Low Tidal Volume Ventilation With Low PEEP During Surgery May Induce Lung Inflammation

Hitoshi Sato; Kyota Nakamura; Yasuko Baba; Shoko Terada; Takahisa Goto; Kiyoyasu Kurahashi

Disclosures

BMC Anesthesiol. 2016;16(47) 

In This Article

Results

Patient Demography

A total of 28 patients were enrolled, and 14 patients were assigned to each group (Fig. 1). Three patients in the TV12 group were excluded because the operation was terminated before the completion of the study due to dissemination of tumor to the peritoneum. No differences were present in the demographic or clinical data between the groups (Table 1).

Figure 1.

Consort flow diagram for the present study

Physiological Parameters

No significant differences were found in pH, bicarbonate concentration, heart rate, or blood pressure between the groups (Fig. 2). The FIO2 was set between 0.3 and 0.5 in all patients. There was no significant difference in the P/F ratio (Fig. 3a) or the PaCO2 (Fig. 3b) between the two groups at any time point. Peak airway pressure was significantly higher in the TV12 group than in the TV6 group (Fig. 3c). To maintain the PaCO2 within the normal range, ventilation frequency was greater in the TV6 group than in the TV12 group (Fig. 3d). All patients were extubated in the operating room and were spontaneously breathing when they arrived at the PACU. The P/F ratio evaluated just after admission to the PACU was higher in the TV12 group than in the TV6 group (417 ± 92 versus 315 ± 49, p = 0.009) (Fig. 4).

Figure 2.

Changes in hemodynamics and BGA data. pH (a) and bicarbonate (b) were analyzed by blood gas analyses, whereas heart rate (c) and mean blood pressure (d) were obtained from a bedside monitor. Mean ± standard deviation. No significant differences were observed in BP, HR, or BGA between the groups

Figure 3.

Changes in arterial blood gases, airway pressure, and ventilation frequency. a Changes in the P/F ratio were calculated by PaO2 analyzed by a blood gas analyzer and FIO2. b Changes in PaCO2 were analyzed by a blood gas analyzer. c, d Changes in peak airway pressure and ventilator frequency. Mean ± standard deviation. Peak airway pressure was significantly higher in the TV12 group. Ventilation frequency was greater in the TV6 group than in the TV12 group

Figure 4.

Postoperative P/F ratio in the PACU. Mean ± standard deviation. The P/F ratio evaluated just after admission to the PACU was higher in the TV12 group than in the TV6 group (p = 0.009)

Biological Parameters

No significant difference was found in the plasma concentration of IL-8 (p = 0.17) (Fig. 5a). TNF-α was below the detection limit (1.6 pg·mL−1) in the plasma and ELF samples obtained from all the patients. Elastase activity in the plasma was minimal in both the groups. ICAM-1 in the plasma was significantly higher in the TV6 group than in the TV12 group (p = 0.03; Fig. 5b). The concentration of IL-8 in the ELF was significantly higher in the TV6 group than in the TV12 group at 6 h (p = 0.03) (Fig. 6a). No significant difference was found in ICAM-1 (p = 0.31) or elastase activity (p = 0.7) in the ELF between the groups (Figs. 6b, c).

Figure 5.

Plasma concentrations of IL-8 and ICAM-1. Mean ± standard deviation. No significant differences were observed in the plasma concentration of IL-8 between the groups (p = 0.17). Plasma ICAM-1 was significantly higher in the TV6 group than in the TV12 group (p = 0.03)

Figure 6.

Concentrations of IL-8, ICAM-1, and elastase activity in the ELF. Mean ± standard deviation. The concentration of IL-8 in the ELF was significantly higher in the TV6 group than in the TV12 group (p = 0.04) and the post hoc analysis revealed a significant difference at 6 h (p = 0.03). No significant difference was observed in ICAM-1 (p = 0.31) or elastase activity (p = 0.7) in the ELF

Sharing our Data

Data supporting our findings are available upon request.

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