res 236 ppt
TRANSCRIPT
Application of mechanical ventilation and patient monitoring
Assessment of the mechanically ventilated patient◦ Physical assessment
◦ Vital signs
◦ Clinical lab studies
◦ Nutritional status
◦ O2 status
Adequacy of arterial and tissue oxygen status
◦ Ventilation status
Critical thinking
◦ Decide what information is needed
◦ Monitor the appropriate values
◦ Collect the data needed
◦ Analyze the data
◦ Determine what changes are needed
◦ Implement changes
Chief Complaint
Primary symptoms of cardiopulmonary disorders: ◦ Cough
◦ Sputum production
◦ Hemoptysis
◦ Shortness of breath (dyspnea)
◦ Chest pain
Color
Quantity
Consistency
Odor
Time of day
Presence of blood
Subjective experience of breathing discomfort◦ SOB - Cardinal symptom of cardiac disease
◦ Causes:
Obstructive and Restrictive conditions
acute hypoxia (high altitudes)
Exercise
heart failure (orthopnea)
kidney failure (uremia) due to acidosis
head injury (Biot’s)
pain.
Cardiac – Nonpleuritic pain◦ Cardiac Ischemia
◦ Cardinal symptom of heart disease (Angina)
Pulmonary - Pleuritic pain◦ Inspiratory, sharp, abrupt in onset
◦ Worsens with inspiration, cough, sneeze, hiccup, or laughter
◦ Increases with pressure and movement
Temporary loss of consciousnessfrom reduced cerebral blood flow and oxygen
Causes:
• Pulmonary: embolism, bouts of coughing, hypoxia
• Vasovagal: most common type of syncope-Loss of peripheral venous tone
• Orthostatic hypotension: Sudden drop in blood pressure when a person stands up
• Elderly, vasodilators, dehydration
Vital signs (VS) are used to:
• Determine general status of the patient
• Establish a baseline
• Monitor response to therapy
• Observe for trends
• Determine the need for further evaluation or intervention
Hematology◦ The complete blood count (CBC)◦ Tests of the blood clotting ability of the
patient’s blood
Blood Chemistry Tests◦ Sodium◦ Potassium◦ Chloride◦ Bicarb
BUN and Creatinine
Adequate nutrition key for healing
Nutritional status has major influence on
patient outcomes◦ Provides energy for breathing and movement
Food quality and quantity affect oxygen needs and CO2 production
Nutrients influence lung immune function
Inspection findings:
◦ Cachectic patients are bony with depressed intercostal spaces
◦ Accessory muscles are often readily visible
◦ Poor cough secondary to muscle weakness
◦ Viscous secretions may suggest dehydration
Auscultation findings:
◦ Basilar coarse or fine crackles may indicate fluid overload or loss of blood protein
◦ Wheezing secondary to food intolerance/allergy
◦ Fine late inspiratory crackles may indicate diminished surfactant secondary to malnutrition
◦ S3 may indicate fluid overload and CHF
◦ S4 may indicate severe anemia
Neurologic dysfunction is difficult to recognize in sedated patient
Obtain history, from family if not from patient
Neurologic examination◦ Mental status◦ Pupillary response and eye movement◦ Corneal and gag reflex◦ Respiratory rate and pattern◦ ICP monitoring (10 to 15 mm Hg normal)◦ Glasgow Coma Scale
Kidney functions◦ Filtering and excretion of wastes
◦ Regulates fluid and electrolyte composition
Renal failure is noted by◦ BUN increases of 10 to 15 mg/dl/day
◦ Creatinine increases of 1 to 2.5 mg/dl/day
◦ Urine volume reflects renal perfusion
Oliguria <400 ml/day in average-sized adult
Anuria occurs with <50 ml/day
PaO2◦ 80-100mmHg (<60 in COPD)
SaO2◦ 92-100% (88-92% in COPD)
VO2◦ 250ml/min
QS/QT◦ 3-5%
PvO2 = 38 – 42 mmHg
SvO2 = 68% - 77%
Decreased mixed venous oxygen levels◦ Decreased Qt, DO2◦ Increased oxygen demands
Increased mixed venous oxygen levels◦ Histotoxic hypoxia◦ Decreased cellular oxygen demands
P(A a)O2
◦ Healthy patient
21% O2, gradient is 5 to 15 mm Hg
100% O2, gradient is < 65mm Hg
◦ Abnormal increase associated with gas exchange problems
PaO2/FIO2 ratio (P/F ratio)◦ Normal P/F ratio is 400 to 500.
◦ In Acute Lung Injury - ALI, this falls below 300.◦ In Acute Respiratory Distress Syndrome - ARDS, will be <
200.
◦ Most reliable index of gas exchange if FIO2 > 0.50 and PaO2 < 100 mm Hg
Pulse oximetry (“fifth vital sign”)
◦ Provides noninvasive measurement of SaO2, referred to as SpO2
◦ Monitors only oxygen, not ventilation
◦ Significant limitations
All of the following are true about pulse oximetry monitoring, except:
A. Provides an SpO2 reading
B. Provides invasive measurement of SaO2
C. Monitors only oxygen, not ventilation
D. Significant limitations
All of the following values affect pulse oximetry, except:
A. Nail polish
B. Deeply pigmented skin
C. Anemia
D. CO2 buildup
Which of the following PaO2/FIO2 ratio identifies a patient with ARDS?
A. 500-600
B. 300-500
C. >200
D. <200
Routine monitoring includes
PaCO2, which defines adequacy of ventilation
VT, f, and VE
Low VT and high f often indicate distress
VD/VT
Normal 0.20 to 0.40
Higher ratio indicates more wasted ventilation
ICU common to be > 0.60
>0.60, patient is unlikely to sustain spontaneous ventilation
End tidal (Exhaled) CO2 monitoring
◦ Normal capnogram (less than 5 mmHg < PaCO2)
◦ 10 to 20 mmHg difference can be used to spot
trends
◦ > 20 mmHg difference indicates significant
deadspace
A patient who had abdominal surgery 4 days ago has the following ABG pH – 7.48 mmHg, PaCO2 – 28 mmHg, PaO2 – 95 mmHg, SaO2 –98%, HCO3 – 21 mEq/L.
What is this patient’s acid-base status?
What is this patient’s oxygenation status?
The patient’s current hemoglobin content is 6 gm%
Does this change the patient’s acid-base balance and/or oxygen status? Explain.
You are the evening shift respiratory therapist at your hospital and have been summoned to the emergency department. Lisa Camps, a 34-year-old woman, has just arrived in the emergency department after a motor vehicle accident. She is on a non-rebreathing mask at a flow rate of 12 L/min. The emergency department physician wants your assistance in assessing and managing Ms. Camps. Your assessment reveled the following about Ms. Camp’s cardiopulmonary status?
• Color – dusky • Pupillary reaction – sluggish • Respiratory rate and pattern – 28/bpm and labored• Level of consciousness – semiconscious and combative• Pulse and blood pressure – 130/min, 130/90• General appearance – Anxious, with bleeding from head laceration• Chest auscultation – bilateral breath sounds diminished in the bases• ECG – sinus tachycardia with a rate of 130/min• ABG – pH 7.30, PCO2 50 torr, PO2 69 torr, HCO3 -25mEg/L
Which of the following would you recommend at this time?
A. Placed patient on a CPAP mask of 5cmH2O and 50% O2
B. Intubate and institute mechanical ventilation.
C. Administer a bronchodilating agent via a SVN, followed by postural drainage and percussion.
D. Administer O2 via a 30% venturi mask.
The patient is combative and disoriented. To facilitate intubation, which of the following would you recommend?
A. Use restraints to immobilize the patient
B. Insert an oropharyngeal airway
C. Sedate and administer 2mg of succinylcholine
D. Administer a bolus of lidocaine
E. Perform blind nasal intubation
The patient is 5ft 2in tall and weighs 50kg (110 lb). What ventilator settings would you recommend?
A. Control mode, RR 10, Vt 750 ml, FIO2 0.50B. AC, RR 10, Vt 500 ml, FIO2 1.0C. SIMV, RR 6, Vt 700 ml, FIO2 7.0D. SIMV, RR 10, Vt 600 ml, FIO2 4.0E. AC, RR 10, Vt 750 ml, FIO2 0.50F. SIMV, RR 2, Vt 850 ml, FIO2 1.0
ABG thirty minutes later reveal: pH 7.44, PaCO2 36 torr, PaO2 189 torr, HCO3 -25 mEg/L. What will you recommend at this time?
A. Maintain current settings and monitor closely
B. Titrate O2 percentage to maintain an SpO2 of more than 93%
C. Decrease Vt by 100 mlD. Add PEEP of 5 cm H20E. Decrease FiO2 to 0.50
After suctioning the ETT, the patient continues to cough repeatedly, setting off the high-pressure alarm. Which of the following would you do at this time?
A. Increase the ventilator rate
B. Decrease the Fio2
C. Instill lidocaine into the ETT
D. Increase the high-pressure limit
E. Decrease the Vt
Twenty-four hour later, you are performing ventilator checks on Ms. Camp’s ventilator when the high-pressure alarm begins to sound with each breath. Ms. Camp is in respiratory distress with a respiratory rate of 32/bpm.
What will you evaluate at this time?
Ms. Camp continued… Ventilator function – functioning normally with appropriately set parameters Sputum color – clear Temperature 37°C MIP -60 cmH2O No obstruction because the suction catheter is inserted and advanced into the
ETT. Breath sounds absent on the right Gag reflex intact Bowel Sound normal Papillary reaction normal Hyperresonant sound over right upper Increased resistance with difficulty to manually ventilate Asymmetrical chest movement, with left lung expanding more than the right lung Heart rate 130/min Trachea deviated to the left of midline
Which of the following would you recommend at this time?
A. Increase the high-pressure limitB. Increase the high VtC. Decrease the ventilator rateD. Insert needle into the second intercostals
space and then place a chest tube in the right lung
E. Place a chest tube in the sixth intercostalspace
One week later, Ms. Camp remains on the ventilator on AC with a Vt of 550 ml and an FiO2 of 0.35. On these settings her ABG results are pH 7.42, PCO2 41 torr, PaO2 90 torr, HCO3 24mEq/L. She has normal results on her chest x-ray and her ICP in 5 mmHg, Temp 37°C, MIP -31 cmH2O, RR 14/bpm, spontaneous Vt 350. Which of the following would you recommend to evaluate the patient readiness to wean?
A. Temp. – 37
B. MIP – 31
C. Spontaneous RR 14/bpm
D. Spontaneous Vt 350
Which of the following would you recommend at this time?
A. Maintain present settings
B. Place on flow-by and 50% O2
C. Place on SIMV, RR 10/bpm, VT 600, FIO2 0.40,PS 10 cmH2O
D. Place on SIMV, RR 4/bpm, VT 600, FIO2 0.40,PS 10 cmH2O
E. Extubate and place on 40% aerosol mask
One hour later, ABG results are pH 7.38, PaCO2 38 torr, PaO2 87 torr, HCO3 -25mEq/L, SaO2 97%, RR 16/bpm and spontaneous Vt 375ml. Which of the following would you recommend at this time?
A. Decrease the Vt by 100 ml
B. Maintain current settings and monitor closely
C. Increase the PS to 15 cm H2O
D. Decrease the RR by 2/bpm
E. Place on flow-by and PS of 5 cmH2O
The next day Ms. Camp is resting comfortably, with a pulse oximeter reading of 98% and a spontaneous Vt of 400 ml. SIMV rate is 2/bpm, with a respiratory rate of 14/bpm and FiO2 of 0.30. Which of the following would you recommend at this time?
A. Increase SIMV rate to 8/bpm
B. Place on flow-by ay 30% O2 and PS 8 cmH2O
C. Extubate and place on 24% air entrainment mask
D. Obtain ABG before making any ventilator changes
E. End of Case Study
Determining position of tubes and catheters◦ ETT position (3 – 5 cm from carina)
◦ Chest tubes
◦ CVP and Swan Ganz
Observing the progression of lung disease◦ Infiltrates and consolidations
Pneumonia
Atelectasis
Pulmonary edema
Pneumothorax and Pleural Effusions
A respiratory therapist working in the emergency department encounters a 28 year-old female with Kussmaul breathing. Her room air ABG values are as follows: pH – 7.06 mmHg, PaCO2 – 12 mmHg, PaO2 – 106 mmHg, SaO2 – 97%, HCO3 – 5 mEq/L.
What acid-base imbalance is present?
What oxygen therapy is appropriate at this time?
What is the most likely cause of this patient’s condition?
CXR Lung abnormalities
A 55 year-old man arrives at the clinic with the complaint of chills, fever and chest pain on inspiration. He is coughing up rusty-colored sputum. He admits to a history of heavy smoking and regular use of alcoholic beverages. Physical examination reveals a heart rate of 125, respiratory rate of 30 and a temperature of 104º F. He has inspiratory crackles in the right lower lobe. Blood gases reveal a pH of 7.34, PaCo2 of 50 and PaO2 of 50
What is the most likely diagnosis? Support your answer based on the clinical signs and symptoms.
What immediate treatment should you initiate?
Give five reasons why the patient is at risk of dying from his condition.
What they measure
◦ CVP – fluid balance
◦ PAP – right ventricular function. Vascular resistance in the lung (afterload)
◦ PCWP – Left ventricular function. Vascular resistance in the systemic circulation
◦ Qt – the total amount of blood pumped by the heart in in minute
MAP (PAW) = pressure in thoracic cage
Lungs & heart in thoracic cage
◦ CVP increased during PPV breath
◦ PAP increased during PPV breath
◦ PCWP increased during PPV breath
Constant pressure exerted in chest
◦ Measure hemodynamics while on PEEP
Patient will deteriorate when patient is discontinued
Physiologic PEEP
◦ ( 0-9 cmH2O )
Therapeutic PEEP
◦ ( ≥ 9 cmH2O )
A 70 year-old man’s chief complaint is dyspnea on exertion. He has a smoking history of two packs per day for the past 50 years. He has a barrel-shaped chest and decreased breath sounds. His chest radiograph shows hyperinflation, especially in the apices; flattened diaphragms; and an enlarged heart. He admits to a morning cough with significant sputum production.
What is the most likely diagnosis?
Calculate the patient’s “pack-years”
What factor should you focus on to help the patient control his condition?
Air trapping during mechanical ventilation
◦ High minute volume
◦ Obstruction (increased exhalation times)
◦ Inspiratory times too long
◦ Irregular ventilatory pattern
◦ Asynchronous patient – ventilator interaction
Eliminate Raw
◦ Bronchodilation, suction, mechanical
Ensure patient – ventilator synchronicity◦ PSV, sedation
Decrease I time◦ Increase peak flow rate
Use extrinsic PEEP to splint airways
Vital Capacity◦ N = 65-75 ml/Kg◦ Ventilate below 15 ml/Kg
Rapid-Shallow breathing index◦ Spontaneous Rate/Vt◦ < 105 is predictive of successful weaning
MIP◦ Normal = - 80 - -120 cmH20◦ Acceptable = - 20 to 30 cmH2O for weaning
Respiratory infections
Increased work of breathing imposed
Operational hazards
◦ Power loss
◦ Circuit disconnect
◦ Expiration valve failure
Stress
◦ Anxiety
Loss of control, drugs, pain
◦ Combativeness
Lack of sleep, unfamiliar with environment
Fear
◦ Psychosis
Sleep deprivation, drugs, illness
Allow appropriate sleep Introduce yourself, explain procedures Allow normal stimuli Minimize sedative drugs Control pain Antipsychotic medication Appropriate communication around the
patient
Metabolic acidosis
◦ Stimulates an increase in ventilation
◦ Increased work of breathing
Metabolic alkalosis
◦ Stimulates a decrease in ventilation
◦ Weaning
Patients should be repositioned often
Take into account increased ICP patients
Unilateral lung disease◦ Bad lung up, good lung down
◦ Will increase perfusion to well ventilated areas
ARDS Patients◦ Will oxygenate better in the prone position
A patient is intubated and is on the ventilator following a head injury. On the third day following his craniotomy, he develops a fever. During routine suctioning the RT notices his secretions are thick and yellow. Breath sounds are decreased in the left lower lobe.
What is the role of the artificial airway in the development of pneumonia?
What test would you recommend at this time to help confirm a diagnosis? Give at least two tests.
Waveforms
4 basic parameters
◦ Pressure
◦ Volume
◦ Flow
◦ Time
Relationship between parameters◦ Flow - Volume Loop
◦ Pressure - Volume Loop
◦ Scalars
Flow – time
Pressure – time
Volume - time
Beginning of inspiration
Inspiration
End of inspiration
Beginning of exhalation
Exhalation
End of exhalation
Essentials of Ventilator Graphics ©2000 RespiMedu
Controlled Mode (Volume- Targeted Ventilation)
Controlled Mode (Volume- Targeted Ventilation)
PressurePressure
Volume Volume Volume
FlowFlowPreset Peak FlowPreset Peak Flow
Preset Preset VVtt
Dependent onDependent on
CCLL & R& Rawaw
Time (sec)Time (sec)
(L/min)(L/min)
(cm H(cm H22O)O)
(ml)(ml)
Essentials of Ventilator Graphics ©2000 RespiMedu
Assisted Mode(Volume-Targeted Ventilation)
Assisted Mode(Volume-Targeted Ventilation)
FlowFlow
PressurePressure
VolumeVolume
Time (sec)Time (sec)
(L/min)(L/min)
(cm H(cm H22O)O)
(ml)(ml)
Essentials of Ventilator Graphics ©2000 RespiMedu
SIMV(Volume-Targeted Ventilation)
SIMV(Volume-Targeted Ventilation)
Time (sec)Time (sec)
FlowFlow
PressurePressure
VolumeVolume
(L/min)(L/min)
(cm H(cm H22O)O)
(ml)(ml)
Essentials of Ventilator Graphics ©2000 RespiMedu
SIMV+PS(Volume-Targeted Ventilation)
SIMV+PS(Volume-Targeted Ventilation)
Time (sec)Time (sec)
FlowFlow
PressurePressure
VolumeVolume
(L/min)(L/min)
(cm H(cm H22O)O)
(ml)(ml)
Set PS levelSet PS level
PIP vs PplatPIP vs Pplat
NormalNormal High RawHigh Raw
High FlowHigh Flow Low CLow CLL
Time (sec)Time (sec)
PIPPIP
PPplatplat
PIPPIP
PIPPIP PIPPIP
PPplatplatPPplatplat
PPplatplat
PPawaw
(cm H(cm H22O)O)
Volume control◦ Square or rectangular waveform
Pressure control◦ Decelerating ramp or waveform
Mimics a more natural breath
Volume control where you can choose your waveform◦ If you have a choice between Square or
decelerating, choose Decelerating. This will allow for better distribution of ventilation
You will be able to see if the sensitivity is appropriately set for your patient
You can also see if the sensitivity is inappropriately set for your patient
Essentials of Ventilator Graphics ©2000 RespiMedu
Pressure-Volume LoopPressure-Volume Loop
Volume Volume
((mLmL))
Insp
irat
ion
Insp
irat
ion
Expir
ati
on
Expir
ati
on
PIPPIP
VVTT
PPawaw (cm H(cm H22O)O)
Essentials of Ventilator Graphics ©2000 RespiMedu
Lung Compliance Changes in the P-V Loop
Lung Compliance Changes in the P-V Loop
Volume (Volume (mLmL))
PIP levelsPIP levels
VVTT
PPawaw (cm H(cm H22O)O)
COMPLIANCE
NormalIncreasedDecreased
COMPLIANCECOMPLIANCE
NormalNormal
IncreasedIncreased
DecreasedDecreased
Volume Targeted VentilationVolume Targeted Ventilation
Essentials of Ventilator Graphics ©2000 RespiMedu
OverdistensionOverdistension
Pressure (cm HPressure (cm H22O)O)
Paw rises with little or no change in VT
PPawaw
(cm H(cm H22O)O)
Essentials of Ventilator Graphics ©2000 RespiMedu
Flow-Volume LoopFlow-Volume Loop
Volume (ml)Volume (ml)
1
2
34
InspirationInspiration
ExpirationExpiration
Flow Flow
(L/min)(L/min)
FRC
A mathematics instructor with a history of CHF is admitted with a complaint of pain on inspiration. Her respirations are rapid and shallow and her heart rate is 104. The pulse oximeter shows a saturation of 93% on room air. Breath sounds are very decreased on the right side, with crackles in the left base. Chest wall movement is markedly less on the right. The chest radiograph shows opacification of the right lung, with shift of mediastinal structures to the left. Diagnostic percussion reveals a dull note on the right.
What do you think is wrong with this patient’s right lung? Support your conclusion with at least five (5) pieces of information from the case.
◦ 1.◦ 2.◦ 3.◦ 4.◦ 5.
What would you recommend as the respiratory therapist?
How could this disorder be resolved?
Volume◦ Used to limit volume and pressure damage
◦ Normal lungs – 8 to 12 ml/Kg
◦ COPD – 8 to 10 ml/Kg
Limit volume, prolong expiratory time
◦ ARDS – 6 to 8 ml/Kg
◦ Neuromuscular – 12 to 15 ml/Kg
Rate◦ Normal lungs – 8 to 12
◦ COPD – 8 to 12
◦ ARDS – may use up to 20 to normalize VE with small Vt
◦ Neuromuscular – 10 to 14
After Vt is calculated use rate to adjust VE for desired PaCO2
Adjust to desired PaO2/SaO2
◦ Most intrapulmonic shunting will not require more than .40
◦ If significant shunting or deadspace occurs
Use PEEP for FIO2 > .60
Keep SaO2 above 90% or PaO2 around 60 torr
Increase inspiratory time or use inverse IE ratio ventilation
A mechanical ventilator is set up to provide volume assist/control ventilation to a postoperative patient. What parameters does the respiratory therapist need to set? During ventilation the patient’s peak inspiratory pressure
reaches approximately 28 cmH2O. What should the respiratory therapist set as the maximum safety pressure?
What is the purpose of the maximum safety pressure? While assessing the patient and checking the ventilator, the
respiratory therapist notices that although a volume of 500 mLhas been set, the patient exhales only 400 mL and the maximum safety pressure is reached on each breath.
What is the most likely causes of the low volume return? Explain your answer.
If the maximum safety pressure was not reached on each breath and the exhaled volume was 100 mL less than the set volume, what would be the possible causes?
Uses
◦ For restrictive lung disease (ARDS) Hypo-inflation causes atelectasis (shunt)
FRC decreases
Use therapeutic levels (5 – 20)
◦ For normal lungs and obstruction Splints airways
Exhalation more effective
Use physiologic levels (3 – 5)
Prevents auto - PEEP
Uses Continued
To decrease lung fluid (pulmonary edema)◦ Increase alveolar pressure extends alveoli and
pushes out fluid from the interstitial space
◦ Increase in compliance from decreased lung water eases the WOB of the patient
Use optimal PEEP studies
◦ Compliance study
◦ C(a-v)O2
◦ Qs/Qt
◦ Deadspace
◦ Direct measurement of Qt
◦ Use the highest PEEP level indicated
Optimum PEEP
◦ Keeps PaO2 > 60 torr with < .40 FIO2
◦ Increases lung static compliance
◦ Little impact on venous return
◦ Shunt is decreased
◦ FRC is increased
Absolute◦ Pneumothorax
Relative◦ Increased ICP
◦ Unstable hemodynamics (i.e.. Hypovolemia)
◦ Recent lung surgery
◦ Hyper aerated lungs (COPD)
Minute ventilation◦ Tidal volume◦ Expiratory time (I:E and rate)
Lung function◦ Resistance◦ Compliance
Increase Pplat, Increase work-of-breathing, hemodynamic effects, pneumothorax, difficulty triggering
Correct by reducing minute ventilation (permissive hypercapnia) and treating lung function.
Increase PEEP until there are no missed trigger efforts
Increase PEEP until Pplat and PIP increase
PEEP to counterbalance auto-PEEP is only effective in the context of flow limitation; e.g., COPD versus asthma
A 35 year-old male with a history of Asthma is admitted to the ICU from the emergency department. The patient is alert and oriented but extremely anxious. He is sitting up and learning on the bedside tray table. Physical examination reveals the following; pulse – 142 beats/min, BP – 178/86 mmHg, Temp – 37.9° C, respirations – 33 breaths/min and labored. Chest auscultation reveals significantly decreased breath sounds throughout with slight wheezing on exhalation. ABG results on 40% air entrainment mask are as follows pH – 7.33 mmHg, PaCO2 – 44 mmHg, PaO2 48 mmHg, SaO2 – 79%, HCO3 – 22 mEq/L, Hb – 14.8 g/dL. The peak expiratory flow meter is 70 L/min after three consecutive bronchodilator treatments.
What is the cause of the patient’s tachycardia? Using the four oxygenation indicators, explain the oxygen status of this
patient (assume PB is 760 mmHg). Although this patient’s PaCO2 in within normal limits, why is it
significant in this case? What respiratory care treatment should be suggested for this patient?
Improve gas exchange Reduce VILI by reducing tension at
boundaries of aerated and non-aerated lung units
Reduce VILI by reducing cyclic opening and closing of lung units
Lung recruitment occurs at high volume and pressures
Maintenance of recruitment requires PEEP
Methods◦ Sustained high pressure inflation 30-40 secs at 35
to 40 cm H2O
◦ Stepwise increase in PEEP with decrease in tidal volume over 2 minutes.
◦ CPAP of 30-40 cm H2O of 30-40 secs
◦ Increasing PIP by 10 cm up to 60 cm (30 s)
◦ PIP of 50 cm for 2 min
Sighs
PEEP
Recruitment maneuvers
Prone positioning
Spontaneous breathing
High frequency ventilation
Gas exchange – SpO2, PaO2, PaCO2
Pressure volume curve
Pressure time scalar
CT scan
ARDS = Lung aeration inhomogeneity Low VT contributes to derecruitment Recruitment is possible - more likely in
collapse vs. consolidation Not all alveoli are recruitable at safe
pressures Lung units are held open at much lower
pressure than is required to open them The open lung is ventilated even during
expiration Effect varies with type of ARDS Greatest effect at low PEEP
A tall, young male respiratory care instructor, is admitted with a complaint of pain on inspiration. His respirations are rapid and shallow and his heart rate is 104. The pulse oximeter shows a saturation of 93% on room air. Breath sounds are very decreased on the right side and clear in the left base. Chest wall movement is markedly less on the right. The chest radiograph shows a dark area without lung markings on the right side with a shift of mediastinal structures to the left. Diagnostic percussion reveals increased resonance on the right side.
What do you think is wrong with this patient’s right lung? Support your conclusion with at least five (5) pieces of information from the case. ◦ 1.
◦ 2.
◦ 3.
◦ 4.
◦ 5.
What would you recommend as the respiratory therapist?
How could this disorder be resolved?
Based on Specific Pathology
Closed head injury
◦ Increase Vt and rate to maintain PaCO2
Decrease to 25 – 30 torr
◦ Causes cerebral vasoconstriction
Decreased blood flow to injured site
Decreased swelling and bleeding
COPD
Ventilate to maintain baseline PaCO2/pH◦ I:E ratio 1:3 or more
◦ Over distended lungs
◦ Obstruction causing decreased flows
Limit air trapping
Prevent auto PEEP
Preventing Intubation◦ Heliox (60% - 80% helium with oxygen◦ Continuous aerosol bronchodilator◦ Noninvasive positive pressure ventilation
Invasive ventilation◦ Oral vs. nasal intubation◦ Ventilator settings◦ Management of air trapping◦ Delivery of inhaled bronchodilators◦ Discontinuation of ventilatory support
ARDS◦ Watch Peak and plateau pressures
◦ Watch for oxygen toxicity
Use PEEP when FIO2 needed > .60
Maintain SaO2 around 90%
◦ Increase rate with small Vt to keep PaCO2/pH normal or permissive hypercapnea
◦ Use inverse I:E pressure control (IRPCV)
Increased oxygenation
Limit peak pressure
Normal lungs
Patients seem to “feel better” with larger Vt
Normal rate
Usually low FIO2
Protect against lung infection
Monitor for changes in Raw & compliance
High Frequency
IRPCV
APRV
ASV
INO
Liquid
ECMO
Ms. Nelson is a 47 year-old woman who was found unconscious on the floor of the apartment by a relative. Empty bottles of diazepam (Valium), effxor (antidepressant), and beer cans were nearby. The relative dialed 911, and the patient was transported to a local emergency room. During transportation, the patient had an adequate pulse rate but required ventilatory assistance with a bag-valve mask on oxygen. An ABG was obtained immediately, and a drug screen was ordered in the emergency room.
What complications are likely to occur in this patient?
What information should the attending physician attempt to get from the relative or paramedics?
Is this patient most likely to be experiencing ventilatory or oxygenation failure?
Should the patient be intubated? If so, why?
What treatment should be provided?
Ms. Nelson continued… Physical Examination General. An unconscious, slightly obese female with an 8.0-mm
endotracheal tube in place being ventilated with a hand resuscitator; Ewald tube in left nostril; gastric lavage fluid containing a large number of pill fragments; strong smell of alcohol; patient approximately 5 foot, 8 inches and 155 pounds.
Vital Signs. Pulse 124/minute, respiratory rate 12 to 16/minute with bag-valve mask, body temperature 35.3°C (95.6°F), blood pressure 120/75 mm Hg
HEENT. No signs of trauma; pupils dilated with sluggish response to light.
Heart. Normal heart sounds with no murmurs. Lungs. Breath sounds clear except in right lower lobe, where
inspiratory crackles are heard. Abdomen. Soft, obese, with no organomegaly or tenderness; bowel
sounds present, but hypoactive. Extremities. Warm to palpation with no edema, clubbing, or cyanosis Initial ABG Findings. (while patient is being ventilated with an FiO2
of 1.0 via a bag-valve mask prior to intubation). pH 7.28, PaCO2 54 mm Hg, PaO2 135 mm Hg, Sao2 99%, HCO3 = 26 mEq/liter
Ms. Nelson continued…
What accounts for the hypothermia?
What accounts for the dilated and sluggishly reactive pupils?
What could account for the crackles heard in the right lower lobe?
How would you interpret the ABG findings?
What is the significance of the pill fragments found in the contents of the stomach? Why was the charcoal given?
Ms. Nelson continued…
Ms. N is transferred from the emergency room to the intensive care unit (ICU). While in the ICU, she is placed on continuous mechanical ventilation with a volume ventilator, and cardiac monitoring is continued.
What laboratory and diagnostic tests would you suggest at this time?
What ventilator settings would you recommend? Specifically suggest the mode of ventilation, tidal volume, rate, FiO2, and PEEP level.
Ms. Nelson cont… The ventilator is set to deliver a tidal volume of 600 mL at
a rate of 12 per minute with an FiO2 of 0.45 in the assist/control mode. Twenty minutes after initiation of mechanical ventilation, an arterial blood sample is drawn and reveals the following: pH 7.51, PaCO2 32 mm Hg, PaO2 88 mm Hg, and HCO3 = 25 mEq. The chest x-ray shows patchy infiltrates in the right lower lobe, which is consistent with aspiration pneumonia. The electrocardiogram monitor reveals a sinus rate of 115 to 120 per minute. Breath sounds are clear in all areas except the right lower lobe.
A drug screen indicates that the patient had also taken acetaminophen. Her blood alcohol level is 0.155, and the presence of antidepressant is confirmed via urinalysis.
How would you interpret the ABG results?
What changes in the ventilator settings would you suggest based on the ABG results?
What is the treatment for the acetaminophen overdose?
What pulmonary complication is associated with aspiration pneumonia?
Indications◦ Peak and plateau pressure increase
◦ Decreased static compliance
◦ Inability to ventilate with pressures under 30 – 50 cmH2O
◦ Decreased FRC due to atelectasis
◦ Inability to oxygenate with conventional ventilation
What is does◦ Delivers breath with a true decelerating waveform Uses less force to deliver the same amount of volume
◦ Increases critical opening time◦ Increases distribution of ventilation◦ Increases oxygen diffusion into the blood◦ Increases MAP (Paw)
Technique
◦ Choose PIP around ¾ of what is being delivered with
◦ Adjust I time to 1.5:1 to 3:1 ratio
◦ Decrease PEEP level to ½ of volume ventilation PEEP
level
◦ Adjust PIP to deliver the desired Vt
Increased distribution of ventilation◦ Increased diffusion area (decreased shunt)
Increased critical opening time◦ Enhanced spread of volume
Time constants◦ Independent areas of alveoli/lobules that have
decreased compliance
Monitoring
◦ Hemodynamics
◦ Fluid balance
◦ Blood gases
◦ Ventilator pressures
Maintaining adequate Vt
Facilitated diffusion
◦ Gas molecules are driven during inspiration
◦ Follow a flow down the center of airways
◦ Expired gas (CO2) is pushed along the sides of the
airways
◦ Conventional ventilator breaths, CPAP or PEEP are
used to keep lung units open
Indications◦ Ventilation at lower peak pressures
◦ Ventilation for patients with ARDS or Bronchopleural Fistula
◦ Treating Pulmonary Interstitial Emphysema ( Pulmonary air leak problems)
Primary Controls◦ Frequency (OXYGENATION)
Expressed in Hertz (Hz)
1Hz = 60 breaths per minute
◦ Driving pressure (VENTILATION)
Used in HFJV
Volume
◦ Amplitude (VENTILATION)
Used in HFOV
Volume
Types◦ HFPPV Rates 60 – 100/min (in Hertz)
Vt close to anatomical deadspace
◦ HFJV Rates 100 – 600/min (in Hertz)
Vt close to anatomical deadspace
Needs special ETT with jet port
May damage airway mucosa
HFO
◦ Rates up to 900/min
◦ Vibration of gas molecule
◦ Kinetic movement of gas molecules
Moving air – base speakers
Uses
◦ Neonates with PPHN
◦ Congenital heart defects
◦ Barotrauma
◦ During bronchoscopy
◦ Investigational in limiting high pressures in adult
with ARDS
A Pressure Control mode with mandatory breaths utilizing 2 pressure levels
A modified form of CPAP, in which the patient is able to breathe spontaneously unrestricted at both levels and if desired with the addition of Pressure Support.
Goals: To provide the lung protective ventilation by
delivering VT
Re-establishing FRC through recruitment and maintained by creating intrinsic PEEP (PEEPi).
Benefits Patients are able to breathe spontaneously throughout
the ventilatory cycle Reduction in intrapulmonary shunting and dead space
ventilation is associated with spontaneous breathing Venous return and cardiac performance can be
improved
Preserved diaphragmatic activity may recruit consolidated lung areas over time and thus improve oxygenation.
Neuromuscular blockade should be avoided: the patient should be allowed to breath spontaneously
Terminology Phigh (PEEP high)
◦ P High is similar to MAP and thus affects oxygenation
Plow (PEEP low)◦ Always set at zero to account for the auto PEEP that
will occur
Thigh (Time high)◦ From your TCT. The amount of time you will be
held at the Phigh
Tlow (Time low)◦ The time to release CO2
T High
P High
T Low
Spontaneous Breaths On P High
Patient Trigger on P High
Spontaneous Breaths With PS
WEANING:
1. The FiO2 should be weaned first
2. Reducing P High, by 2cmH20 increments until the P High is below 20 cmH2O
3. Increasing T High to change vent set rate by 5 releases/minute until the patient is essentially on CPAP with very few releases
4. Patients should be increasing their spontaneous rate to compensate
5. Add Pressure Support with caution. Add Pressure Support to P-High to decrease WOB
while avoiding overdistention, P-High + PS < 30cmH2O
Introduced in 1994
You set patient’s height
ASV assumes that adequate minute ventilation is 10L/min of IBW in Kg
RR and Vt are then automatically determined based on the patient’s lung compliance
Used for patients with severe refractory hypoxia
Monitored by measuring PAP
Improves pulmonary blood flow◦ Improved V/Q
◦ Decreased shunt-deadspace
◦ Improved PaO2
Used for ARDS
Persistent pulmonary hypertension in neonates
Congenital heart disease
Heart valve disorders
When combined with O2 forms NO2
Capillary smooth muscle dilation
◦ Gas molecule – can be delivered directly to the
pulmonary capillaries (selective vasodilatation)
◦ Systemic vasodilatation is avoided
No loss of blood pressure
Artificial membrane that mimics the AC membrane’s function◦ Used for refractory ARDS
Done with a apparatus outside the body
Venoarterial◦ Provides cardiac and pulmonary support
◦ More dangerous (hemolysis, bleeding)
Venovenous
Technique
◦ Catheters are placed and 30 -80% of the blood is
pumped through a membrane oxygenator
◦ The patient is ventilated to maintain PaCO2
Liquid perfourocarbon (Perflubrontm)◦ More soluble to oxygen
Approximately 50X carrying capacity
◦ Dense liquid
Moves easily
◦ Distributes throughout the lung effectively
There is no build up of pressure in one area
◦ Volatile solution (evaporates)
Technique◦ Fill FRC with solution until a meniscus is seen in the
endotracheal tube
◦ Ventilate the patient
The liquid distributes itself throughout the entire diffusion area of the lung
Alveoli remain open
Debris floats to the top of the solution and is easily removed
Solution has an anti-inflammatory effect