The value of continuous fever monitoring in the early detection of sepsis
Today, we understand the mechanism and effects of sepsis quite thoroughly. However, traditional diagnostic tools prove to be unreliable in preventing deaths from sepsis, owing to the rapid onset of the disease.
What is Sepsis?
The body has a complex immune system comprising of a variety of immune cells. During an infection, the body mounts an inflammatory response against the invading agent (e.g bacteria, viruses, fungi). This response is upregulated and downregulated through a very precise cascade of biochemical changes involving pro-inflammatory and anti-inflammatory cytokines (cellular messengers).
In sepsis, this regulation becomes dysfunctional, causing an uncontrolled inflammatory response, which damages host tissues. The most common signs of sepsis are fever, increased heart rate and confusion. Although about 90% of patients with sepsis present with a fever, some might have a normal or even low temperature (cold sepsis). Left unchecked, sepsis causes multiple organ failure or septic shock, often resulting in death.
Sepsis and Body Temperature
A patient with sepsis could either be hyperthermic (>38°C/100.4°F) or hypothermic (< 36°C/96.8°F). Both of these present a unique set of problems - Hyperthermia increases the risk of arrhythmia, tachycardia and brain damage, which make for a poor prognosis; On the other hand, hypothermia destabilizes the immune response and delays phagocytosis, resulting in the infection getting worse. Moreover, in hypothermic patients, the heart’s stroke volume (volume of blood pumped out per heartbeat) drops, which reduces tissue blood perfusion and further increases the infection’s risk.
Therefore, it is vital for the physician to weigh the specific requirements of each unique situation and decide on an appropriate temperature maintenance strategy.
Although there is some disagreement on the ideal temperature range, to be maintained during sepsis, targeted temperature measurement is universally agreed to be an essential component in the management and treatment of sepsis.
Why Continuous fever monitoring?
Sepsis is a notoriously hard condition for physicians to diagnose. There is no standard diagnostic method for sepsis. A physician usually has to rely on a variety of non-specific symptoms and lab readings. The most common signs of sepsis - fever and increased WBC count - are not exclusive and therefore, aren’t conclusive. Moreover, in many critically ill patients, cardinal symptoms of hospital-acquired sepsis are often mistaken for signs of underlying illnesses, further complicating and often, delaying diagnosis. And with a time-sensitive condition like sepsis, a delay in diagnosis often means death.
A continuous fever monitoring device could prove to be invaluable in this situation. In healthy individuals, the baseline body temperature is 37.0°C (98.4°F) and typically, varies diurnally (within a day) by approximately 0.5°C. In critically ill patients, even when there is no fever, aberrations are noticed in this baseline temperature pattern. These abnormal temperature patterns could be changes in the amplitude or frequency and in some cases, even small changes in the baseline, with loss of variability.
In a study conducted with critically ill patients with bacterial infections, subtle alterations in the temperature pattern were noted as early as 24-72 hours before the first fever or the clinical diagnosis of sepsis. Studies also show that significant temperature fluctuations during the day are strongly associated with sepsis.
Continuous temperature monitoring makes it possible to study temperature patterns, in real time and notice alarming trends before it is too late. Especially in conditions such as sepsis, which are hospital-acquired and extremely risky, this technology could go a long way towards ensuring patient wellbeing and positive treatment outcomes.