Hemodynamic Effects of Norepinephrine Reduction on Critical Closing Pressure in Distributive Shock
12. juni 2026 oppdatert av: Bin Du, Peking Union Medical College Hospital
Changes in Critical Closing Pressure and Derived Hemodynamic Parameters Following Norepinephrine Dose Reduction in Distributive Shock Patients: a Prospective Observational Study
This study prospectively observes changes in critical closing pressure (Pcc) and derived hemodynamic parameters in mechanically ventilated distributive shock patients when clinically indicated norepinephrine dose reduction is performed by the attending physician.
Pcc is measured before and 30 minutes after dose reduction using a stepwise inspiratory hold maneuver via PiCCO monitoring.
Studieoversikt
Status
Rekruttering
Intervensjon / Behandling
Detaljert beskrivelse
In distributive shock patients receiving norepinephrine with MAP maintained in the 75-85 mmHg range, attending physicians may reduce norepinephrine dose based on clinical judgment.
This study observes hemodynamic changes associated with such reductions without any investigator-initiated intervention.
Critical closing pressure (Pcc) and derived parameters including tissue perfusion pressure (TPP), mean systemic filling pressure analogue (Pmsf), and vascular waterfall (VW) are measured at baseline and 30 minutes after dose reduction, provided MAP variability is less than 5 mmHg.
Pcc is derived from linear regression of simultaneously measured cardiac output (CO) and mean arterial pressure (MAP) during stepwise inspiratory hold maneuvers.
Steady-state CO and MAP values are recorded during the final 3 seconds of 12-second inspiratory holds at plateau pressures of 5, 15, 25, and 35 cmH2O.
The x-intercept of the CO-MAP regression line is taken as Pcc.
Studietype
Observasjonsmessig
Registrering (Antatt)
30
Kontakter og plasseringer
Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.
Studiekontakt
- Navn: Bin Du, Dr
- Telefonnummer: 86+15136289398
- E-post: sunyaliii@163.com
Studiesteder
-
-
Beijing Municipality
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Beijing, Beijing Municipality, Kina, 100730
- Rekruttering
- Peking Union Medical College Hospital
-
Ta kontakt med:
- Bin Du
- Telefonnummer: 86-15136289398
- E-post: sunyaliii@163.com
-
-
Deltakelseskriterier
Forskere ser etter personer som passer til en bestemt beskrivelse, kalt kvalifikasjonskriterier. Noen eksempler på disse kriteriene er en persons generelle helsetilstand eller tidligere behandlinger.
Kvalifikasjonskriterier
Alder som er kvalifisert for studier
- Voksen
- Eldre voksen
Tar imot friske frivillige
Nei
Prøvetakingsmetode
Ikke-sannsynlighetsprøve
Studiepopulasjon
Adult distributive shock patients receiving invasive mechanical ventilation and norepinephrine treatment
Beskrivelse
Inclusion Criteria:
- Adult distributive shock patients aged ≥18 years;
- Receiving norepinephrine infusion with MAP in the 75-85 mmHg range;
- PiCCO catheter in situ;
- Under mechanical ventilation;
- Clinically indicated norepinephrine dose reduction per attending physician judgment.
Exclusion Criteria:
- Significant cardiac arrhythmia affecting CO measurement reliability;
- Contraindication to airway plateau pressure maneuver;
- Active titration of other vasoactive agents within 30 minutes prior to measurement;
- Hemodynamic instability making it impossible to reduce norepinephrine dose.
Studieplan
Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.
Hvordan er studiet utformet?
Designdetaljer
Kohorter og intervensjoner
Gruppe / Kohort |
Intervensjon / Behandling |
|---|---|
|
Distributive shock patients undergoing norepinephrine dose reduction
Mechanically ventilated distributive shock patients in whom the attending physician clinically indicated norepinephrine dose reduction, with MAP transitioning from the 75-85 mmHg range to the 65-75 mmHg range.
|
Observation of hemodynamic parameters before and after clinically indicated norepinephrine dose reduction.
No investigator-initiated intervention was performed.
|
Hva måler studien?
Primære resultatmål
Resultatmål |
Tiltaksbeskrivelse |
Tidsramme |
|---|---|---|
|
Change in critical closing pressure (Pcc, Unit: mmHg) before and after norepinephrine dose reduction
Tidsramme: Baseline and 30 minutes after norepinephrine dose reduction
|
Pcc is derived from linear regression of simultaneously measured cardiac output against mean arterial pressure during stepwise inspiratory hold maneuvers via PiCCO monitoring.
The x-intercept of the regression line (at zero flow) represents Pcc.
Measurement is performed at baseline and 30 minutes after norepinephrine dose reduction.
|
Baseline and 30 minutes after norepinephrine dose reduction
|
|
Change in tissue perfusion pressure (TPP, unit: mmHg) before and after norepinephrine dose reduction
Tidsramme: Baseline and 30 minutes after norepinephrine dose reduction
|
TPP is calculated as the difference between mean arterial pressure (MAP) and critical closing pressure (Pcc): TPP = MAP minus Pcc, unit: mmHg
|
Baseline and 30 minutes after norepinephrine dose reduction
|
Sekundære resultatmål
Resultatmål |
Tiltaksbeskrivelse |
Tidsramme |
|---|---|---|
|
Change in mean systemic filling pressure analogue (Pmsf, unit: mmHg) before and after norepinephrine dose reduction
Tidsramme: Baseline and 30 minutes after norepinephrine dose reduction
|
Pmsf is estimated as the x-intercept of the linear regression of cardiac output against central venous pressure (CVP), representing the venous pressure at zero flow.
|
Baseline and 30 minutes after norepinephrine dose reduction
|
|
Change in Vascular waterfall (VW, unit: mmHg) before and after norepinephrine dose reduction
Tidsramme: Baseline and 30 minutes after norepinephrine dose reduction
|
Vascular waterfall (VW) is calculated as Pcc minus Pmsf.
|
Baseline and 30 minutes after norepinephrine dose reduction
|
|
Change in capillary refill time (CRT, unit: seconds）
Tidsramme: Baseline and 30 minutes after norepinephrine dose reduction
|
Capillary refill time is assessed by applying pressure to the fingertip for 5 seconds and measuring the time for color to return after release.
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Baseline and 30 minutes after norepinephrine dose reduction
|
Samarbeidspartnere og etterforskere
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Studierekorddatoer
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Studer hoveddatoer
Studiestart (Faktiske)
1. september 2025
Primær fullføring (Antatt)
1. juli 2027
Studiet fullført (Antatt)
1. september 2027
Datoer for studieregistrering
Først innsendt
8. juni 2026
Først innsendt som oppfylte QC-kriteriene
12. juni 2026
Først lagt ut (Faktiske)
17. juni 2026
Oppdateringer av studieposter
Sist oppdatering lagt ut (Faktiske)
17. juni 2026
Siste oppdatering sendt inn som oppfylte QC-kriteriene
12. juni 2026
Sist bekreftet
1. juni 2026
Mer informasjon
Begreper knyttet til denne studien
Nøkkelord
Ytterligere relevante MeSH-vilkår
Andre studie-ID-numre
- pumch-micu202606
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