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Moderate hypothermia attenuates changes in respiratory system mechanics and cytokine production during low lung volume ventilation in rats

Introduction

Hypothermia was shown to attenuate ventilator-induced lung injury (VILI) in high end-inspiratory lung volume models of VILI [13]. Experimental evidence suggests that moderate tidal volumes may, under certain clinical conditions that induce alveolar instability, lead to a lung injury [4]. Recent studies have also suggested that insults like shock [5] or surgery [6] sensitize the lung to injury by priming for an exaggerated response to a second stimulus. The aim of this study was to investigate whether moderate hypothermia attenuates low lung volume injury during low PEEP, high FiO2 and moderate tidal volume ventilation in animals sensitized to injury by previous anesthesia and surgery.

Methods

Sixteen male adult Sprague–Dawley rats, instrumented under ether anesthesia with vascular catheters on the previous day, were anesthetized, tracheostomized, connected to a ventilator and randomly allocated to groups of normothermia (37 ± 0.5°C, group N, n = 8) or hypothermia (33 ± 0.5°C, group H, n = 8). After 2 hours of mechanical ventilation (FiO2 1,0, respiratory rate 60/min, tidal volume 10 ml/kg, PEEP 2 cmH2O) inspiratory pressures were recorded, rats were sacrificed, the P–V curve of the respiratory system constructed, and bronchoalveolar lavage and aortic blood samples obtained.

Results

Group H animals exhibited in comparison with group N animals a lower increase in peak inspiratory pressures (0.7 ± 1.1 vs 2.4 ± 0.5 mmHg, P < 0.001), significant shift of the P–V curve to the left and lower total protein (113 ± 42 vs 201 ± 97 μg/ml, P = 0.047) and TNF (23.5 ± 8.0 vs 35.2 ± 8.5 pg/ml, P = 0,022) levels in BAL samples.

Conclusion

Moderate hypothermia attenuated lung injury during low PEEP, high FiO2 and moderate tidal volume ventilation in animals sensitized to injury by previous anesthesia and surgery.

References

  1. 1.

    Lim CM, et al.: Lung. 2003, 181: 23-34. 10.1007/s00408-002-0111-x

    PubMed  Article  Google Scholar 

  2. 2.

    Suzuki S, et al.: Crit Care Med. 2004, 32: 144-149. 10.1097/01.CCM.0000098857.14923.44

    PubMed  Article  Google Scholar 

  3. 3.

    Hong S-B, et al.: Crit Care Med. 2005, 33: 2049-2055. 10.1097/01.CCM.0000178186.37167.53

    PubMed  Article  Google Scholar 

  4. 4.

    Muscedere JG, et al.: Am J Respir Crit Care Med. 1994, 149: 1327-1334.

    PubMed  CAS  Article  Google Scholar 

  5. 5.

    Fan J, et al.: J Immunol. 1998, 161: 440-447.

    PubMed  CAS  Google Scholar 

  6. 6.

    Kaneko A, et al.: J Surg Res. 2006, 134: 215-222. 10.1016/j.jss.2006.01.003

    PubMed  Article  Google Scholar 

Download references

Acknowledgements

Supported by the Research project MZO 00179906.

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Dostal, P., Senkerik, M., Cerny, V. et al. Moderate hypothermia attenuates changes in respiratory system mechanics and cytokine production during low lung volume ventilation in rats. Crit Care 11, P15 (2007). https://doi.org/10.1186/cc5175

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Keywords

  • Lung Injury
  • Versus Curve
  • Inspiratory Pressure
  • Peak Inspiratory Pressure
  • Moderate Hypothermia