P/V Tool®

  • Respiratory mechanics maneuver that records a quasi-static pressure/volume curve
  • Easy to assess recruitability of ARDS patients
  • Simple and safe way to perform lung recruitment maneuvers
  • Can be combined with esophageal pressure measurement

Protective ventilation tool for diagnosis and recruitment

The Protective Ventilation Tool (P/V Tool) performs a respiratory mechanics maneuver that records a quasi-static pressure/volume curve showing both the inflation and deflation curves. This data can then be analyzed to determine the lung recruitability and recruitment strategy to apply.

The P/V Tool can also be used for lung recruitment maneuvers by applying sustained inflation. Once completed, the P/V Tool displays the volume of the lung effectively recruited. The P/V Tool is particularly helpful for ARDS patients, as appropriate lung recruitment and correct setting of PEEP as an anti-derecruiting force are critical.

The combination of P/V Tool and esophageal pressure measurement is useful for titrating the recruitment maneuver, allowing for the appropriate setting of PEEP and tidal volume to adequately ventilate the patient without injuring the lungs (Talmor 2008).

What customers say about the P/V Tool

Dr. Ross Freebairn

Medical Director Intensive Care Services

Hawke’s Bay Hospital, Hastings, New Zealand

We have used the P/V Tool to provide a mechanism of producing a repeatable recruitment maneuver, which can be done by anybody trained in the simple art of pushing buttons.

Camille Neville

Clinical Educator for the Respiratory Department

Florida Hospital, Orlando (FL), USA

We recommend our respiratory therapists to use the P/V Tool as soon as they put the patient on the ventilator to obtain optimum PEEP. The therapists find it very helpful, especially on the sicker patients.

Ken Hargett

Director Respiratory Care

Methodist Hospital, Houston (TX), USA

We use the P/V Tool to determine initial PEEP settings on almost all ventilator patients once they have been sedated for the intubation. We also use the recruitment portion of the P/V Tool a lot, particularly for patients who are having repeated atelectasis.

Scientific evidence

Quasi static P/V curve

  • The P/V Tool is equivalent to the CPAP method for tracing static PV curves of the respiratory system (Piacentini 2009).
  • Survival is higher with protective ventilation, including PEEP set based on LIP, than conventional ventilation (Amato 1998).
  • In ARDS patients, linear compliance of the respiratory system (Crs) is correlated with recruitability (Veillard-Baron 2003).
  • Hysteresis of the PV curve can be used to assess the recruitability of the lung at the bedside (Demory 2008).

Recruitment maneuver by sustained inflation

  • In early ARDS it was possible to open the lung in the majority of patients (Borges 2006).
  • During a sustained inflation, most of the recruitment occured during the first 10 seconds (Arnal 2011).

How the P/V Tool works

P/V Tool maneuvers can be performed with the patient connected and the patient settings intact. Normal ventilation can be resumed at any time.

Quasi-static P/V curve

The P/V Tool records the pressure-volume relation of the lungs at low flow conditions (2 cmH2O/s). The breathing circuit is pressurized linearly to the operator-set pressure target. When the pressure reaches the target, pressure is reduced back to the starting pressure. The resulting curves can be used to analyze:

  • The lower inflection point of the inflation pressure/volume curve
  • The linear compliance of the inflation pressure/volume curve
  • The hysteresis (the difference in volume between the two curves)

Sustained inflation recruitment maneuver

The breathing circuit is pressurized linearly to the operator-set target pressure at the operator-set ramp speed, and the resulting volume changes are recorded. When the pressure reaches the target, an operator-set pause is executed. After the pause, pressure is released linearly to the operator-set end-PEEP level. The integration of the flow during the pause is the recruited volume.

Availability of the P/V Tool

The P/V Tool is available as an option on the HAMILTON-G5 , HAMILTON-C3 , and HAMILTON-C6 mechanical ventilator and is a standard feature on the HAMILTON-S1.



P/V Tool brochure

PDF / 1.2 MB

PN 689202.03


White papers

Lung recruitment maneuvers

PDF / 3.7 MB




P/V curves bibliography

PDF / 632.9 KB




Lung recruitment bibliography

PDF / 781.5 KB



User reports

P/V Tool in ARDS

PDF / 298.5 KB



Michael Bingman RRT, Kelly Cresci RRT, Jason Stamm MD, FCCP, Geisinger Medical Center, Danville, PA

White papers

Utilizing slow pressure-volume loops to determine optimal PEEP and improve patient outcomes

PDF / 839.2 KB



More downloads


Amato MB, Barbas CS, Medeiros DM, Magaldi RB, Schettino GP, Lorenzi-Filho G, Kairalla RA, Deheinzelin D, Munoz C, Oliveira R, Takagaki TY, Carvalho CR. Effect of a protective-ventilation strategy on mortality in the acute respiratory distress syndrome. N Engl J Med. 1998 Feb 5;338(6):347-54

Arnal JM, Paquet J, Wysocki M, Demory D, Donati S, Granier I, Corno G, Durand-Gasselin J. Optimal duration of a sustained inflation recruitment maneuver in ARDS patients. Intensive Care Med. 2011 Oct;37(10):1588-94.

Borges JB, Okamoto VN, Matos GF, Caramez MP, Arantes PR, Barros F, Souza CE, Victorino JA, Kacmarek RM, Barbas CS, Carvalho CR, Amato MB. Reversibility of lung collapse and hypoxemia in early acute respiratory distress syndrome. Am J Respir Crit Care Med. 2006 Aug 1;174(3):268-78.

Demory D, Arnal JM, Wysocki M, Donati S, Granier I, Corno G, Durand-Gasselin J. Recruitability of the lung estimated by the pressure volume curve hysteresis in ARDS patients. Intensive Care Med. 2008 Nov;34(11):2019-25

Grasso S, Mascia L, Del Turco M, Malacarne P, Giunta F, Brochard L, Slutsky AS, Marco Ranieri V. Effects of recruiting maneuvers in patients with acute respiratory distress syndrome ventilated with protective ventilatory strategy. Anesthesiology. 2002 Apr;96(4):795-802. 

Piacentini E, Wysocki M, Blanch L. Intensive Care Med. A new automated method versus continuous positive airway pressure method for measuring pressure-volume curves in patients with acute lung injury. 2009 Mar;35(3):565-70

Talmor D, Sarge T, Malhotra A, O'Donnell CR, Ritz R, Lisbon A, Novack V, Loring SH. Mechanical ventilation guided by esophageal pressure in acute lung injury. N Engl J Med. 2008 Nov 13;359(20):2095-104

Vieillard-Baron A, Prin S, Chergui K, Page B, Beauchet A, Jardin F. Early patterns of static pressure-volume loops in ARDS and their relations with PEEP-induced recruitment. Intensive Care Med. 2003 Nov;29(11):1929-35

Villar J, Kacmarek RM, Pérez-Méndez L, Aguirre-Jaime A. A high positive end-expiratory pressure, low tidal volume ventilatory strategy improves outcome in persistent acute respiratory distress syndrome: a randomized, controlled trial. Crit Care Med. 2006 May;34(5):1311-8