Cath Lab Digest

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  Infrared thermography was used to measure skin surface temperature in the Ferreira study.²⁴ Infrared thermography is described as “a real-time temperature measurement technique used to produce a colored visualization of thermal energy emitted by the measured site at a temperature above absolute zero.”³⁴ Ryan³⁵ describes the principles of thermography as being based on cellular metabolism: “Body heat is produced by cellular metabolism and is distributed by blood and lymph to the rest of the body, and particularly to the overlying skin, for loss by radiation and convection to the surrounding air…areas of impaired blood supply show a loss of temperature due to retarded cellular metabolism. Heat loss by convection cannot easily be measured, but heat radiation in the infrared section of the spectrum can be measured accurately and shown on a screen, from which a pictorial representation can be made.”

  Verhonick et al³² published the first article on the use of infrared thermography in human volunteers to measure vascular responses to warmth, cold, and pressure in an attempt to assess risk of pressure ulcer formation. In their preliminary report, the authors cite the resolution and information obtained on the induced lesions and the advantage of being able to appreciate the temperature patterns of the contextual tissues as unique benefits of infrared thermography. Thermography has undergone significant technological advances, including the use of infrared thermographic cameras/thermometers that perform a computerized analysis of temperature patterns emanating from solid surfaces.

Methods

  An observational, retrospective, correlational study was conducted of recorded skin temperature observations on PRIDAS during routine consults. The study was approved by the institutional review board of Staten Island University Hospital where the records were generated. Consent was waived as personally identifiable data were not collected for this report and skin temperature observations were part of standard documentation for skin integrity consultation during the study period. The investigator tracked the medical record numbers of patients who met the inclusion criterion and periodically retrospectively extracted the data for the study. Linkage data to patient identity were destroyed once data collection and preliminary analyses were completed.

  Setting. The study was conducted in an urban 714-bed university hospital comprised of two facilities, 10 miles apart. Only patients admitted to medical/surgical, ventilator, and critical care units were included, because these units regularly use skin integrity consultation services. Each medical/surgical unit had a subspecialty predominance of patients (eg, renal, cardiac/telemetry, medical geriatric, and oncology).

  Sample. All records of patients with a PRIDAS identified during skin integrity consult assessments between August 2009 and February 2011 were included in this analysis. Initial reasons for consultations were to assist nursing staff in identifying DTI (an educational initiative) and to examine and assess patients with extensive and/or nonresolving skin integrity issues. All consults were documented in the patients’ progress notes.

  Inclusion criteria. Inclusion criterion was a record of a directly observed PRIDAS measuring at least 4 cm² by the PI and hospitalization >6 days. If a patient had more than one PRIDAS documented at initial assessment, only data on the largest PRIDAS were abstracted. Although skin temperatures on all PRIDAS per patient were obtained as part of the routine skin integrity consult, only one PRIDAS per patient was included in the study.