title: Timer switch to convert suction apparatus for negative pressure wound therapy application.
abstract: BACKGROUND
  Negative pressure wound therapy (NPWT) is an established modality in the treatment of chronic wounds, open fractures, and post-operative wound problems. This method has not been widely used due to the high cost of equipment and consumables. This study demonstrates an indigenously developed apparatus which gives comparable results at a fraction of the cost. Readily available materials are used for the air-tight dressing.
  
  
  METHODS
  Equipment consists of suction apparatus with adjustable pressure valve set to a pressure 125-150 mmHg. An electronic timer switch with a sequential working time of 5 min and a standby time of 3 min provides the required intermittent negative pressure. Readily available materials such as polyvinyl alcohol sponge, suction drains and steridrapes were used to provide an air tight wound cover.
  
  
  RESULTS
  A total of 90 cases underwent 262 NPWT applications from 2009 to 2014. This series, comprised of 30 open fractures, 21 post-operative and 39 chronic wounds. The wound healing rate in our study was comparable to other published studies using NPWT.
  
  
  CONCLUSIONS
  The addition of electronic timer switch will convert a suction apparatus into NPWT machine, and the results are equally effective compared to more expensive counter parts. The use of indigenous dressing materials reduces the cost significantly.
authors.affiliation: Department of Orthopaedics, NRI Medical College and General Hospital, Chinnakakani, Guntur, Andhra Pradesh, India.
authors.forename: Surath
authors.initials: S
authors.lastname: Amarnath
authors.affiliation: Department of Orthopaedics, NRI Medical College and General Hospital, Chinnakakani, Guntur, Andhra Pradesh, India.
authors.forename: Mettu Rami
authors.initials: MR
authors.lastname: Reddy
authors.affiliation: Department of Orthopaedics, NRI Medical College and General Hospital, Chinnakakani, Guntur, Andhra Pradesh, India.
authors.forename: Chayam Hanumantha
authors.initials: CH
authors.lastname: Rao
authors.affiliation: Department of Orthopaedics, NRI Medical College and General Hospital, Chinnakakani, Guntur, Andhra Pradesh, India.
authors.forename: Harsha Vardan
authors.initials: HV
authors.lastname: Surath
keywords: Cost effective dressing materials; negative pressure wound therapy; timer switch; wound healing