What is a ventilator(Breathing machine)?
A medical ventilator(Breathing Machine) is a machine designed to mechanically move breathable air into and out of the lungs, to provide the mechanism of breathing for a Patient who is physically unable to breathe, or breathing insufficiently.
While modern ventilators are computerized machines, Patients can be ventilated with a bag valve mask, a simple hand-operated machine. After Hurricane Katrina, dedicated staff “bagged” patients in New Orleans hospitals for days with simple bag valve units attached to a Breathing Tube or Endotracheal Tube, a “ventilator” system which can be used with no definite time limit.
Ventilators are chiefly used in intensive care medicine, home care(www.intensivecareathome.com.au) , and emergency medicine (as standalone units) and in anesthesia (as a component of an anesthesia machine).
Medical ventilators are sometimes colloquially called “respirators,” a term which stems from commonly used devices in the 1950′s (particularly the “Bird Respirator”). However, in modern hospital and medical terminology, these machines are never referred to as respirators, and use of “respirator” in this context is now a deprecated anachronism which signals technical unfamiliarity.
Some Ventilators might take over the function of breathing completely, while others might assist and support the critically ill Patient in Intensive Care to breathe for themselves.
Puritan Bennet Ventilator
How does it work?
Ventilators come in many shapes and sizes but in general they have the same functionality. They all tend to have different ventilation modes that can support your loved one from being fully ventilated(breathing is completely taken over by the ventilator and this usually goes hand in hand with sedation and/or coma) or the ventilators have modes that ‘support’ your loved one whilst being ventilated. In a support mode, your loved one triggers every single breath themselves and once the breath has been triggered by either overcoming a pressure or a volume resistance within the ventilator circuits. In either mode- fully ventilated and/or in support ventilation- your loved one will have either a Breathing Tube or Endotracheal Tube(tube in lungs inserted via mouth or nose) or a Tracheostomy tube(tube in windpipe inserted through neck), in order for the delivered breaths to reach the lungs. Both tubes are secured with tape, in order to hold them in place safely.
Patients who are ventilated in Intensive Care need very close monitoring and in most instances have one nurse looking after them.
There are some Intensive Care Units(mainly US), where one nurse is looking after two ventilated Patients and those nurses are usually supported by a respiratory therapist.
Should your loved one require ongoing ventilation and it is foreseeable that he or she will be a slow and long wean off the ventilator, a Tracheostomy insertion might be necessary. The Tracheostomy insertion will make the weaning process off the ventilator easier for your loved one, as he or she will be able to tolerate mechanical ventilation with no or minimal sedation. Please find more information in our Tracheostomy section.
For Patients who require mechanical long term ventilation with Tracheostomy, there is also the opportunity to go home. Please find more information on www.intensivecareathome.com.au
Why is ventilation needed?
Mechanical ventilation is indicated when the patient’s spontaneous ventilation is inadequate to maintain life. It is also indicated as prophylaxis for imminent collapse of other physiologic functions, or ineffective gas exchange in the lungs. Because mechanical ventilation only serves to provide assistance for breathing and does not cure a disease, the Patient’s underlying condition should be correctable and should resolve over time. In addition, other factors must be taken into consideration because mechanical ventilation is not without its complications (see below)
Common medical indications for use include:
- Acute lung injury (including Adult Respiratory Distress Syndrome (ARDS), Multi Trauma(Polytrauma)
- Apnea with respiratory arrest, including cases from intoxication
- Acute respiratory acidosis with partial pressure of carbon dioxide (pCO2) > 50 mmHg and pH < 7.25, which may be due to paralysis of the diaphragm due to Guillain-Barré Syndrome, Myasthenia Gravis, spinal cord injury, or the effect of anaesthetic and muscle relaxant drugs
- Increased work of breathing as evidenced by significant tachypnea, retractions, and other physical signs of respiratory distress
- Hypoxaemia(lack of oxygen) with arterial partial pressure of oxygen (PaO2) < 55 mm Hg with supplemental fraction of inspired oxygen (FiO2) = 1.0
- Hypotension(low blood pressure) including sepsis, Shock , congestive Heart Failure
- Neurological diseases such as Muscular Dystrophy and Amyotrophic Lateral Sclerosis
High Frequency Oscillation Ventilator
Are There Any Complications?
Barotrauma — Pulmonary barotrauma is a well-known complication of positive pressure mechanical ventilation. This includes pneumothorax and subcutaneous emphysema
Ventilator-associated lung injury — Ventilator-associated lung injury (VALI) refers to acute lung injury that occurs during mechanical ventilation. It is clinically indistinguishable from acute lung injury or acute respiratory distress syndrome (ALI/ARDS).
Diaphragm — Controlled mechanical ventilation may lead to a rapid type of disuse atrophy involving the diaphragmatic muscle fibers, which can develop within the first day of mechanical ventilation. This cause of atrophy in the diaphragm is also a cause of atrophy in all respiratory related muscles during controlled mechanical ventilation.
Motility of mucocilia in the airways— Positive pressure ventilation appears to impair mucociliary motility in the airways. Bronchial mucus transport was frequently impaired and associated with retention of secretions and Pneumonia(sometimes also referred to as Ventilator associated Pneumonia)
Of course, if you have any questions or concerns, please discuss them with the ICU nurses and doctors.
All Intensive Care interventions and procedures carry a degree of potential risk even when performed by skilled and experienced staff. Please discuss these issues with the medical and nursing staff who are caring for your loved one.
The information contained on this page is general in nature and therefore cannot reflect individual Patient variation. It is meant as a guideline to specific information which will be discussed with you by the Doctors and Nurses caring for your loved one. INTENSIVE CARE HOTLINE attests to the accuracy of the information contained here BUT takes no responsibility for how it may apply to an individual Patient. Please refer to the full disclaimer.