OBJECTIVES: To determine the effect of different levels of positive end-expiratory pressure (PEEP) on pulse pressure variation
DESIGN: An observational study.
SETTING: Operating theatres of a tertiary training hospital.
SUBJECTS: Ventilated patients who required intra-arterial blood pressure monitoring.
OOUTCOME MEASURES: PPV during different levels of PEEP.
METHOD: Patients were anaesthetised by means of a standard technique and ventilated with a tidal volume of 9 ml/kg ideal
body mass. The PPV was calculated at PEEP levels of 2, 5, 8 and 10 cmH2O. PPV was compared at the various PEEP levels.
RESULTS: PPV at a PEEP of 8 cmH2O and 10 cmH2O was significantly larger than that at 2 cmH2O (p-value < 0.001). PPV at
a PEEP of 10 cmH2O was significantly larger than that at 8 cmH2O (p-value < 0.001). PPV at a PEEP of 8 cmH2O was larger
than that at 5 cmH2O (p-value = 0.002). PPV at a PEEP of 2 and 5 cmH2O did not differ significantly (p-value = 0.194).
CONCLUSION: We have demonstrated that, in patients with normal lungs, PEEP has a significant influence on PPV. PPV may be
overestimated if PEEP ≥ 8 cmH2O is applied in patients who are ventilated with a tidal volume of 9 ml/kg. It is recommended
that in patients with healthy lungs PPV should be measured at a standardised PEEP of ≤ 5 cmH2O.
Barac, Karin; Coetzee, Philna; Van Staden, Marianne(University of Johannesburg, 2016-07)
Internal auditing has been called upon to enhance its value proposition for organisations and one way of doing this is to demonstrate its effectiveness. By using the responses of participants from the BRICS countries on ...