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01.12.2018 | Letter | Ausgabe 1/2018 Open Access

Critical Care 1/2018

Feasibility, safety, and utility of bronchoscopy in patients with ARDS while in the prone position

Zeitschrift:
Critical Care > Ausgabe 1/2018
Autoren:
Or Kalchiem-Dekel, Carl B. Shanholtz, Jean Jeudy, Ashutosh Sachdeva, Edward M. Pickering
Wichtige Hinweise
A comment to this article is available online at https://​doi.​org/​10.​1186/​s13054-018-2069-y.
Abbreviations
ARDS
Acute respiratory distress syndrome
EtCO2
end-tidal carbon dioxide
FB
Flexible bronchoscopy
FIO2
Fraction of inspired oxygen
ICU
Intensive care unit
MV
Mechanical ventilation
PaO2
Partial pressure of arterial oxygen
PP
Prone position

Prone positioning (PP) was shown to reduce mortality in mechanically ventilated (MV) patients with severe ARDS [ 1]. Despite its common use, safety concerns inhibit use of flexible bronchoscopy (FB) in patients with ARDS, and there are few reports of FB performed in PP [ 2]. We reviewed all adults receiving FB in PP in one institution between April 2016 and September 2017. The study was approved by the institutional review board. Four men and three women were identified (Table  1). In five patients, FB was indicated for clearance of thick secretions, and in two patients for microbial analysis. The mode of mechanical ventilation was not changed for FB, but FIO 2 was universally set to 100%. All subjects had invasive hemodynamic and pulse oximetry monitoring. End-tidal carbon dioxide (EtCO 2) was monitored in 3/7 subjects. With the subject’s head tilted to the side, the bronchoscope was advanced into the airways, repeatedly, and in short cycles, allowing time for oxygenation, ventilation, and lung recruitment between insertions. Therapeutic aspiration was performed in 6/7 subjects. Bronchoalveolar lavage was performed in two subjects. No significant hemodynamic compromise was observed during any of the procedures. Significant oxygen desaturation and rising EtCO 2 were observed in one case (patient 4). Both derangements resolved with withdrawal of the bronchoscope and recruitment. No additional complications were documented. Figure  1 illustrates evolution of the PaO 2:FIO 2 ratio over time for each subject. Six subjects had antibiotics modified based on FB-obtained cultures. Consistent with previous data [ 3], 4/7 subjects survived 30 days following discharge from the ICU.
Table 1
Individual patient parameters, flexible bronchoscopy performance, and outcomes ( n = 7)
Variable
Patient 1
Patient 2
Patient 3
Patient 4
Patient 5
Patient 6
Patient 7
Age (years)
63
18
44
79
53
23
61
Sex
Female
Female
Male
Male
Male
Female
Male
Ethnicity
Black
Caucasian
Caucasian
Asian
Caucasian
Black
Caucasian
Etiology of ARDS
MRSA sepsis
Massive pulmonary embolism
Fulminant hepatic failure, Klebsiella sepsis
Pneumonia
Massive aspiration
Massive aspiration
Pneumonia
Total ICU LOS (days)/day of FB
27/9
30/13
97/32
35/29
9/2
49/11
16/1
Prone-positioning protocol (total hours)
28
18
16
236
20
133
18
30-day survival post ICU discharge
No
Yes
Yes
No
Yes
Yes
No
Ventilator-related parameters at FB a
 Mode
PRVC
PC/AC
VC/AC
PRVC
VC/AC
PC/AC
PC/AC
 Peak pressure (cmH 2O)
32
29
24
37
30
20
32
 Plateau pressure (cmH 2O)
27
NA
NA
30
26
NA
27
 PEEP (cmH 2O)
11
12
15
8
10
10
14
 FIO 2 (%)
100
100
100
100
100
100
100
FB-related data
 Δ-diameter ETT to bronchoscope (mm)
1.7
2.0
1.7
2.0
2.0
4.0
3.1
 Therapeutic aspiration
Yes
Yes
Yes
No
Yes
Yes
Yes
 Bronchial washings / BAL
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Monitoring data
 MAP
  Baseline a
69
67
87
68
72
67
80
  Trough during FB
69
64
72
66
71
67
68
 SpO 2
  Baseline a
94
98
97
100
100
100
100
  Trough during FB
94
92
97
87
99
99
100
 EtCO 2
  Baseline a
48
30
NA
43
NA
NA
NA
  Trough during FB
49
30
NA
51
NA
NA
NA
Change in antibiotic regimen based on culture results
De-escalation
De-escalation
No
Additional coverage
De-escalation
De-escalation
De-escalation
ARDS adult respiratory distress syndrome, ICU intensive care unit, LOS length of stay, FB flexible bronchoscopy, MRSA methicillin-resistant Staphylococcus aureus, PRVC pressure-regulated volume control, PC/AC pressure-cycled assist-controlled, VC/AC volume-cycled assist-controlled, PEEP positive end-expiratory pressure, ETT endotracheal tube, BAL bronchoalveolar lavage, MAP mean arterial pressure as measured with an arterial line, NA not available,  SpO 2 oxygen saturation as measured with pulse oximetry, EtCO 2 end-tidal carbon dioxide, FIO 2 fractional concentration of inspired oxygen
aAs documented prior to first bronchoscope insertion
Although PP is lung-protective, it may result in mobilization of secretions into the airways, impairing oxygenation and providing nidus for infection [ 4]. Despite documented risks [ 5], FB may be beneficial in this situation.
Several limitations need to be addressed when interpreting our data. This is a retrospective analysis. Although physiologic monitoring was automatically captured, ventilator data were not and ventilator output during FB could not be accurately analyzed. Additionally, EtCO 2 was not measured in all cases during FB. Finally, PP was shown to reduce mortality in patients with moderate to severe ARDS, however, our study subjects’ oxygenation had started to improve by the time FB was performed (Fig. 1, T1). This likely reflects reluctance to perform FB in subjects with severe hypoxemia due to excessive risks.
Our report demonstrates the feasibility of FB performed in brief increments in carefully monitored patients with ARDS ventilated in PP. Further studies are needed to better delineate optimal ventilator management during FB in PP.

Acknowledgements

This manuscript was presented as a thematic poster during the American Thoracic Society International Conference, Washington DC, USA, May 2017.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Ethics approval and consent to participate

The study was conducted at University of Maryland Medical Center in accordance with Good Clinical Practice (Declaration of Helsinki 2002) and University of Maryland, Baltimore Campus Institutional Review Board approvals (IRB reference number HP-00073462). Patients were included from April 2016 to September 2017. A waiver of consent has been approved per 45 CFR 46.116(d).

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

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Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License ( http://​creativecommons.​org/​licenses/​by/​4.​0/​), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( http://​creativecommons.​org/​publicdomain/​zero/​1.​0/​) applies to the data made available in this article, unless otherwise stated.
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