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Positive end-expiratory pressure during infrarenal aortic clamping limits hemodynamic impairment risk

Giustiniano, Enrico; Cancellieri, Franco; Battistini, Gian M; Dominoni, Cristina; Brancato, Gabriella; Spoto, Maria R

Journal of Cardiovascular Medicine: March 2009 - Volume 10 - Issue 3 - p 282–287
doi: 10.2459/JCM.0b013e3283249b00
Research trial protocol

Background: Aortic clamping and unclamping abruptly impact hemodynamic assessment. First, vascular resistance and venous blood return increase, causing a cardiac stress; second, when the clamp has been replaced, vascular resistance falls and hypotension with low perfusion pressure risk occurs. We hypothesized that positive end-expiratory pressure (PEEP) during clamping could limit hemodynamic alterations, then its zeroing just before unclamping could guarantee a more stable blood pressure after restoring total circulation.

Methods: Seventy-one patients submitted to aortic infra-renal aneurismectomy were divided into three groups according to PEEP application (0, 5 and 10 cmH2O) during the clamping phase. Just before restoring total circulation, PEEP was zeroed for all patients. Data were collected before clamping, during clamping and after clamp release.

Results: After aortic clamping, PEEP of 10 cmH2O significantly limited the mean arterial pressure increase (P = 0.017). The same occurred with a PEEP of 5 cmH2O, but it was not statistically significant (P = 0.341). In group A (PEEP 0 cmH2O), mean and systolic blood pressure did not rise significantly (P = 0.478 and P = 0.403, respectively), but after unclamping, we recorded a significant reduction in mean arterial pressure (from 89.8 ± 10.2 to 80.6 ± 12.7 mmHg; P = 0.002) and systolic blood pressure (from 131.3 ± 14.7 mmHg to 116.8 ± 22.2 mmHg; P = 0.002). It did not occur in the PEEP 5 cmH2O group. In the PEEP 10 cmH2O group, only mean arterial pressure reduced significantly, even if its variation was more limited than in the zero end-expiratory pressure (ZEEP) group (from 86.9 ± 12.1 to 81.4 ± 8.1 mmHg; P = 0.028).

Conclusion: PEEP–mechanical ventilation during the clamping phase of infrarenal aortic aneurismectomy can limit blood pressure variation due to clamping and unclamping.

Dipartimento di Anestesia e Terapia Intensiva Generale, Istituto Clinico Humanitas, IRCCS, Rozzano, Milan, Italy

Received 24 July, 2008

Revised 8 November, 2008

Accepted 1 December, 2008

Correspondence to Enrico Giustiniano, Dipartimento di Anestesia e Terapia Intensiva Generale, Istituto Clinico Humanitas, Via Manzoni 56, 20089 Rozzano, Milan, Italy Tel: +39 02 82244115; fax: +39 02 82244190; e-mail: enrico.giustiniano@gmail.com

© 2009 Italian Federation of Cardiology. All rights reserved.