GE CARESCAPE - Page 333

PatientSpirometry
●x=Time
●y=
1.Inspiration
2.Expiration
Compliance
Themeasurementofpressureandvolumeallowsforthecalculationofthelungs’
dynamiccompliance-inotherwords,howwellanadditionalvolumeentersthelungs
whenpressureisexertedontheairway.Compliancedescribestheextensibility
ofthelung-thoracicsystembutisdominatedbyalveolar(thatis,purelyperipheral)
properties.
Typicalcomplianceforadultsvariesbetween35ml/cmH
2
Oand60ml/cmH
2
O,and
typicalcomplianceforchildrenismorethan15ml/cmH
2
O.
DecreaseincompliancemayindicatetoohighaPEEPlevel,acutelunginjury,or
increasedintra-abdominalpressure(bleeding,ascites).Decreasedcompliance
indicatesaworseningventilatorystatus.
Typicalcompliance
●x=Paw
●y=Vol
Lowcompliance
●x=Paw
●y=Vol
Airwayresistance(Raw)
Airwayresistanceexpressestherelationshipbetweenthepressuredifferenceacross
theairway(betweenthemouthandthealveoli)andtherateatwhichgasisowing
throughtheairway.Anincreasingairwayresistanceusuallyindicatesanairway
obstructionandmayleadtobarotrauma.Incriticallyillpatients,factorscausing
increasedairwayresistanceshouldbeidentiedasquicklyaspossibletoavoidlung
overdistensionordecreasedoxygendelivery.
NOTE
AnendotrachealtubegreatlycontributestoRaw.The
resistanceofthetubeisnormallyhigherthanthatofthe
remaininginternalairways.
2062971-001CARESCAPEModularMonitors333