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SUPPLEMENTARY MATERIAL Estimation of arterial carbon dioxide based on end-tidal gas pressure and oxygen saturation Raisa Rentola 1, Johanna Hästbacka 1, Erkki Heinonen 2, Per H Rosenberg 3, Tom Häggblom 2, and Markus B Skrifvars 1,* Division of Intensive Care, Department of Anaesthesiology, Intensive Care and Pain Medicine, Helsinki University Hospital and University of Helsinki, Helsinki 00290, Finland;
[email protected];
[email protected] 2 Clinical Care Solutions, Anaesthesia and Respiratory Care, Helsinki 00510, GE Healthcare Finland OY;
[email protected];
[email protected] 3 Division of Anaesthesia, Department of Anaesthesiology, Intensive Care and Pain Medicine, Helsinki University Hospital and University of Helsinki, Helsinki 00290 Finland;
[email protected] * Correspondence:
[email protected]; Tel.: +358504272424 1
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Figure S1. The flowchart of experimental protocol.
EKG, SpO2
Premedication
Induction
-Intramuscular medetomidine (80 μg/kg) and ketamine (10 mg/kg)
-Intravenous propofol (4–5 mg/kg)
Endotrache al intubation
Mechanical ventilation
1. ABG sample
Intervention -metabolic acidosis (lactate infusion, pig 1 and 5) -air embolism (pig 4) -endobronchial ventilation (pig 6) -lung injury (pig 7) -trendelenburg position (pig 7) -elevated intraabdominal pressure (pig 919)
- Target: normoventila tion
15 minutes
15 minutes
2. ABG sample
Second intervention Release of pneumoperitoneum Different ventilation mode Natrium bicarbonate iv Defibrillation Emergence
3. ABG sample
3.,4., 5., 6., 7., 8. and 9. ABG sample
Euthanization -potassium chloride
Figure S2a. The Bland-Altman plot demonstrating the difference between estimated PaCO2 (Formula 1) and measured PaCO2 with 95% confidence intervals in animals 9-19.
Figure S2b. The Bland-Altman plot demonstrating the difference between estimated PaCO2 (Formula 2) and measured PaCO2 with 95% confidence intervals in animals 9-19.
J. Clin. Med. 2018, 7, 290
Figure S3. The differences between measured PaCO2 and end-tidal CO2 values at each time point.
Figure S4. The Bland-Altman plot demonstrating the difference between measured PaCO2 and end-tidal carbon dioxide (ETCO2) with 95% confidence intervals.
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J. Clin. Med. 2018, 7, 290
Figure S5a. The Bland-Altman plot demonstrating the difference between estimated PaCO2 (Formula 1) and paCO2 with 95% confidence intervals in 26 cases prior to any intervention aiming at modifying CO2.
Figure S5b. The Bland-Altman plot demonstrating the difference between end-tidal carbon dioxide (ETCO2) and paCO2 with 95% confidence intervals in 26 cases prior to any intervention aiming at modifying CO2.
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Table S1. Weight, interventions performed, number of ABG analyses, values of measured PaCO2 and pH values in the study subjects. The numbering of animals are based on timing, with the first experimental animal labelled number one and the last number nineteen.
Cas e no.
Weigh t (kg)
Intervention
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
34 37 29 30 17,5 17,5 46,5 31 27 25 19 23 21 26 15,5 25 47 25 51
Metabolic acidosis Metabolic alkalosis CPR+defibrillation Air embolism* Metabolic acidosis Left lung blocked** Trendelenburg+NaCl*** Emergence CO2 insufflation**** CO2 insufflation CO2 insufflation CO2 insufflation CO2 insufflation CO2 insufflation CO2 insufflation CO2 insufflation CO2 insufflation CO2 insufflation CO2 insufflation
No. of ABG analyse s 2 10 2 9 4 5 5 4 5 4 3 4 4 3 4 3 3 3 6
Lowest PaCO2 , kPa 5.24 4.92 4.82 5.43 4.97 5.28 5.31 4.88 5.29 5.16 5.65 5.64 5.6 5.21 5.81 5.86 5.41 5.6 5.86
Highest , PaCO2, kPa 9.85 6.81 6.72 10.55 5.74 7.02 6.27 5.25 6.81 6.53 6.16 6.42 6.67 6.13 13.75 6.08 5.95 6.2 7.41
Mean PaCO2 , kPa 7.55 6.21 5.77 6.75 5.30 6.13 5.74 5.10 6.14 5.96 5.93 5.95 6.21 5.75 8.40 5.94 5.68 5.88 6.54
Highest pH
Lowe st PH
Mea n pH
7.48 7.66 7.47 7.52 7.60 7.49 7.48 7.55 7.41 7.48 7.46 7.50 7.44 7.82 7.50 7.50 7.53 7.53 7.52
7.19 7.36 7.33 7.20 7.35 7.40 7.42 7.47 7.50 7.41 7.43 7.46 7.39 7.49 7.18 7.49 7.51 7.50 7.44
7.34 7.53 7.40 7.44 7.44 7.44 7.47 7.52 7.47 7.43 7.45 7.48 7.41 7.50 7.44 7.49 7.52 7.52 7.49
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ABG analysis= arterial blood gas analysis, CPR = cardiopulmonary resuscitation, PaCO2= arterial partial pressure of carbon dioxide *Air embolism: injection of 60 ml of air into the central vein ** left lung blocked by placing a Swanz catether in the left bronchus ***400 ml of sodium chloride infused into lungs, ****CO2 insufflation (15 mmHg) to abdominal cavity for simulation of laparoscopic operation Data about study subjects: weight, interventions, number of ABG analyses, lowest measured arterial partial pressure of carbon dioxide (PaCO2) value, highest measured PaCO2 value, mean of measured PaCO2 values, highest measured potential of hydrogen (pH) value, lowest measured pH value, mean of measured pH values. Table S2. Hemodynamic variables, etCO2, etO2, PaO2 and PaO2/FiO2 ratios of each animal during the experiment.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
PETCO2 (kPa), Median (IQR) 5.37 (4.96.1) 5.31 (4.95.73) 4.95 (3.185.05 5.04 (4.945.13) 5 (4.715.34) 5.68 (5.146.22) 4.98 (4.895.29) 5.02 (4.935.13) 5.01 (4.965.25) 5.16 5.38 (5.245.45 5.45 (5.26.02 5.1 (4.95.3) 5.12 (4.95.3) 5.39 (5.096.7) 5.22 (4.945.29) 5.22 (4.965.33) 5.12 (5.045.27)
PETO2 (kPa), Median (IQR) 33.9 (23.742.7) 32.0 (31.832.6) 29 (25.465.1) 37,63 (36.7-42.4) 33.4 (33.148.9) 34 (33.734.25) 35.5 (35.236.1) 35.2 (3535.4) 40.1 (36.640.8) 34.4 (34.134.9) 29.6 (29.429.9) 25.23 (24.2-26.3) 24.9 (24.625.1) 30.1 (29.730.5) 25.2 (24.326.3) 24.8 (24.525.1) 25.9 (25.0-26.2) 25.0 (24.925.3)
PaO2 (kPa), Median 10.05 24.51 24.92 8.95 28.61
HR, Median (IQR) 119 (115122) 116 (112122) 118 (111130) 115 (109141) 117 (113124) 139 (138141)
MAP (mmHg), Median (IQR) 116 (107122) 93(77-107)
PaO2/FiO2 Ratio, Mean 248 462
85 (10-93)
553
93 (87105)
277
51 (40-74)
554
106 (103109 139 (136140) 126 (126139) 126 (117130) 105 (99115)
125 (114132) 89 (83103) 88 (81109) 131 (129134 98 (89103) 94 (87109) 89 (81105)
16.25
95 (90-100)
85 (77-92)
437
23.10
120 (108127)
91 (74116)
491
18.28
92 (85-117)
89 (79-95)
482
84(76-99)
483
91 (78101)
481
76 (74-85)
493
24.40 27.16 27.61 32.53 26.23 23.32 24.49
18.55 19.68 18.67
96 (92-100)
127 (117146) 120 (120136) 113 (106130)
650 475 516 430 543 527 500
FiO2 %, Median (IQR) 36 (3043) 36 (3637) 32 (3066) 42 (4146) 38 (3753) 39 (3940) 40 (4040) 35 (3535) 44 (4445) 39 (3939) 34 (3434) 30 (2932) 29 (2930) 35 (3435) 31 (3033) 29 (2829) 31 (3031) 29 (2930)
PEEP, (cmH2O) Median (IQR) 2 (1-2) 2 (2-3) 2 (2-3) 5 (3-12) 3 (2-5) 2 (1-2) 8 (2-9) 2 (2-2) 2 (2-2) 5 (2-5) 5 (5-5) 5 (4-5) 5 (4-5) 5 (5-5) 5 (5-6) 5 (2-5) 5 (5-6) 5 (5-5)
19
5.07
33.5 (25.148.8)
26.00
95 (93-104)
104 (93113)
548
38 (2952)
8 (6-8)
etCO2 = end-tidal carbon dioxide; etO2 = end-tidal oxygen; PaO2 = arterial partial pressure of oxygen; HR = heart rate; MAP = mean arterial pressure; FiO2 = fraction of inspired oxygen; PEEP= positive end-expiratory pressure. Table S3. Estimation of PaO2 based on values of oxygen-dissociation curve.
SpO2(%) 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75
PaO2(kPa) 3,6 3,66 3,71 3,76 3,82 3,87 3,93 3,98 4,04 4,11 4,19 4,26 4,33 4,4 4,47 4,54 4,61 4,69 4,76 4,83 4,9 4,97 5,06 5,17 5,28 5,39
SpO2(%)2 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
2
PaO2(kPa) 5,49 5,6 5,71 5,82 5,92 6,05 6,22 6,38 6,55 6,72 6,88 7,08 7,33 7,59 7,85 8,16 8,56 8,96 9,5 10,08 10,92 12,14 14 15,43 24
