- 12 -

Volume-targeted Modes of Modern Neonatal Nentilators – How stable is the delivered tidal volume?

Electronic Supplementary Material

Authors:

1Jaecklin Thomas, 2Morel Denis R., 1Rimensberger Peter C. (*)

Affiliation:

1Pediatric Intensive Care Unit

Geneva University Hospital

CH-1211 Geneva 14, Switzerland

2Anesthesiologic Investigation Unit

Geneva University Hospital

CH-1211 Geneva 14, Switzerland

Results

Leak change (Table E1). Under full-term infant settings, leak decrease (Figure E1) was well managed by most machines. Several ventilators delivered smaller than set Vt under steady state pre-change conditions with 20% leak. The only one to increase the Vt by 10% was the Galileo Gold. The Evita XL dropped the delivered Vt by 29% before achieving a new steady state at 90% of pre-change value. We observed the mirrored picture with leak increase (Figure E2). While the Galileo Gold decreased slightly it’s Vt, the Evita XL increased it before achieving a steady state at 110% of baseline. All other ventilator managed well the leak increase, despite not using the inbuilt automatic leak compensation algorithm. Under preterm infant settings, no major volume variation occurred after leak decrease. The Evita XL showed considerable breath-to-breath Vt variation (between 4 and 9 ml) and the Galileo Gold showed a sinusoidal pattern of Vt delivery with a periodicity of 12 inflations and Vt varying between 4 and 15 ml. In both machines these variations were unaffected by the leak change. The baseline Vt was maintained after leak increase and decrease by all other machines.

High-level resistance increase (50 to 500 cmH2O/l/s;Table E2, Figure E3). Under full-term infant settings, most ventilators dropped their Vt for the first few inflations after resistance change and progressively adapted PIP in order to readjust towards pre-change Vt level. The Evita XL achieved this adaptation within 5 inflations, whereas the Babylog 8000 plus Galileo Gold and the Servo-i needed 11 to 14 inflations. The SLE 5000 decreased considerably it’s Vt (down to 62% of the initial Vt) without signs of adaptation, behaving rather like a pressure control mode in this setting, but delivered Vt was close to the set value. Even though most ventilators adjusted their Vt after the resistance increase, none of them came close the set value. Under preterm infant settings, again considerable baseline Vt variations between the various machines were observed under low resistance conditions varying from 5 to 12 ml (68 to 150% of the set 8 ml and 10 ml for VIP Gold and Galileo Gold). The Evita XL again showed major breath-to-breath variations of delivered Vt (between 4 and 9 ml) and this “oscillation” was abolished after the resistance increase, a steady state was achieved at 6 ml under the high resistance setting. The Babylog 8000 plus gave inconstant Vt in this small volume range and dropped transiently the Vt during over 5 inflations after the resistance increase. The Galileo Gold showed an initial offset with Vt of around 6 ml (10 ml set) but delivered more adequate volumes of 9 ml after under high resistance settings. The Servo-i, even though it delivered a very low Vt of around 5.5 ml (69% of set Vt), dropped the delivered volume by only 1 ml after the resistance increase for 8 inflations before correcting to baseline level. The SLE 5000 delivered again a high Vt of 12 ml (150%) before the change and dropped it down to 10 ml after the resistance increase, without correction towards baseline. The VIP Gold decreased the Vt from 9 to 7 ml after the resistance change and it was unable to match pre-change levels again.

High-level resistance decrease (500 to 50 cmH2O/l/s;Table E2, Figure E4). Full-term infant settings: Under high resistance conditions all ventilators delivered a Vt lower than 20 ml despite the set value of 28 ml. The VIP Gold only delivered 9 ml instead of the set 25 ml. After rapid resistance decrease all machines increased the delivered Vt. The VIP Gold did this in a relatively controlled way and delivered a volume close to the set value. The Servo-i administered one inflation of 34 ml (120% of set value) and lowered significantly the volume of the next inflation, before increasing progressively the delivered Vt in order to achieve the steady state close to the set value after 6 inflations. All other machines showed volume overshooting over several inflations: The Babylog 8000 plus delivered a maximum volume of 38 ml (134% of set Vt) and came back to steady state after 10 inflations, the Evita XL went up to 35 ml (124%) and lowered the Vt progressively over 5 inflations whereas the Galileo Gold overshot up to 51 ml (184%) and needed 13 inflations to reach baseline again. The SLE 5000 limited the delivery of Vt to 134% of set value, but again it did not show any signs of volume adaptation thereafter. Preterm infant settings: Pre-change Vt varied between a maximum of 11 ml (132%, SLE 5000) and a minimum of 5 ml (61%, Servo-i). All ventilators showed volume overshooting after resistance relief. It was a minor overshooting for the Servo-i (maximum Vt 6 ml during 3 inflations), the Babylog 8000 plus (maximum Vt 10 ml, reached baseline at 9 ml after 4 inflations) and the VIP Gold (maximum Vt 9 ml, no tendency to baseline), whereas high volumes were delivered by the Galileo Gold (maximum Vt of 17 ml, 167%). It started a sinusoidal pattern of Vt delivery after resistance relief with Vt between 4 to 15 ml (40 to 150%) with a periodicity of 16 inflations. The SLE 5000 increased it’s Vt up to 12 ml (154%) after the resistance decrease without downward trend during the measurement period.

Figure Legends

Figure E1. Leak decrease from 20 to 0% (30 to 0%) in full-term (preterm) infant settings. Vt: tidal volume. Horizontal solid bar: set Vt of 28 ml (8 ml) in full-term (preterm) infant settings. Horizontal dotted bar: set Vt of 25 ml (10 ml) for Galileo Gold (Galileo Gold and VIP Gold) ventilator in full-term (preterm) infant settings. Vertical bar: compliance change before inflation number six (nine) in full-term (preterm) infant settings. l Babylog 8000 plus, n Evita XL, p Galileo Gold, Servo-i, o SLE 5000, r VIP Gold.

Figure E2. Leak increase from 0 to 20% (0 to 30%) in full-term (preterm) infant settings. Vt: tidal volume. Horizontal solid bar: set Vt of 28 ml (8 ml) in full-term (preterm) infant settings. Horizontal dotted bar: set Vt of 25 ml (10 ml) for Galileo Gold (Galileo Gold and VIP Gold) ventilator in full-term (preterm) infant settings. Vertical bar: compliance change before inflation number six (nine) in full-term (preterm) infant settings. l Babylog 8000 plus, n Evita XL, p Galileo Gold, Servo-i, o SLE 5000, r VIP Gold.

Figure E3. Resistance increase from 50 to 500 cmH2O/l/s in full-term and preterm infant settings. Vt: tidal volume. Horizontal solid bar: set Vt of 28 ml (8 ml) in full-term (preterm) infant settings. Horizontal dotted bar: set Vt of 25 ml (10 ml) for Galileo Gold (Galileo Gold and VIP Gold) ventilator in full-term (preterm) infant settings. Vertical bar: compliance change before inflation number six (nine) in full-term (preterm) infant settings. l Babylog 8000 plus, n Evita XL, p Galileo Gold, Servo-i, o SLE 5000, r VIP Gold.

Figure E4. Resistance decrease from 500 to 50 cmH2O/l/s in full-term and preterm infant settings. Vt: tidal volume. Horizontal solid bar: set Vt of 28 ml (8 ml) in full-term (preterm) infant settings. Horizontal dotted bar: set Vt of 25 ml (10 ml) for Galileo Gold (Galileo Gold and VIP Gold) ventilator in full-term (preterm) infant settings. Vertical bar: compliance change before inflation number six (nine) in full-term (preterm) infant settings. l Babylog 8000 plus, n Evita XL, p Galileo Gold, Servo-i, o SLE 5000, r VIP Gold.


Figure E1

Figure E2

Figure E3

Figure E4

- 12 -

Table E1 Vt delivery by the various volume-targeted modes before and after airway leak decrease and increase

Leak decrease / Babylog 8000+ / Evita XL / Galileo Gold / Servo-i / SLE 5000 / VIP Gold
Full-term settings (target Vt 28 ml, resp. 25 ml, leak decrease from 20 to 0%)
Vt before the change (% of set Vt)1 / 98 ± 0.8 / 82 ± 0.3 / 82 ± 0.4 / 74 ± 0.6 / 97 ± 0.5 / 84 ± 0.1
Vt after the change (% of set Vt)2 / 95 ± 0.5 / 79 ± 0.3 / 81 ± 0.2 / 80 ± 0.2 / 103 ± 0.6 / 91 ± 0.8
DVt after/before the change (%)3 / -3† / -3† / -2† / 8† / 6† / 9†
max. volume offset (% of set Vt)4 / 101 / 71 / 90 / 81 / 102 / 91

Preterm settings (target Vt 8 ml, resp. 10 ml, leak decrease from 30 to 0%)

Vt before the change (% of set Vt)1 / 111 ± 0.8 / 84 ± 29.6 / 87 ± 9.5 / 54 ± 1.8 / 97 ± 0.9 / 81 ± 1.3
Vt after the change (% of set Vt)2 / 106 ± 1.6 / 77 ± 29.1 / 70 ± 4.2 / 67 ± 1.6 / 109 ± 1.8 / 90 ± 1.4
DVt after/before the change (%)3 / -5† / -8 / NA / 23† / 12† / 12†
max. volume offset (% of set Vt)4 / 114 / 46 / 58 / 67 / 113 / 94

Leak increase

/ Babylog 8000+ / Evita XL / Galileo Gold / Servo-i / SLE 5000 / VIP Gold
Full-term settings (target Vt 28 ml, resp. 25 ml, leak increase from 0 to 20%)
Vt before the change (% of set Vt)1 / 98 ± 1.1 / 75 ± 1.0 / 86 ± 0.3 / 74 ± 1.5 / 101 ± 0.4 / 90 ± 0.3
Vt after the change (% of set Vt)2 / 101 ± 0.6 / 80 ± 0.3 / 87 ± 0.4 / 73 ± 0.3 / 96 ± 0.2 / 83 ± 0.3
DVt after/before the change (%)3 / 3‡ / 6† / 1‡ / -2 / -5† / -8†
max. volume offset (% of set Vt)4 / 94 / 85 / NA / 79 / 97 / 83

Preterm settings (target Vt 8 ml, resp. 10 ml, leak increase from 0 to 30%)

Vt before the change (% of set Vt)1 / 111 ± 1.1 / 76 ± 21.0 / 47 ± 9.7 / 67 ± 2.1 / 111 ± 2.2 / 87 ± 1.4
Vt after the change (% of set Vt)2 / 113 ± 0.9 / 85 ± 30.3 / 45 ± 10.3 / 56 ± 0.3 / 101 ± 1.8 / 77 ± 1.1
DVt after/before the change (%)3 / 1† / 13 / NA / -16† / -9† / -11†
max. volume offset (% of set Vt)4 / 114 / 120 / 133 / 71 / 98 / 79
1mean value (± standard deviation) of first five (eight) inflations expressed as % of set Vt in full-term (preterm) infant setting
2mean value (±standard deviation) of last five (eight) inflations expressed as % of set Vt in full-term (preterm) infant settings
3Vt increase/decrease expressed as % of Vt before the change
4highest/lowest Vt expressed as % of set Vt
†p < 0.001, ‡p < 0.05; compared to measured pre-change Vt; NA: non-applicable

Table E2 Vt delivery by the various volume-targeted modes before and after resistance increase and decrease

Resistance increase / Babylog 8000+ / Evita XL / Galileo Gold / Servo-i / SLE 5000 / VIP Gold
Full-term settings (target Vt 28 ml, resp. 25 ml, resistance increase from 50 to 500 cmH2O/l/s)
Vt before the change (% of set Vt)1 / 86 ± 0.7 / 80 ± 0.4 / 81 ± 0.2 / 74 ± 1.0 / 135 ± 0.4 / 91 ± 0.5
Vt after the change (% of set Vt)2 / 58 ± 0.4 / 47 ± 0.3 / 55 ± 0.3 / 60 ± 0.5 / 50 ± 0.5 / 36 ± 0.4
DVt after/before the change (%)3 / -33† / -41† / -32† / -19† / -63† / -61†
max. volume offset (% of set Vt)4 / 37 / 27 / 33 / 31 / 50 / 36

Preterm settings (target Vt 8 ml, resp. 10 ml, resistance increase from 50 to 500 cmH2O/l/s)

Vt before the change (% of set Vt)1 / 104 ± 1.8 / 85 ± 31.4 / 55 ± 9.5 / 68 ± 0.9 / 149 ± 2.2 / 93 ± 1.4
Vt after the change (% of set Vt)2 / 101 ± 2.7 / 79 ± 1.5 / 88 ± 1.7 / 66 ± 2.5 / 128 ± 2.1 / 71 ± 0.6
DVt after/before the change (%)3 / -3 / -7 / 60† / -3 / -14† / -24†
max. volume offset (% of set Vt)4 / 81 / 53 / 71 / 55 / 125 / 71

Resistance decrease

/ Babylog 8000+ / Evita XL / Galileo Gold / Servo-i / SLE 5000 / VIP Gold
Full-term settings (target Vt 28 ml, resp. 25 ml, resistance decrease from 500 to 50 cmH2O/l/s)
Vt before the change (% of set Vt)1 / 59 ± 0.6 / 47 ± 0.6 / 55 ± 0.4 / 58 ± 0.5 / 51 ± 0.6 / 36 ± 0.2
Vt after the change (% of set Vt)2 / 82 ± 1.2 / 80 ± 0.5 / 72 ± 0.5 / 78 ± 1.0 / 134 ± 0.8 / 92 ± 0.8
DVt after/before the change (%)3 / 40† / 71† / 30† / 35† / 162† / 159†
max. volume offset (% of set Vt)4 / 132 / 124 / 184 / 120 / 136 / 93

Preterm settings (target Vt 8 ml, resp. 10 ml, resistance decrease from 200 to 50 cmH2O/l/s)

Vt before the change (% of set Vt)1 / 97 ± 1.5 / 81 ± 1.7 / 87 ± 0.7 / 61 ± 2.3 / 132 ± 1.9 / 68 ± 1.6
Vt after the change (% of set Vt)2 / 113 ± 1.2 / 89 ± 31.5 / 49 ± 8.3 / 68 ± 1.8 / 149 ± 1.6 / 91 ± 1.3
DVt after/before the change (%)3 / 16† / 10 / NA / 11† / 13† / 33†
max. volume offset (% of set Vt)4 / 130 / 120 / 167 / 77 / 154 / 88
1mean value (± standard deviation) of first five (eight) inflations expressed as % of set Vt in full-term (preterm) infant setting
2mean value (±standard deviation) of last five (eight) inflations expressed as % of set Vt in full-term (preterm) infant settings
3Vt increase/decrease expressed as % of Vt before the change
4highest/lowest Vt expressed as % of set Vt
†p < 0.001, ‡p < 0.05; compared to measured pre-change Vt; NA: non-applicable