A pocket valve mask , abbreviated to BVM and sometimes known as the Ambu bag or commonly as manual resuscitator or "self-inflating bag", are handheld devices commonly used to provide positive pressure ventilation to patients who are not breathing or not breathing adequately. This device is a necessary part of resuscitation equipment for out-of-hospital trained professionals (such as ambulance crews) and is also frequently used in hospitals as part of standard equipment found in strollers, emergency rooms or other critical care. Settings. Underscoring the frequency and superiority of BVM use in the United States, the American Heart Association (AHA) Guidelines for Cardiac Resuscitation and Emergency Heart Treatment recommends that "all health care providers should be familiar with the use of mask-bag devices." Manual resuscitation is also used in hospitals for temporary ventilation of patients who depend on mechanical ventilators when mechanical ventilators need to be checked for possible malfunctions, or when ventilator-dependent patients are transported in the hospital. Two main types of manual resuscitation exist; one version of its own filling with air, although supplemental oxygen (O 2 ) can be added but not required for the device to function. Another major type of manual resuscitator (flow-inflation) is greatly used in non-emergency applications in the operating room for patient ventilation during induction of anesthesia and recovery.
The use of manual resuscitation for patient ventilation is often called "pocketing " of the patient and is regularly required in a medical emergency when the patient's breathing is inadequate (respiratory failure) or has completely stopped (respiratory breathing). The use of a manual resuscitator forces air-feeding or oxygen to the lungs to inflate them under pressure, thus providing a means for manually ventilating positive pressure. These are used by professional saviors in preference for mouth-to-mouth ventilation, either directly or through an additional such as a pocket mask.
Video Bag valve mask
History
The bag-valve mask concept was developed in 1953 by German engineer Holger Hesse and his partner, Danish anesthesiologist Henning Ruben, after their initial work on suction pumps. Then Hesse company was renamed Ambu, which has been manufacturing and marketing this device since the late 1950s. The complete form of AMBU is the Manual Breathing Units. Ambu Bag Ã,® is a self-inflating bag resuscitator from Ambu company, which still produces and markets its own resuscitation resuscitation.
Today there are several manufacturers of resuscitators self-inflating bag. Some, like the original Ambu bag, are durable and are intended for reuse (after being thoroughly cleaned). Others are cheap and intended for single use.
Originally produced in one size, now BVM is available in sizes for use with babies, children or adults.
Maps Bag valve mask
Standard components
Mask
BVM consists of a flexible air chamber ("bag", approximately the length of the foot), attached to the face mask through the shutter valve. When the face mask is applied properly and the "bag" is squeezed, the device will force air into the patient's lungs; when the bag is released, the sac itself expands from the other end, drawing either ambient air or the low pressure oxygen flow supplied by the regulated cylinder, while also allowing the patient's lungs to deflate into the surrounding environment (not the bag) through a one-way valve.
Bag and valve
Combination bags and valves can also be attached to additional additional air ducts instead of masks. For example, it can be attached to the endotracheal ducts or laryngeal laryngeal breathing channels. Small heat and moisture exchangers, or bacterial moisturizers/filters, can be used.
Bag-valve masks can be used without attaching to the oxygen tank to provide "air space" (21% oxygen) for the patient, but the manual resuscitator device can also be connected to a separate bag reservoir that can be filled with pure oxygen. from a compressed oxygen source - this can increase the amount of oxygen delivered to the patient to nearly 100%.
The valve-bag mask is available in various sizes to suit babies, children and adults. The size of the face mask can be detached from the size of the bag; for example, a child-sized bag can be used with different masks for several face sizes, or pediatric masks may be used with adult bags for patients with small faces.
Most types of devices can be used disposable and therefore disposable, while others are designed to be cleaned and reused.
Operation method
Manual resuscitation causes the gas inside the inflatable socket to be force-fed into the patient through a one-way valve when compressed by the rescuer; The gas is then ideally conveyed through the mask and into the patient's trachea, bronchi and into the lungs. To be effective, the bag pouch mask should provide between 500 and 800 milliliters of air to the lungs of a normal male adult patient, but if additional oxygen is provided, 400 ml may still be adequate. Squeeze the bag every 5-6 seconds for adults or every 3 seconds for infants or children to provide adequate breathing rates (10-12 respirations per minute in adults and 20 per minute in children or infants).
Professional rescuers are taught to ensure that the mask portion of the BVM is sealed properly around the patient's face (ie, to ensure proper "seal mask"); otherwise, the pressure required to force-expand the lungs is released into the environment. This is difficult when a single rescuer tries to keep the face mask seal with one hand while squeezing the bag with the other. Therefore, the general protocol uses two rescuers: one rescuer to hold the mask to the patient's face with both hands and focus completely on retaining the anti-leak mask seal, while other rescuers squeeze the bag and focus on the breath (or tidal volume) and time.
An endotracheal tube (ET) can be inserted by an advanced practitioner and can replace the mask part of manual resuscitation. It provides a safer air channel between the resuscitator and the patient, since the ET tube is sealed with a blowing cuff in the trachea (or windpipe), so that any regurgitation is less likely to enter the lungs, and so inflation pressure is forced only to enter the lungs, lungs and do not accidentally go to the stomach (see "complications" below). The ET tube also maintains an open and safe airway at all times, even during CPR compression; than when manual resuscitation is used with a mask when the face mask seal is difficult to maintain during compression.
Complications
In normal breathing, the lungs develop under a slight vacuum as the muscles of the chest wall and diaphragm expand; this "pulls" the open lungs, causing air to enter the lungs to expand under a gentle vacuum. However, when using a manual resuscitator, as with other methods of positive pressure ventilation, the lungs are forcibly pumped with compressed air or oxygen. This inherently causes the risk of multiple complications, many of which depend on whether a manual resuscitator is used with a face mask or ET tube. Complications are associated with over-inflating or over-pressurizing the patient, which may cause: (1) air to inflate the stomach (called stomach inflammation); (2) lung injury caused by excessive stretching (called volutrauma); and/or (3) lung injury from over-pressurization (called barotrauma).
Pulmonary inflammation/lung aspiration
When a face mask is used together with manual resuscitation, the goal is to drain air or oxygen to inflate the lungs. But the air entering the patient also has access to the stomach through the esophagus, which can expand if the resuscitator is too tight (causing too much airflow for the lungs to absorb itself) or too much (causing excess air to be diverted to the stomach. causing the subsequent vomiting and aspiration of the contents of the stomach to the lungs, which has been referred to as the main hazard of bag-valve-mask ventilation, with one study showing this effect difficult to avoid even for the most skilled and experienced users, stating " -inflatable, even experienced anesthesiologists in our study may have ventilated with too short a time of inspiration and/or too large tidal volume, resulting in stomach inflation in some cases. "The study goes on to state that" Gastric inflation is a complex problem that can cause regurgitation, acid aspiration stomach, and, possibly, death. "When gastric inflation causes very acidic vomiting. Stomach acid, subsequent breath delivery can force this caustic acid into the lungs where they cause life-threatening or fatal lung injuries including Mendelson's syndrome, aspiration pneumonia, adult respiratory distress syndrome and a "pulmonary disease similar to those seen in victims of chlorine gas. exposure. "Regardless of the risk of stomach inflation causing vomiting and regurgitation, at least two reports have been found indicating that the insufficiency of the stomach itself remains clinically problematic even when vomiting does not occur.In one case of failed resuscitation (causing death), gastric in- 3-month-old men put adequate pressure on the lungs that "block effective ventilation." Other complications reported are cases of abdominal rupture caused by over-inflation of the stomach from manual resuscitation.Causes of cause and level of risk of unintentional stomach inflation has been examined, with one published study revealing that during prolonged resuscitation up to 75% of the air delivered to patients may be inadvertently sent to the stomach instead of the lungs.
Lung injury and air embolism
When an endotracheal tube (ET) is placed, one of the main advantages is that a direct air-tight channel is provided from the output of the manual resuscitator to the lungs, thus eliminating the possibility of unintentional stomach inflation or lung injury from stomach acid. aspiration. However this puts the lungs at increased risk of a separate lung injury pattern caused by accidental over-inflation (called volutrauma and/or barotrauma). Spongy lung tissue is smooth, and over-stretching can cause adult respiratory distress syndrome - a condition that requires long-term mechanical ventilator assistance in the ICU and is associated with poor survival (eg, 50%), and significantly increases maintenance costs up to $ 30,000 per day. Lung volutrauma, which can still be achieved through "cautious" delivery of large, slow breaths, may also cause "popped" or collapsed lungs (called pneumothorax), with at least one published report describing "a patient who suddenly tension pneumothorax was developed during ventilation with a pocket-valve device. "In addition, there is at least one report of the use of manual resuscitation in which the lungs inadvertently over-accumulate to the point where" the heart contains large volumes of air, "and" the aortic and pulmonary arteries -completely filled with air "- a condition called the" almost fatal uniform "air embolism.
Public health risks from manual resuscitator complications
Two factors appear to make people particularly at risk from complications from manual resuscitators: (1) the prevalence of their use (leading to high probability of exposure), and (2) a real inability for providers to protect patients from uncontrollable, unintentionally, inflation.
The prevalence of manual resuscitator use
Manual resuscitation is usually used for temporary ventilation support, especially the inflation-flow versions used during induction/recovery of anesthesia during routine operation. Thus, most residents tend to be "bagged" at least once during their lifetime because they undergo a procedure that involves general anesthesia. In addition, large numbers of newborns are ventilated with manual resuscitators of baby size to help stimulate normal breathing, making manual resuscitation among the first therapeutic medical devices encountered at birth. As stated earlier, manual resuscitators are the first-line devices recommended for emergency-made emergency critical care patients, and are thus used not only throughout hospitals but also in off-site care by firefighters, paramedics and outpatient clinics.
The inability of professional providers to use manual resuscitation in established safety guidelines
The manual resuscitators do not have a built-in tidal volume control - the amount of air used to force-inflate the lungs during each breath completely depends on how many carriers squeeze the bag. In response to the dangers associated with the use of manual resuscitation, specific guidelines from the American Heart Association and the European Resuscitation Council are issued which establish recommendations for maximum tidal volume (or breath size) and safe levels of ventilation for patients. Although no known study has assessed the frequency of complications and/or deaths due to the uncontrolled use of manual resuscitation, many peer-reviewed studies have found that, despite established safety guidelines, over-inflationary events with manual resuscitation continue to be " endemic "and unrelated to provider training or skill level. Another clinical study found "tidal volumes delivered by manual resuscitators showed large variations", concluding that "manual resuscitator is not a suitable device for accurate ventilation." Separate assessment of other high-skilled groups with frequent use of emergency resuscitation (paramedic ambulance) solutions found that "Although training appears to be sufficient, EMS personnel consistently hyperventilate during CPR outside the hospital", with the same study group concluding that "Hyperventilation unrecognized and unintentional ones may contribute to survival rates that are currently bleak due to a heart attack. "A peer-reviewed study published in 2012 assessed the possibility of an uncontrolled over-inflation incident in newborn neonates found that "the large differences between the delivered and the current guideline values ​​are observed for all parameters," and that "regardless of profession or technical handling... 88.4% exerting excessive pressure, while... 73.8% exceeded the volume range recommended ", concluding that" most pe as well as from all professional groups exerting excessive pressures and volumes. "A recent follow-up examination was conducted to assess whether the solution to over-ventilation problems might lie in the use of adult-sized manual resuscitation in adults or the use of a more sophisticated version of inflation-flow (or" Mapleson C ") from manual resuscitators: temporary "pediatric self-inflating pouches deliver ventilation with the most consistent guidelines", it does not lead to full adherence compliance as "the lung of patients who have hyperventilated the lungs in a simulated heart attack with all three devices."
Sets non-compliance because of excessive levels of excessive pulmonary inflation
"Hyperventilation" can be achieved by shipping (1) too many breaths per minute; (2) the breath is too large and exceeds the patient's natural lung capacity; or (3) a combination of both. With the use of manual resuscitation, both the rate and volume of inflating can be controlled physically through the inherent safety adjustments within the device itself, and as highlighted above, studies show service providers often exceed the prescribed safety guidelines for ventilation levels (10 breaths per minute) and volume (5-7 mL/kg body weight) as outlined by the American Heart Association and the European Resuscitation Council. Numerous studies have concluded that ventilation at more levels than current guidelines could disrupt blood flow during cardiopulmonary resuscitation, but the pre-clinical trials associated with these findings involve the delivery of inspiratory volumes that exceed current guidelines (eg, they assess hyperventilation effects either through the level excessive and excessive volume simultaneously). A more recent study published in 2012 extends knowledge of this topic by evaluating the effects apart from (1) excessive levels of isolation with inspirational volumes according to the guidelines; (2) compliance level of the guidelines with excessive inspiration volume; and (3) combined guidance of non-conformity with excessive levels and volumes. The study found that excessive levels more than triple the current guidelines (eg, 33 breaths per minute) should not interfere with CPR when inspiration volumes are delivered in appropriate levels of guidelines, suggesting that the ability to maintain breathing sizes within guideline limits can be individualized reducing clinical risks. the danger of excessive levels. It was also found that when excessive tidal volumes were delivered, a temporary observed change in blood flow at low ventilation levels but sustained when both tidal volumes and levels were simultaneously redundant, indicating that excessive tidal volume of the guidelines was the primary mechanism. side effects, with the level of ventilation acting as a multiplier of this effect. Consistent with previous studies in which both excessive levels and volumes were found to produce side-effects of blood flow disruption during CPR, a troubling factor may be insufficient time to allow large respiratory expiration between adjacent high breaths, leading to lung- lungs. never allowed to fully exhale between vents (also called "piling" the breath). Recent advances in manual ventilation safety may be the increasing use of time-relief devices that emit audible and/or visual tones or flashing lights at prescribed intervals with appropriate guidelines for the frequency of breathing; one study found this device could lead to almost 100% adherence guidelines for ventilation levels. While these advances seem to provide a solution to the "level problems" associated with the use of manual resuscitation using excessive guidance, this may not address the "volume problem" that can continue to make manual resuscitation a danger to patients (since complications can still occur from above- even when levels are delivered in the guidelines).
Currently the only device that can provide a pre-set, the physically determined volume of inflation in a safety guide is a mechanical ventilator that requires a compressed power source and/or compressed oxygen source, a higher level of training to operate, and usually the cost hundreds to thousands of dollars more than disposable manual resuscitation.
Additional components/features
Filters
The filter is sometimes placed between the mask and the sac (before or after the valve) to prevent contamination of the sac.
Final positive expiratory pressure
Some devices have PEEP valve connectors, for better maintenance of positive air pressure.
Drug delivery
Closed ports can be inserted into the valve assembly to allow inhalation drugs injected into the airflow, which may be very effective in treating patients with severe asthma-related respiratory problems.
Airway pressure port
Separate closed ports can be inserted into the valve assembly to allow pressure monitoring devices to be installed, allowing the savior to continuously monitor the amount of positive pressure generated during forced lung inflation.
Pressure release valve
Pressure release valves (often known as "pop-up valves") are usually included in pediatric versions and some adult versions, whose purpose is to prevent accidental over-pressurization of the lungs. A cutting clip is usually incorporated into this valve assembly in case medical needs call for inflation at pressures beyond the normal cutoff of the pop-up valve.
Device storage features
Some bags are designed to go bankrupt for storage. A bag that is not designed to be kept unconscious can lose elasticity when stored compressed for a long time, reducing its effectiveness. The foldable design has a longitudinal rating so that the bag collapses at the "pivot" point, as opposed to the normal compression direction of the bag.
Alternative manual resuscitator
At the hospital, long-term mechanical ventilation is provided using a more complex automatic ventilator. However, frequent use of manual resuscitation is temporarily providing manual ventilation whenever dealing with mechanical ventilator problems is required, if the ventilator circuit needs to be changed, or if there is loss of electric power or compressed and/or oxygenated air sources.
A type of mechanical ventilator mechanical device that has the advantage of not requiring electricity is an oxygen-powered ventilation device (FROPVD). This is similar to manual resuscitation in oxygen driven through a mask to force the patient's lungs, but unlike the manual resuscitator where the pressure used to force the patient's lung-derived originates from someone manually squeezing the bag, with the required pressure FROPVD to force-expand the lungs to come directly from the pressurized oxygen tube. This device will stop functioning when the compressed oxygen tank becomes exhausted.
Type of manual resuscitation
- Self-inflating bags: This type of manual resuscitator is the most commonly used standard design both in hospitals and outside hospitals. The material used for the bag portion of the self-inflating manual resuscitator has "memory", which means that after being manually compressed it will automatically resume itself between breaths (drawing air for the next breath). This device may be used alone (thereby providing an air-chamber) or it can be used in connection with an oxygen source to produce nearly 100% oxygen. As a result of this feature, this type of manual resuscitator is suitable for use in hospitals and outside hospitals (eg, ambulances).
- Bags flowing: Also called "anesthesia pouch", this is a special form of a manual resuscitator with a soft pockets and does not re-expand itself. This requires a source of external flow of pressurized inflation gas for the bag to expand; once increased the provider can manually squeeze the bag or, if the patient is breathing on himself, the patient can inhale directly through the bag itself. This type of manual resuscitation is used extensively during induction and recovery of anesthesia, and is often attached to the anesthetic console so that an anesthetic gas can be used to ventilate the patient. They are primarily used by anesthesiologists in general anesthesia administration, but also during some hospital emergencies that may involve an anesthesiologist or respiratory therapist. They are not normally used outside of hospital settings. As a recent Indian study, this flow inflation bag can also be used to provide CPAP in children who breathe spontaneously. This study cites that this CPAP model is cost-effective in limited resource settings
See also
- Artificial Respiracy
- Mechanical Ventilation
- Respiratory Therapy
References
External links
- Free transparent reality simulation from self-inflating manual resuscitator
Source of the article : Wikipedia
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