title: Effects on heart pumping function when using foam and gauze for negative pressure wound therapy of sternotomy wounds.
abstract: BACKGROUND
  Negative pressure wound therapy (NPWT) has remarkable effects on the healing of poststernotomy mediastinitis. Foam is presently the material of choice for NPWT in this indication. There is now increasing interest in using gauze, as this has proven successful in the treatment of peripheral wounds. It is important to determine the effects of NPWT using gauze on heart pumping function before it can be used for deep sternotomy wounds. The aim was to examine the effects of NPWT when using gauze and foam on the heart pumping function during the treatment of a sternotomy wound.
  
  
  METHODS
  Eight pigs underwent median sternotomy followed by NPWT at -40, -70, -120 and -160 mmHg, using foam or gauze. The heart frequency, cardiac output, mean systemic arterial pressure, mean pulmonary artery pressure, central venous pressure and left atrial pressure were recorded.
  
  
  RESULTS
  Cardiac output was not affected by NPWT using gauze or foam. Heart frequency decreased during NPWT when using foam, but not gauze. Treatment with foam also lowered the central venous pressure and the left atrial pressure, while gauze had no such effects. Mean systemic arterial pressure, mean pulmonary artery pressure and systemic vascular resistance were not affected by NPWT. Similar haemodynamic effects were observed at all levels of negative pressure studied.
  
  
  CONCLUSIONS
  NPWT using foam results in decreased heart frequency and lower right and left atrial filling pressures. The use of gauze in NPWT did not affect the haemodynamic parameters studied. Gauze may thus provide an alternative to foam for NPWT of sternotomy wounds.
authors.affiliation: Department of Ophthalmology, Lund University Hospital, Sweden. malin.malmsjo@med.lu.se
authors.forename: Malin
authors.initials: M
authors.lastname: Malmsjö
authors.forename: Sandra
authors.initials: S
authors.lastname: Lindstedt
authors.forename: Richard
authors.initials: R
authors.lastname: Ingemansson
mesh_terms: D000818:Animals; D001458:Bandages; D004195:Disease Models, Animal; D004322:Drainage / Q000295:instrumentation*; D008480:Mediastinitis / Q000209:etiology / Q000628:therapy*; D054843:Negative-Pressure Wound Therapy / Q000295:instrumentation*; D056346:Sternotomy / Q000009:adverse effects*; D013552:Swine; D016896:Treatment Outcome; D014945:Wound Healing