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1、Mechanical Ventilation in Chronic Obstructive Pulmonary Disease,Tim Opt Holt, Ed.D., R.R.T. Professor Cardiorespiratory Care University of South Alabama Mobile, Alabama,Discussion Points,Determining the need for ventilation Noninvasive versus invasive ventilation Instituting noninvasive ventilation
2、Instituting invasive ventilation Managing ventilation Drug delivery during mechanical ventilation Managing auto-PEEP Weaning the patient,Determining the Need for Ventilation,Hypercapnic respiratory failure Pathophysiologic deterioration,Acute Hypercapnic Respiratory Failure,PaCO2 50 mm Hg with a pH
3、50 mm Hg Near normal pH, due to renal compensation Common in COPD Not an independent indication for ventilation,Example pH 7.38 PaCO2 70 mm Hg PaO2 62 mm Hg HCO3- 41 mEq/L SaO2 90%,Acute on Chronic Respiratory Failure,PaCO2 50 mm Hg pH 7.3, insufficient renal compensation Severe hypoxemia Exacerbati
4、on of COPD, often with pneumonia Ventilation indicated,Example pH 7.25 PaCO2 82 mmHg PaO2 35 mmHg HCO3- 35 mEq/L SaO2 40%,Pathophysiologic Deterioration,Mechanical ventilation is considered when physiologic indicators exceed normal ranges,Noninvasive versus Invasive Ventilation,Consider Noninvasive
5、Ventilation Acute exacerbation of COPD Respiratory acidosis (pH 7.25-7.35) despite optimal oxygen and medical therapy Able to protect airway Conscious and cooperative,Hemodynamically stable NIV may be a ceiling for therapy if intubation is not an option Secretions may limit the effectiveness of NIPP
6、V in bronchiectasis,Noninvasive versus Invasive Ventilation,Consider Invasive Ventilation The airway cannot be protected (patient is semi or unconscious) Life-threatening hypoxemia Severe comorbidity (heart failure) Confusion/agitation,Copious respiratory secretions Focal consolidation on chest radi
7、ograph Severe acidosis (pH 7.25) Patient has no teeth Poor nutritional status,Instituting Noninvasive Ventilation,Noninvasive ventilator Pressure controlled PIP up to 30 cm H2O Flow up to 60 L/min A/C and BiPAP Rate up to 40 bpm Flow triggered Disconnect alarm,Instituting Noninvasive Ventilation,Oxy
8、gen Added at or near the mask From separate flowmeter Humidification Not normally necessary Alarms Pressure, flow, and/or volume,Instituting Noninvasive Ventilation,Nasal masks After first 24 hours Gel cushioned masks Full face masks Used for first 24 hours Nasal pillows Chin strap,How to Setup Noni
9、nvasive Ventilation,Decide what to do if NIV fails Determine site of NIV trial Explain to patient Fit a facemask and hold it on the patient Setup the ventilator Attach a pulse oximeter Commence NIV, holding the mask in place Secure the mask in place with the headgear,Reassess after a few minutes Adj
10、ust settings as necessary Add oxygen if SpO2 85% Instruct the patient how to remove the mask and summon help Reassess and obtain ABG in 1-2 hours Adjust settings as necessary Institute alternative management plan,Setting-up the Noninvasive Ventilator,Mode: Spontaneous or timed EPAP: 4-5 cm H2O IPAP:
11、 12-15 cm H2O Trigger: maximum sensitivity Backup rate: 15 breaths/minute Backup I:E ratio: 1:3,Adjusting NIV Settings,PaCO2 elevated Oxygen may be set too high Leaks in the circuit Rebreathing (check expiratory valve) Patient-ventilator dyssynchrony Adjust rate, trigger, IPAP,PaCO2 OK, but PaO2 low
12、 Increase oxygen flow Increase EPAP,Why Use NIV in COPD?,Tracheal intubation rate is substantially reduced Complications, particularly pneumonia are attributed to intubation Reduced need for intubation Decreased in-hospital mortality No intubation-related compliactions Fewer ICU days Decreased cost
13、of hospitalization,Institution of Invasive Ventilation: Airway Access,Intubation 8.0 mm tube 22 cm at incisors 25 cm H2O cuff pressure Assure proper placement Assure security Manually ventilate,Modes: FVS vs. PVS,FVS Total VE T,P, F triggering PC, VC-CMV SIMV with normal rate PRVC Inadequate VA Apne
14、a & hypercapnic failure,PVS Part or no VE T,P,F triggering Low rate SIMV, PSV, VSV, CPAP, APRV Hypoxemic or hypercapnic failure,SIMV,VC or PC mandatory breaths CPAP or PS spontaneous breaths FVS or PVS Useful throughout course of ventilation Most commonly used,Set PC level,Time (sec),SIMV + PS + CPA
15、P (Pressure-Targeted Ventilation),Set PS level,CPAP level,SIMV+PS + CPAP (Volume-Targeted Ventilation),Set PS level,CPAP level,Time (sec),PSV,F, T triggered Deliver desired Vt, overcome circuit & ETT resistance Used with SIMV to increase spont VT Used independently for weaning Unloads ventilatory muscles Decreases weaning time Used for hypoventilation syndromes,CPAP + PSV,Set PS level,Time (sec),Flow L/m,Pressure cm H2O,Volume mL,Institution of Invasive Ventilation,
