Intermittent Positive Pressure Ventilation (IPPV)

IPPV ventilation is an indispensable form of ventilation in emergency medicine; it can save lives in critical situations such as resuscitation or acute respiratory failure. IPPV ventilation can improve patient outcome compared to manual bag mask ventilation¹ , but every move needs to be right in an emergency - after all, every second counts. 

The innovative ventilators from WEINMANN are tailored specifically to the requirements of the emergency medical services and facilitate straightforward, intuitive handling of IPPV ventilation, saving valuable time at critical moments.

Volume-controlled ventilation (VCV) with IPPV and S-IPPV

Volume-controlled ventilation (VCV) is a form of ventilation in which the ventilator delivers a constant minute volume and takes on the work of breathing. This ensures an optimum oxygen supply. This ventilation method furthermore provides reliable ventilation of the lungs which is of particular significance in the case of acute respiratory insufficiency. 

A central aspect of volume-controlled ventilation is the limiting of pressure: During inspiration, a maximum airway pressure (pMax) is specified to limit inspiratory pressure (pInsp). Once pMax has been reached, the device can either maintain the pressure at a constant level for the specified inspiratory time or cancel inspiration. Key parameters such as tidal volume and respiratory rate can be preset in this process.

Ventilation modes in volume-controlled ventilation include IPPV (Intermittent Positive Pressure Ventilation) and S-IPPV (Synchronized Intermittent Positive Pressure Ventilation).

IPPV ventilation

The volume-controlled ventilation mode IPPV (Intermittent Positive Pressure Ventilation) stands for ventilation with an intermittent positive pressure. During inspiration, a positive pressure is exerted on the lung to make it inflate. During expiration, the pressure drops to PEEP level, with the result that alveolar pressure moves closer to atmospheric pressure without achieving negative values.

In IPPV ventilation, tidal volume is regulated by the device. If pMax is reached during inspiration, the device maintains this pressure until the end of inspiratory time and then switches to expiration. This means that the preset tidal volume is not always administered in full so as to prevent barotrauma of the lung.²

In addition, a positive end-expiratory pressure (PEEP) can be generated during IPPV ventilation to prevent alveolar collapse. In contrast to pure IPPV ventilation, this mode is also called CPPV (Continuous Positive Pressure Ventilation). 

Applications for IPPV ventilation

As IPPV ventilation completely replaces physiological breathing in patients with no spontaneous breathing, it is used primarily during cardiopulmonary resuscitation in intensive care and emergency medicine in order to ensure an oxygen supply during CPR. 

In addition, IPPV ventilation is used for acute respiratory insufficiency if disease or injury prevent patients from breathing adequately on their own. 

Setting the parameters for IPPV ventilation

Setting IPPV ventilation parameters allows the ventilator to be precisely adapted to suit a patient’s individual clinical status. The following parameters can be set in IPPV mode:

Benefits of IPPV ventilation

Mechanical IPPV ventilation delivers key benefits compared to manual ventilation with a bag-valve mask:

IPPV ventilation allows tidal volume to be controlled precisely to guarantee adequate alveolar ventilation and rapid adaptation in the event of changes in the patient’s condition.

Precise settings of ventilation parameters increase patient safety, as they can be adapted to suit individual requirements such as height, weight, and clinical picture. This is particularly important when treating patients with complex pulmonary and extrapulmonary diseases, as well as enabling complications such as ventilator-associated lung injury (VALI) or the consequences of hypercapnia (such as fasciculations, cramps, and respiratory acidosis) to be avoided. 

S-IPPV ventilation

S-IPPV ventilation (Synchronized Intermittent Positive Pressure Ventilation) is a further development of IPPV ventilation. It stands for synchronized IPPV ventilation, as in contrast to classic IPPV, S-IPPV detects the patient’s own breaths by means of a trigger and synchronizes mechanical ventilation with that. The trigger window, typically reacting to a drop in pressure in the ventilation hose, is active throughout the whole of expiratory time. This means that patients can initiate mechanical breaths spontaneously.

Applications for S-IPPV ventilation

S-IPPV ventilation is particularly suitable for patients with continued, but restricted spontaneous breathing. Synchronization with respiratory effort divides the work of breathing between the patient and the ventilator, a particular benefit in weak or post-operative patients. Ventilation also seems more natural and is felt to be less invasive.

Setting the parameters for S-IPPV ventilation

The parameters for S-IPPV ventilation correspond largely to those of IPPV ventilation: 

• Tidal volume (VT) in ml
• Respiratory rate (freq) in 1/min
• Positive end-expiratory pressure (PEEP) in mbar
• Maximum airway pressure (pMax) in mbar
• Ratio of inspiratory to expiratory time (I:E)
• Inspiratory trigger (InTr)

The inspiratory trigger (InTr) is also set in S-IPPV ventilation. This parameter determines how sensitively the device reacts to the patient’s efforts to breathe and when a supported breath is to be initiated.

Benefits of S-IPPV ventilation

A key benefit of S-IPPV ventilation is thevariable mechanical minute volume (MV). The ventilator increases MV if spontaneous breathing is reduced, and reduces support if the patient’s independent breathing is stronger. Minute volume and respiratory rate thus adapt flexibly to suit the patient’s individual requirements.

WEINMANN ventilators provide IPPV and S-IPPV for the emergency medical services

WEINMANN developed the MEDUMAT Standard² and MEDUVENT Standard ventilators for optimum IPPV ventilation in the emergency medical services. Both devices provide both modes - IPPV and S-IPPV ventilation.

MEDUMAT Standard² 

Despite its extensive functions, MEDUMAT Standard² is remarkably lightweight and handy at just 2.5 kg. With a battery runtime of up to 10 hours, it provides reliable support, even in extended applications. 

The ventilator has IPPV ventilation mode as standard and can have S-IPPV mode as an optional extra. This allows assisted, volume-controlled ventilation in which the device uses the whole expiratory phase as a trigger window and thus perfectly synchronizes ventilation with the patient’s own breaths.

MEDUMAT Standard² is suitable for patients weighing 3 kg or more. The ventilation process starts with a question about patient body weight to ensure rapid ventilation in accordance with the guidelines. 

The device clearly shows all the important respiratory parameters and ventilation curves such as flow measurement and CO₂ measurement, allowing comprehensive monitoring. Intuitive operation of the ventilator is supported by clearly arranged controls, unambiguous symbols, and acoustic and visual warning signals.

MEDUVENT Standard

MEDUVENT Standard is a compact, lightweight ventilator developed specifically for use by the emergency medical services. With a weight of just 2.1 kg and a volume of 3.5 l, it is one of the most lightweight emergency ventilators in the world. 

MEDUVENT Standard, too, has the integrated IPPV mode of ventilation and can have the S-IPPV ventilation mode added. The intuitive operation enables the ventilation process to be started quickly by entering the patient’s weight to customize treatment. 

MEDUVENT Standard is characterized by the fact that it maintains oxygen supply even when there is no external gas source. Assuming typical settings for adults, the device can guarantee an oxygen supply for up to 7.5 hours, administering oxygen concentrations of 21% to 100% FiO₂.

The device provides clear monitoring by displaying the pressure and flow curves in real time. Important parameters such as expiratory tidal volume and minute volume, as well as respiratory rate, can be deduced from the flow measurements, allowing deviations or changes in patient requirements to be detected quickly and the necessary measures taken.

Our MEDUMAT Standard² and MEDUVENT Standard ventilators for IPPV and S-IPPV ventilation ensure that patients in emergency situations receive optimum ventilation, thus providing reliable support for emergency response by professional EMS field providers. 

¹ Hernández-Tejedor A et. al. Ventilatory improvement with mechanical ventilator versus bag in non-traumatic out-of-hospital cardiac arrest: SYMEVECA study, phase 1. Resuscitation. 2023 Nov;192

²https://www.sciencedirect.com/science/article/abs/pii/S0261988121000975