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Interaction between intra-abdominal pressure and positive-end expiratory pressure.

Torquato JA, Lucato JJ, Antunes T, Barbas CV - Clinics (Sao Paulo) (2009)

Bottom Line: Increasing the Positive-End Expiratory Pressure levels from zero to 10 cm H2O without weight on the belly did not result in any increase in intra-abdominal pressure (p=0.165).However, plateau pressures increased significantly (p< 0.001).Maintaining Positive-End Expiratory Pressure at 10 cm H2O and placing 5 kg on the belly increased intra-abdominal pressure from 12.3 +/- 1.7 to 16.8 +/- 1.7 (p<0.001) but did not increase plateau pressure (26.6+/-1.2 to 27.2 +/-1.1 -p=0.83).

View Article: PubMed Central - PubMed

Affiliation: Departamento de Patologia, Faculdade de Medicina e Instituto Central, Central do Hospital das Clinicas, Universidade Cruzeiro do Sul, São Paulo/SP, Brasil. jamilianbar@yahoo.com

ABSTRACT

Objective: The aim of this study was to quantify the interaction between increased intra-abdominal pressure and Positive-End Expiratory Pressure.

Methods: In 30 mechanically ventilated ICU patients with a fixed tidal volume, respiratory system plateau and abdominal pressure were measured at a Positive-End Expiratory Pressure level of zero and 10 cm H2O. The measurements were repeated after placing a 5 kg weight on the patients' belly.

Results: After the addition of 5 kg to the patients' belly at zero Positive-End Expiratory Pressure, both intra-abdominal pressure (p<0.001) and plateau pressures (p=0.005) increased significantly. Increasing the Positive-End Expiratory Pressure levels from zero to 10 cm H2O without weight on the belly did not result in any increase in intra-abdominal pressure (p=0.165). However, plateau pressures increased significantly (p< 0.001). Increasing Positive-End Expiratory Pressure from zero to 10 cm H2O and adding 5 kg to the belly increased intra-abdominal pressure from 8.7 to 16.8 (p<0.001) and plateau pressure from 18.26 to 27.2 (p<0.001). Maintaining Positive-End Expiratory Pressure at 10 cm H2O and placing 5 kg on the belly increased intra-abdominal pressure from 12.3 +/- 1.7 to 16.8 +/- 1.7 (p<0.001) but did not increase plateau pressure (26.6+/-1.2 to 27.2 +/-1.1 -p=0.83).

Conclusions: The addition of a 5 kg weight onto the abdomen significantly increased both IAP and the airway plateau pressure, confirming that intra-abdominal hypertension elevates the plateau pressure. However, plateau pressure alone cannot be considered a good indicator for the detection of elevated intra-abdominal pressure in patients under mechanical ventilation using PEEP. In these patients, the intra-abdominal pressure must also be measured.

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Different phases of the protocol (I, II, III, IV)
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f1-07-oa-0170: Different phases of the protocol (I, II, III, IV)

Mentions: After this selection, the parameters of each patient’s ventilator were recorded and vital signs were observed through ICU monitors, pulse oximeters, cardiac monitors, and noninvasive arterial pressure measurements. All patients were ventilated with a constant current volume according to the standard protocol used at our facility for the measurement of respiratory plateau pressure and intra-abdominal pressure in cm H2O. As soon as the measurements were recorded, the initial parameters of the ventilator were restored. In order to measure intra-abdominal pressure we used the original method proposed by Kron22 as our reference. We used cm H2O as our preferred unit (1 mmHg = 1.36 cm H2O). We also measured the plateau pressure with PEEP = 0 cm H2O and again with PEEP = 10 cm H2O with no weight on the abdomen after a stabilization period of 5 minutes. Our measurements of intra-abdominal pressure and respiratory system plateau were then repeated with a 5kg weight placed on the patient’s abdomen. The intra-abdominal and plateau pressures were measured across all four phases of the protocol (Figure 1).


Interaction between intra-abdominal pressure and positive-end expiratory pressure.

Torquato JA, Lucato JJ, Antunes T, Barbas CV - Clinics (Sao Paulo) (2009)

Different phases of the protocol (I, II, III, IV)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2666478&req=5

f1-07-oa-0170: Different phases of the protocol (I, II, III, IV)
Mentions: After this selection, the parameters of each patient’s ventilator were recorded and vital signs were observed through ICU monitors, pulse oximeters, cardiac monitors, and noninvasive arterial pressure measurements. All patients were ventilated with a constant current volume according to the standard protocol used at our facility for the measurement of respiratory plateau pressure and intra-abdominal pressure in cm H2O. As soon as the measurements were recorded, the initial parameters of the ventilator were restored. In order to measure intra-abdominal pressure we used the original method proposed by Kron22 as our reference. We used cm H2O as our preferred unit (1 mmHg = 1.36 cm H2O). We also measured the plateau pressure with PEEP = 0 cm H2O and again with PEEP = 10 cm H2O with no weight on the abdomen after a stabilization period of 5 minutes. Our measurements of intra-abdominal pressure and respiratory system plateau were then repeated with a 5kg weight placed on the patient’s abdomen. The intra-abdominal and plateau pressures were measured across all four phases of the protocol (Figure 1).

Bottom Line: Increasing the Positive-End Expiratory Pressure levels from zero to 10 cm H2O without weight on the belly did not result in any increase in intra-abdominal pressure (p=0.165).However, plateau pressures increased significantly (p< 0.001).Maintaining Positive-End Expiratory Pressure at 10 cm H2O and placing 5 kg on the belly increased intra-abdominal pressure from 12.3 +/- 1.7 to 16.8 +/- 1.7 (p<0.001) but did not increase plateau pressure (26.6+/-1.2 to 27.2 +/-1.1 -p=0.83).

View Article: PubMed Central - PubMed

Affiliation: Departamento de Patologia, Faculdade de Medicina e Instituto Central, Central do Hospital das Clinicas, Universidade Cruzeiro do Sul, São Paulo/SP, Brasil. jamilianbar@yahoo.com

ABSTRACT

Objective: The aim of this study was to quantify the interaction between increased intra-abdominal pressure and Positive-End Expiratory Pressure.

Methods: In 30 mechanically ventilated ICU patients with a fixed tidal volume, respiratory system plateau and abdominal pressure were measured at a Positive-End Expiratory Pressure level of zero and 10 cm H2O. The measurements were repeated after placing a 5 kg weight on the patients' belly.

Results: After the addition of 5 kg to the patients' belly at zero Positive-End Expiratory Pressure, both intra-abdominal pressure (p<0.001) and plateau pressures (p=0.005) increased significantly. Increasing the Positive-End Expiratory Pressure levels from zero to 10 cm H2O without weight on the belly did not result in any increase in intra-abdominal pressure (p=0.165). However, plateau pressures increased significantly (p< 0.001). Increasing Positive-End Expiratory Pressure from zero to 10 cm H2O and adding 5 kg to the belly increased intra-abdominal pressure from 8.7 to 16.8 (p<0.001) and plateau pressure from 18.26 to 27.2 (p<0.001). Maintaining Positive-End Expiratory Pressure at 10 cm H2O and placing 5 kg on the belly increased intra-abdominal pressure from 12.3 +/- 1.7 to 16.8 +/- 1.7 (p<0.001) but did not increase plateau pressure (26.6+/-1.2 to 27.2 +/-1.1 -p=0.83).

Conclusions: The addition of a 5 kg weight onto the abdomen significantly increased both IAP and the airway plateau pressure, confirming that intra-abdominal hypertension elevates the plateau pressure. However, plateau pressure alone cannot be considered a good indicator for the detection of elevated intra-abdominal pressure in patients under mechanical ventilation using PEEP. In these patients, the intra-abdominal pressure must also be measured.

Show MeSH
Related in: MedlinePlus