Mechanical ventilator

i m going to present presentation on mechanical ventilator. this is useful for all health care provider who are working in ICU .

1. MECHANICAL Ventilator Mr. Naveen Pareek Ph.D Scholar Associate Professor Ramsnehi College OF nursing , Bhilwara

2. Introduction It is a respirator or breathing machine, is a medical device that provides a patient with oxygen when they are unable to breathe on their own.  The ventilator gently pushes air into the lungs and allows it to come back out like the lungs would typically do when they are able.

3. Mechanical Ventilation:- Mechanical Ventilation is used on patients who are unable to sustain adequate ventilation that is needed to maintain normal levels of gas exchange. Mechanical ventilation helps normalize arterial blood gas levels and acid-base imbalance by providing oxygenation and by removing carbon dioxide

4. What is a Mechanical Ventilator:- A mechanical ventilator is a machine that aids in a patient’s ability ventilate . In other words their ability to take in oxygen and remove carbon dioxide. This machine is most often used for patients with breathing difficulties and those recovering from surgery or critical illness .

5. Benefits of Mechanical Ventilation:- Helps the patient get adequate amounts of oxygen. It allows medication to work while the patient heals. It helps the patient achieve stable oxygenation and ventilation. Maintains a patent airway. Maintains effective gas exchange.

6. Complications of Mechanical Ventilation:- Barotrauma  – This is a condition in which the tiny air sacs within the lungs known as alveoli, burst or rupture due to increased pressure. As a result, the lungs collapse and this can lead to very serious lung conditions that can affect breathing. Volutrauma  – This condition occurs when the alveoli become filled with fluid due to high tidal volumes. Tidal volume refers to the amount of the air transported into the lungs when you inhale .. Ventilator-Associated Pneumonia (VAP)  – This condition is a form of lung infection induced by mechanical ventilation. Because mechanical ventilation often involves the insertion of tubes into the airway of the patient, there is a chance that various microorganisms can enter the lungs and cause infection.  Intrinsic positive end-expiratory pressure/ AutoPEEP  – Intrinsic positive end-expiratory pressure, also known as AutoPEEP , is characterized by over-inflation of the lungs due to large tidal volumes, restrictive airways, or prolonged inhalation time ..

7. How do Ventilators Work:- Before a patient is connected to a mechanical ventilator, a healthcare provider must first establish a patent airway. This can be done in two ways: 1. Intubation – This involves placing a tube known as endotracheal or ET tube into the mouth and down into the trachea of the patient to establish an airway. 2. Tracheostomy – A tracheostomy involves creating a surgical incision into the patient’s neck and inserting a tube into the patient’s trachea to establish an airway. This procedure is performed by the physician . Once a tube is secured into the patient’s trachea, the tube can then be connected to the mechanical ventilator. The ventilator works by blowing pressure (air plus oxygen as needed) into a patient’s lungs. With this process, the machine can do all the breathing or just assist with the patient’s breathing.

8. Mechanical Ventilation Indications:- Insufficient oxygen levels – Inadequate oxygenation, known as hypoxia, can damage the tissues and other vital organs in the body if left untreated. Mechanical ventilation helps treat hypoxia by providing a sufficient amount of oxygen into the patient’s lungs that can then be distributed throughout the body to its tissues. Inadequate ventilation – Mechanical ventilator helps the patient take in oxygen during inhalation and excrete carbon dioxide during exhalation. Inability to protect the airway – Unconscious patients with breathing difficulties are at increased risk for aspiration. Aspiration occurs when the patient accidentally inhales nasal and oral secretions directly into the lungs. Establishing a patent airway and maintaining spontaneous breathing through mechanical ventilation can help prevent this condition.

9. Mechanical Ventilation Modes:- 1. Volume Modes – These modes work by delivering a set tidal volume. Assist-Control Ventilation (AC) or Continuous mandatory ventilation (CMV) – In this mode, the patient makes an effort to breathe while the mechanical ventilator assists by delivering a necessary mechanical breath. AC is contraindicated for patients who breathe rapidly because it may result in lung hyperinflation. Synchronized Intermittent-Mandatory Ventilation (SIMV) – SIMV detects the patient’s inspiratory effort and provides a certain number of breaths depending on the set rate. For instance, if the set rate is 12 breaths per minute, the mechanical ventilator will provide 12 mandatory breaths in one minute while also allowing the patient to take spontaneous breaths between the mandatory breaths.

10. CONT… 2. Pressure Modes – These modes work by delivering a set pressure. Pressure-Controlled Ventilation (PCV) – In this mode, ventilator provides constant pressure during patient’s inhalation. PCV is recommended for patients with neuromuscular disease but with normal lungs. Pressure Support Ventilation (PSV) – This mode allows spontaneous ventilation by allowing the machine to deliver support while the patient regulates his or her own respiratory rate and tidal volume. Pressure Controlled Inverse Ratio Ventilation (PCIRV) – In this mode, the operator sets the time of inspiration to be longer than expiration. PCIRV is recommended for patients with ARDS. Airway Pressure Release Ventilation (APRV) – This unique mode of ventilation allows the patient to spontaneously ventilate at both low and high pressures. This mode of ventilation is recommended for ARDS patients as well.

11. CONT… 3. Dual Modes – These mode work by allowing you to set the volume and pressure. Pressure Regulated Volume Control (PRVC) – This mode delivers constant pressure applied throughout inspiration, regardless of whether breath is initiated by the patient or an assist breath.

12. Mechanical Ventilation Settings:- five basic ventilator settings that you should know : 1. Tidal volume (VT) – This refers to the lung volume. VT represents the normal volume of air displaced during normal inhalation and exhalation when a patient does not exert extra effort during breathing. In young, healthy male adults, the value of VT is approximately 5–8 mL per pound of ideal body weight (IBW). 2. Respiratory rate (RR) – This refers to the number of breaths a patient takes per minute. Normally, healthy adults who are at rest have an RR of 12 to 20 breaths per minute. 3. Positive end-expiratory pressure (PEEP) – This is the pressure applied by the mechanical ventilator at the end of each patient’s breath to ensure that the alveoli do not collapse. Normally, the alveoli expands during inhalation to allow the air to come in. Gas exchange then happens as the blood flows past the alveoli’s wall.

13. CONT… 4. Fraction of inspired oxygen (FiO2) – This simply refers to how much of the air a patient breathes is actually oxygen. Usually, FiO2 is set at 100% at the initiation of mechanical ventilation so that the patient receives maximal amounts of oxygen during the adjustment period and during initial attempts to achieve a stable condition. 5. Flow Rate – The flow rate refers to the maximum flow delivered by the mechanical ventilator during inhalation. It’s volume divided by time. Normally, flow rate of 60 L per minute or more is enough to stabilize a patient’s condition. A low flow rate can lead to dyspnea and other breathing problems.

14. Ventilator Alarms:-   If an alarm occurs, this indicates that there is a problem with the pressure, volume, or rate of air being delivered. In most cases, the healthcare provider should assess the patient first prior to troubleshooting the mechanical ventilator . 1. Kinked or blocked circuits or tubing – When an alarm sounds, the role of the healthcare provider is to immediately check the patient’s condition to assess the severity of the problem and determine the need for immediate resuscitation. If the patient is stable, the next step is to find kinked or blocked tubing that’s impairing air flow.

15. CONT… 2. Problems causing high airway pressure alarms – High-pressure alarms occur if the mechanical ventilator reaches the set limit or if the breath ends . The following are the most common causes of high airway pressure alarms: Accumulation of mucus or other secretions in the patient’s airway due to inadequate humidity. Biting of the ET tube Bronchospasm Coughing, gagging, or “fighting” the ventilator breath Decreased respiratory system compliance due to parenchymal disease, pneumothorax, or decreased ventilation in the lungs Inappropriate settings (e.g. excessive tidal volume or flow rate, shorter inspiratory time, or very low high airway pressure) Kinked or blocked circuits or tubing Ventilator malfunction Water in the ventilator circuit or filter

16. CONT… 3. Problems causing low airway pressure alarms – Low-pressure alarms occur if the pressure inside the breathing circuit falls below the set limit on the mechanical ventilator. The most common causes of low-pressure alarms are the following: ET tube is disconnected from the ventilator circuit. Tracheostomy tube cuff is not well inflated. Poorly fitting tubes or prongs Loose circuit and tubing connections The patient requires higher levels of air than the mechanical ventilator is delivering.

17. CONT… 4. Problems causing high and low rate alarms – High and low rate alarms can be caused by increases or decreases beyond the limit set for the alarm. A low rate alarm, or also known as “apnea alarm”, indicates that the patient has stopped breathing. This alarm is usually triggered by disconnected tubing. On the other hand, high rate alarm occurs when the patient experiences an increase in respiratory rate due to agitation or fatigue. 5. Problems caused by high and low inspiratory volume alarms – High volume inspiratory alarms can be caused by several factors such as leaking or disconnected tubes, increased respiratory rate, or increased demand for air due to pain, anxiety, or improper ventilator settings. On the other hand, low volume inspiratory alarms may be caused by accumulation of mucus secretions, tube obstruction, or a lower respiratory rate.

18. Common Drugs given to Patients Receiving Mechanical Ventilation:- 1. Epidural analgesia  – Epidural administration involves injection of an anesthetic agent into the epidural space around the spinal cord. This route of injection blocks pain sensation by inhibiting nerve signal transmission in the fibers of the spinal cord. 2. Opioids  – Opioids selectively work on neurons that transmit and modulate painful stimuli, leaving certain body functions such as sensation and motor function intact. While opioids are effective at controlling pain, dependence and withdrawal effects can occur with prolonged continuous infusion.  3. Morphine  – Morphine is the oldest opioid used for relief of moderate to severe pain. This medication works by acting on the brain and nervous system to reduce  perception  of pain. 

19. CONT … 4. Benzodiazepines – Benzodiazepines belong to a class of anti-anxiety drugs. They work by enhancing the effect of the neurotransmitter (brain chemical) gamma- Amino butyric acid (GABA), which in turn stimulates receptors that inhibit or calm down brain activity.  5. Propofol  –is a short-acting sedative-hypnotic agent that causes a decreased level of consciousness and lack of memory for events.  6 . Dexmedetomidine  –  Dexmedetomidine is an anti-anxiety drug, sedative, and pain medication. This drug works by activating brain and spinal receptors which in turn relaxes the nerves, causes sedation, and reduces pain sensation. Unlike other sedatives, dexmedetomidine has the ability to provide sedation without risk of respiratory depression. However, it is not recommended for long-term deep sedation . 7. Bronchodilators – Of course, as a Respiratory Therapist, you will most certainly administer bronchodilators to patients receiving Mechanical Ventilation. 

20. Airways are used in Mechanical Ventilation:- Endotracheal (ET) Tube – a catheter (tube) that is inserted into the trachea (through the mouth or nose) for the purpose of establishing and maintaining an airway to ensure the adequate exchange of oxygen and carbon dioxide during ventilation. Tracheostomy ( Trach ) Tube – similar to an ET Tube, except the catheter is inserted directly into the neck through an incision (stoma). Double-lumen Endotracheal Tube – has two independent lumens or different lengths that allow you to ventilate the lungs separately. This airway is used for independent lung ventilation. Esophageal Tracheal Combitube (ETC) – a blind insertion airway device that is used in pre-hospital emergencies. This airway should be replaced with an ET Tube as soon as possible. Laryngeal Mask Airway (LMA) – a supraglottic airway that consists of an inflatable mask that fits directly over the opening into the trachea. It is used for short-term ventilation only when intubation is not possible. It is not intended to be used with Mechanical Ventilation. King Laryngeal Tube – a supraglottic airway device that is easier to insert than an ET Tube. It can be used in with positive pressure ventilation .

21. Common Methods for Airway Insertion:- Endotracheal intubation – This is an emergency procedure performed in patients who are unconscious or have  difficulty   of  breathing in order to maintain an open airway. During the procedure, the patient is given anesthesia and a flexible plastic tube known as  endotracheal  tube (ET) is inserted through the mouth and placed into the patient’s trachea (windpipe ). Tracheostomy  – This medical procedure involves creating a surgical incision in the neck of the patient (just below  the Adam’s  apple) in order to place a tube directly into the windpipe. A tracheostomy can either be temporary or permanent . Cricothyrotomy  – This emergency surgical procedure involves the creation of a hole through a membrane in the patient’s neck into the windpipe in order to establish a patent airway during life-threatening situations.

22. Noninvasive Mechanical Ventilation:- Noninvasive ventilation (NIV) involves the administration of ventilator support without using ET tube or tracheostomy tube. This method has been used for several decades as an alternative method  to  invasive ventilation. NIV makes use of a sealed mask in order to deliver air to patients who cannot breathe on their own . The following are the indications for applying NIV: Acute congestive heart failure with pulmonary edema Acute lung injury Asthma Bronchiolitis Chronic muscle conditions that cause breathing problems (e.g. Multiple sclerosis) Chronic obstructive pulmonary disease (COPD) Cystic fibrosis Impending respiratory muscle fatigue Minimal need for respiratory support Obstructive sleep apnea syndrome Pneumonia Preventing lung collapse Weaning from the ventilator

23. NIV is contraindicated in patients with the following conditions: Air leak syndrome Apnea Difficulty swallowing Extreme anxiety Lack of respiratory drive Large amounts of oral or nasal secretions Low level of consciousness Morbid obesity Need for continuous or nearly continuous ventilatory assistance Trauma, burns, or surgical procedure involving the face Uncooperative patients Unstable cardiorespiratory status