Digital Ischemia Reduction in Critically Ill Patients (DIR)

The reason for suspending the study is the current lack of research infrastructure, primarily a research coordinator. Email dated 23JUN23

Patients requiring high dose pressors (minimum 2) who are unlikely to be weaned off them over 1 day will be identified. Patients will have the device applied to one hand while expectant medical management will continue to the contralateral hand.

The proposed study offers no foreseeable risk to patients. The device relies on a wound vac system for vacuum generation which is industry standard and approved for creating safe suction applied to wounds. In this application, the same suction and device would be used to apply suction to an enclosure through which the hand is placed. Similarly, a heat exchanger would be used to run lukewarm water through a warming bad, which is technology that is routinely used in surgery. Heater coolers are used in every bypass surgery, and warming fluid blankets are common for helping to rewarm patients on the operating room table.

Each patient will act as their own control. By applying the vacuum assisted warmer to one hand, results can be compared to the contralateral hand. In this way, patient outcomes can be assessed between patients and indexed to each patient.

The novel idea that this study proposes, is the combined use of vacuum assisted suction and heat exchanger warming. It is well known that heat causes capillary vasodilation, where warming hands and toes improves blood flow while cooling them causes vasoconstriction. Applying a vacuum across a capillary bed increases the transcapillary gradient increasing the driving force of blood flow into tissues. The combination of these two mechanisms can work synchronously to improve blood flow to ischemic extremities and digits.

Heat causes capillary vasodilation, where warming hands and toes improves blood flow while cooling them causes vasoconstriction. Applying a vacuum across a capillary bed increases the transcapillary gradient increasing the driving force of blood flow into tissues. The combination of these two mechanisms can work synchronously to improve blood flow to ischemic extremities and digits.

rate of digital ischemia characterized by tissue loss or destruction - measure incidence rate as a ratio of patients who got digital ischemia with the number of patients who were on vasopressors

extent of digital ischemia - determined by degree of length of digits involved (like distal finger joint, proximal finger joint, entire finger, into the palm, etc)

Inclusion Criteria: Patients in the cardiac critical care unit/cardiovascular intensive care unit with cardiac pathologies on vasopressor support Exclusion Criteria: Patients who are not on vasopressor support Patients under the age of 18