Skip to main content

Table 2 Ventilatory and surgical variables in the included patients

From: Low tidal volume ventilation for patients undergoing laparoscopic surgery: a secondary analysis of a randomised clinical trial

 

Overall

(n = 328)

Low Tidal Volume

(n = 158)

Conventional Tidal Volume

(n = 170)

p value

Tidal volume

 Absolute (mL)

480 (400–630)

400 (350–450)

610 (520–700)

<  0.001

 Adjusted (mL/kg PBW)a

8.8 (6.0–10.0)

6.0 (6.0–6.2)

10.0 (9.9–10.1)

<  0.001

PEEP (cmH2O)

5 (5–5)

5 (5–5)

5 (5–5)

–

Peak pressure (cmH2O)

27 (23–32)

26 (22–30)

29 (24–32)

<  0.001

Respiratory rate (breaths/min)

14 (12–17)

16 (14–18)

12 (10–14)

<  0.001

SpO2 (%)

97 (96–98)

97 (95–98)

97 (96–98)

0.144

FiO2 (%)

70 (50–96)

70 (50–95)

66.5 (50–99.5)

0.580

etCO2 (%)

40 (37–44)

42 (40–47)

39 (36–42)

<  0.001

Arterial blood gas after induction

 pH

7.40 (7.37–7.43)

7.39 (7.35–7.41)

7.42 (7.39–7.45)

<  0.001

 PaO2 (mmHg)

211 (158–274)

203 (157–272)

219 (164–275)

0.256

 PaCO2 (mmHg)

41 (38–45)

43 (40–47)

39 (36–42)

<  0.001

 HCO3 (mmol/L)

25 (24–26)

25 (24–27)

25 (24–26)

0.007

 PaO2 / FiO2 (mmHg)

412 (313–492)

405 (300–481)

417 (339–497)

0.190

 Haemoglobin (g/dL)

127 (112–138)

128 (114–139)

125 (110–138)

0.312

 Base excess (mEq/L)

1.0 (−0.3–2.0)

0.8 (−0.4–2.0)

1.0 (−0.1–2.0)

0.896

 Lactate (mmol/L)

1.1 (0.9–1.4)

1.1 (0.8–1.4)

1.1 (0.9–1.5)

0.197

Arterial blood gas prior to closure

 pH

7.34 (7.30–7.39)

7.32 (7.27–7.36)

7.37 (7.33–7.41)

<  0.001

 PaO2 (mmHg)

172 (132–219)

168 (132–213)

178 (133–221.8)

0.316

 PaCO2 (mmHg)

45 (41–52)

50 (43–55)

42 (38–46)

<  0.001

 HCO3 (mmol/L)

24 (23–25.5)

24 (23–26)

24 (22–25)

0.010

 PaO2 / FiO2 (mmHg)

367 (279–445)

357 (264–438)

371 (290–450)

0.282

 Haemoglobin (g/dL)

124 (111–137)

126 (113–140)

122 (110–134)

0.143

 Base excess (mEq/L)

–1.0 (−2.4–0.1)

–1.0 (−2.6–0.0)

−0.9 (−2.2–0.5)

0.205

 Lactate (mmol/L)

1.1 (0.8–1.5)

1.0 (0.8–1.4)

1.2 (0.9–1.6)

0.039

Duration of surgery (minutes)

185 (140–240)

190 (145–240)

184 (135–238)

0.598

Use of regional anaesthesia (no. / N [%])b

59 / 322 (18.3)

29 / 156 (18.6)

30 / 166 (18.1)

0.999

 Epidural

0 / 322 (0.0)

0 / 156 (0.0)

0 / 166 (0.0)

–

 Spinal opioid

26 / 322 (8.1)

13 / 156 (8.3)

13 / 166 (7.8)

0.999

 TAP/abdominal blockc

22 / 322 (6.8)

12 / 156 (7.7)

10 / 166 (6.0)

0.660

 Otherd

25 / 322 (7.8)

11 / 156 (7.1)

14 / 166 (8.4)

0.682

  1. Data are median (25th–75th quartile) or N (%)
  2. Abbreviations: ABG arterial blood gas, etCO2 end-tidal carbon dioxide, FiO2 inspired fraction of oxygen, HCO3 bicarbonate, PaO2 partial pressure of oxygen, PaCO2 partial pressure of carbon dioxide, PBW predicted body weight, SpO2 pulse oximetry, PEEP positive end-expiratory pressure
  3. a PBW was calculated as 50 + 0.91 x (height [cm] – 152.4) for men and 45.5 + 0.91 x (height [cm] – 152.4) for women
  4. b In addition to general anaesthesia
  5. c Transversus abdominis plane block (TAP) is defined as block of a peripheral nerve designed to anaesthetise the nerves supplying the anterior abdominal wall (T6 to L1)
  6. d Other: brachial plexus block, femoral nerve block, fascia iliaca block, sciatic nerve block, intercostal nerve block, interpleural catheter, wound catheter
Back to article page

BMC Anesthesiology

ISSN: 1471-2253

Contact us