Ventilator high pressures: Difference between revisions
Kurtucla05 (talk | contribs) No edit summary |
ClaireLewis (talk | contribs) No edit summary |
||
(13 intermediate revisions by 6 users not shown) | |||
Line 1: | Line 1: | ||
==High Pressure Alarms== | ==High Pressure Alarms== | ||
*In volume control mode, (high)pressure alarm sounds. In pressure control mode (low) volume alarm sounds--BOTH signify similar problems and troubleshoot with the following 4 maneuvers. | *In volume control mode, (high)pressure alarm sounds. In pressure control mode (low) volume alarm sounds--BOTH signify similar problems and troubleshoot with the following 4 maneuvers. | ||
=== | ===Measure Peak Plateau Pressure=== | ||
*Need to measure peak plateau pressure P(Plat) not only peak airway pressure P(Peak). | *Need to measure peak plateau pressure P(Plat) not only peak airway pressure P(Peak). | ||
**Press and hold the “inspiratory hold” button-waveform shows peak pressure and then lower plateau. | **Press and hold the “inspiratory hold” button-waveform shows peak pressure and then lower plateau. | ||
*P(Plat) >30 thought to be potentially injurious to lung. | *P(Plat) >30 thought to be potentially injurious to lung. | ||
*P(Plat) reflects equilibration of airway pressures without flow, accounts for airway resistance. | *P(Plat) reflects equilibration of airway pressures without flow, accounts for airway resistance. | ||
=== | ===Determine Airway Resistance=== | ||
*When airway resistance high, P(Peak)>> P(Plat) | *When airway resistance high, P(Peak)>> P(Plat) | ||
**Normal P(Peak)-P(Plat) | **Normal P(Peak)-P(Plat) < 5cm H2O | ||
***Airway resistance increased with: asthma, mucus plugging, small tube, tube kinking, tube obstructed | ***Airway resistance increased with: asthma, mucus plugging, small tube, tube kinking, tube obstructed | ||
=== | ===Eval for Dynamic Hyperinflation=== | ||
*Flow at end of expiration has not stopped, ie breath stacking, ie need more time to exhale and each breath adding volume to lungs | *Flow at end of expiration has not stopped, ie breath stacking, ie need more time to exhale and each breath adding volume to lungs | ||
*Consequence of dynamic hyperinflation | *Consequence of dynamic hyperinflation | ||
Line 16: | Line 16: | ||
#Increased dead space- hypoxic/hypercapneic | #Increased dead space- hypoxic/hypercapneic | ||
#Elevated intra-thoracic pressures decrease venous return | #Elevated intra-thoracic pressures decrease venous return | ||
*Look to make sure expiratory | *Look to make sure expiratory flow returns to baseline. | ||
===Measure Hyperinflation=== | |||
=== | *If you suspect dynamic hyperinflation, perform “expiratory hold”, then PEEP on ventilator may be higher than PEEP on ventilator settings | ||
*If you suspect dynamic hyperinflation, perform “expiratory hold”, then PEEP on | *Differences in PEEP with “expiratory hold” and PEEP set on ventilator suggest hyperinflation. | ||
*Differences in PEEP with “expiratory hold” and PEEP set on | |||
==Management== | ==Management== | ||
Line 27: | Line 26: | ||
**Kinked tube- pass suction catheter? | **Kinked tube- pass suction catheter? | ||
**Mucus plug- pass suction catheter and suction | **Mucus plug- pass suction catheter and suction | ||
**Bronchospasm- inhaled bronchodilators | **Bronchospasm- inhaled [[bronchodilators]] | ||
**Tube too small- swap tube | **Tube too small- swap tube | ||
=== High P(Peak), | ===High P(Peak), High P(Plat)=== | ||
*Suggests decreased compliance, not an isolated resistance problem | *Suggests decreased compliance, not an isolated resistance problem | ||
**Mainstem bronchus- pull back ETT, CXR? | **Mainstem bronchus- pull back ETT, [[CXR]]? | ||
**Atelectasis- bronchoscopy | **Atelectasis- bronchoscopy | ||
**Cardiogenic | **Cardiogenic [[[pulmonary edema]]-[[diuretics]] vs [[vasopressors|inotropes]] | ||
**ARDS- lower Vt | **[[ARDS]]- lower Vt | ||
**Pneumothorax- Chest | **[[Pneumothorax]]- [[Chest tube]] | ||
**Pneumonia- Antibiotics | **[[Pneumonia]]- [[Antibiotics]] | ||
===PEEP measured > PEEP Vent Setting=== | |||
*Suggests Dynamic Hyperinflation | |||
**Remove from vent, allow complete exhalation | |||
**Lower ventilator rate | |||
**Shorten I-time to change I:E around 1:4 | |||
**Tidal volume 6-8mL/kg [[predicted body weight]] | |||
**Increase inspiratory flow rate to 60-80L/min to allow more exhalation time | |||
**[[Opioid]] sedation blunts intrinsic tachypnea | |||
**Treat bronchospasm | |||
==See Also== | |||
{{Mechanical ventilation pages}} | |||
*[[EBQ:ARDSnet]] | |||
[[Category:Critical Care]] | |||
[[Category:Pulmonary]] |
Latest revision as of 15:29, 27 September 2019
High Pressure Alarms
- In volume control mode, (high)pressure alarm sounds. In pressure control mode (low) volume alarm sounds--BOTH signify similar problems and troubleshoot with the following 4 maneuvers.
Measure Peak Plateau Pressure
- Need to measure peak plateau pressure P(Plat) not only peak airway pressure P(Peak).
- Press and hold the “inspiratory hold” button-waveform shows peak pressure and then lower plateau.
- P(Plat) >30 thought to be potentially injurious to lung.
- P(Plat) reflects equilibration of airway pressures without flow, accounts for airway resistance.
Determine Airway Resistance
- When airway resistance high, P(Peak)>> P(Plat)
- Normal P(Peak)-P(Plat) < 5cm H2O
- Airway resistance increased with: asthma, mucus plugging, small tube, tube kinking, tube obstructed
- Normal P(Peak)-P(Plat) < 5cm H2O
Eval for Dynamic Hyperinflation
- Flow at end of expiration has not stopped, ie breath stacking, ie need more time to exhale and each breath adding volume to lungs
- Consequence of dynamic hyperinflation
- Harder to trigger vent- dys-synchrony
- Increased dead space- hypoxic/hypercapneic
- Elevated intra-thoracic pressures decrease venous return
- Look to make sure expiratory flow returns to baseline.
Measure Hyperinflation
- If you suspect dynamic hyperinflation, perform “expiratory hold”, then PEEP on ventilator may be higher than PEEP on ventilator settings
- Differences in PEEP with “expiratory hold” and PEEP set on ventilator suggest hyperinflation.
Management
High P(Peak), Low P(Plat)
- Suggests increased airway resistance, not compliance problem
- Kinked tube- pass suction catheter?
- Mucus plug- pass suction catheter and suction
- Bronchospasm- inhaled bronchodilators
- Tube too small- swap tube
High P(Peak), High P(Plat)
- Suggests decreased compliance, not an isolated resistance problem
- Mainstem bronchus- pull back ETT, CXR?
- Atelectasis- bronchoscopy
- Cardiogenic [[[pulmonary edema]]-diuretics vs inotropes
- ARDS- lower Vt
- Pneumothorax- Chest tube
- Pneumonia- Antibiotics
PEEP measured > PEEP Vent Setting
- Suggests Dynamic Hyperinflation
- Remove from vent, allow complete exhalation
- Lower ventilator rate
- Shorten I-time to change I:E around 1:4
- Tidal volume 6-8mL/kg predicted body weight
- Increase inspiratory flow rate to 60-80L/min to allow more exhalation time
- Opioid sedation blunts intrinsic tachypnea
- Treat bronchospasm