Respiratory Flashcards
Thumbprint sign
Possible epiglottitis (lateral neck view)
ABG values:
pCO2 high= pH low (acidosis)
pCO2 low= pH high (alkalosis)
pH low= HCO3 low (acidosis)
pH high= HCO3 high (alkalosis)
pCO2= 35-45 respiratory pH= 7.35-7.45 metabolic HCO3= 22-26 metabolic
First adjustment on ventilator
Tidal volume, not rate
PaO2
Plasma measured as pressure
SaO2
Hemoglobin measured as percentage
Bariobariatrauma
Nitrogen release in obese patients, administer high flow oxygen 15 minutes to lift off to wash out nitrogen
Three killers of ventilator patients during flight
Pericardial tamponade
Tension pneumothorax
Hypovolemia
Hypoxic hypoxia
Altitude hypoxia, decreased alveolar oxygen, tension pneumo (e.g., altitude)
Hypemic hypoxia
Decreased O2 carrying capacity in blood
Histotoxic hypoxia
Poisoning (e.g., nitrates)
Stagnant hypoxia
Decreased cardiac output, poor circulation ( e.g., g-forces, CHF)
Primary cause of death with ventilator dependent patients
Ventilator acquired pneumonia
ARDS:
Treatment
CXR
Treatment: PEEP
CXR: CXR reveals widespread pulmonary infiltrates; glass-like appearance
PEEP:
Effects of PEEP
Normal physiological PEEP
Increased pulmonary vascular resistance
Can cause hypotension over 15 cm H2O
Normal range: 3-5 cm H2O
To change CO2
Adjust rate, tidal volume
To change oxygenation
Adjust PEEP, PAP
O2 adjustment calculation to maintain saturation at altitude
% oxygen patient is already on X pressure at departure (mmHg) pressure at altitude. This percentage needed in flight. Example: Patient on FIO2 of 0.40 Depart: 681 mm Hg Altitude: 565 mm Hg Answer: patient needs 48% oxygen
Ventilator modes:
CMV
Preset volume or PIP at set rate. Patient can’t initiate breath.
Ventilator modes:
AC
Preset volume or PIP with every breath. Can trigger breath, can’t control tidal volume
Ventilator modes:
IMV/SIMV
IMV: preset breaths, TV, PIP. Patient breaths allowed.
SIMV: allows variation of support
Oxyhemoglobin disassociation curve:
Left shift
“L” stands for alkalosis
Left shift= low hemoglobin holding oxygen alkalosis
Low CO2
Low temperature
Low DPG
Mxydema coma
Oxyhemoglobin disassociation curve:
Right shift
Right=raise/releases oxygen
Acidosis
Raised CO2
Raised temperature
Raised DPG
Thyroid storm
ABG rules
CO2 and pH
CO2 up 10= pH down .08(inverse)
ABG rules
Bicarbonate and pH
HCO3 up 10= pH up 15 (proportional)
ABG rules:
Bicarb replacement
kg/4 x base deficit = meq of bicarbonate needed
ABG rules:
PaO2 at altitude
PaO2 drops 5 for every 1000 feet elevation
Stages of hypoxia:
Elevation
Signs or symptoms
Indifferent: (10,000 feet MSL): increased HR and RR, decreased night vision
Compensatory: (10, 000-15,000 feet MSL):HTN, task impairment
Disturbance: (15,000-20,000 feet MSL): dizzy, sleepy, cyanosis
Critical: ( 20,000-30, 000 feet MSL): ALOC, incapacitated
Acute respiratory failure
pO2 below 60, pCO2 above 50
Breathing and waveforms
Record pressure measurements at the end of exhalation
- in a spontaneously breathing patient, inspiration is the fall in pressure, expiration is the rise in pressure. End-expiration occurs just prior to the respiratory drop in pressure.
- positive pressure mechanical ventilated patients will cause cardiac pressure to rise upon inspiration
Steeple sign
Possible croup (laryngotracheobronchitis) A/P neck view
ETT depth
Adult: 3 x ETT size or average is 19-23cm
Peds: 10 + age in years
Neonatal: 6 + age weight in kg
