Airway Obstruction + Ventilation Flashcards
Medullary center
Dorsal respiratory Group DRG
Controls inspiratory movements + timing
Medullary Center
Ventral respiratory group VRG
Controls voluntary forced exhalation + up inspiration. Inactive in quiet breathing
Pontine Centers
Pneumotaxic center
- Coordinates speed of inhalation/ exhalation. *Sends inhibitory impulses to DRG.
- Fine tuning of RR
Apneustic Center
- Inspiration
- depth of breathing
- signals to DRG in medulla
- stimulatory impulses to inspiratory area
- inhibited by stretch receptors
- cyclic, gradual increase then decrease
* HF, Stroke, Kidney failure, opiate, high altitude
Cheyne-Stokes Breathing
HYPERCAPNEA
CNS sleep apnea
2ndary
Central sleep apnea
Tx
CPAP
Obesity Hypoventilation
Gradual high PCO2, makes you sleepy
- BMI = >35-40
- daytime hypoventilation (UP CO2, Low O2)
- Sleep-disordered breathing
- hypercapnia = 20% dead in 18 months if untreated
Obesity Hypoventilation Syndrome (OHS)
Path
- leptin deficiency/resistance (hunger UP)
- more work load
- upper airway obstruction
=
Poor ventilatory response
HYPERCAPNEA + HYPOXEMIA
Obesity-Hypoventilation Syndrome
Tx
- weight loss
- CPAP (exhalation)
- BIPAP (inhalation + exhalation)
- tracheostomy w/ nighttime positive pressure ventilation
Hyperpnia
- NOT hyperventilation syndrome
* UP depth+rate of breathing = sepsis, fever, hypoxemia
Central Sleep Apnea
- brain stop sending signals to the muscles of respiration
- Lack of abnormal + thoracic movement
- primary : Ondine’s Curse to Palemon
Apnea =
Cessation of breathing >10 seconds
*hypopnea = DOWN airflow w/ DOWN O2 Sat >4%
Apnea-hypopnea index (AHI)
- severity of sleep apnea
- 0-4 = Normal
- 5-14 = Mild
- 15-29 = Moderate (CPAP)
- 30+ = Severe (CPAP)
*Obesity
*Loud / frequent snoring
(Only if crescendo)
*Silent Pauses in breathing
*Choking/gasping
*Daytime sleepiness/fatigue
*Unrefreshing sleep
*insomnia
*Morning headaches
(Back of head = HTN)
*nocturia (waking to urinate)
Sleep Disorder Breathing
Signs + Symptoms
Acute respiratory failure
- pneumonia
- ARDS
- Status asthmaticus
- Acute COPD exacerbation
VENTILATE
Acute on Chronic repsiratory failure
Hypercarbia = OHS
VENTILATE
pulmonary edema
Heart failure
Renal failure (dialysis)
VENTILATE
Inability to protect airway
Coma
Seizures
VENTILATE
Neuromusclular dysfunction
ALS
VENTILATE
Stabilize chest wall after trauma
VENTILATE
Mechanical ventilation makes
External Negative pressure => chest expands
Bulbar polio mortality treated w/ iron lung ventilation
90% mortality
- affects medulla oblongata = swallowing mechanism + breathing
- drown in own secretions
Pulmonary edema (fluid)
Effect on compliance curve
Need more pressure to even approach normal volume
Tx: positive pressure w/ tracheotomy
Lungs full of secretions
Neg pressure ventilators?
NOPE, will not inflate lungs
Need positive pressure w/ tracheotomy
ventilator measures
Flow + pressure
Volume calculated
Positive pressure types
Volume cycled = volume constant, pressure varies w/ patient’s lung compliance
Pressure cycled
Pressure constant but volume varies w/ patients lung compliance. (Dangerous, can cause barotrauma with too much inhalation)
*use w/ reduced compliance/stiff lungs
Positive Pressure Ventilation Injury
- upper airway
- tracheomalcia
- ventilator associated pneumonia
- Lung parenchymal damage
- large tidal volumes
- Super ‘PEEP’
- Zeep/zero peep
Patient - ventilator interaction + asynchrony
- barotrauma
* longer time on ventilator + ICU
Expiratory Asynchrony
Ineffective breathing efforts
*abrupt increase in flow during expiration
From: high ventilatory requirements, autoPEEP, respiratory muscle weakness, insensitive trigger setting
Double triggering asynchrony
*2 consecutive internals with interval
*sedation + neuromuscular paralysis
- daily interruption of sedation (morning)
* paralyze patient for first 48 hours
- Deep, rapid continuous inspirations
* no stopping between breaths
Kussmaul’s Respiration
*metabolic acidosis
- irregular respirations, quick, shallow
* irregular periods of apnea
Biot’s Breathing
*medulla oblongata damage/opioid use
Apnea =
Cessation of breathing 10 secs
Hypopnea =
Decrease in airflow w/ decrease in artery O2 sat >4%
Apnea-Hypopnea index
(# events per hour of sleep)
- normal
- moderate
- severe
- normal = 0-4
- moderate = 15-29
- severe = 30+
Signs
- large neck
- loud/frequent snoring
- silent pauses in breathing
- choking gasping
- daytime sleepness
- morning headaches (back of head=HTN)
- nocturia
Sleep disordered breathing
Long term issues
- pulmonary hypertension
- cor pulmonale
- arrthymias
- LHF
- HTN
- stroke
Repetitive episodes of airflow reduction (hypopnea) + cessation (apnea)
Obstructive sleep apnea
Tx. CPAP (pressure at END of EXPIRATION)
