G Model
ARTICLE IN PRESS
RESUS 5993 1–3
Resuscitation xxx (2014) xxx.e1–xxx.e3
Contents lists available at ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
1
Letter to the Editor
2
Assessment of regional ventilation with the electrical impedance tomography in a patient after asphyxial cardiac arrest 3
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Sirs, Survival from cardiac arrest presenting initially with asystole or pulseless electrical activity is very unlikely unless all relevant reversible causes are recognized and treated effectively.1 In some patients, extensive differential diagnosis is needed to ascertain the cause of cardiac arrest, especially if differentiation between cardiovascular and respiratory aetiology is necessary. Routine initial evaluation, including chest X-ray may not be sufficient to diagnose alterations in distribution of ventilation that may be present in some respiratory disorders. Although examination with chest ultrasound could assess lung and pleural cavity pathologies,2 this technique requires expertise and does not directly quantify regional ventilation, while the benefits of computed tomography (CT) should always be weighted to the risks and disadvantages of patient’s intra-hospital transportation. Use of a non-invasive method, an electrical impedance tomography (EIT), which has already been used for assessment of lung volumes and distribution of ventilation under various clinical conditions,3,4 has not become common in post-resuscitation care. We report the case of a 61-year-old man admitted after successful resuscitation from asystolic out-of-hospital cardiac arrest (OHCA) following a short period of severe dyspnoea. His personal history included chronic obstructive pulmonary disease of unknown grading, and an already survived OHCA few years ago. On admission, there were non-specific changes on the ECG. An echocardiography showed right ventricular hypertrophy, normal
left ventricular function, and no signs of massive pulmonary embolism. A left-sided pneumothorax was suspected based on a chest X-ray, but inserted chest tube released only a minimal amount of air. The patient remained haemodynamically stable and did not require catecholamines. Arterial blood gases revealed metabolic acidosis with no retention of carbon dioxide (pH 7.3, PaCO2 4.64 mmHg, BE – 8.5 mmol/l, PaO2 21.6 mmHg on 40% oxygen and positive end-expiratory pressure of 6 cm H2 O). Inflammatory markers were low. EIT scanning (PulmoVista 500, Dräger, Germany) was initiated and showed excessive abnormality in distribution of ventilation. The right lung was receiving 80%, while the left one only 20% of a tidal volume; normal ratio is approx. 55–45%5 (Fig. 1a). A chest ultrasound did not reveal any signs of pleural pathology or lung consolidation, but flexible bronchoscopy proved signs of tracheobronchomalacia. These examinations suggested high probability of respiratory disorder as a primary cause of cardiac arrest. Later, a contrast enhanced CT scan confirmed initial findings: severe left lower lobe hyperinflation due to heterogeneous panlobular emphysema and no signs of pulmonary embolism (Fig. 1b). After initial treatment with corticosteroids, empiric antibiotics and bronchodilatators, the difference in distribution of ventilation diminished with final ratio 67–33% of tidal volume between both sides. The patient was successfully weaned from mechanical ventilation, and transferred to a rehabilitation facility few days later. In this patient, an EIT was used to visualize and quantify the distribution of ventilation, which helped to recognize the cause of cardiac arrest. We suggest that assessment of regional ventilation using a non-invasive bedside method may be helpful in confirmation of respiratory causes of OHCA, and prevent unnecessary or logistically complicated examinations.
http://dx.doi.org/10.1016/j.resuscitation.2014.04.028 0300-9572/© 2014 Published by Elsevier Ireland Ltd.
Please cite this article in press as: Dostal P, et al. Assessment of regional ventilation with the electrical impedance tomography in a patient after asphyxial cardiac arrest. Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.04.028
28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
G Model
ARTICLE IN PRESS
RESUS 5993 1–3
Letter to the Editor / Resuscitation xxx (2014) xxx.e1–xxx.e3
xxx.e2
Fig. 1. (a) Electrical impedance tomography (PulmoVista 500, Draeger, Germany) screenshot showing the difference in distribution of ventilation between right lung [region of interest (ROI) 1: 60%, and 3: 20%] and left lung [ROI 2: 12%, and 4: 8%] in a patient after OHCA. The heterogeneous panlobular lung emphysema with tracheobronchomalacia were considered significant factors contributing to acute respiratory failure. (b) A reference CT scan shows hyperinflation of the left lower lobe.
58
59
Conflict of interest statement
Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic
None.
Truhlar a,b,∗,1
Anatolij Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic b Emergency Medical Services of the Hradec Kralove Region, Hradec Kralove, Czech Republic a
60
61 62 63 64 65 66 67 68 69 70 71 72 Q1 73 74
References 1. Nolan JP, Soar J, Zideman DA, et al., ERC Guidelines Writing Group. European Resuscitation Council Guidelines for Resuscitation 2010 Section 1. Executive summary. Resuscitation 2010;81:1219–76. 2. Lichtenstein DA, Mezière GA. Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest 2008;134:117–25. 3. Costa EL, Lima RG, Amato MB. Electrical impedance tomography. Curr Opin Crit Care 2009;15:18–24. 4. Blankman P, Gommers D. Lung monitoring at the bedside in mechanically ventilated patients. Curr Opin Crit Care 2012;18:261–6. 5. Darke CS, Astin TW. Differential ventilation in unilateral pulmonary artery occlusion. Thorax 1972;27:480.
Dostal 1
Pavel Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of
Josef Polak 1 Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic Sedlak 2
Vratislav Department of Pulmonary Medicine, Charles University Prague, Faculty of Medicine Hradec
Please cite this article in press as: Dostal P, et al. Assessment of regional ventilation with the electrical impedance tomography in a patient after asphyxial cardiac arrest. Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.04.028
75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91
G Model RESUS 5993 1–3
ARTICLE IN PRESS Letter to the Editor / Resuscitation xxx (2014) xxx.e1–xxx.e3
93
Kralove, University Hospital Hradec Kralove, Czech Republic
94
Turek 1
92
95 96 97 98
99 100 101 102 103
Zdenek Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic ∗ Corresponding author at: Emergency Medical Services of the Hradec Kralove Region, Hradecka 1690/2A, 500 12 Hradec Kralove, Czech Republic. E-mail address: [email protected] (A. Truhlar)
xxx.e3
1 Department of Anaesthesiology and Intensive Care Medicine, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic. 2
Department of Pulmonary Medicine, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
104 105 106 107 108 109 110
29 April 2014
111
29 April 2014
112
Please cite this article in press as: Dostal P, et al. Assessment of regional ventilation with the electrical impedance tomography in a patient after asphyxial cardiac arrest. Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.04.028
ARTICLE IN PRESS
RESUS 5993 1–3
Resuscitation xxx (2014) xxx.e1–xxx.e3
Contents lists available at ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
1
Letter to the Editor
2
Assessment of regional ventilation with the electrical impedance tomography in a patient after asphyxial cardiac arrest 3
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Sirs, Survival from cardiac arrest presenting initially with asystole or pulseless electrical activity is very unlikely unless all relevant reversible causes are recognized and treated effectively.1 In some patients, extensive differential diagnosis is needed to ascertain the cause of cardiac arrest, especially if differentiation between cardiovascular and respiratory aetiology is necessary. Routine initial evaluation, including chest X-ray may not be sufficient to diagnose alterations in distribution of ventilation that may be present in some respiratory disorders. Although examination with chest ultrasound could assess lung and pleural cavity pathologies,2 this technique requires expertise and does not directly quantify regional ventilation, while the benefits of computed tomography (CT) should always be weighted to the risks and disadvantages of patient’s intra-hospital transportation. Use of a non-invasive method, an electrical impedance tomography (EIT), which has already been used for assessment of lung volumes and distribution of ventilation under various clinical conditions,3,4 has not become common in post-resuscitation care. We report the case of a 61-year-old man admitted after successful resuscitation from asystolic out-of-hospital cardiac arrest (OHCA) following a short period of severe dyspnoea. His personal history included chronic obstructive pulmonary disease of unknown grading, and an already survived OHCA few years ago. On admission, there were non-specific changes on the ECG. An echocardiography showed right ventricular hypertrophy, normal
left ventricular function, and no signs of massive pulmonary embolism. A left-sided pneumothorax was suspected based on a chest X-ray, but inserted chest tube released only a minimal amount of air. The patient remained haemodynamically stable and did not require catecholamines. Arterial blood gases revealed metabolic acidosis with no retention of carbon dioxide (pH 7.3, PaCO2 4.64 mmHg, BE – 8.5 mmol/l, PaO2 21.6 mmHg on 40% oxygen and positive end-expiratory pressure of 6 cm H2 O). Inflammatory markers were low. EIT scanning (PulmoVista 500, Dräger, Germany) was initiated and showed excessive abnormality in distribution of ventilation. The right lung was receiving 80%, while the left one only 20% of a tidal volume; normal ratio is approx. 55–45%5 (Fig. 1a). A chest ultrasound did not reveal any signs of pleural pathology or lung consolidation, but flexible bronchoscopy proved signs of tracheobronchomalacia. These examinations suggested high probability of respiratory disorder as a primary cause of cardiac arrest. Later, a contrast enhanced CT scan confirmed initial findings: severe left lower lobe hyperinflation due to heterogeneous panlobular emphysema and no signs of pulmonary embolism (Fig. 1b). After initial treatment with corticosteroids, empiric antibiotics and bronchodilatators, the difference in distribution of ventilation diminished with final ratio 67–33% of tidal volume between both sides. The patient was successfully weaned from mechanical ventilation, and transferred to a rehabilitation facility few days later. In this patient, an EIT was used to visualize and quantify the distribution of ventilation, which helped to recognize the cause of cardiac arrest. We suggest that assessment of regional ventilation using a non-invasive bedside method may be helpful in confirmation of respiratory causes of OHCA, and prevent unnecessary or logistically complicated examinations.
http://dx.doi.org/10.1016/j.resuscitation.2014.04.028 0300-9572/© 2014 Published by Elsevier Ireland Ltd.
Please cite this article in press as: Dostal P, et al. Assessment of regional ventilation with the electrical impedance tomography in a patient after asphyxial cardiac arrest. Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.04.028
28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
G Model
ARTICLE IN PRESS
RESUS 5993 1–3
Letter to the Editor / Resuscitation xxx (2014) xxx.e1–xxx.e3
xxx.e2
Fig. 1. (a) Electrical impedance tomography (PulmoVista 500, Draeger, Germany) screenshot showing the difference in distribution of ventilation between right lung [region of interest (ROI) 1: 60%, and 3: 20%] and left lung [ROI 2: 12%, and 4: 8%] in a patient after OHCA. The heterogeneous panlobular lung emphysema with tracheobronchomalacia were considered significant factors contributing to acute respiratory failure. (b) A reference CT scan shows hyperinflation of the left lower lobe.
58
59
Conflict of interest statement
Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic
None.
Truhlar a,b,∗,1
Anatolij Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic b Emergency Medical Services of the Hradec Kralove Region, Hradec Kralove, Czech Republic a
60
61 62 63 64 65 66 67 68 69 70 71 72 Q1 73 74
References 1. Nolan JP, Soar J, Zideman DA, et al., ERC Guidelines Writing Group. European Resuscitation Council Guidelines for Resuscitation 2010 Section 1. Executive summary. Resuscitation 2010;81:1219–76. 2. Lichtenstein DA, Mezière GA. Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest 2008;134:117–25. 3. Costa EL, Lima RG, Amato MB. Electrical impedance tomography. Curr Opin Crit Care 2009;15:18–24. 4. Blankman P, Gommers D. Lung monitoring at the bedside in mechanically ventilated patients. Curr Opin Crit Care 2012;18:261–6. 5. Darke CS, Astin TW. Differential ventilation in unilateral pulmonary artery occlusion. Thorax 1972;27:480.
Dostal 1
Pavel Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of
Josef Polak 1 Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic Sedlak 2
Vratislav Department of Pulmonary Medicine, Charles University Prague, Faculty of Medicine Hradec
Please cite this article in press as: Dostal P, et al. Assessment of regional ventilation with the electrical impedance tomography in a patient after asphyxial cardiac arrest. Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.04.028
75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91
G Model RESUS 5993 1–3
ARTICLE IN PRESS Letter to the Editor / Resuscitation xxx (2014) xxx.e1–xxx.e3
93
Kralove, University Hospital Hradec Kralove, Czech Republic
94
Turek 1
92
95 96 97 98
99 100 101 102 103
Zdenek Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic ∗ Corresponding author at: Emergency Medical Services of the Hradec Kralove Region, Hradecka 1690/2A, 500 12 Hradec Kralove, Czech Republic. E-mail address: [email protected] (A. Truhlar)
xxx.e3
1 Department of Anaesthesiology and Intensive Care Medicine, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic. 2
Department of Pulmonary Medicine, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
104 105 106 107 108 109 110
29 April 2014
111
29 April 2014
112
Please cite this article in press as: Dostal P, et al. Assessment of regional ventilation with the electrical impedance tomography in a patient after asphyxial cardiac arrest. Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.04.028
