The Use of Volumetric Capnography in the Management of ...The

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The Use of Volumetric Capnography in the Management of ...The

  1. 1. Volumetric Capnography: Clinical Applications Donna Hamel, RRT, RCP, FAARC Pediatric Critical Care Medicine Duke Children’s Hospital Durham, N.C.
  2. 2. Pop Quiz!!!! 1. Pressure limited modes are best. 2. Volume limited modes are best. 3. Mixed modes should be used whenever possible. 4. Mixed modes are of absolutely no benefit. 5. I don’t care, I just do what the Doc orders.
  3. 3. Guess what? ♦ To date, no literature exists that proves one mode is superior to another. ♦ So if you answered 1 – 4 You are all right!
  4. 4. However…. If you answered # 5
  5. 5. Why can’t we find the ‘perfect’ mode? ♦ Injured lungs are not hemogenous. ♦ Not all patients respond the same even given the same disease process. ♦ Dynamic properties of the lung make optimizing ventilatory parameters an ongoing process.
  6. 6. In response…. New technology ♦Ventilators with myriad ventilatory modes and flow options. ♦Capability to sculpt each breath to meet the specific needs of individual patients. ♦Clinicians can now choose from a multitude of options when initiating & managing mechanical ventilation.
  7. 7. But now ♦ Clinicians must now choose from a multitude of options when initiating & managing mechanical ventilation. ♦ How do we assess the effectiveness of our choices? ♦Arterial blood gases ♦Pulse oximetry ♦ETCO2 monitoring ♦Volumetric capnography
  8. 8. Volumetric Capnography ♦ Overview with emphasis on SBCO2 waveform ♦ Clinical significance ♦Tidal volume delivery ♦Efficacy of delivered breaths ♦Extubation success indication ♦Length of ventilation ♦ Case series
  9. 9. What is volumetric capnography? ♦ Integration of flow and carbon dioxide. ♦ Measures, calculates, and displays breath-by- breath measurements throughout the entire respiratory cycle. ♦Digital numeric display ♦Multiple graphics ♦Single breath waveform (SBCO2) ♦ Multitude of information including VCO2
  10. 10. Volume-based Capnography Integration of flow and CO2
  11. 11. Volumetric capnography ♦ This integration allows for the display of breath by breath measurements throughout the entire respiratory cycle. ♦ Data is both digitally and graphically displayed.
  12. 12. Graphical displays ♦ Graphics provide rapid assessment of various parameters. ♦ Help generate and test hypotheses of patient management. ♦ Monitor for the presence of adverse effects of mechanical ventilation.
  13. 13. Graphical display ♦ Trending bars ♦ Waveforms ♦ Flow loops ♦ Scalars
  14. 14. Graphical displays ♦ Trending bars ♦Especially useful during the weaning phase of ventilation ♦Useful for assessing effects of PEEP titration ♦ SBCO2 waveform ♦Consists of 3 distinct phases ♦Useful in determining pathophyiology ♦Instrumental in designing optimal treatment strategies
  15. 15. SBCO2 Measurements ♦ CO2 elimination (VCO2) ♦ Alveolar ventilation (MValv) ♦ Deadspace ventilation (Vd/Vt) ♦ Assess pulmonary capillary blood flow %CO2 Exhaled Volume
  16. 16. ExpiredCO2 I II VT III SBCO2 waveform Three distinct phases
  17. 17. SBCO2 Waveform ExpiredCO2 I VT Phase I = large airway ventilation
  18. 18. SBCO2 Waveform ExpiredCO2 I II VT Phase II = mixed large airway and alveolar ventilation Phase I = large airway ventilation
  19. 19. SBCO2 Waveform ExpiredCO2 I II VT Phase II = mixed large airway and alveolar ventilation Phase I = large airway ventilation III Phase III = exhaled volume of alveolar gas
  20. 20. SBCO2 Waveform ExpiredCO2 I II VT Phase II = pulmonary perfusion Phase I = dead space III Phase III = gas exchange
  21. 21. Phases of SBCO2 waveform ♦ Phase 1: ♦represents gas exhaled from the upper airways which generally is void of carbon dioxide ♦ Phase 2: ♦transitional phase from upper to lower airway ventilation and tends to depict changes in perfusion ♦ Phase 3: ♦area of alveolar gas exchange representative of gas distribution
  22. 22. Clinical relevance ♦ ↑ phase 1 ♦indicates ↑ in anatomic dead space ventilation (VDANA) ♦ ↓ phase 2 ♦depicts ↓ in perfusion ♦ ↑ phase 3 ♦indicates a mal-distribution of gas
  23. 23. Volumetric Capnography ♦ Overview with emphasis on SBCO2 waveform ♦ Clinical significance ♦Tidal volume delivery ♦Efficacy of delivered breaths ♦Extubation success indication ♦Length of ventilation ♦ Case series
  24. 24. Tidal Volume Determination The current practice of ventilating with low lung volumes makes accurately determining delivered tidal volume essential.
  25. 25. Tidal Volume Determination Delivered tidal volume can be determined at two different locations: ♦at the expiratory valve of the ventilator ♦at the ETT with a pneumotach
  26. 26. Tidal Volume Determination Measuring tidal volume at the expiratory valve of the ventilator does not account for the volume “lost” due to the distensibility of the ventilator circuit.
  27. 27. Tidal Volume Determination Can you calculate the tidal volume “lost” due to the distensibility of the ventilator circuit and compensate for it? Calculated effective Vt = Vt at exp valve - [circuit comp x (PIP - PEEP)]
  28. 28. ventilator inspiration expiration ETT EtCO2 adapter flow/pressure transducer pneumotachometer
  29. 29. Results: Infant Circuit Vt (ml) p Exp valve Vt 70.4 ± 31.1 Calculated Vt 59.2 ± 28.8 < 0.0001 Pneumotach Vt 39.4 ± 21.5 < 0.0001 n = 70 The expiratory Vt measured at the ETT was on average 56% of that measured at the expiratory valve of the ventilator. Cannon, AJRCCM, 2000.
  30. 30. Results: Infant Circuit 0 50 100 150 200 0 20 40 60 80 100 120 ExpiratoryvalveVt Pneumotachometer Vt R2 = 0.54 y = 1.06x + 29
  31. 31. Results: Infant Circuit 0 20 40 60 80 100 120 140 160 0 20 40 60 80 100 120 EffectiveVt Pneumotachometer Vt R2 = 0.58 y = 1.02x + 19
  32. 32. Conclusion Calculating delivered tidal volumes are not sufficient because of multiple uncontrolled variables: ♦in-line suction catheters ♦condensation ♦secretions ♦EtCO2 adapters ♦humidifiers / heaters ♦etc.
  33. 33. Volumetric Capnography ♦ Overview with emphasis on SBCO2 waveform ♦ Clinical significance ♦Tidal volume delivery ♦Efficacy of delivered breaths ♦Extubation success indication ♦Length of ventilation ♦ Case series
  34. 34. Efficacy of delivered breaths Mechanical ventilators are routinely set to deliver a minute ventilation based on ideal body weight and physiologic respiratory rate. MVTOTAL = VT (6cc/kg) x RR (physiologic)
  35. 35. Effective Ventilation Many factors effect the ability of this delivered gas to actually reach the alveoli and participate in gas exchange ♦Bronchospasm ♦Increased deadspace (VD) ♦Decreased cardiac output ♦Etc………
  36. 36. Effective Ventilation To determine the amount of gas that reaches the lungs and actually participates in gas exchange, it is important to determine the alveolar minute ventilation (MVALV).
  37. 37. Alveolar Minute Ventilation MVALV is calculated from a SBCO2 waveform which is continuously displayed when monitoring with volumetric capnography. ExpiredCO2 VT
  38. 38. MVALV Calculation from a SBCO2 Waveform Exhaled Volume Volume CO2 ExpiredCO2 EtCO2
  39. 39. Exhaled Volume Volume CO2 ExpiredCO2 PaCO2 EtCO2 ♦ A line is drawn parallel to the alveolar phase of the EtCO2 waveform. ♦ A 2nd line corresponding to PaCO2 is drawn.
  40. 40. Exhaled Volume ExpiredCO2 PaCO2 EtCO2 q p A 3A 3rdrd line is drawn perpendicular to the xline is drawn perpendicular to the x axis so that area q = area p.axis so that area q = area p.
  41. 41. Exhaled Volume ExpiredCO2 PaCO2 EtCO2 q p X = alveolar ventilation Y = alveolar dead space Z = airway dead space MValv = ‘X’ x RR XXZZ YY
  42. 42. Clinical Significance ♦ 20 heterogeneous mechanically ventilated PICU pts (0-18 yrs) ♦ Continuous volumetric capnography (NICO2 Respiratory Profile Monitor, Respironics / Novametrix, Inc. Wallingford CT) ♦ Compared MVTOTAL to MVALV over a 24 hr period
  43. 43. MVTOTAL vs. MVALV ♦ 45% (9/20) had an r2 < 0.7 ♦ 20% (5/20) had an r2 < 0.5 ♦ 1 pt demonstrated no correlation (r2 < 0.03) ♦ Additionally, linear regression ranged from 0.03 ⇒ 0.96 demonstrating that differences between MVTOTAL and MVALV are not consistent and, therefore, can not be predicted
  44. 44. pt # r2 data points pt # r2 data points 1 0.96 1470 11 0.49 1442 2 0.81 1245 12 0.37 1298 3 0.89 1115 13 0.88 1467 4 0.42 1290 14 0.89 1462 5 0.93 1452 15 0.78 1443 6 0.91 1470 16 0.54 1461 7 0.31 1460 17 0.54 1463 8 0.69 1475 18 0.03 1463 9 0.80 1410 19 0.92 1443 10 0.58 1359 20 0.91 1432
  45. 45. MVTOTAL vs. MVALV These data suggest continuous monitoring of MVALV provides a more accurate assessment of ventilator management strategies as well as the efficacy of delivered gas.
  46. 46. Volumetric Capnography ♦ Overview with emphasis on SBCO2 waveform ♦ Clinical significance ♦Tidal volume delivery ♦Efficacy of delivered breaths ♦Extubation success indicator ♦Length of ventilation ♦ Case series
  47. 47. Extubation Criteria ♦ Respiratory frequency to tidal volume ratio ♦Yang, NEJM, 1991 ♦Tahvanainen, CCM, 1983 ♦ T-piece trials ♦Sahn, Chest, 1973 ♦ Negative insp effort measurements ♦Sahn, Chest, 1973 ♦ CROP index (compliance, rate, oxygenation, pressure) ♦Yang, NEJM, 1991 ♦ Numerous SBT studies Adult Patients
  48. 48. What about infants and children? There are no widely accepted criteria for predicting successful extubation in the pediatric population.
  49. 49. Conventional Approaches Clinical evaluation ♦ Physical exam ♦ Patient work of breathing ♦ Chest radiography ♦ Weight change from baseline ♦ Minimal ventilator settings ♦ Blood gas analysis
  50. 50. The use of VD/VT measurements to determine extubation readiness  The purpose of this study was to identify aThe purpose of this study was to identify a minimal physiological deadspace (Vd/Vt)minimal physiological deadspace (Vd/Vt) value using single breath carbon dioxidevalue using single breath carbon dioxide capnography for predicting successfulcapnography for predicting successful extubation from mechanical ventilation inextubation from mechanical ventilation in pediatric patients.pediatric patients. Hubble, CCM, 2000
  51. 51. Extubation Readiness: Methods ♦ Ventilation ♦PS set to deliver Vt of 6 ml / kg ♦PEEP & FiO2 not altered for study ♦ 20 minute equilibration ♦ Vd/Vt calculated ♦ Extubation ♦ Clinical team blinded to Vd/Vt ratio
  52. 52. Results: Individual Outcomes * # p < 0.001 0.10 - 0.50 24 / 25 (96%) N IV (1) 0.51 - 0.64 6 / 9 (67%) N IV (3) 0.65 - 0.95 2 / 10 (20%) N IV (6), PPV (2) Vd/Vt Successful Extubation Failed Extubation Hubble, CCM, 2000
  53. 53. VD/VT: Results ♦ 0.10 – 0.50 very predictive of success ♦ 0.51 – 0.64 moderately predictive ♦ 0.65 – 0.95 very predictive of failure
  54. 54. Volumetric Capnography ♦ Overview with emphasis on SBCO2 waveform ♦ Clinical significance ♦ Tidal volume delivery ♦ Efficacy of delivered breaths ♦ Extubation success indication ♦ Length of ventilation ♦ Case series
  55. 55. Effects on length of ventilation Does continuous monitoring of volumetric capnography with single breath CO2 technology decrease length of ventilation?
  56. 56. Randomized, non-blinded, prospective trial ♦ Intervention group ♦Continuously monitored with volumetric capnography (NICO2 Monitor Respironics Inc.) at initiation of CMV in PICU ♦ Control group ♦standard care including intermittent use of advanced resp mechanics at the discretion of the pt care team Hamel et al, 2005Hamel et al, 2005
  57. 57. Study Criteria ♦ Inclusion criteria ♦all ventilated patients ≤ 18 yrs ♦ Exclusion criteria ♦none
  58. 58. Outcome Variables ♦ Primary endpoint ♦length of ventilation ♦ Secondary endpoints ♦# of CXRs and ABGs ♦complication rate
  59. 59. Preliminary Results ♦ NICO2 group (n = 104) ♦LOV = 117.3 ♦ Control group (n = 103) ♦LOV = 171.4 ♦ Statistical analysis: p = 0.002 ♦ Clinical analysis: ♦LOV ↓ by 54 hrs (2.25 days) ♦32% decrease Hamel et al, 2005
  60. 60. Preliminary Conclusions Continuous monitoring of volumetric capnography decreases length of ventilation in a heterogeneous group of infants and children. ♦ Accurate tidal volume determination ♦ VCO2 ♦ MVALV ♦ VD/VT Hamel et al, 2003
  61. 61. Volumetric Capnography ♦ Overview with emphasis on SBCO2 waveform ♦ Clinical significance ♦Tidal volume delivery ♦Efficacy of delivered breaths ♦Extubation success indication ♦Length of ventilation ♦ Case series
  62. 62. Case: 1 ♦ 15 month ♦ 10 kg little boy ♦ History of prematurity (former 26 wk) ♦ Presents in ED in respiratory failure ♦ Orally intubated ♦ Transferred to PICU
  63. 63. Mechanical ventilation Servo 300 ventilator ♦SIMV volume limited ♦FiO2 0.50 ♦RR 22 bpm ♦Vt set 75 mL ♦PEEP + 5 cm H2O ♦PSV +10 cm H2O
  64. 64. Patient parameters ♦ Arterial blood gas ♦pH 7.37 ♦PaCO2 56 torr ♦PaO2 113 torr ♦ Placed on NICO2 Respiratory Profile Monitor ♦VCO2 64 mL/min ♦SaO2 95%
  65. 65. Patient condition ♦ Increased work of breathing ♦RR 36 ♦Retractions ♦Appearance of ‘discomfort’ ♦ Bilateral wheezes ♦ Decreased oxygen saturation (88%)
  66. 66. Response ♦ Bronchodilator tx given ♦ PEEP was ↑ from 5 to 8 cmH2O ♦ SaO2 ↑ to 95% ♦ However…….
  67. 67. VCO2 rapidly decreased ♦ Inspection of SBCO2 waveform showed ♦↑in phase 1: indicative of ↑ VDANA ♦↓in phase 2: indicative of perfusion↓
  68. 68. 0 10 20 30 40 0 10 20 30 40 50 Expired Tidal Volume (ml) ETCO2(mmHg) Phase I Phase II Phase III VCO2
  69. 69. ↑Phase 1: ↑VDANA ♦ ↑ airway obstruction ♦Patient has RAD ♦? Give another bronchodilator treatment ♦ Excessive PEEP ♦Recent ↑ PEEP ♦? Decrease PEEP level
  70. 70. ↓ Phase 2: perfusion↓ ♦ ↓ venous return ♦Fluid related? ♦Ventilator related? ♦Excessive PEEP? ♦ ↑ intrathoracic pressure ♦Is it ventilator related? ♦Excessive PEEP?
  71. 71. Our patient ♦ Changes in both phase 1 & 2 of SBCO2 waveform ♦ Phase 1 ♦No worsening RAD ♦PEEP was just increased ♦ Phase 2 ♦Fluid status unchanged ♦PEEP was just increased
  72. 72. Based on SBCO2 findings ♦ No additional bronchodilator tx given ♦ No additional vascular volume given ♦ PEEP was to 6 cmH↓ 2O ♦ SaO2 remained 95%
  73. 73. Day 3: weaning ♦ (S)IMV rate 5bpm↓ ♦ Patient began taking over ventilation ♦ After 1 hour VCO2 dramatically↓ ♦No visible signs of fatigue ♦No changes in ETCO2 ♦No changes in SBCO2 waveform
  74. 74. Now what? Look for trends in bar graph ♦MV stable? ♦Are spon. volumes stable?
  75. 75. What does that mean? ♦ A in VCO↓ 2 followed by a in VT↓ SPON indicative of weaning failure ♦ If continued will lead to ↑ in PaCO2 & EtCO2 ♦ IMV ↑ to 14 bpm
  76. 76. Next day ♦ ↑ spontaneous effort ♦ VCO2 ↑ suggesting ↑’d metabolic activity due to additional task of breathing ♦ Delivered mechanical VT had not been changed & spontaneous VT is increasing ♦ ↓IMV to 5bpm
  77. 77. Successful weaning
  78. 78. Outcome ♦ After 93 hours of mechanical ventilation, the patient was successfully extubated. ♦ Continuous monitoring of VCO2 allowed for rapid response to this patient’s changing ventilatory needs.
  79. 79. Case: 2 ♦ 6 month ♦ 5.2 kg ♦ White female ♦ PICU S/P B-T shunt (HLHS) ♦ Orally intubated with 3.5 uncuffed ETT
  80. 80. Patient parameters ♦ Minimal ventilator settings ♦VSV, FiO2 = 0.40, VTSET = 40cc, RRset 22 bpm, PEEP + 5 cm H2O, TI 0.5 ♦ Patient parameters ♦SaO2 - 70s ♦ETCO2 - 34 ♦VCO2 - 32 ♦BP - 80/36 ♦HR - 150 bpm
  81. 81. Case progression ♦ SaO2 decreased to 58% ♦ BP 80/36 ♦ HR 150 bpm ♦ ETCO2 → 34 ♦essentially unchanged ♦ VCO2 → 16
  82. 82. Initial Response ♦ Adjusted ventilator settings ♦VSV → SIMV / 40 / 14 ♦Increase FiO2 ♦ No response to ventilator management strategies ♦ Patient returned to VSV
  83. 83. Assessment ♦ Noted that VCO2 had previously been in the high 20’s
  84. 84. 1631591:50 1633591:49 1735701:48 1634741:47 1637731:46 1836751:45 3237751:44 VCO2 ETCO2 SpO2TIME
  85. 85. Assessment ♦ SBCO2 showed in phase 2↓ ♦ MV unchanged ♦ No ↑ PEEP Decreased Perfusion Baseline
  86. 86. Response ♦ During preparation to administer volume ♦BP ↓ 50/28 ♦HR ↑ 164 bpm ♦ 10cc’s / kg of volume administered ♦ SaO2 stabilized ♦ HR returned to baseline trend ♦ BP returned to baseline
  87. 87. Case Study: 2 VCO2 responded to change in perfusion 5 minutes before SaO2, and even longer before ETCO2, HR, BP changed!
  88. 88. Summary ♦ Five minutes can be very significant in a hemodynamically unstable child. ♦ Had this patient been in a more acute phase of her convalescence her outcome could have been very different.
  89. 89. Case: 3 ♦ 12 year female ♦ Previously healthy ♦ Presents at ED with ♦SOB ♦Tachypneic (RR = 22) ♦Mild hypoxia (SaO2 = 90% on RA)
  90. 90. ED treatment ♦ 2 LPM nasal cannula ♦ Bronchodilator administered ♦ Improved SaO2 (98%) ♦ Discharged to home ♦Albuteral MDI PRN ♦F/U with primary care physician on Monday
  91. 91. Physician follow up ♦ Diagnosed new onset RAD ♦ Asthma treatment plan initiated ♦Flovent daily ♦Peak flow daily ♦Yellow zone – Albuterol ♦Yellow zone x 3 requires Dr. visit ♦Red zone – albuterol tx & immediate ED visit
  92. 92. Next two weeks ♦ 4 ED visits ♦ 4th visit via ambulance ♦ Admitted to a tertiary non-academic medical center ♦ Diagnosis – status asthmaticus ♦ * Significant weight loss
  93. 93. Case progression ♦ Continuous albuterol ♦ O2 therapy ♦ Worsening condition ♦ Intubated ♦ Transferred to Duke PICU
  94. 94. Duke: Day 1 ♦ Continuous albuterol ♦ Artrovent Q6 ♦ IV steroids ♦ (S)PRVC ♦ FiO2 0.70 ♦ VT 7 ml/kg ♦ RR 18 ♦ PEEP 5 cmH2O ♦ PIP 30 cmH2O
  95. 95. Patient assessment ♦ ABG ♦7.26, PaCO2 56, PaO2 50 ♦ SaO2 89% ♦ HR & BP WNL ♦ VCO2 - 245
  96. 96. Case progression ♦ Worsening clinical status ♦PaCO2 ↑ ♦VCO2 ↓ ♦ Assessment of SBCO2 waveform ♦Slight ↑ phase 1 ♦Significant ↑ phase 3
  97. 97. SBCO2
  98. 98. Increased phase 1 & 3 ♦ Phase 1 - VDANA ♦Excessive PEEP ♦↑ airway obstruction ♦ Phase 3 – gas distribution ♦↑ V/Q mismatch ♦? Excessive PEEP ♦↑ airway obstruction
  99. 99. Assessment ♦ PEEP ♦Mild PEEPi present indicative of airway obstruction ♦PEEP titrated to meet PEEPi level ♦ Airway obstruction ♦Bronchodilator therapy already maximized ♦Added Heliox
  100. 100. PICU day 4 ♦ Continued worsening of condition ♦pH at threshold ♦PaCO2 severely elevated ♦Oxygenation (already impaired) unchanged ♦VCO2 continued to ↓ ♦ Bronchoscopy ♦Non-diagnostic ♦Cultures sent
  101. 101. PICU day 5: New information ♦ 1 month prior to admission ♦Visited zoo ♦Visited the aviary where inhaled ??? substance which led to spasmodic coughing episode. ♦ Laboratory cultures sent for differential diagnosis
  102. 102. New diagnosis ♦ Laboratory cultures positive for histoplasma capsulatum ♦Symptoms occur 5-18 days post exposure ♦RAD like symptoms occurred 2 weeks following zoo visit. ♦ Anti-fungals started
  103. 103. Outcome ♦ Histoplasmosis had disseminated ♦Family offered lung transplant ♦Declined due to poor prognosis ♦She was extubated and able to return home where she did succumb to her disease.
  104. 104. Summary ♦ While monitoring with volumetric capnography did not change the final outcome, it did provide information valuable in optimizing her support. ♦ She was able to be extubated and return home to her family.
  105. 105. Case: 4 ♦ 2 m/o male ♦ Vaters syndrome ♦Vertebral anomalies ♦TE fistula ♦Renal anomalies ♦Limb anomalies
  106. 106. Of concern ♦ Trachea ♦Deviated ∼ 300 angle to right ♦Sporadic areas of narrowing ♦Fixed obstruction ♦ Hypoplastic left lung ♦ 2 subcutaneous soft tissue masses in the chest (L>R)
  107. 107. Chest CT
  108. 108. Airway issues ♦ Trached ♦Anomalous airway structure ♦Fixed obstructions & restrictions ♦Metal trach due to occlusion issues with standard trachs ♦ Mechanically ventilated ♦Pressure limited (S)IMV, VT 6 cc/kg, PEEP 8, RR 16, FiO2 0.40 ♦ Heliox 60/40 ♦To assist in gas delivery
  109. 109. Patient parameters ♦ ABG ♦7.26, 50, 80, 87% ♦ VCO2 – 40 ml/min ♦ HR & BP WNL ♦ Urine output - ↓
  110. 110. Case progression ♦ Pt. asleep ♦ SaO2 stable ♦ HR & BP stable ♦ Urine output continuing to ↓
  111. 111. Case progression ♦ VCO2 ↓ 20 ♦ Within minutes VT ↓ to 3 cc/kg ♦ Followed by ↓ SaO2 – 50s
  112. 112. Considerations ♦ Fluid overload? ♦Renal insufficiency present ♦ Inadequate PEEP ♦Not meeting critical opening pressure hence ↓ in VT delivery
  113. 113. SBCO2 waveform ♦ No significant changes in slopes of any phases
  114. 114. What does that tell us? ♦ No changes in phase 1slope ♦PEEP not excessive ♦No ↑ in obstruction ♦ No changes in phase 2 slope ♦No evidence of fluid overload (would most likely result in ↓ phase 2) ♦ No changes in phase 3 slope ♦Inadequate PEEP ruled out (would most likely result in ↑ mal distribution of gas)
  115. 115. What should we do? ♦ ↑ FiO2? ♦Remember this patient is dependent on heliox for gas delivery ♦ Why ↓in VT? ♦Is patient awakening? ♦Is patient fatigued?
  116. 116. Look at trending bar ♦ Is VE stable? ♦ Are spontaneous efforts increased?
  117. 117. Our patient ♦ Bar graphs indicated fatigue ♦ Patient began waking ♦ When taking over ventilation, pt tired almost immediately!
  118. 118. Our response ♦ Patient not ready to take over ventilation ♦ No ventilator changes made ♦ No change in diuretics ♦ Patient sedated
  119. 119. Summary ♦ With the information provided with volumetric capnography we were able to respond quickly to this pt’s ventilatory needs. ♦ Were able to rule out the need to ↑ ventilatory support. ♦ We ruled out need for additional diuretics. ♦ We could treat the pt with objective data.
  120. 120. What did we learn? ♦ We do not know if volumetric capnography really changed this pt’s course. ♦ We do know is that we did not ‘over’ treat him. ♦ We do know that without this data, this pt would most likely have had more ventilatory & renal support than needed.
  121. 121. When provided with the right information… we may spend less time doing the wrong thing!
  122. 122. Conclusion ♦ Monitoring with volumetric capnography will most likely not change clinical practice. ♦ What it will do is provide information that will enhance clinical practice. ♦ Management strategies can be based on objective data.
  123. 123. Thank you!

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