Why a sepsis app?
As is it often the case, it’s personal. Sepsis has affected people very close to us and we wanted to do something about it. And we’re not alone. Every year, over 700,000 people are affected by sepsis and over 200,000 die from it in the US. It is one of the biggest killers in America’s hospitals. The personal stories of just a few of the survivors and victims of sepsis can be read on the Faces of Sepsis website of the Sepsis Alliance.
Although sepsis is considered bread-and-butter medicine, and every doctor has at least some familiarity with the approach to its diagnosis and treatment, the unfortunate truth is that septic patients are still often misdiagnosed and mistreated, at great cost in health, money, and lives. With so many doctors now accessing clinical information on their smart phones, we felt a comprehensive mobile application dedicated exclusively to this topic would be a very welcome addition to physicians’ mobile toolset.
Why is sepsis a difficult problem?
The key to the successful treatment of sepsis is early recognition and aggressive management. This is, however, a challenge because the early symptoms of sepsis are shared by many far less dangerous infections and other conditions. Not every patient who appears ill, has a fever, and blood tests pointing to infection, is septic. In fact, the majority are not. Clues that point to early sepsis may therefore easily be missed or ignored, leading to delayed treatment.
However, the clues are there. Although there is no fool-proof method to the early diagnosis of sepsis, certain symptoms and tests in the right context should make one suspicious enough to initiate treatment. Doctors must always be vigilant for these signs and know when they are indicative of something more serious than just a common infection. And once sepsis is suspected, time is of the essence, and the right treatment steps must be taken very fast! Even minor delays in treatment can lead to a far worse prognosis.
What is sepsis?
Sepsis occurs when an infectious agent enters the blood stream and causes a dangerous systemic immune response in the body. Although viruses and fungi can cause sepsis, especially in very young or immunocompromised patients, the agents with the greatest potential to cause severe sepsis are bacteria, and among these, certain bacteria that are particularly toxic.
When you bump against something or get scratched, that area swells and turns red. If you get a bad infection, your body develops a fever and you don’t feel so well. These responses are perfectly natural immune responses the body uses to fight infections and are driven by the release of certain chemicals by the body’s immune cells.
However, if these responses become too excessive, they can lead to serious problems. In sepsis, bacterial toxins that have found their way in the blood stimulate the immune system to such a degree that it becomes dangerous. The immune system goes into hyperdrive, the body’s blood vessels become leaky, and breathing and circulation get compromised. This is called the systemic inflammatory response syndrome, or SIRS. If allowed to progress, blood pressure can collapse, tissue oxygenation can become seriously impaired, and organs can get damaged and shut down, eventually causing death. This is called septic shock. In sepsis, it is not the bacteria that kills the patient, it is the patient’s response to the bacteria.
To prevent this outcome, the most important thing doctors must do is to recognize sepsis early and treat the infection source before the body’s immune response to it passes a critical threshold. Once this threshold is passed and a patient enters septic shock, doctors can do little but give cardiovascular support and hope for the best. Patients with septic shock have a chance of survival of about 50%, it is not a good prognosis.
So what are the key signs, symptoms and lab tests of early sepsis?
Clinicians have defined a specific set of diagnostic criteria to help identify sepsis. These are called the SIRS Criteria, from the name of the systemic inflammatory response syndrome (SIRS) caused by sepsis. A patient must have 2 or more of the following to be diagnosed with SIRS:
1. Temperature >38.3ºC (>100.94ºF) or <36ºC (<96.8ºF)
2. Heart rate >90 beats per minute
3. Respiratory rate >20 breaths per minute
4. White blood cell (WBC) count >12,000 cells/mm3, <4,000 cells/mm3, or >10% immature (band) forms
High heart and respiratory rates in feverish patients are especially suspicious signs, so it is important to carefully measure them. The respiratory rate, in particular, is often not accurately measured if performing vitals in a rush. The normal rate is 12 respirations per minute, or about one breath every 5 seconds. If a patient breathes as if she has just climbed up a flight of stairs, doctors should be very cautious.
Tissue cultures must be done to attempt to identify the infectious agent. However, sepsis is ultimately a clinical diagnosis that doesn’t require positive cultures. Cultures should only be used to confirm the diagnosis, identify the infectious agent, and adjust and narrow antibiotic treatment appropriately. They should not be used as a primary test for sepsis diagnosis, one, because they are negative or inconclusive in a large number of septic patients, and secondly, because they take 24 hours to several days to return results. By then, the patient could be in serious condition or worse. It is important to always remember that blood cultures, specifically, are positive in fewer than 50% of patients with severe sepsis, and an even smaller percentage in patients with mild or early sepsis.
Other subtle signs of sepsis that could alert the practitioner of early signs of trouble include altered mental status (mild confusion, forgetfulness), urinary symptoms such as insufficient urine (oliguria), elevated creatinine, dark or discolored urine (perhaps bloody indicating a possible urinary source of infection), swelling of the body from vascular failure, or decreased capillary refill due to poor blood perfusion.
Lactate is also becoming a very helpful early marker of sepsis and should be measured in patients suspected of it. High lactate levels are indicative of poor tissue oxygenation and are a harbinger of progression to more serious sepsis and deterioration.
Lastly, it’s important to consider context when diagnosing sepsis. Patients in the ICU and mechanically ventilated patients are at extremely high risk. Old, sick and frail patients, patients with serious chronic conditions (like cancer, immunodeficiency, etc.), post-surgical patients, patients who have been in the hospital for long periods of time, all of these are high-risk populations for obvious reasons. Hospitals are home to virulent and antibiotic-resistant bacteria and the longer a patient is there and the more invasive the procedures, the higher the chances that sepsis will occur. These risk factors should lower a clinician’s threshold of suspicion for sepsis.
The Sepsis Clinical Guide app describes in detail the high-risk populations, symptoms, tests and various approaches to diagnosing sepsis, especially in the early stages.
So you’ve done the workup and suspect sepsis, what now? The most important thing is to start treatment early, within 1 hour of symptom onset, if at all possible.
The first treatment step is to give empiric broad-spectrum antibiotics. Empiric means the antibiotics are given before having a diagnostic confirmation and knowing what you’re treating. Broad spectrum means that the antibiotics should cover the entire bacterial spectrum as much as possible (Gram positive/negative, aerobes, anaerobes). This typically requires a combination of 2-3 antibiotics in different antibiotic classes depending on the patient’s risk factors and institutional guidelines.
Every effort should be made to identify the infectious agent through tissue cultures and other tests, but this effort should not delay early broad-spectrum antibiotic treatment. If the specific infectious agent is identified, then the antibiotics should immediately be narrowed and adjusted for that agent to minimize antibiotic overuse and resistance. However, antibiotics should not be stopped until the clinical picture improves and the full course is administered. Due to the increase in antibiotic resistance, there is an understandable reluctance to prescribe antibiotics in many institutions, but this can prove costly in septic patients. Practitioners should not hesitate to administer early antibiotics if symptoms, tests and clinical judgment point towards possible sepsis.
Oxygen should be administered early to prevent hypoxia and tissue damage, and this may require early mechanical ventilation. Blood pressure should be monitored closely, through central catheters if necessary, and vasoactive agents should be administered to maintain blood pressure, if necessary.
All of these steps and more are discussed in detail in the Sepsis Clinical Guide app. The Sepsis app also discusses sepsis in pediatric patients, who are approached considerably different from adults. Armed with the right knowledge at the right time, practitioners can dramatically reduce morbidity and mortality from sepsis in America’s hospitals. The ESCAVO’s Sepsis app is another valuable professional tool in the fight against this serious condition.