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Short term non-invasive ventilation post-surgery improves arterial blood-gases in obese subjects compared to supplemental oxygen delivery - a randomized controlled trial.

Zoremba M, Kalmus G, Begemann D, Eberhart L, Zoremba N, Wulf H, Dette F - BMC Anesthesiol (2011)

Bottom Line: The two groups were compared using repeated-measure analysis of variance (ANOVA) and t-test analysis.During the PACU stay, pulmonary function in the NIV group was significantly better than in the controls (p < 0.0001).The effect lasted 24 hours after discontinuation of NIV.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anaesthesia and Intensive Care Medicine, University of Marburg, D-35033 Marburg, Germany. zoremba@med.uni-marburg.de.

ABSTRACT

Background: In the immediate postoperative period, obese patients are more likely to exhibit hypoxaemia due to atelectasis and impaired respiratory mechanics, changes which can be attenuated by non-invasive ventilation (NIV). The aim of the study was to evaluate the duration of any effects of early initiation of short term pressure support NIV vs. traditional oxygen delivery via venturi mask in obese patients during their stay in the PACU.

Methods: After ethics committee approval and informed consent, we prospectively studied 60 obese patients (BMI 30-45) undergoing minor peripheral surgery. Half were randomly assigned to receive short term NIV during their PACU stay, while the others received routine treatment (supplemental oxygen via venturi mask). Premedication, general anaesthesia and respiratory settings were standardized. We measured arterial oxygen saturation by pulse oximetry and blood gas analysis on air breathing. Inspiratory and expiratory lung function was measured preoperatively (baseline) and at 10 min, 1 h, 2 h, 6 h and 24 h after extubation, with the patient supine, in a 30 degrees head-up position. The two groups were compared using repeated-measure analysis of variance (ANOVA) and t-test analysis. Statistical significance was considered to be P < 0.05.

Results: There were no differences at the first assessment. During the PACU stay, pulmonary function in the NIV group was significantly better than in the controls (p < 0.0001). Blood gases and the alveolar to arterial oxygen partial pressure difference were also better (p < 0.03), but with the addition that overall improvements are of questionable clinical relevance. These effects persisted for at least 24 hours after surgery (p < 0.05).

Conclusion: Early initiation of short term NIV during in the PACU promotes more rapid recovery of postoperative lung function and oxygenation in the obese. The effect lasted 24 hours after discontinuation of NIV. Patient selection is necessary in order to establish clinically relevant improvements. TRIAL REGISTRATION#: DRKS00000751; http://www.germanctr.de.

No MeSH data available.


Related in: MedlinePlus

Postoperative lung function measurements (FVC/FEV1/MEF25-75/PEF) - Bars indicate SD. n.s.=no significance. For abbreviations, see text.
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Figure 2: Postoperative lung function measurements (FVC/FEV1/MEF25-75/PEF) - Bars indicate SD. n.s.=no significance. For abbreviations, see text.

Mentions: Preoperative in- and expiratory spirometry values (baseline) were within the normal range between the upper limit of normal and the lower limit of normal (LLN) as previously described (Table 2) [19]. Postoperative spirometry values, except of peak inspiratory, showed a similar pattern to pulse oximetry (Figure 2). The NIV group recovered lung function faster during the PACU stay, almost reaching preoperative baseline values (Figure 2; p < 0.001-between interaction) while the control group recovered in- and expiratory lung volumes only moderately. This time effect (T0h-T1h; p < 0.0001) within the study groups ceased during course. Even after the first postoperative mobilisation and on the first day after surgery, lung function values in the controls were up to 20% below baseline (Figure 2 p < 0.05). Although the overall difference in lung function between groups had decreased 24 hours after surgery, significant differences still remained.


Short term non-invasive ventilation post-surgery improves arterial blood-gases in obese subjects compared to supplemental oxygen delivery - a randomized controlled trial.

Zoremba M, Kalmus G, Begemann D, Eberhart L, Zoremba N, Wulf H, Dette F - BMC Anesthesiol (2011)

Postoperative lung function measurements (FVC/FEV1/MEF25-75/PEF) - Bars indicate SD. n.s.=no significance. For abbreviations, see text.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3117807&req=5

Figure 2: Postoperative lung function measurements (FVC/FEV1/MEF25-75/PEF) - Bars indicate SD. n.s.=no significance. For abbreviations, see text.
Mentions: Preoperative in- and expiratory spirometry values (baseline) were within the normal range between the upper limit of normal and the lower limit of normal (LLN) as previously described (Table 2) [19]. Postoperative spirometry values, except of peak inspiratory, showed a similar pattern to pulse oximetry (Figure 2). The NIV group recovered lung function faster during the PACU stay, almost reaching preoperative baseline values (Figure 2; p < 0.001-between interaction) while the control group recovered in- and expiratory lung volumes only moderately. This time effect (T0h-T1h; p < 0.0001) within the study groups ceased during course. Even after the first postoperative mobilisation and on the first day after surgery, lung function values in the controls were up to 20% below baseline (Figure 2 p < 0.05). Although the overall difference in lung function between groups had decreased 24 hours after surgery, significant differences still remained.

Bottom Line: The two groups were compared using repeated-measure analysis of variance (ANOVA) and t-test analysis.During the PACU stay, pulmonary function in the NIV group was significantly better than in the controls (p < 0.0001).The effect lasted 24 hours after discontinuation of NIV.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anaesthesia and Intensive Care Medicine, University of Marburg, D-35033 Marburg, Germany. zoremba@med.uni-marburg.de.

ABSTRACT

Background: In the immediate postoperative period, obese patients are more likely to exhibit hypoxaemia due to atelectasis and impaired respiratory mechanics, changes which can be attenuated by non-invasive ventilation (NIV). The aim of the study was to evaluate the duration of any effects of early initiation of short term pressure support NIV vs. traditional oxygen delivery via venturi mask in obese patients during their stay in the PACU.

Methods: After ethics committee approval and informed consent, we prospectively studied 60 obese patients (BMI 30-45) undergoing minor peripheral surgery. Half were randomly assigned to receive short term NIV during their PACU stay, while the others received routine treatment (supplemental oxygen via venturi mask). Premedication, general anaesthesia and respiratory settings were standardized. We measured arterial oxygen saturation by pulse oximetry and blood gas analysis on air breathing. Inspiratory and expiratory lung function was measured preoperatively (baseline) and at 10 min, 1 h, 2 h, 6 h and 24 h after extubation, with the patient supine, in a 30 degrees head-up position. The two groups were compared using repeated-measure analysis of variance (ANOVA) and t-test analysis. Statistical significance was considered to be P < 0.05.

Results: There were no differences at the first assessment. During the PACU stay, pulmonary function in the NIV group was significantly better than in the controls (p < 0.0001). Blood gases and the alveolar to arterial oxygen partial pressure difference were also better (p < 0.03), but with the addition that overall improvements are of questionable clinical relevance. These effects persisted for at least 24 hours after surgery (p < 0.05).

Conclusion: Early initiation of short term NIV during in the PACU promotes more rapid recovery of postoperative lung function and oxygenation in the obese. The effect lasted 24 hours after discontinuation of NIV. Patient selection is necessary in order to establish clinically relevant improvements. TRIAL REGISTRATION#: DRKS00000751; http://www.germanctr.de.

No MeSH data available.


Related in: MedlinePlus