Influence of patient positioning on shunting during one-lung ...

<strong>Influence</strong> <strong>of</strong> <strong>patient</strong>
<strong>positioning</strong> on shunting
during one-lung ventilation:
supine vs. lateral decubitus.
L. Biesemans
E. Vandermeersch
Table <strong>of</strong> content
1. Introduction
2. Methods
3. Results
4. Discussion
5. Conclusion
6. References
1

1. Introduction
o Gravity induced blood flow redistribution
towards dependent ventilated lung:
limiting arterial desaturation in lat.
decubitus
o Study: document redistribution
o n=48 consecutive pts./no selection
o thoracic interventions: OLV in lat. decubitus
2. Methods (I)
o Premedication: 0.5mg
alprazolam
o Thoracic epidural
catheter: not used perop.
o Induction:
o 4 µg/kg/min prop<strong>of</strong>ol
o 0.25 → 0.15 µg/kg/min
remifentanil
o 0.15 mg/kg cisatracurium
o neosynephrine infusion
(sBP 20% <strong>of</strong> baseline)
o Insertion DL-ET
2

2. Methods (II)
1. DLV: 50% O2-air, ET CO2: 35 mmHg
o parameters + art./mixed ven. blood samples
2. OLV-supine:
o
o
o
o
clamping airway to operative side
operative side open to atmosphere
close operative side to atmosphere at max.
insufflation <strong>of</strong> ventilated lung
evolution oxygen saturation
o parameters + art./mixed ven. blood samples after 10
min.
2. Methods (III)
3. OLV-lat. decubitus: turning pt. under OLV
o parameters + art./ mixed ven. blood samples after 10
min.
4. OLV-lat. decubitus: non-dependent lung
open to atmosphere: 5 min. passive
ventilation out <strong>of</strong> phase
o
Parameters + art./mixed ven. blood samples
3

3. Results (I)
Patient Distribution
N=48 (30 lung + 18
non-lung)
Non-Lung, 18,
38%
Lung , 30, 62%
Right lat.
Decubitus, 24,
50%
Positioning for Operation
24 left lat. decub., 24
right lat. decub.
Left lat.
Decubitus, 24,
50%
3. Results (II): Figure 1
Significant ↓ saturation after 4 min. OLV
100
oxygen saturation (%)
95
90
*
85
0 1 2 3 4 5 6 7 8 9 10
time (min) after clamping one lung
4

3. Results (III): figure 2
OLV-SP: ↓PaO2:
92±30 mmHg
OVL-LD: ↑PaO2:
100±33 mmHg (not
sign.)
PO2 (mmHg)
300
200
100
*
*
*
*
*
OLV p atm: ↑PaO2:
143±34 mmHg
0
DLV
DLV
OLV-SP
OLV-SP
OLV-lD
OLV-LD
OLV-Patm
OLV-Patm
3. Results (IV): figure 3: evolution <strong>of</strong>
mixed venous p oxygen
Verloop pO2 v
pO2 v (mm Hg)
90
80
70
60
50
40
30
20
10
0
0 1 2 3 4 5
1=DVL,2=OVL ruglig, 3=OLV zijlig, 4=OLV Patm
5

3. Results (V): figure 4: separation <strong>of</strong>
groups
LEFT LUNG
RIGHT LUNG
300
300
LUNG PATHOLOGY
PO2 (mmHg)
200
100
0
250
DLV
OLV-SP
OLV-LD
OLV-Patm
PO2 (mmHg)
200
100
0
300
DLV
OLV-SP
OLV-LD
OLV-Patm
NOT-LUNG PATHOLOGY
PO2 (mmHg)
200
150
100
50
0
DLV
OLV-SP
OLV-LD
OLV-Patm
PO2 (mmHg)
200
100
0
DLV
OLV-SP
OLV-LD
OLV-Patm
4. Discussion (I)
o Clinical anesthesia, Barash
Thoracical anesthesia, Kaplan
o Lat. decubitus : redistribution <strong>of</strong> blood
flow from non-dependent to dependent
lung.
o Blood flow to dependent lung signif. greater
than to non-dependent lung
shunt when turning patiënt.
6

4. Discussion (II)
o Study: not-signif. ↑ sat. and paO2 with
re<strong>positioning</strong> in lat. decubitus
o type <strong>of</strong> anesthesia and HPV
o prop<strong>of</strong>ol: no inhibition <strong>of</strong> HPV
o remifentanil: no publication?
o ↔ literature: thesis Szegedi
o setup: selection <strong>of</strong> pts. , FIO2, turning under
DLV
4. Discussion
Patients
Surgery
FIO2
Turning
Study UZ GHB
consecutive
no selection
reflects clinical
practice
lung
non-lung
0.5
OVL supine =>
turning under OLV:
direct effect gravity!
Thesis Zsegedi
COPD
lung
0.4/0.6/1.0
OLV supine =>
turning under DLV
=> OLV lat.
decubitus
7

5. Conclusion
Gravity induced redistribution <strong>of</strong> blood flow
Signif.↑ PaO2 and sat. during dependent
OLV
6. References
o Two-lung and one-lung ventilation in <strong>patient</strong>s with chronic
obstructive pulmonary disease: the effects <strong>of</strong> <strong>positioning</strong>
and FIO2, Bardoczky et al., Anesth Analg. 2000;90:35-41
o Sequential changes <strong>of</strong> arterial oxygen tension in supine
position during one-lung ventilation, Watanabe et al.,
Anesth Analg. 2000; 90:28-34
o Prop<strong>of</strong>ol does not inhibit hypoxic pulmonary
vasoconstriction in humans, Van Keer et al., J. Clin.
Anesth., 1989, vol. 1, no.4
o The effects <strong>of</strong> remifentanil and thorachic epidural on
oxygenation and pulmonary shunt fraction during onelung
ventilation, Mark Yew-Hoong Chow et al., J.
Cardiothor. and Vasc. Anesth., Vol. 17, No 1, 2003: pp
69-72
8

Back-up slide I: SD in stead <strong>of</strong> SEM
Significant ↓ saturation after 4 min. OLV
oxygen saturation (%)
100
95
90
85
*
0 1 2 3 4 5 6 7 8 9 10
time (min) after clamping one lung
Back-up slide II
300
PO2 (mmHg)
200
100
0
DLV
OLV-SP
OLV-lD
OLV-Patm
9