Supplemental Data s3

Supplemental Data

Extravascular lung water, B-type natriuretic peptide and blood volume contraction enable diagnosis of weaning-induced pulmonary edema

Martin DRES, MD(1,2), Jean-Louis TEBOUL, MD, PhD(1,2), Nadia ANGUEL, MD(1,2), Laurent GUERIN, MD(1,2), Christian RICHARD, MD(1,2), Xavier MONNET, MD, PhD(1,2)

Material and methods

Patients.

The flow chart of the study is depicted in the Supplemental Figure 1 (Supplemental

Digital Content 2, http://links.lww.com/CCM/A888). The outcome of the spontaneous breathing trial are given in the Supplemental Figure 2 (Supplemental Digital Content 3, http://links.lww.com/CCM/A889).

Predefined readiness to wean criteria

In our unit and based upon current guidelines (1), all patients receiving mechanical ventilation are daily screened to detect the potential of ventilation discontinuation. The screening criteria are (1) evidence for some reversal of the underlying

cause of respiratory failure, (2) adequate oxygenation (PEEP requirement  5 cmH2O, FiO2 

0.5, pH > 7.25), (3) hemodynamic stability (no need for high dose vasopressive agents), (4) body temperature < 39°C, (4) adequate mentation and no continuous administration of sedative agents and (5) capability to initiate an inspiratory effort at examination and to cough. If the patient fulfills the above criteria, he undergoes a weaning trial. This trial is performed by disconnecting the patient from the ventilator and by adapting on a T-piece at the tip of the endotracheal tube. Additional oxygen is administered for obtaining a pulse oxygen saturation  90 %. The patient is left at spontaneous breathing for a 60-min maximum duration.

Definition of intolerance to the spontaneous breathing trial

Clinical intolerance to the spontaneous breathing trial (SBT) was defined if the patient exhibited acute respiratory distress as witnessed by at least one of the following signs: (1) diaphoresis, (2) use of accessory respiratory muscles, (3) worsening of discomfort,

(4) respiratory rate  35 breaths/min, (5) pulse oxygen saturation  90%, (6) increase in

PaCO2  10 mmHg, (7) heart rate  140 beats /min and (8) systolic arterial pressure  180 mmHg.

Spontaneous breathing trial protocol

As soon as the patients fulfilled the readiness-to-wean criteria, the position of the pulmonary artery catheter was checked on X-Ray and a 60 minutes-SBT was performed with the patient disconnected to the ventilator on T-tube.

Performances of the variation of extravascular lung water, plasma protein concentration, hemoglobin and B-type natriuretic peptide during SBT to detect weaning- induced pulmonary edema after restricted analysis to the first SBT of each patient.

In order to confirm the results of the primary analysis computed from all the SBTs of each patient, we performed a secondary analysis made from only the first SBT. At the end

2 we obtained 21 SBTs, 10 patients with weaning-induced pulmonary edema and 11 without.

Supplemental Table 1 (Supplemental Digital Content 4, http://links.lww.com/CCM/A890) describes the changes in collected variables in patients with and without weaning-induced pulmonary edema during SBT and Supplemental Table 2 (Supplemental Digital Content 5, http://links.lww.com/CCM/A891) describes the performance of the changes in extravascular lung water, plasma protein concentration, hemoglobin and B-type natriuretic peptide during

SBT to detect weaning-induced pulmonary edema.

References

1. Boles J-M, Bion J, Connors A, et al. Weaning from mechanical ventilation. Eur Respir

Journal 2007; 29:1033–1056

Supplemental Figure 1. Flow chart of the study. Supplemental Figure 2. Outcomes of the spontaneous breathing trial.