive types Apnea hypopnea index (AHI) ???? - \Mild: 5-15 Moderate: 15-30 Severe: >30 Apnea of prematurity - tx - indications for infant apnea monitoring - apnea monitoring - \tx: Caffeine Indications: sibling of a SIDS baby (sudden infant death syndrome) Monitoring: Alert docx of reoccurring apnea, bradycardia, and/or hypoxemia NIPPV: Contraindications - \- Cardiac or respiratory arrest - Upper airway obstruction - Unable to protect airway (aspiration risk, dysphagia) - Unable to clear secretions - Facial/head trauma or surgery Continuous Positive Airway Pressure (CPAP) - Purpose - troubleshooting - \- Improves oxygenation; supports oxygenation at lower FiO2 - nasal CPAP is useful w/neonates bc they are OBLIGATE NOSE BREATHERS Troubleshoot: - Loss of pressure: Leak, insufficient flow - Increased pressure: Obstruction, if excessive pop-off valve venting will occur Bilevel Continuous Positive Airway Pressure (BiPAP) - Initial settings - \IPAP: 8-12 (affects CO2 / ventilation) EPAP: 4-6 (affects O2 / oxygenation) Bronchial hygiene - indications - \• Accumulated or retained secretions • Ineffective cough • Ciliary dysfunction • Cystic fibrosis • Bronchiectasis Bronchial Hygiene vs. Hyperinflation therapy - \*Bronchial Hygiene:* (↑ airway clearance) - CPT, Vest - Cough Assist - Oscillatory/Vibrating PEP devices on expiration → flutter, acapella, quake, coronet *Hyperinflation Therapy: *(↑ lung vol for good VC & atelectasis) - Positive Airway Pressure (PAP) on inspiration→ EzPAP, TheraPEP, threshold PEP, CPAP - Intermittent Positive Pressure Breathing (IPPB) via Bird or Vortran - same as Partial rebreather *High Flow Devices: *NON-variable FiO2 @ *> 40 LPM *inspiratory flow 1. *Ventimask* (up to 80 LPM bc has entrainment port, but only 50% FiO2 max) 2. *GIN* (2 high flow meters = 120 LPM theoretically, but we keep ~60 LPM) ???? 3. *Aerosol Mask* (> 7 LPM; can use humidifer or neb) 4. *T-Piece* (> 7 LPM; up to 100% FiO2 w/reservoir) - Can be humidified or neb 5. *Face Shield or Trach Mask* (> 7 LPM; up to 100% FiO2) 6. *High Flow Oxygen, High Flow Nasal Cannula (HFO HFNC)* example: "Vapotherm" (40-60 LPM heated) Ways to create high flow for pts with high flow demand and potential high RR - \1. GIN - uses two flowmeters 2. Large Volume Neb (LVN) w/bleed in ???? ask chad? - if FiO2 desired < 60% → hook LVN to air & bleed in O2 - if FiO2 desired > 60% → hook LVN to O2 & bleed in air - if FiO2 desired 100% → hook both to O2 3. Tandem using 2 LVNs 4. Blender - uses two flowmeters as well; can do 100% 5. Use a high flow flowmeter to get up to ~70 LPM Transtracheal Catheter - insertion - FiO2 & flow - \- delivers up to 35% FiO2 with 0.25-4 LPM flow (LOW FLOW) - inserted into trachea btwn 2nd & 3rd tracheal rings to ~3 cm above carina - no need for humidifier Nasal cannula - indications - troubleshoot - \Indications: for mild hypoxemia; initial device for COPD & stable RR & VT - Delivered FiO2: 24-41% (4% rule) - Flow: 1-6 L/min Troubleshoot: - No gas flow felt from device? Check connection - Skin irritation?: Place cushions on irritated areas - Mouth breathing on cannula? Switch to simple mask or venturi Non-rebreather mask (NRB) - FiO2 & flow - Indications - \Delivered FiO2: 21-100% Flow: 10-15 LPM to keep bag inflated Indications: for moderate hypoxemia, *mixed gas therapy* (Heliox or CO2/O2), suspected *CO poisoning* Has 2 one-way valves to prevent rebreathing T-piece (Brigg's adapter) - FiO2 - troubleshooting w/aerosol - \Delivered FiO2: 0.21-1.0 Troubleshoot: If aerosol disappears... - increase flow / set up a device to provide more flow if already maxed (ie blender, tandem set-up, high flow flowmeter) - add more reservoir tubing - set up a device to provide more flow ???? you must see the aerosol? can't disappear?? Gas Injected Nebulizer (GIN) - \- uses two flowmeters - and if each normal flowmeter is 15... then ~30 LPM - but if using high flow flowmeter each at 60 LPM then theoretically 120 LPM... ???? ask Chad? Magic Box - calculation - 1:1 ratio - example question - \Used to *calculate TOTAL flow in an entrainment *device (ie AP neb) - whereas for the GIN you have 2 flowmeters you can just look at the #s and add KNOW that *1:1 Air:O2 ratio is ~60% FiO2* • If *FiO2 < 60%, then AIR will be larger #* • If FiO2 > 60%, then O2 will be larger # Example Question: Calculate total gas flow from 40% venturi mask w/an O2 flow of 6 LPM. Calculated Air:O2 ratio = 60:20 = 3:1 Total Gas Flow = 24 + 6 = 30 LPM Oxygen hood - \Flow range: 7-14 L/min to prevent CO2 buildup use O2 analyzer to measure FiO2 closest to baby Bubble humidifier - indications - troubleshooting - \Indications: - when > 4 LPM Troubleshooting: - If no sound occurs: Leak - If whistling occurs: Oxygen flow is excessively high or kinking in tubing What to do if there are thick secretions? - \- use ultra sonic neb (USN) for thick secretions - humidify to help mobilize Special Equipment for certain drugs - SPAG - Altera Neb - Pari Neb - Respiguard II - \• Small particle aerosol generator *(SPAG) → for RSV* respiratory syncytial virus • *Altera Neb → Aztreonam (Cayston) *for mgmt of Pseudomonas in CF pts • *Pari Neb → Tobramycin *for mgmt of Pseudomonas in CF pts • *Respiguard II → Pentamidine *for PCP in AIDS pts Metered dose inhaler (MDI) vs. Dry Power Inhaler (DPI) - \MDI: - Must be able to understand and cooperate or use spacer - watch counter - store upright & not lying down DPI: - keep dry & avoid caking or clumping - must generate enough suck Calculating duration of cylinder flow - tank factors (E, H) for O2 - example question - \*Minutes cylinder will last = (Gauge pressure) x (tank factor/liter flow)* • E cylinder: 0.28 L/psi (0.3) • H cylinder: 3.14 L/psi (3.0) → Remember to convert min to hrs - since it is calculated, it assumes there is no abnormal forms of Hb (ie COHb, MetHb) SpO2 = % saturation of O2 on Hb as *MEASURED *using *pulse oximeter* - units: % - since non-invasive, does not register abnormals HbO2 = % satuation of O2 on Hb as *MEASURED *using *co-oximeter* - units: % - since it is measured, it is *more accurate *& takes into account abnormals (ie COHb, MetHb) ABG analyzer: In control situation - \All the values are within 2 standard deviations of the mean → GOOD! ABG analyzer: Random errors / Imprecision errors - \Random Errors / Imprecision Errors one sporadic data point out of 2 standard deviation range, but rest is ok - indicates errors of imprecision - ignore it ABG analyzer: Systemic errors / Bias - \occurs when there is a abrupt shift or trending of data points down/up but within acceptable 2 standard deviations ABG analyzer: Out of control situation - \Steadily increasing or decreasing trend that is moving outside the standard deviation range - this indicates *electrode needs to be recalibrated or replaced* - if there is Bias & Imprecision, then also requires corrective action Physiologic effects of hypoxia & hypercapnia - \*Leads to pulmonary vasoCONSTRICTION* - bc wants to shunt blood to better perfused areas to improve V/Q mismatch - in neonates, this is beneficial bc it allows more blood to shunt through PDA so goes from pulmonary artery → aorta to get to body *But causes systemic & cerebral vasoDILATION* - try to get more perfusion & O2 to brain and organs Different types of Hypoxia - HASH - \*Hypoxemic hypoxia*: caused by low PiO2 (inspired) - shunt or venous admixture, Qs/Qt - poor ventilation, Vd/Vt - AC diffusion defect - hypoventilation *Anemic hypoxia*: caused by low or loss of Hgb - Hb changes prohibiting O2 binding (ie MetHb or COHb) *Stagnant hypoxia*: caused by decreased circulatory situations - decreased CO or CV failure - hemorrhage / shock *Histotoxic hypoxia*: caused by disruption of cellular enzymes - cyanide poisoning Oxygen Hemoglobin Dissociation Curve (OHDC): - Left shift - Right shift - \*Left Shift → Lock O2* bc *increased affinity*, but deprives tissues - Increase: pH (basic) - Decrease: PaCO2, temp, 2-3 DPG - HbF, HbM, COHb - Polycythemia *Right Shift → Release O2 *easily bc decreased affinity, but *prevents reloading *at alveoli; *"appears" best *for feeding the tissues - Decrease: pH (acid) - Increase: PaCO2, temp, 2-3 DPG - Sickle Cell (HbS) - Chronic hypoxemia - Anemia (It's Right to Release Acid on the Sick & Blue. 2 Thumbs ↑) 4 Primary variables during mechanical ventilation - \1) *Trigger* 2) *Control or Target* 3) *Limit*: est a max value that a variable can reach during inspiration (pressure, volume, time, flow) 4) *Cycling* Indications for Mechanical Ventilation - \• Apnea • Acute ventilatory failure/ acute respiratory failure → Insufficient spontaneous ventilation • VC <1000 • MIP <20 • PaCO2 >45 IBW calculation in Adults - \Male = 50+2.3(ht in inches - 60) Female = 45.5+2.3(ht in inches - 60) Initial settings for adult mechanical ventilation - \• *Tidal volume: *6-10 mL/kg IBW • *Minute ventilation (Ve):* 5-10 LPM • *Pressure Ctrl: *start at 10-15 cmH2O, adjust to get desired Vt & Pplat < 35 • *Pressure Support: *set to transairway pressure (PIP-Plat), adjust to get desired Vt • *f: *12-18 bpm • *Trigger sensitivity: *1-2 LPM (flow) or 0.5-2 cmH2O (pressure) • *Inspiratory time: *0.8-1.2 sec • *PEEP: *0-10 cmH2O • *Itime: *0.8-1.2 sec • *I:E ratio:* 1:2 to 1:3 • *FiO2:* 40-60% Initial settings for infant mechanical ventilation - \• VT: 4-6 mL/kg • PIP: 20-30 cmH2O • f: 20-30 b/m • FiO2: 40-60% • PEEP: 2-4 cmH2O with 8 max Ventilator alarms: - High/Low pressure - Minimum exhaled pressure - Oxygen - RR - Vt - \- *High/ Low pressure: *10 cmH2O ± PIP (low P is the most important alarm!) - *Minimum exhaled pressure: *100 mL below exhaled Vt (2nd most important alarm) - *Oxygen: *5% ± set FiO2 - *RR: *10 ± spontaneous - *Vt: *10% ± Vt exhaled Ventilator alarms: Troubleshooting - troubleshooting Low pressure - troubleshooting High pressure - troubleshooting Low exhaled volume - \*Troubleshooting Low pressure:* - Patient disconnect - Leak in the circuit - Insufficient flow - ET/Trach cuff leak Normalizing low PaO2: 1. *↑ FiO2 *by 5-10% (up to 60%) 2.* ↑ PEEP *5, 8, 10 then by 2's until 20 until acceptable or unacceptable side effects occur (ie: ↓ CL, ↓ cardiac f(x), barotrauma) Estimating PaO2 based on FiO2 - \*PaO2 ~= FiO2 x 5* (ie pt breathing 100% FiO2 should have PaO2 500) Desired MV-PaCO2 equation - \desired (PaCO2)(MV) = known (PaCO2)(MV) Desired FiO2-PaO2 equation - \(desired FiO2)/(known FiO2) = (desired PaO2)/(known PaO2) High frequency ventilation (HFOV) - function - changing settings to accomplish ABG goals - \Improves oxygenation in patients with severe lung injury (ie ARDS, RDS, pneumothorax) •* ∆P (amplitude)*controlled by *Power knob*, increase to have adequate chest wiggle to thighs - *↑∆P to ↓ CO2 *(it's like getting a *bigger Vt*) • *MAP *is set to that read on *conventional ventilator + 2 to 4 cmH2O* - *↑ MAP to ↑ PaO2* • ƒ is weight based (↑ weight... ↓ Hz) to ~10-15 Hz - RECALL: 1 Hz = 60 breaths/min - *inversely: ↓ Hz to ↓ CO2 *(bc ↓ breaths/min, so longer Itime) • *Insp time* = 33% • *Bias flow* = weight based • *Piston *will fluctuate back & forth as CL & RAW ↑↓... be sure to *center it* Amplitude vs. frequency measured in Hertz (Hz) - \Amplitude = how high the wave is Frequency = how often the wave cycles • 1 Hz = 60 breaths/min Recruitment maneuvers - \• Increase PIP to 40 and PEEP to 20 for for 40 seconds • Increase CPAP to 30-40 for 40 seconds • Sighs technique (inspiratory hold) • If SpO2 rises then falls consider repeating maneuver Waveform: Auto-PEEP & Air trapping - \Expiratory flow fails to return to the baseline Waveform: Ineffective/wasted effort - \Patient inspiratory effort fails to trigger vent. Waveform: Flow starvation - \Caused by discomfort, fatigue, or dyspnea Scooping or distortion instead of a smooth rise in the pressure curve Waveform: Active expiration - \High and variable expiratory flow pattern Waveform: Airway secretions - \Sawtooth pattern Waveform: Auto cycling - \When RR increases suddenly without patient input (exhaled volume and minute ventilation decrease) Typically occurs due to a leak Waveform: Double triggering - \Caused by patient flow or volume demand exceeding ventilator settings Continued patient inspiratory effort through the end of delivered breath Loop graphics: Spontaneous breath - \oval - pt starts and finishes breath Loop graphics: Assisted breath - \fish tail - pt starts inspiration - machine finishes breath Loop graphics: Mandatory breath - \leaf - machine starts and finishes breath Loop graphics: overdistension - \*beak *represents overdistension as too much volume is delivered Loop graphics: Adjusting PEEP level - \PEEP is set at 0 Normalized by increasing the PEEP Loop graphics: Adjusting PIP and/or VT - \Overdistention "duck bill" Normalized by reducing the VT or PIP - "belly" line of the duck is inspiration; "back" is expiration - mandatory breath bc there is no negative inflection - PEEP is present Loop graphics: Evaluating/treating lung compliance problems - \Low compliance (ARDS, pneumonia, pulmonary edema) Normalized by increasing PEEP Loop graphics: Evaluating/treating airway resistance problems - \High airway resistance/decreased expiratory flow (Bronchospasm, secretions, other obstructions) Normalize by suction or bronchodialator Loop graphics: Evaluating/treating an air leak problem - \Leak Normalize by fixing the leak Loop graphics: Evaluating/treating tubing compensation - \Water is present in the circuit Drain condensate from tubing using water traps Scalar graphics: Evaluating/treating air trapping (auto-PEEP) - \Expiratory flow does not return to baseline Scalar graphics: Patient ventilator asynchrony/dyssyncrony - \Causes: Auto-PEEP, inappropriate trigger setting, weak patient effort Correct: Adjust trigger setting Scalar graphics: Auto trigger (auto-cycle) - \Causes: Leak in circuit or airway, inappropriate trigger setting (too sensitive), condensation in circuit, Bounding pulse or cardiac movement causing ventilator to trigger - Indications - Dosage - Side Effects - DC - \Indications: for pulmonary HTN bc *iNO is a vasodilator!* Dosage = *20-40 ppm* ???? slide said 5-20 ppm? • < 20 ppm when weaning • When high calibrating, the expected value is 45 ppm Side Effects: Methmoglobin (MetHb) levels may increase DC: • To avoid rebound: Titration is 20 ppm → 10 ppm → 5 ppm → then DC ???? • Correct rebound: Return to previous iNO level ???? • Can form small amounts of toxic NO2 (nitrogen dioxide); so you MUST monitor this Chest tubes: Pneumothorax vs. Hemothorax or Pleural Effusion or empyema - \*Pneumothorax:* • <10% may not require tx unless pt shows significant distress • to drain air, place 14-16 needle gauge in *2nd intercostal space (just above 2nd rib) mid-clavicular line*, then put in chest tube afterwards *Hemothorax or Pleural Effusion or empyema:* • to drain FLUID, place in *5th-7th intercostal space mid-axillary* Chest Tubes: Three bottle water-seal suction drainage system - Collection Chamber - Waterseal Chamber - Suction Control Chamber - \Right to Left: *Collection chamber*: collects fluid • if no bubbles or continuous bubbles, could indicate air leak *Waterseal chamber*: one-way valve allowing air to escape but not re-enter chest cavity • bubbles here indicates air leak! • but tidaling is GOOD! (falls w/inhalation; rises w/exhalation) *Suction Control chamber*: height of H2O in here regulates neg pressure sxn ~15-20 cmH2O Chest tubes: Removing - \Just before removing the tube, the patient takes a *deep breath*, exhales and preforms a *valsalva maneuver *(exhaling w/the nostrils & mouth closed to ↑ pressure in middle ear & chest; typ used to equalize ear pressure) Palliative care - \Control of pain and other symptoms Maximizing the psychological, social, and spiritual well-being Disinfection vs. Sterilization - \•* Disinfection *= Destroying PATHOGENIC microbes except for spores (ie chemical disinfection, pasteurization) •* Sterilization *= Killing ALL microbes (good & bad) (ie autoclave, flash sterilization, low temp sterilization) CHEMICAL method of disinfection and sterilization - \• Ethylene oxide = Sterilizes • Alkaline glutaraldehyde (Cidex & Sonacid) = Disinfection and sterilization - for reusable plastics & bronchoscopes • Bleach = Used to clean blood spills PHYSICAL methods of disinfection and sterilization - \• *Autoclave* = Steam under extreme pressure @ 15psi @ 121° • *Flash Sterilization *= rapid penetration of steam • *Pasteurization* = Type of disinfection using moderate temperatures - used for high level disinfection of nondisposable ventilator tubing • *Incineration *= Best method of treating contaminated disposable items and supplies • *Irradiation *= Gamma rays used to sterilize pre-packaged equipment Preventing ventilator-associate pneumonia (VAP): - cause - prevention - \Secretions that pool above airway cuff are aspirated through small folds in the cuff; accidental lavage of condensation Prevention: • Closed Sxn w/regular oral hygiene • HOB 30-45° • *DON'T often change vent circuits* • drain vent condensation • MDI instead of SVN • daily sedation vacation Home care: Clean equipment - \Soak in *white distilled vinegar (acetic acid) *solution for 20 min. Dry carefully Oxygen concentrators - \- If bubbles are present, device is working correctly - after oxygen concentrator has been installed, RT's job is to *change the filters *as maintenance procedure Liquid bulk O2 systems - \- If it spills let it evaporate - Can cause frostbite - will leak over time if not used - can store more of it compared to gas O2 - 1 cu ft of liquid O2 = 860 cu ft of gaseous O2 Units for Pressures (general trend) - \cmH2O → anything related to the vent (like PIP or CL) mmHg → anything related to blood (like ABG's PaCO2 or PaO2)