Weaning and Discontinuation From Mechanical Ventilation Flashcards
Weaning and Discontinuation From Mechanical Ventilation
-Servaral facts must be taken into condsideration if vent is to be discontinued successfully
-Weaning is frequently used to describe the gradual reduction of vent support from PT whose is improving
-Other terms that are used describe the process include discontinuation, gradual withdrawal, or liberation -Servaral facts must be taken into condsideration if vent is to be discontinued successfully -Fist PT may require vent support during weaning -Second supplemental O2 and PEEP may be required to support oxygenation -Third some individuals may require maintenance of the artificial airway even after vent support has be discontinued -Fourth many PTs require more than one of these therapeutic interventions -Although each of the first three components mentioned van be treated separately, they are an integral part of the overall process of ventilation discontinuation
-Vent support should be discontinued and artificial airway removal as soon as possible to avoid
the risk associated with mechanical ventilation, such as vent induced lung injury, vent associated pneumonia (VAP), airway trauma from ET and unnecessary sedation
-However, it is important to recognize the premature withdrawal of vent support of of the airway can result in vent muscle fatigue, compromised gas exchange, and loss of airway protection -Premature discontinuation is also associated with higher mortality rate
-the decision to wean a PT from the vent depends on
-the PTs level of recovery from the medical problems that imposed the need for mechanical ventilation and the PTs overall clinical condition and psychological state
-Therefore the PT physiological capacity and mental and emotional status must be evaluated before an attempt is made to remove the OT from vent support
-Evaluation of readiness
-Most PT who have required a ventilator for less than 2 days can be weaned quickly and simply. PT who have been sick and dependent on the vent longer will adjust more slowly
-The problem that caused the PT top require MV must have been resolved -Certain measurable criteria should be assessed to help establish a PT readiness for discontinuation of ventilation -An SBT should be performed to firmly establish readiness to wean
-Types of PTs
-Short termers, Some PTs seem ready for weaning after only 1 or 2 days of ventilation. You should feel free to accelerate the weaning process (or adhere to the protocol of thee facility) for this group of PTs
-Long termers, Pts attached to a vent for more than 3 days are harder to wean because the muscles of ventilation become deconditioned. Also,, the disease that make ventilation of these PTs necessary are usually more serious and requires more time to resolve
Weaning and Discontinuation from Mechanical Ventilation
-As soon as you have solved the problem involved in the beginning to ventilate a PT, start thinking about how you are going to stop ventilating them
-If possible, weaning should take place early. It is easier to wean of they are rested
-Clinical Criteria for Weaning
-Determine if the Pt has a drive to breathe
-Most Pts will have been triggering the ventilator at least intermittently. If this has not occurred, the vent should be adjusted for easy triggering by the PT. In addition, the level of sedation should be decreased
-Consider whether the heart or thorax are ready for the stress of weaning
-Weaning places stress on at least 2 structures, the heart and the chest wall. If the cardiovascular system is not stabilized, weaning can only make matters worse. Usually weaning should deferred until circulation cardiovascular problems have been minimized
-The stability of the chest wall should be evaluated. If a flail segment or recent thoracotomy has not yet stabilized, weaning will only make matter worse
-the readiness of the respiratory muscles to provide the effort required can be evaluated on the facts of measurement of lung mechanics. The following bedside vent parameters should be satisfied before attempting weaning
-Rapid shallow breathing index (RSBI) <100
-A Rate (F) 8-20 bpm (during MV) -A peak pressure (during MCV) less than 30 cmH20 -Maximum inspiratory pressure (MIP) -20 cmH20 -Maximum Expiratory Pressure (MEP) 40 cmH20 -VC greater than 10 ml/kg -Spontaneous Tidal Volume > 5 ml/kg
-Clinical measurements
-A-aDO2< 300 TPRR
-Qs/Qt < 20% -Vd/Vt < 60% -Pulse and blood pressure normal -weaning should be deferred until the PaO2 is greater than 60mmHg on an Fi02 less than 50% Side note: RSBI= F/VT
-To the extent possible, other problems should be minimized the evening before weaning. Consider the following
-Depressed consciousness
-Depressed cough -Enough secretions -Bronchospasm -Fever -Electrolyte imbalances -Abdominal distention -Anemi -Anxiety -Atelectasis
Spontaneous Breathing Trail (SBT)/ Spontaneous Awake Trail (SAT)
-Best method to evaluate weaning
-Administer CPAP with or without PSV -Minimum trail of 30 mins -Maximum trial of 2 hours
-Criteria for termination of SBT
-RR increases to > 35 for 5 min or more
-HR > 140/min or 20% over baseline -cardiac arrhythmias or new arrhythmias -Change in blood pressure -Systolic >180 -Systolic<90 -Excessive agitation -Oxygen sat<90% or decreased by $% or more form baseline -pH < 7.30 -If physiologic parameters show failure of SBT, return the pt to MV for 24 hous -Rest the pt overnight -Do not attempt SBT later that day
-Do a leak test
-Make sure there is no edema within the upper airway after removing the ET tube by deflating the cuff and listening
-Weaning methods include
-SIMV
-SIMV with PSV -CPAP -CAP with PSV -T piece
-Drugs that suppress ventilation should be discontinued
-Narcotics
-Neuromuscular blocking agents -Anesthetics
-Assessment of the PT during weaning
-Heart and lungs
-If the HR increases 20 bpm or more from baseline, stop warning and resume MV
-If the HR increases less than 20 bmp, continue weaning and observe closely, may increase the FIO2 -Blood pressure, RR, Vt, and VC should be assessed every 20 minute
-Assessment of the PT during weaning
-Sensorium
-PT should be alert and responsive
-Any change in mental status or level of consciousness would indicate the need to resume MV -Observe the PT for anxiety, confusion, combativeness, lethargy, unresponsiveness, or loss of consciousness
-Assessment of the PT during weaning cont.
-An ABG should be drawn after 20-30 min to assess the PT ventilation and oxygenation status
-Continuous observation for signs and/ or symptoms of any problems -Auscultation of breath sounds and checking the position/ Patency of the artificial airway is appropriate -Monitor urine output (40-60ml/ hr) -Recommended IPPB or SMI to prevent atelectasis following extubation
-Post extubation difficulties
-Hoarseness, sore throat, cough, subglottic edema, increased WOB from secretions, airways obstruction, laryngospasm, aspiration
-Cool-aerosol therapy -Racemic Epinephrine
-Factors that may contribute to extubation failures
-Type of PT, older age, severity of illness at weaning onset, repeated traumatic intubation, continuous IV sedation, duration of MV, female gender, anemia, transport outside of ICY, number of SBTs, mode before extubation, protocol-driven weaning by RTs
-The benzodiazepine antagonist flumazenil (Romazicon) can be administered to reverse the effects of benzodiazepines
