Ppeak rises; Pplateau changes little
Increased resistance or flow-related pressure is more likely.
Open resistance branchHAMILTON-T1
Ppeak, Pplateau, and driving pressure
The T1 reports pressure mechanics differently from ventilators that use a conventional inspiratory-hold occlusion.
T1 distinction: Because the C1/T1/MR1 platform uses valveless pneumatics, a conventional inspiratory-hold maneuver cannot be used to obtain Pplateau. Use the displayed monitored values and confirm that end-inspiratory flow is at or near zero.
Check the unit: Button paths below were verified against the U.S. software 3.0.x manual. On the ventilator, open System → Info to confirm its software version and installed options.
1Read PpeakNo special maneuver is required
- Ppeak is the highest airway pressure during the previous breath.
- It reflects both flow/resistance and respiratory-system compliance.
- The operator’s manual describes Ppeak as continuously displayed.
2Read Pplateau on the T1Monitoring → General; verify end-inspiratory flow
- Open Monitoring → General and look for Pplateau.
- Confirm the displayed breath is mandatory or time-cycled.
- Inspect the flow-time waveform. Pplateau is meaningful only when end-inspiratory flow is at or close to zero.
- If the value is absent or does not fit the waveform, treat it as unavailable or questionable rather than forcing a hold maneuver.
Do not substitute the Manual Breath key. Pressing and holding Manual Breath prolongs inspiration; it is not the conventional inspiratory occlusion used to measure plateau pressure.
3Read driving pressureMonitoring → General → ΔP
- The T1 displays driving pressure as a calculated monitored value.
- The manual defines it as tidal volume divided by static compliance, reflecting the difference between Pplateau and PEEP.
- Its reliability depends on a credible Cstat measurement and minimal confounding patient effort.
Driving pressureΔP = VTE ÷ Cstat
4Estimate Pplateau when the display is absent or questionableUse only when the assumptions are credible
Step 1ΔP = VTE ÷ Cstat
Step 2Pplateau ≈ PEEP + ΔP
- This workaround comes from Hamilton Medical’s T1/C1/MR1 technical note.
- It depends on an accurate Cstat and no significant patient effort.
- Hamilton notes that inspiratory pressure should be approximately 10 cm H₂O or greater for the calculation.
The website shows the formula but does not calculate a patient-specific result.
5Separate resistance from complianceUse the relationship, then open the focused branch
Ppeak and Pplateau rise together
Reduced compliance, greater alveolar pressure, or overdistension is more likely.
Open compliance branch
Sources and version notesOfficial manual, Pplateau note, and current product resources
Button paths and monitored-parameter descriptions were checked against the HAMILTON-T1 U.S. operator’s manual for software 3.0.x. Hamilton currently advertises newer 3.1.x software, so labels, enabled options, and available functions may differ on the unit in front of you.
Important: Earlier T1 software may display an end-inspiratory pressure even when flow is still present; newer versions display Pplateau only when end-inspiratory flow is close to zero. Even then, the displayed value can be higher than true static plateau pressure.
HAMILTON-T1 U.S. operator’s manual — software 3.0.xHamilton Medical: calculating Pplateau on C1/T1/MR1Current HAMILTON-T1 product resources
Content check: 2026-09-10. Confirm the installed software under System → Info and follow local respiratory-therapy and institutional policy.