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Positive end-expiratory pressure does not decrease cardiac output during laparoscopic liver surgery
HPB
http://dx.doi.org/10.1016/j.hpb.2016.10.009
ORIGINAL ARTICLE
Positive end-expiratory pressure does not decrease cardiac output during laparoscopic liver surgery A prospective observational evaluation Denis Bernard1, Antoine Brandely1, Olivier Scatton2, Pierre Schoeffler3, Emmanuel Futier3, Thomas Lescot1 & Marc Beaussier1 1
Department of Anesthesiology and Critical Care Medicine, St-Antoine University Hospital, Paris, 2Department of Hepatobiliary Surgery and Liver Transplantation, St-Antoine University Hospital, Paris, France, and 3Department of Anesthesiology and Critical Care Medicine, Estaing Hospital, University Teaching Hospital of Clermont-Ferrand, Clermont-Ferrand, France
Abstract Background: Positive end-expiratory pressure (PEEP) has beneficial pulmonary effects but may worsen the hemodynamic repercussions induced by pneumoperitoneum (PNP) in patients undergoing liver laparoscopic liver resection. However, by the increase of intraluminal vena cava (VC) pressures, PEEP may prevent PNP-induced VC collapse. The aim of this original article was to test the validity of this hypothesis. Methods: After IRB approval and written inform consents, 20 patients were prospectively evaluated. Measurements were performed before and after the application of a 10 cmH2O PEEP on patient without PNP (Control group) and during a 12 cmH20 PNP. Results are in means [95%CI]. Comparison used paired-sample t test. Results: PEEP induced a decrease in CI in Control subgroup (2.3 [2.0–2.6] and 2.1 [1.8–2.4] l min−1 m−2 before and after PEEP. P < 0.05). In contrast, PEEP on a pre-established PNP did not significantly modify CI. Transmural pressure on abdominal vena cava decreased with PNP but was partly reversed by the addition of PEEP. Conclusion: The application of PEEP on a pre-established PNP during laparoscopic liver resection in normovolemic patients did not decrease CI. Analysis of transmural VC pressure variations confirms that the addition of PEEP may prevent the vena cava collapse induced by PNP. Received 19 July 2016; accepted 19 October 2016
Correspondence: Marc Beaussier, Département d’Anesthésie-Réanimation chirurgicale, Hôpital St-Antoine, 184 rue du Fbg St-Antoine, 75571 Paris, France. E-mail: [email protected]
Introduction Recent developments have emphasized the feasibility and the safety of laparoscopic approach for major liver surgery1,2 with excellent short and long-term outcomes.3 This evolution toward laparoscopic procedures brings up new challenges in intraoperative anesthetic management. Increase in the abdominal pressure induced by the pneumoperitoneum (PNP) has ventilatory and hemodynamic consequences that have been well characterized.4 PNP induces a This study has been presented as an abstract at the Annual Congress of the French Society of Anesthesiology and Intensive Care. 2014. Paris.
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decrease in venous return and cardiac output.5 In addition, PNP promotes pulmonary atelectasis that may compromise gas exchange and induce postoperative pulmonary complications.6 It has been shown that the intraoperative application of positive end-expiratory pressure (PEEP) may be able to prevent the occurrence of pulmonary complications induced by PNP.7,8 However, beneficial effects of PEEP on pulmonary function may be counterbalanced by its detrimental effect on right atrial pressure and cardiac output that may worsen the haemodynamic repercussions due to PNP.9,10 Based on previous physiologic studies, an alternative hypothesis about the haemodynamic effects of PEEP on a preestablished PNP can be constructed from hydrodynamic
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Please cite this article in press as: Bernard D, et al., Positive end-expiratory pressure does not decrease cardiac output during laparoscopic liver surgery, HPB (2016), http://dx.doi.org/10.1016/j.hpb.2016.10.009
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pathophysiologic concepts.11 Blood flow in the vena cava is dependent on pressure gradients between abdominal and thoracic compartments. Due to increased intra-abdominal pressure, inferior vena cava may collapse at the diaphragmatic level, reducing venous return from abdominal compartment.12,13 This deleterious effect may be worsened if the downstream intrathoracic pressure is low.11 From this viewpoint, a moderate elevation of intrathoracic pressure, inducing a downstream increase in intrathoracic vena cava pressure, may be able to prevent vessel collapse and to restore the pressure gradient between intrathoracic and intraabdominal compartment as the main determinant of venous return, especially in normovolemic patients.11 In such conditions, it could be speculated that the application of PEEP during laparoscopic liver resection could have beneficial effects on pulmonary function without detrimental consequences on hemodynamics. The aim of this prospective observational evaluation was to test the validity of this theoretical hypothesis.
Material and methods This prospective observational study was designed and reported according to the STROBE Guidelines.14 It received an Ethical Committee Approval (CPP IdF 3 n 3081). All eligible patients scheduled to undergo major laparoscopic liver resection, requiring hemodynamic monitoring, from June to December 2013 were asked for informed consent. Exclusion criteria were ASA physical status 3, cardiac and/or pulmonary insufficiency, Child & Pugh score B or C, pregnancy, inability to understand the protocol and refusal to participate. Anesthesia was conducted according to the usual standard of care at our institution. A single team of anesthesiologists and surgeons was involved in this evaluation. Anesthesia was induced using propofol, sufentanil and atracurium. The trachea was intubated and the lungs were mechanical ventilated with a 7 ml/ kg tidal volume and a respiratory rate adjusted to keep end-tidal CO2 partial pressure between 33 and 37 mmHg. Anesthesia was maintained using desflurane in a mixture of 50% O2 and 50% N2O, with continuous infusions of sufentanil and atracurium. Infusion of atracurium was adapted to ensure about optimal muscle relaxation checked by neuromuscular monitoring. All patients had an internal jugular central venous access and a radial artery catheter. A transesophageal Doppler probe (Cardio Q®, Deltex medical. Chichester, UK) was inserted in order to continuously monitor Stroke volume (SV) and Cardiac index (CI). A 30 cm catheter (Teleflex Medical, Research Triangle Park, NC, USA) was inserted via the jugular vein and the distal extremity positioned under fluoroscopic control in the infradiaphragmatic part of the inferior vena cava. Pressures in the supra diaphragmatic vena cava and in the right atrium were monitored concurrently via the same access. A urinary bladder catheter (Foley catheter) was used to measure variations in intraabdominal pressures.
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Study protocol Once the monitoring had been correctly placed, and stable haemodynamic conditions obtained, a fluid challenge was performed according to the usual guidelines,15 in order to optimize the circulatory volume before the study assessments. Briefly, boluses of 200 ml saline solution were infused until SEV, monitored by transesophageal Doppler probe, did not increase by more than 10% of the pre-bolus value. The study started with the patient in the supine position (Control subgroup), without PEEP nor PNP (Fig. 1). An initial set of measurements was obtained, including Cardiac index (CI), Stroke volume (SV), Heart rate (HR), Mean arterial pressure (MAP), Pressure inside the infradiaphragmatic vena cava (Pivc), Central venous pressure (CVP), and Intraabdominal pressure (Pabd). Transmural pressure was calculated as the difference between Pivc and Pabd. Subsequently, similar measurements were performed after application of a 10 cmH2O PEEP. All values were obtained after a 5-minutes waiting period to achieve stability. A second set of similar measurements was carried out with the patients positioned 15 head-up (Head-up subgroup). A third and fourth sets of similar measurements was performed after the application of a 12 cmH20 PNP (PNP subgroup) in supine and 15 head-up position (Fig. 1). A last set of measurements was performed after PEEP discontinuation to ensure about return to Control values. Statistical analysis The values before and after the application of PEEP in the 4 sets of experiments were compared using a paired-sample t test, after a normal distribution was confirmed by the Kolmogorov–Smirnov test. Data comparing different subgroups were analyzed using independent-samples t test. The threshold of statistical significance was set at P < 0.05. The sample size of 20 patients has been calculated to be able to detect as significant a difference of 0.3 l min−1 m−2 on CI between pre- and postPEEP periods with a P value of 5% and a false negative probability of 10%. This value has been chosen because it represents approximately a variation of 10%, which can be considered as a threshold for clinical pertinence. Results are presented as means [95%CI].
Results Twenty-two consecutive patients were included. Two patients were withdrawn from final analysis because of poor transesophageal Doppler signal. A total of 20 patients were included in the final analysis. Demographic data and surgical procedures are presented in Table 1. All patients received a preoperative fluid infusion during the fluid challenge maneuver (325 ml [250–400]). The hemodynamic consequences of the application of 10 cmH2O PEEP are presented in Table 2. In patients lying flat, the addition of a 10 cmH2O PEEP to a 12 cmH2O PNP did not
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Please cite this article in press as: Bernard D, et al., Positive end-expiratory pressure does not decrease cardiac output during laparoscopic liver surgery, HPB (2016), http://dx.doi.org/10.1016/j.hpb.2016.10.009
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Table 1 Demographic data
n [ 20 Age (y)
61 ± 13
Gender (M/F) −2
BMI (kg m )
Figure 1 Schematic representation of the study protocol. Exp. refers
to experimental sets of measurements
change CI (P = 0.37), whereas CI decreased by 4.9% in patients without PNP (P < 0.05). The increase in intra-abdominal compartment pressure induced by PNP (17.6 mmHg [15.5–19.8] vs 9.2 mmHg [7.6–10.8] without PNP. P < 0.05) (Table 2) was further
9/11 26 ± 5
Hepatocellular carcinoma (n)
16
Liver adenoma (n)
2
Metastasectomy (n)
1
Liver abscess (n)
1
significantly increased by the introduction of PEEP (18.3 mmHg [16.0–20.7] vs 17.6 mmHg [15.5–19.8] without PEEP. P < 0.01) (Table 2). The application of PNP significantly increased the pressure gradient between Pivc and CVP (Table 2 and Fig. 2) and decrease the transmural pressure in the abdominal vena cava (0.9 mmHg [−0.7 to +2.5] vs −2.4 mmHg [−4.8 to 0.0] respectively before and after PNP. P < 0.05). This decrease in vena cava transmural pressure was significantly reversed by the application of PEEP (−2.4 mmHg [−4.8 to 0.0] vs −1.2 [−3.6 to +1.1] before and after PEEP respectively. P < 0.01) (Table 2 and Fig. 2). Moving the patients to the head-up position, without any PNP or PEEP, did not significantly modify cardiac index (P = 0.6), as did the combination of PNP and head-up position (P = 0.5) (Table 2), whereas in this subgroup the addition of PEEP significantly decreased the cardiac index by 5.6% as compared to head-up and PNP alone (P = 0.01).
Discussion
Figure 2 Schematic representation of the effect of PEEP on
abdomino-thoracic pressure gradients
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In this study, evidence was provided that the addition of a 10 cmH20 PEEP on a pre-established 12 cmH20 PNP in normovolemic subjects undergoing liver surgery was haemodynamically well tolerated without any decrease in cardiac output. The results of the current study are consistent with the haemodynamic effects of both PEEP and PNP reported in previous studies. A significant reduction in cardiac index (about 5%) was observed after the application of PNP alone.4 Joris et al. found a reduction of 18% of the cardiac index after the application of a 14 mmHg PNP.16 Difference in the magnitude of the effect could be explained by a lower level of PNP, but mainly by the presumed normovolemic status of the patients after fluid challenge in the current study. Similarly, in patients without PNP, the application of PEEP decreased cardiac index by about 5%, in accordance with previous observations.9,10 This effect was of limited magnitude, probably because our patients were normovolemic. From a theoretical point of view, the combination of the hemodynamic effects of PNP and PEEP on venous return might have been detrimental on the intraoperative cardiac index, especially under hypovolemic conditions. Previous animal17,18 and human19 investigations cautioned about the risk of
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Table 2 Hemodynamic and pressure variations induced by PEEP according to subgroups
Control
Head-up
PNP
Head-up + PNP
Cont
PEEP 10
Cont
PEEP 10
Cont
PEEP 10
Cont
PEEP 10
2.3 [2.0; 2.6]
2.1* [1.8; 2.4]
2.1 [1.8; 2.4]
1.9* [1.6; 2.2]
2.2 [1.8; 2.5]
2.2 [1.8; 2.6]
2.1 [1.7; 2.5]
2.0* [1.6; 2.3]
SV (ml)
75 [62; 87]
72 [60; 83]
70 [59; 82]
60*# [51; 69]
64# [55–73]
63# [54; 72]
61# [52; 69]
59# [51; 68]
HR (b min−1)
56 [51; 62]
54* [49; 59]
56 [51; 61]
55 [51; 60]
59 [55; 64]
61#d [56; 66]
62 [57–66]
59* [54; 64]
MAP (mmHg)
73 [67; 78]
73 [67; 78]
62# [56; 67]
61#d [54; 67]
96# [90; 102]
104*#d [98; 110]
93# [86; 99]
88*#d [81; 95]
CVP (mmHg)
9.2 [8.0; 10.4]
10.9* [9.8; 12.0]
6.0# [4.8; 7.2]
8.6*d [7.6; 9.6]
13.5# [12.0; 15.0]
16.3*#d [15.1; 17.4]
12.4# [11.3; 13.5]
13.9*#d [12.9; 14.9]
Pivc (mmHg)
10.0 [8.6; 11.3]
11.9* [10.7; 13.0]
6.6# [5.5; 7.7]
8.9*d [7.9; 9.8]
15.0# [13.6; 16.3]
16.9*#d [15.6; 18.1]
13.4# [12.3; 14.5]
14.8*#d [13.7; 15.9]
Pabd (mmHg)
9.2 [7.6; 10.8]
9.7* [8.1; 11.4]
10.9 [9.1; 12.7]
10.8 [8.6; 13.1]
17.6# [15.5; 19.8]
18.3*#d [16.0; 20.7]
18.5# [16.2; 20.7]
19.1#d [16.8; 21.3]
CI (l min
−1
−2
m )
Results in means [95%CI]. PNP = Pneumoperitoneum group. SV = Stroke volume. HR = Heart rate. CI = Cardiac index. MAP = Mean arterial pressure. CVP = Central venous pressure. Pivc = Infradiaphragmatic vena cava pressure. Pabd = Pressures in abdominal compartment. Pivc = Pressures in inferior vena cava. Values are rounded to the nearest decimal. *P < 0.05 vs before PEEP, #P < 0.05 vs Control without PEEP, dP < 0.01 vs Control with PEEP.
damaging hemodynamic status when PEEP is associated to PNP. This makes some physicians reluctant to apply PEEP during laparoscopic surgery.19 However, conflicting results about the hemodynamic tolerance of adding PEEP to PNP have been reported17,18,20–23 because many factors, such as the volume loading, the magnitude of applied pressures, depth of anesthesia, and patient position are likely to play a major role in these pathophysiologic repercussions. In the current study, cardiac index was found to be unchanged by the addition of 10 cmH2O PEEP during a 12 cmH2O PNP. Several explanations have to be addressed. In accordance with the work by Giebler et al. and the theory of the vascular waterfall, if it turns out that the intraabdominal pressure around the vena cava becomes superior to the intraluminal pressure, the vessel collapses and the venous return is impaired, becoming relatively independent of the pressure gradient between abdominal vena cava and right atria.11 It has been shown that the critical point for this obstacle is at the level where the vena cava crosses the diaphragm. By increasing the downstream intrathoracic pressure, the addition of PEEP may prevent the collapse of the vena cava and restore the pressure gradient between CVP and Pivc as the main determinant of the venous return. This is illustrated by the evolution of the vena cava transmural pressure, corresponding to the difference between Pivc and Pabd. Addition of PNP significantly increases the pressure applied on the vena cava, inducing a collapse and a decrease of transmural pressure. Transmural pressure is increased by the increase in Pivc induced by PEEP, thereby partly reducing the vessel collapse. This may explain why the addition of PEEP on a pre-established PNP did not decrease cardiac index despite a reduction in the Pivc/CVP gradient.
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Moreover, it should be noted that the cardiac workload in patients with PNP was significantly reduced by the application of a 10 cmH2O PEEP, thereby confirming the beneficial hemodynamic effect of PEEP (reduction in the increase in cardiac afterload induced by abdominal pressure) in this setting as previously demonstrated by Fellahi et al.21 Such results would have been very different according to a number of confounding parameters. Among them, one the most relevant is the volume status of the patients. Indeed, it has been shown that the haemodynamic repercussions of both PEEP24 and PNP25 are far more severe in hypovolemic patients. In the current study, a preoperative optimization of intravascular volume was performed before the evaluation, in order to ensure normovolemia and the homogeneity of the filling pressures among the studied subjects. This assertion is confirmed by the narrow range of CVP at the start of the study. Furthermore, fluid challenge is commonly recommended to improve overall perioperative tissue oxygenation and reduce postoperative complication after major abdominal surgery.26 Volume loading during liver surgery is of major importance and should be a balance between overloading (risk of blood loss) and hypovolemia (risk of organ vascular hypoperfusion). This problematic is far more complex during laparoscopic approach than during open surgery, because pneumoperitoneum may contribute to reduce cardiac index, thereby compromising myocardial, cerebral and renal vascular perfusion in hypovolemic patients. A recent study by Ratti et al., highlights the unreliability of CVP to monitor volemic status during laparoscopic liver surgery and the risks associated with a CVP-guided volume loading in these conditions.27
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The magnitude of the pressures applied in the abdominal and thoracic compartment is also likely to play a role in the observed hemodynamic consequences. In the current study, the values chosen for PNP and PEEP are those commonly used in routine clinical practice and were similar for all patients. Finally, another parameter of major importance is the positioning of the patients. In order to facilitate surgical exposure, laparoscopic liver resections are usually performed in the head-up position. A nonsignificant reduction of the cardiac index, of almost similar magnitude than in previous reports,5 was observed after the patients were moved from the supine to the head-up position. However, in contrast to the observations in the supine position, the application of PEEP in head-up patients having PNP led to a modest, but significant decrease in cardiac index. This study was not designed to test the influence of PEEP on intraoperative blood loss, which could be a matter of concern during liver surgery. A recent report shows that PEEP within a multi-faceted lung protective strategy was not associated with increased bleeding compared with non-protective ventilation using zero PEEP.28 In conclusion, using intraoperative mechanical ventilation with PEEP does not cause any haemodynamic detrimental effect during laparoscopic liver resection in normovolemic patients. Analysis of transmural vena cava pressure variations confirms that the addition of PEEP may prevent the vena cava collapse induced by PNP.
Dr. Beaussier reports grants and personal fees from Baxter SAS, personal fees from MSD, outside the scope of the submitted work. Dr. Schoeffler, Dr. Scatton and Dr. Brandely have nothing to disclose. References 1. Buell JF, Cherqui D, Geller DA, O’Rourke N, Iannitti D, Dagher I et al. (2009) The international position on laparoscopic liver surgery: the Louisville Statement, 2008. Ann Surg 250:825–830. 2. Dagher I, Gayet B, Tzanis D, Tranchart H, Fuks D, Soubrane O et al. (2014) International experience for laparoscopic major liver resection. J Hepatobiliary Pancreat Sci 21:732–736. 3. Xiong JJ, Altaf K, Javed MA, Huang W, Mukherjee R, Mai G et al. (2012) Meta-analysis of laparoscopic vs open liver resection for hepatocellular carcinoma. World J Gastroenterol 18:6657–6668. 4. Grabowski JE, Talamini MA. (2009) Physiological effects of pneumoperitoneum. J Gastrointest Surg 13:1009–1016. 5. Hirvonen EA, Poikolainen EO, Paakkonen ME, Nuutinen LS. (2000) The adverse hemodynamic effects of anesthesia, head-up tilt, and carbon dioxide pneumoperitoneum during laparoscopic cholecystectomy. Surg Endosc 14:272–277. 6. Andersson LE, Baath M, Thorne A, Aspelin P, Odeberg-Wernerman S. (2005) Effect of carbon dioxide pneumoperitoneum on development of atelectasis during anesthesia, examined by spiral computed tomography. Anesthesiology 102:293–299. 7. Futier E, Constantin JM, Pelosi P, Chanques G, Kwiatkoskwi F, Jaber S et al. (2010) Intraoperative recruitment maneuver reverses detrimental
Acknowledgment
pneumoperitoneum-induced respiratory effects in healthy weight and
The authors would like to thank Dr Arthur Atchabahian, M.D. for assistance in manuscript writing and critical review.
obese patients undergoing laparoscopy. Anesthesiology 113:1310–1319. 8. Meininger D, Byhahn C, Mierdl S, Westphal K, Zwissler B. (2005) Positive end-expiratory pressure improves arterial oxygenation during prolonged pneumoperitoneum. Acta Anaesthesiol Scand 49:778–783.
Conflict of interest
9. Fessler HE, Brower RG, Wise RA, Permutt S. (1991) Effects of positive
None declared.
end-expiratory pressure on the gradient for venous return. Am Rev Respir Dis 143:19–24. 10. Pinsky MR. (1985) The influence of positive-pressure ventilation on
Author contributions
cardiovascular function in the critically ill. Crit Care Clin 1:699–717.
Antoine Brandely and Denis Bernard were involved in data recording and interpretation. Olivier Scatton was involved in patient inclusion. Marc Beaussier, Denis Bernard, Emmanuel Futier, Thomas Lescot and Pierre Schoeffler were involved in data interpretation. All authors were involved in writing the manuscript.
11. Giebler RM, Behrends M, Steffens T, Walz MK, Peitgen K, Peters J. (2000) Intraperitoneal and retroperitoneal carbon dioxide insufflation evoke different effects on caval vein pressure gradients in humans: evidence for the starling resistor concept of abdominal venous return. Anesthesiology 92:1568–1580. 12. Permutt S, Riley RL. (1963) Hemodynamics of collapsible vessels with tone: the vascular waterfall. J Appl Physiol 18:924–932. 13. Takata M, Wise RA, Robotham JL. (1990) Effects of abdominal pressure on venous return: abdominal vascular zone conditions. J Appl Physiol
Financial disclosure
(1985) 69:1961–1972.
Dr. Bernard reports personal fees from MSD, outside the scope of the submitted work. Dr. Futier reports receiving personal fees from Baxter (board membership), GE Healthcare (consultancy) and Drager (consultancy); lecture fees from Fresenius-Kabi; and travel reimbursement from Fisher & Paykel Healthcare. Dr. Lescot reports personal fees from Baxter SAS and MSD, outside the scope of the submitted work.
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14. von Elm E, Altman DG, Egger M, Pocock SJ, Gotzsche PC, Vandenbroucke JP. (2007) The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Lancet 370:1453–1457. 15. Roche AM, Miller TE, Gan TJ. (2009) Goal-directed fluid management with trans-oesophageal Doppler. Best Pract Res Clin Anaesthesiol 23:327–334. 16. Joris JL, Noirot DP, Legrand MJ, Jacquet NJ, Lamy ML. (1993) Hemodynamic changes during laparoscopic cholecystectomy. Anesth Analg 76:1067–1071.
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Please cite this article in press as: Bernard D, et al., Positive end-expiratory pressure does not decrease cardiac output during laparoscopic liver surgery, HPB (2016), http://dx.doi.org/10.1016/j.hpb.2016.10.009
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17. Luz CM, Polarz H, Bohrer H, Hundt G, Dorsam J, Martin E. (1994) He-
23. Russo A, Di Stasio E, Scagliusi A, Bevilacqua F, Isgro MA, Marana R
modynamic and respiratory effects of pneumoperitoneum and PEEP
et al. (2013) Positive end-expiratory pressure during laparoscopy: car-
during laparoscopic pelvic lymphadenectomy in dogs. Surg Endosc 8: 25–27.
diac and respiratory effects. J Clin Anesth 25:314–320. 24. Luecke T, Pelosi P. (2005) Clinical review: positive end-expiratory
18. Moffa SM, Quinn JV, Slotman GJ. (1993) Hemodynamic effects of carbon dioxide pneumoperitoneum during mechanical ventilation and positive end-expiratory pressure. J Trauma 35:613–617.
pressure and cardiac output. Crit Care 9:607–621. 25. Kashtan J, Green JF, Parsons EQ, Holcroft JW. (1981) Hemodynamic effect of increased abdominal pressure. J Surg Res 30:249–255.
19. Kraut EJ, Anderson JT, Safwat A, Barbosa R, Wolfe BM. (1999)
26. Gan TJ, Soppitt A, Maroof M, el-Moalem H, Robertson KM, Moretti E
Impairment of cardiac performance by laparoscopy in patients receiving
et al. (2002) Goal-directed intraoperative fluid administration reduces
positive end-expiratory pressure. Arch Surg 134:76–80.
length of hospital stay after major surgery. Anesthesiology 97:
20. Ekman LG, Abrahamsson J, Biber B, Forssman L, Milsom I, Sjoqvist BA. (1988) Hemodynamic changes during laparoscopy with positive endexpiratory pressure ventilation. Acta Anaesthesiol Scand 32:447–453. 21. Fellahi JL, Caille V, Charron C, Daccache G, Vieillard-Baron A. (2012) Hemodynamic effects of positive end-expiratory pressure during abdominal hyperpression: a preliminary study in healthy volunteers.
820–826. 27. Ratti F, Cipriani F, Reineke R, Catena M, Paganelli M, Comotti L et al. (2016) Intraoperative monitoring of stroke volume variation versus central venous pressure in laparoscopic liver surgery: a randomized prospective comparative trial. HPB 18:136–144. 28. Neuschwander A, Futier E, Jaber S, Pereira B, Eurin M, Marret E et al. (2016) The effects of intraoperative lung protective ventilation with
J Crit Care 27:33–36. 22. Rist M, Hemmerling TM, Rauh R, Siebzehnrubl E, Jacobi KE. (2001)
positive end-expiratory pressure on blood loss during hepatic resection
Influence of pneumoperitoneum and patient positioning on preload and
surgery: a secondary analysis of data from a published randomised
splanchnic blood volume in laparoscopic surgery of the lower abdomen.
control trial (IMPROVE). Eur J Anaesthesiol 33:292–298.
J Clin Anesth 13:244–249.
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http://dx.doi.org/10.1016/j.hpb.2016.10.009
ORIGINAL ARTICLE
Positive end-expiratory pressure does not decrease cardiac output during laparoscopic liver surgery A prospective observational evaluation Denis Bernard1, Antoine Brandely1, Olivier Scatton2, Pierre Schoeffler3, Emmanuel Futier3, Thomas Lescot1 & Marc Beaussier1 1
Department of Anesthesiology and Critical Care Medicine, St-Antoine University Hospital, Paris, 2Department of Hepatobiliary Surgery and Liver Transplantation, St-Antoine University Hospital, Paris, France, and 3Department of Anesthesiology and Critical Care Medicine, Estaing Hospital, University Teaching Hospital of Clermont-Ferrand, Clermont-Ferrand, France
Abstract Background: Positive end-expiratory pressure (PEEP) has beneficial pulmonary effects but may worsen the hemodynamic repercussions induced by pneumoperitoneum (PNP) in patients undergoing liver laparoscopic liver resection. However, by the increase of intraluminal vena cava (VC) pressures, PEEP may prevent PNP-induced VC collapse. The aim of this original article was to test the validity of this hypothesis. Methods: After IRB approval and written inform consents, 20 patients were prospectively evaluated. Measurements were performed before and after the application of a 10 cmH2O PEEP on patient without PNP (Control group) and during a 12 cmH20 PNP. Results are in means [95%CI]. Comparison used paired-sample t test. Results: PEEP induced a decrease in CI in Control subgroup (2.3 [2.0–2.6] and 2.1 [1.8–2.4] l min−1 m−2 before and after PEEP. P < 0.05). In contrast, PEEP on a pre-established PNP did not significantly modify CI. Transmural pressure on abdominal vena cava decreased with PNP but was partly reversed by the addition of PEEP. Conclusion: The application of PEEP on a pre-established PNP during laparoscopic liver resection in normovolemic patients did not decrease CI. Analysis of transmural VC pressure variations confirms that the addition of PEEP may prevent the vena cava collapse induced by PNP. Received 19 July 2016; accepted 19 October 2016
Correspondence: Marc Beaussier, Département d’Anesthésie-Réanimation chirurgicale, Hôpital St-Antoine, 184 rue du Fbg St-Antoine, 75571 Paris, France. E-mail: [email protected]
Introduction Recent developments have emphasized the feasibility and the safety of laparoscopic approach for major liver surgery1,2 with excellent short and long-term outcomes.3 This evolution toward laparoscopic procedures brings up new challenges in intraoperative anesthetic management. Increase in the abdominal pressure induced by the pneumoperitoneum (PNP) has ventilatory and hemodynamic consequences that have been well characterized.4 PNP induces a This study has been presented as an abstract at the Annual Congress of the French Society of Anesthesiology and Intensive Care. 2014. Paris.
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decrease in venous return and cardiac output.5 In addition, PNP promotes pulmonary atelectasis that may compromise gas exchange and induce postoperative pulmonary complications.6 It has been shown that the intraoperative application of positive end-expiratory pressure (PEEP) may be able to prevent the occurrence of pulmonary complications induced by PNP.7,8 However, beneficial effects of PEEP on pulmonary function may be counterbalanced by its detrimental effect on right atrial pressure and cardiac output that may worsen the haemodynamic repercussions due to PNP.9,10 Based on previous physiologic studies, an alternative hypothesis about the haemodynamic effects of PEEP on a preestablished PNP can be constructed from hydrodynamic
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pathophysiologic concepts.11 Blood flow in the vena cava is dependent on pressure gradients between abdominal and thoracic compartments. Due to increased intra-abdominal pressure, inferior vena cava may collapse at the diaphragmatic level, reducing venous return from abdominal compartment.12,13 This deleterious effect may be worsened if the downstream intrathoracic pressure is low.11 From this viewpoint, a moderate elevation of intrathoracic pressure, inducing a downstream increase in intrathoracic vena cava pressure, may be able to prevent vessel collapse and to restore the pressure gradient between intrathoracic and intraabdominal compartment as the main determinant of venous return, especially in normovolemic patients.11 In such conditions, it could be speculated that the application of PEEP during laparoscopic liver resection could have beneficial effects on pulmonary function without detrimental consequences on hemodynamics. The aim of this prospective observational evaluation was to test the validity of this theoretical hypothesis.
Material and methods This prospective observational study was designed and reported according to the STROBE Guidelines.14 It received an Ethical Committee Approval (CPP IdF 3 n 3081). All eligible patients scheduled to undergo major laparoscopic liver resection, requiring hemodynamic monitoring, from June to December 2013 were asked for informed consent. Exclusion criteria were ASA physical status 3, cardiac and/or pulmonary insufficiency, Child & Pugh score B or C, pregnancy, inability to understand the protocol and refusal to participate. Anesthesia was conducted according to the usual standard of care at our institution. A single team of anesthesiologists and surgeons was involved in this evaluation. Anesthesia was induced using propofol, sufentanil and atracurium. The trachea was intubated and the lungs were mechanical ventilated with a 7 ml/ kg tidal volume and a respiratory rate adjusted to keep end-tidal CO2 partial pressure between 33 and 37 mmHg. Anesthesia was maintained using desflurane in a mixture of 50% O2 and 50% N2O, with continuous infusions of sufentanil and atracurium. Infusion of atracurium was adapted to ensure about optimal muscle relaxation checked by neuromuscular monitoring. All patients had an internal jugular central venous access and a radial artery catheter. A transesophageal Doppler probe (Cardio Q®, Deltex medical. Chichester, UK) was inserted in order to continuously monitor Stroke volume (SV) and Cardiac index (CI). A 30 cm catheter (Teleflex Medical, Research Triangle Park, NC, USA) was inserted via the jugular vein and the distal extremity positioned under fluoroscopic control in the infradiaphragmatic part of the inferior vena cava. Pressures in the supra diaphragmatic vena cava and in the right atrium were monitored concurrently via the same access. A urinary bladder catheter (Foley catheter) was used to measure variations in intraabdominal pressures.
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Study protocol Once the monitoring had been correctly placed, and stable haemodynamic conditions obtained, a fluid challenge was performed according to the usual guidelines,15 in order to optimize the circulatory volume before the study assessments. Briefly, boluses of 200 ml saline solution were infused until SEV, monitored by transesophageal Doppler probe, did not increase by more than 10% of the pre-bolus value. The study started with the patient in the supine position (Control subgroup), without PEEP nor PNP (Fig. 1). An initial set of measurements was obtained, including Cardiac index (CI), Stroke volume (SV), Heart rate (HR), Mean arterial pressure (MAP), Pressure inside the infradiaphragmatic vena cava (Pivc), Central venous pressure (CVP), and Intraabdominal pressure (Pabd). Transmural pressure was calculated as the difference between Pivc and Pabd. Subsequently, similar measurements were performed after application of a 10 cmH2O PEEP. All values were obtained after a 5-minutes waiting period to achieve stability. A second set of similar measurements was carried out with the patients positioned 15 head-up (Head-up subgroup). A third and fourth sets of similar measurements was performed after the application of a 12 cmH20 PNP (PNP subgroup) in supine and 15 head-up position (Fig. 1). A last set of measurements was performed after PEEP discontinuation to ensure about return to Control values. Statistical analysis The values before and after the application of PEEP in the 4 sets of experiments were compared using a paired-sample t test, after a normal distribution was confirmed by the Kolmogorov–Smirnov test. Data comparing different subgroups were analyzed using independent-samples t test. The threshold of statistical significance was set at P < 0.05. The sample size of 20 patients has been calculated to be able to detect as significant a difference of 0.3 l min−1 m−2 on CI between pre- and postPEEP periods with a P value of 5% and a false negative probability of 10%. This value has been chosen because it represents approximately a variation of 10%, which can be considered as a threshold for clinical pertinence. Results are presented as means [95%CI].
Results Twenty-two consecutive patients were included. Two patients were withdrawn from final analysis because of poor transesophageal Doppler signal. A total of 20 patients were included in the final analysis. Demographic data and surgical procedures are presented in Table 1. All patients received a preoperative fluid infusion during the fluid challenge maneuver (325 ml [250–400]). The hemodynamic consequences of the application of 10 cmH2O PEEP are presented in Table 2. In patients lying flat, the addition of a 10 cmH2O PEEP to a 12 cmH2O PNP did not
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Table 1 Demographic data
n [ 20 Age (y)
61 ± 13
Gender (M/F) −2
BMI (kg m )
Figure 1 Schematic representation of the study protocol. Exp. refers
to experimental sets of measurements
change CI (P = 0.37), whereas CI decreased by 4.9% in patients without PNP (P < 0.05). The increase in intra-abdominal compartment pressure induced by PNP (17.6 mmHg [15.5–19.8] vs 9.2 mmHg [7.6–10.8] without PNP. P < 0.05) (Table 2) was further
9/11 26 ± 5
Hepatocellular carcinoma (n)
16
Liver adenoma (n)
2
Metastasectomy (n)
1
Liver abscess (n)
1
significantly increased by the introduction of PEEP (18.3 mmHg [16.0–20.7] vs 17.6 mmHg [15.5–19.8] without PEEP. P < 0.01) (Table 2). The application of PNP significantly increased the pressure gradient between Pivc and CVP (Table 2 and Fig. 2) and decrease the transmural pressure in the abdominal vena cava (0.9 mmHg [−0.7 to +2.5] vs −2.4 mmHg [−4.8 to 0.0] respectively before and after PNP. P < 0.05). This decrease in vena cava transmural pressure was significantly reversed by the application of PEEP (−2.4 mmHg [−4.8 to 0.0] vs −1.2 [−3.6 to +1.1] before and after PEEP respectively. P < 0.01) (Table 2 and Fig. 2). Moving the patients to the head-up position, without any PNP or PEEP, did not significantly modify cardiac index (P = 0.6), as did the combination of PNP and head-up position (P = 0.5) (Table 2), whereas in this subgroup the addition of PEEP significantly decreased the cardiac index by 5.6% as compared to head-up and PNP alone (P = 0.01).
Discussion
Figure 2 Schematic representation of the effect of PEEP on
abdomino-thoracic pressure gradients
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In this study, evidence was provided that the addition of a 10 cmH20 PEEP on a pre-established 12 cmH20 PNP in normovolemic subjects undergoing liver surgery was haemodynamically well tolerated without any decrease in cardiac output. The results of the current study are consistent with the haemodynamic effects of both PEEP and PNP reported in previous studies. A significant reduction in cardiac index (about 5%) was observed after the application of PNP alone.4 Joris et al. found a reduction of 18% of the cardiac index after the application of a 14 mmHg PNP.16 Difference in the magnitude of the effect could be explained by a lower level of PNP, but mainly by the presumed normovolemic status of the patients after fluid challenge in the current study. Similarly, in patients without PNP, the application of PEEP decreased cardiac index by about 5%, in accordance with previous observations.9,10 This effect was of limited magnitude, probably because our patients were normovolemic. From a theoretical point of view, the combination of the hemodynamic effects of PNP and PEEP on venous return might have been detrimental on the intraoperative cardiac index, especially under hypovolemic conditions. Previous animal17,18 and human19 investigations cautioned about the risk of
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Table 2 Hemodynamic and pressure variations induced by PEEP according to subgroups
Control
Head-up
PNP
Head-up + PNP
Cont
PEEP 10
Cont
PEEP 10
Cont
PEEP 10
Cont
PEEP 10
2.3 [2.0; 2.6]
2.1* [1.8; 2.4]
2.1 [1.8; 2.4]
1.9* [1.6; 2.2]
2.2 [1.8; 2.5]
2.2 [1.8; 2.6]
2.1 [1.7; 2.5]
2.0* [1.6; 2.3]
SV (ml)
75 [62; 87]
72 [60; 83]
70 [59; 82]
60*# [51; 69]
64# [55–73]
63# [54; 72]
61# [52; 69]
59# [51; 68]
HR (b min−1)
56 [51; 62]
54* [49; 59]
56 [51; 61]
55 [51; 60]
59 [55; 64]
61#d [56; 66]
62 [57–66]
59* [54; 64]
MAP (mmHg)
73 [67; 78]
73 [67; 78]
62# [56; 67]
61#d [54; 67]
96# [90; 102]
104*#d [98; 110]
93# [86; 99]
88*#d [81; 95]
CVP (mmHg)
9.2 [8.0; 10.4]
10.9* [9.8; 12.0]
6.0# [4.8; 7.2]
8.6*d [7.6; 9.6]
13.5# [12.0; 15.0]
16.3*#d [15.1; 17.4]
12.4# [11.3; 13.5]
13.9*#d [12.9; 14.9]
Pivc (mmHg)
10.0 [8.6; 11.3]
11.9* [10.7; 13.0]
6.6# [5.5; 7.7]
8.9*d [7.9; 9.8]
15.0# [13.6; 16.3]
16.9*#d [15.6; 18.1]
13.4# [12.3; 14.5]
14.8*#d [13.7; 15.9]
Pabd (mmHg)
9.2 [7.6; 10.8]
9.7* [8.1; 11.4]
10.9 [9.1; 12.7]
10.8 [8.6; 13.1]
17.6# [15.5; 19.8]
18.3*#d [16.0; 20.7]
18.5# [16.2; 20.7]
19.1#d [16.8; 21.3]
CI (l min
−1
−2
m )
Results in means [95%CI]. PNP = Pneumoperitoneum group. SV = Stroke volume. HR = Heart rate. CI = Cardiac index. MAP = Mean arterial pressure. CVP = Central venous pressure. Pivc = Infradiaphragmatic vena cava pressure. Pabd = Pressures in abdominal compartment. Pivc = Pressures in inferior vena cava. Values are rounded to the nearest decimal. *P < 0.05 vs before PEEP, #P < 0.05 vs Control without PEEP, dP < 0.01 vs Control with PEEP.
damaging hemodynamic status when PEEP is associated to PNP. This makes some physicians reluctant to apply PEEP during laparoscopic surgery.19 However, conflicting results about the hemodynamic tolerance of adding PEEP to PNP have been reported17,18,20–23 because many factors, such as the volume loading, the magnitude of applied pressures, depth of anesthesia, and patient position are likely to play a major role in these pathophysiologic repercussions. In the current study, cardiac index was found to be unchanged by the addition of 10 cmH2O PEEP during a 12 cmH2O PNP. Several explanations have to be addressed. In accordance with the work by Giebler et al. and the theory of the vascular waterfall, if it turns out that the intraabdominal pressure around the vena cava becomes superior to the intraluminal pressure, the vessel collapses and the venous return is impaired, becoming relatively independent of the pressure gradient between abdominal vena cava and right atria.11 It has been shown that the critical point for this obstacle is at the level where the vena cava crosses the diaphragm. By increasing the downstream intrathoracic pressure, the addition of PEEP may prevent the collapse of the vena cava and restore the pressure gradient between CVP and Pivc as the main determinant of the venous return. This is illustrated by the evolution of the vena cava transmural pressure, corresponding to the difference between Pivc and Pabd. Addition of PNP significantly increases the pressure applied on the vena cava, inducing a collapse and a decrease of transmural pressure. Transmural pressure is increased by the increase in Pivc induced by PEEP, thereby partly reducing the vessel collapse. This may explain why the addition of PEEP on a pre-established PNP did not decrease cardiac index despite a reduction in the Pivc/CVP gradient.
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Moreover, it should be noted that the cardiac workload in patients with PNP was significantly reduced by the application of a 10 cmH2O PEEP, thereby confirming the beneficial hemodynamic effect of PEEP (reduction in the increase in cardiac afterload induced by abdominal pressure) in this setting as previously demonstrated by Fellahi et al.21 Such results would have been very different according to a number of confounding parameters. Among them, one the most relevant is the volume status of the patients. Indeed, it has been shown that the haemodynamic repercussions of both PEEP24 and PNP25 are far more severe in hypovolemic patients. In the current study, a preoperative optimization of intravascular volume was performed before the evaluation, in order to ensure normovolemia and the homogeneity of the filling pressures among the studied subjects. This assertion is confirmed by the narrow range of CVP at the start of the study. Furthermore, fluid challenge is commonly recommended to improve overall perioperative tissue oxygenation and reduce postoperative complication after major abdominal surgery.26 Volume loading during liver surgery is of major importance and should be a balance between overloading (risk of blood loss) and hypovolemia (risk of organ vascular hypoperfusion). This problematic is far more complex during laparoscopic approach than during open surgery, because pneumoperitoneum may contribute to reduce cardiac index, thereby compromising myocardial, cerebral and renal vascular perfusion in hypovolemic patients. A recent study by Ratti et al., highlights the unreliability of CVP to monitor volemic status during laparoscopic liver surgery and the risks associated with a CVP-guided volume loading in these conditions.27
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The magnitude of the pressures applied in the abdominal and thoracic compartment is also likely to play a role in the observed hemodynamic consequences. In the current study, the values chosen for PNP and PEEP are those commonly used in routine clinical practice and were similar for all patients. Finally, another parameter of major importance is the positioning of the patients. In order to facilitate surgical exposure, laparoscopic liver resections are usually performed in the head-up position. A nonsignificant reduction of the cardiac index, of almost similar magnitude than in previous reports,5 was observed after the patients were moved from the supine to the head-up position. However, in contrast to the observations in the supine position, the application of PEEP in head-up patients having PNP led to a modest, but significant decrease in cardiac index. This study was not designed to test the influence of PEEP on intraoperative blood loss, which could be a matter of concern during liver surgery. A recent report shows that PEEP within a multi-faceted lung protective strategy was not associated with increased bleeding compared with non-protective ventilation using zero PEEP.28 In conclusion, using intraoperative mechanical ventilation with PEEP does not cause any haemodynamic detrimental effect during laparoscopic liver resection in normovolemic patients. Analysis of transmural vena cava pressure variations confirms that the addition of PEEP may prevent the vena cava collapse induced by PNP.
Dr. Beaussier reports grants and personal fees from Baxter SAS, personal fees from MSD, outside the scope of the submitted work. Dr. Schoeffler, Dr. Scatton and Dr. Brandely have nothing to disclose. References 1. Buell JF, Cherqui D, Geller DA, O’Rourke N, Iannitti D, Dagher I et al. (2009) The international position on laparoscopic liver surgery: the Louisville Statement, 2008. Ann Surg 250:825–830. 2. Dagher I, Gayet B, Tzanis D, Tranchart H, Fuks D, Soubrane O et al. (2014) International experience for laparoscopic major liver resection. J Hepatobiliary Pancreat Sci 21:732–736. 3. Xiong JJ, Altaf K, Javed MA, Huang W, Mukherjee R, Mai G et al. (2012) Meta-analysis of laparoscopic vs open liver resection for hepatocellular carcinoma. World J Gastroenterol 18:6657–6668. 4. Grabowski JE, Talamini MA. (2009) Physiological effects of pneumoperitoneum. J Gastrointest Surg 13:1009–1016. 5. Hirvonen EA, Poikolainen EO, Paakkonen ME, Nuutinen LS. (2000) The adverse hemodynamic effects of anesthesia, head-up tilt, and carbon dioxide pneumoperitoneum during laparoscopic cholecystectomy. Surg Endosc 14:272–277. 6. Andersson LE, Baath M, Thorne A, Aspelin P, Odeberg-Wernerman S. (2005) Effect of carbon dioxide pneumoperitoneum on development of atelectasis during anesthesia, examined by spiral computed tomography. Anesthesiology 102:293–299. 7. Futier E, Constantin JM, Pelosi P, Chanques G, Kwiatkoskwi F, Jaber S et al. (2010) Intraoperative recruitment maneuver reverses detrimental
Acknowledgment
pneumoperitoneum-induced respiratory effects in healthy weight and
The authors would like to thank Dr Arthur Atchabahian, M.D. for assistance in manuscript writing and critical review.
obese patients undergoing laparoscopy. Anesthesiology 113:1310–1319. 8. Meininger D, Byhahn C, Mierdl S, Westphal K, Zwissler B. (2005) Positive end-expiratory pressure improves arterial oxygenation during prolonged pneumoperitoneum. Acta Anaesthesiol Scand 49:778–783.
Conflict of interest
9. Fessler HE, Brower RG, Wise RA, Permutt S. (1991) Effects of positive
None declared.
end-expiratory pressure on the gradient for venous return. Am Rev Respir Dis 143:19–24. 10. Pinsky MR. (1985) The influence of positive-pressure ventilation on
Author contributions
cardiovascular function in the critically ill. Crit Care Clin 1:699–717.
Antoine Brandely and Denis Bernard were involved in data recording and interpretation. Olivier Scatton was involved in patient inclusion. Marc Beaussier, Denis Bernard, Emmanuel Futier, Thomas Lescot and Pierre Schoeffler were involved in data interpretation. All authors were involved in writing the manuscript.
11. Giebler RM, Behrends M, Steffens T, Walz MK, Peitgen K, Peters J. (2000) Intraperitoneal and retroperitoneal carbon dioxide insufflation evoke different effects on caval vein pressure gradients in humans: evidence for the starling resistor concept of abdominal venous return. Anesthesiology 92:1568–1580. 12. Permutt S, Riley RL. (1963) Hemodynamics of collapsible vessels with tone: the vascular waterfall. J Appl Physiol 18:924–932. 13. Takata M, Wise RA, Robotham JL. (1990) Effects of abdominal pressure on venous return: abdominal vascular zone conditions. J Appl Physiol
Financial disclosure
(1985) 69:1961–1972.
Dr. Bernard reports personal fees from MSD, outside the scope of the submitted work. Dr. Futier reports receiving personal fees from Baxter (board membership), GE Healthcare (consultancy) and Drager (consultancy); lecture fees from Fresenius-Kabi; and travel reimbursement from Fisher & Paykel Healthcare. Dr. Lescot reports personal fees from Baxter SAS and MSD, outside the scope of the submitted work.
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14. von Elm E, Altman DG, Egger M, Pocock SJ, Gotzsche PC, Vandenbroucke JP. (2007) The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Lancet 370:1453–1457. 15. Roche AM, Miller TE, Gan TJ. (2009) Goal-directed fluid management with trans-oesophageal Doppler. Best Pract Res Clin Anaesthesiol 23:327–334. 16. Joris JL, Noirot DP, Legrand MJ, Jacquet NJ, Lamy ML. (1993) Hemodynamic changes during laparoscopic cholecystectomy. Anesth Analg 76:1067–1071.
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Please cite this article in press as: Bernard D, et al., Positive end-expiratory pressure does not decrease cardiac output during laparoscopic liver surgery, HPB (2016), http://dx.doi.org/10.1016/j.hpb.2016.10.009
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17. Luz CM, Polarz H, Bohrer H, Hundt G, Dorsam J, Martin E. (1994) He-
23. Russo A, Di Stasio E, Scagliusi A, Bevilacqua F, Isgro MA, Marana R
modynamic and respiratory effects of pneumoperitoneum and PEEP
et al. (2013) Positive end-expiratory pressure during laparoscopy: car-
during laparoscopic pelvic lymphadenectomy in dogs. Surg Endosc 8: 25–27.
diac and respiratory effects. J Clin Anesth 25:314–320. 24. Luecke T, Pelosi P. (2005) Clinical review: positive end-expiratory
18. Moffa SM, Quinn JV, Slotman GJ. (1993) Hemodynamic effects of carbon dioxide pneumoperitoneum during mechanical ventilation and positive end-expiratory pressure. J Trauma 35:613–617.
pressure and cardiac output. Crit Care 9:607–621. 25. Kashtan J, Green JF, Parsons EQ, Holcroft JW. (1981) Hemodynamic effect of increased abdominal pressure. J Surg Res 30:249–255.
19. Kraut EJ, Anderson JT, Safwat A, Barbosa R, Wolfe BM. (1999)
26. Gan TJ, Soppitt A, Maroof M, el-Moalem H, Robertson KM, Moretti E
Impairment of cardiac performance by laparoscopy in patients receiving
et al. (2002) Goal-directed intraoperative fluid administration reduces
positive end-expiratory pressure. Arch Surg 134:76–80.
length of hospital stay after major surgery. Anesthesiology 97:
20. Ekman LG, Abrahamsson J, Biber B, Forssman L, Milsom I, Sjoqvist BA. (1988) Hemodynamic changes during laparoscopy with positive endexpiratory pressure ventilation. Acta Anaesthesiol Scand 32:447–453. 21. Fellahi JL, Caille V, Charron C, Daccache G, Vieillard-Baron A. (2012) Hemodynamic effects of positive end-expiratory pressure during abdominal hyperpression: a preliminary study in healthy volunteers.
820–826. 27. Ratti F, Cipriani F, Reineke R, Catena M, Paganelli M, Comotti L et al. (2016) Intraoperative monitoring of stroke volume variation versus central venous pressure in laparoscopic liver surgery: a randomized prospective comparative trial. HPB 18:136–144. 28. Neuschwander A, Futier E, Jaber S, Pereira B, Eurin M, Marret E et al. (2016) The effects of intraoperative lung protective ventilation with
J Crit Care 27:33–36. 22. Rist M, Hemmerling TM, Rauh R, Siebzehnrubl E, Jacobi KE. (2001)
positive end-expiratory pressure on blood loss during hepatic resection
Influence of pneumoperitoneum and patient positioning on preload and
surgery: a secondary analysis of data from a published randomised
splanchnic blood volume in laparoscopic surgery of the lower abdomen.
control trial (IMPROVE). Eur J Anaesthesiol 33:292–298.
J Clin Anesth 13:244–249.
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Please cite this article in press as: Bernard D, et al., Positive end-expiratory pressure does not decrease cardiac output during laparoscopic liver surgery, HPB (2016), http://dx.doi.org/10.1016/j.hpb.2016.10.009