BVM introduction, indications, contraindication, complications etc in an adult.
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Bag and mask Ventilation Samriddhi Rimal Intern KMCTH
Introduction This is a basic airway management technique that allows for oxygenation and ventilation of patients until a more definitive airway can be establishe d. Also used in cases where endotracheal intubation or other definitive control of the airway is not possible. Always the first response to inadequate oxygenation and ventilation The first “bail-out” maneuver to a failed intubation attempt Attenuates the urgency to intubate
C ontd... In the pediatric population, BVM may be the best option for prehospital airway support. BVM ventilation is also appropriate for elective ventilation in the operati on theatre when intubation is not required, but it is now often substituted by the laryngeal mask airway
The Three Pillars of Airway Management : ( Assessment of Compromises or Threats ) Patency of Upper Airway ( airflow integrity ) Protection against aspiration Assurance of oxygenation and ventilation
Bag and mask equipment *P rovide a volume of 6-7 mL /kg per breath (approximately 500 mL for an average adult). *F or a patient with a perfusing rhythm, ventilate at a rate of 10-12 breaths per minute . *Adult size: 2 litres, Paediatric size:500 ml
Types of Bag used 1.Flow inflating bag (Anaesthesia Bag) Fill s only when oxygen from a compressed source flows into it Depend on a compressed gas source Must have a tight face-mask seal to inflate Use a flow-control valve to regulate pressure-inflation
2.Self inflating bag (AMBU Bag) Fill spontaneously after they are squeezed, pulling oxygen or air into the bag Remain inflated at all times Can deliver positive-pressure ventilation without a compressed gas source . Require attachment of an oxygen reservoir to deliver 100% oxygen
Advantages and disadvantages of types of bags Advantages Disadvantages Flow Inflating Bag Delivers 100% oxygen at all times Easy to determine the adequacy of seal Stiffness of lungs can be felt C an deliver PEEP or CPAP Requires a tight seal to remain inflated Requires a gas source to inflate No safety pop-off valve Requires more experience Self Inflating Bag Does not need a gas source to inflate Pressure release valve / Pop – off valve set at 30 – 40 cm H 2 Easier to use Will inflate even without adequate seal Requires a reservoir to deliver 100% oxygen Can not be used to deliver 100% free flow oxygen
Procedure One hand to maintain face seal position head maintain patency Other hand for ventilation
Technique “ Sniffing”position if C-spine OK Thumb + index finger to maintain face seal Middle finger under mandibular symphysis Ring and little finger under the angle of mandible
Why sniffing position? Sniffing position allows for greater occipito-atlanto-axial angulation. No exact definition has been established. However, 35 degrees neck flexion and 15 degrees head extension is generally considered worldwide. Sniffing position p revents falling of tongue thus preventing obstruction of the upper airway.
BVM during CPR During cardiopulmonary resuscitation (CPR), give 2 breaths after each series of 30 chest compressions until an advanced airway is placed. Then ventilate at a rate of 8-10 breaths per minute. Give each breath over 1 second. If the patient has intrinsic respiratory drive, assist the patient’s breaths. In a patient with tachypnea , assist every few breaths. Ventilate with low pressure and low volume to decrease gastric distension.
Cricoid pressure C ricoid pressure consisten cy should be maintained not in all but in emergency cases while appling BVM . It is the backward Pressure on cricoid cartilage with a force of 30-40 newtons This pressure is meant to compress the esophagus and reduce the risk of aspiration. However , it does not completely protect against regurgitation, especially in cases of prolonged ventilation or poor technique. Care must be taken to avoid excessive pressure, which can result in compression of the trachea.
BVM Ventilation: Assessment of adequacy Observe the chest rise and fall Good bilateral air entry Improving color Lack of air entering the stomach Feeling the bag Pulse oximetry (oxygen saturation)
Indications Respiratory failure Failure of ventilation Failure of oxygenation Failed intubation Elective ventilation in the operating room
Contraindications BVM ventilation is not possible in the case of complete upper airway obstruction. BVM ventilation is relatively contraindicated after paralysis and induction (because of the increased risk of aspiration ). C aution is advised in patients with severe facial trauma and eye injuries. In addition, foreign material (e.g. gastric contents) in the airway may lead to aspiration pneumonitis . In these circumstances, alternative approaches, including endotracheal intubation, may be necessary.
Predictors of a Difficult Airway : BVM Upper airway obstruction Edentulous patients Beard H/O Snoring Obese Elderly >70 years Facial burns, dressings, scarring Poor lung mechanics resistance or compliance
Difficult Airway Adage The first response to failure of bag-mask ventilation is always “ better ” bag-mask ventilation optimize airway position , triple airway maneuvre (head tilt, chin lift, jaw thrust) place OP and NP airways two-handed technique try lifting head off pillow to open airway Generate as much positive pressure as possible wi th out inflating the stomach
C ontd... If bag and mask still fails: Intubate If C ant ventilate, cant intubate *Larngeal mask airway *Cricothyroidotomy *N eedle Cricothyroidotomy and Transtracheal Je t Ventilation
Complications of bvm R elated to over-inflating or over-pressurizing the patient, which can cause: Hypoventilation/ Hyperventilation Inflated a ir in the stomach (called gastric insufflation ) L ung injury from over-stretching (called volutrauma ) L ung injury from over-pressurization (called barotrauma ). Aspiration Undesirable CV effects such as hypotension, secondary to caval compression.
References http://emedicine.medscape.com/article/80184-overview www.proceduresconsult.com/.../bag-mask-ventilation-EM-082-procedur es https://en.wikipedia.org/wiki/ Bag _valve_ mask https://meds.queensu.ca/central/assets/modules/basic-airway-management/bagmask_ventilation.html www.ncbi.nlm.nih.gov/pubmed/14717873 www.slideshare.net