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| ==Weaning==
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| ===Overview===
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| The gradual withdrawal of ventilatory assistance with modifying spontaneous breathing and resting periods for muscles .When a patient shows an improvement as clinical indicator of disease resolution ,the weaning should be started as the patient is able to maintain airways opened with physiologically normal ventilation cycles .
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| The close continuous monitoring of patient's ventilatory status should be accompanying the disease correction process .Weaning competency assessed by measurement of cardiovascular and respiratory functions to avoid the possibility of weaning complications.
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| ===Criteria for Spontaneous Breathing Trial (SBT)===
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| Spontaneous Breathing trials assess patient’s ability to breathe without or with the least
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| respiratory support. In order to accomplish this, ventilators' modes are switched
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| from full respiratory support such as volume-assist control or pressure
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| control to ventilatory modes such as pressure support, continuous positive airway
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| pressure (CPAP), or ventilation with a T-piece (in which there is no positive endexpiratory
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| pressure). Typically, the patient is awake and not sedated during a trial of spontaneous breathing is initiated while the
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| The typical readiness criteria for SBT are:
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| *Respiratory Criteria
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| #PaO2>= '''60 mm hg''' ( FiO2<40-50,PEEP<5-8cm H2O)
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| #PaCo2 normal or base line
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| #the Patient able to initiate inspiratory effort
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| *Cardiovascular Criteria
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| #No evidence of myocardial ischemia
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| #HR<140/min
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| #BP normal without vasopressor or minimal vasopressor support
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| #Adequate mental status :''arousable/GCS.13''
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| *Absence of correctable comorbid conditions
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| #Patient is afebrile
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| #No significant electrolytes abnormalities
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| ===Patient Who Will Tolerate Weaning<ref name="pmid23215559">{{cite journal| author=McConville JF, Kress JP| title=Weaning patients from the ventilator. | journal=N Engl J Med | year= 2012 | volume= 367 | issue= 23 | pages= 2233-9 | pmid=23215559 | doi=10.1056/NEJMra1203367 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23215559 }} </ref>===
| | [[File:Captura de Pantalla 2024-05-18 a la(s) 9.33.11 p.m..png]] |
| For a spontaneous-breathing trial to be successful, a patient must breathe spontaneously
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| with little or no ventilator support for at least 30 minutes '''without any of
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| the following:'''
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| # respiratory rate>35 breaths/min for more than 5 minutes
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| #an oxygen saturation <90%
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| #heart rate >140 beats per minute
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| #a sustained change in the heart rate of 20%
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| #systolic blood pressure >180 mm Hg or <90 mm Hg
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| #increased anxiety or diaphoresis
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| ===Rapid Shallow Breathing Index===
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| '''DEFINITION''' —As a predictor for successful weaning, The rapid shallow breathing index (RSBI) is the ratio of respiratory frequency to tidal volume (f/VT). It was originally measured using a hand-held spirometer attached to the endotracheal tube while a patient breathed room air for one minute without any ventilator assistance. As an example, a patient who has a respiratory rate of 25 breaths/min and a tidal volume of 250 mL/breath has an RSBI of (25 breaths/min)/(.25 L) = 100 breaths/min/L.
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| Patients who cannot tolerate independent breathing and thus weaning tend to have rapid (high frequency) and shallow (low tidal volume)breathing . Thus, they generally have a high RSBI.
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| The sensitivity is the probability that a patient who successfully weans will have an '''RSBI <105<ref name="pmid2023603">{{cite journal| author=Yang KL, Tobin MJ| title=A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation. | journal=N Engl J Med | year= 1991 | volume= 324 | issue= 21 | pages= 1445-50 | pmid=2023603 | doi=10.1056/NEJM199105233242101 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2023603 }} </ref>'''
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| breaths/min/L and the specificity is the probability that a patient who fails weaning will have
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| an '''RSBI ≥105<ref name="pmid2023603">{{cite journal| author=Yang KL, Tobin MJ| title=A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation. | journal=N Engl J Med | year= 1991 | volume= 324 | issue= 21 | pages= 1445-50 | pmid=2023603 | doi=10.1056/NEJM199105233242101 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2023603 }} </ref>''' breaths/min/L. The positive predictive value is the probability of successfully
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| weaning when the RSBI is <105 breaths/min/L and the negative predictive value is the
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| probability of failing weaning when the RSBI is >105 breaths/min/L.
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| ===Risk Factors For Unsuccessful Weaning ===
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| #Failure of two or more consecutive spontaneous-breathing trials
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| #Chronic heart failure
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| #Partial pressure of arterial carbon dioxide >45 mm Hg after extubation
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| #More than one coexisting condition other than heart failure
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| #Weak cough
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| #Upper-airway stridor at extubation
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| #Age ≥65 yr
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| #APACHE II score >12 on day of extubation(Acute Physiology and Chronic Health Evaluation (APACHE II)range from 0 to 71, with higher scores indicating greater impairment.)
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| #Patient in medical, pediatric, or multispecialty ICU
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| #Pneumonia as cause of respiratory failure
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| ==References==
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| {{Reflist|2}}
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