UNDIAGNOSED SEPSIS

SUMMARY: Sepsis is a common cause of both death and medical malpractice litigation. Some of the early signs of sepsis were identified after many senior physicians were in medical school. General practice office, emergency department and intensive care unit have different characteristic errors.

Sepsis is the tenth commonest cause of death in the US^1.

Delayed diagnosis of sepsis is a common Cause of medical malpractice Action in the Emergency Room², the post-operative surgical ward and the general and family practitioner’s office.

In the early stages, most cases of sepsis can be treated and cured.

When the stage of septic shock is reached, death commonly results.

At the intermediate severe sepsis stage, the outcome of appropriate treatment is more unpredictable and Causation issues may be more contentious.

With the benefit of hindsight it is often easy to see the evolution of symptoms and signs that the potential Defendant care-givers missed.

Terminology and definitions of sepsis, severe sepsis and septic shock have been and remain confused and contentious.

The terminology Systemic Inflammatory Response Syndrome (SIRS) has been proposed³ as a replacement for sepsis, but not yet commonly adopted.

Practice Point

Suspicion of Sepsis (SIRS): 2 or more of

1.     temperature
        a. >38°C or
        b. <30°C
2.     heart rate >90
3.     a. respiratory rate >20 or b. PaCO₂ <32
4.     White Blood Cell Count
        a. >12,000 or
        b. <4000 or
        c. >10% immature forms

When 2 or more of these conditions are present, the clinician should be considering sepsis in the differential diagnosis of unexplained symptoms.

1. Low-grade fever (up to 38.5° C) is very common in the post-operative period and is frequently of no significance.

In the emergency-room, checking of the temperature is part of the triage or admitting nursing ritual, particularly when there is uncertainty about diagnosis. General and family practitioners characteristically measure temperatures much less frequently.

2. An increased heart-rate may be caused by a variety of other clinical circumstances, notably anxiety and conditions that compromise lung and heart function.

3. Respiratory rate is frequently “guestimated” by attending nurses, even though precise values may be recorded.

Part of the problem is that measuring respiratory rate remains a standard nursing routine in many clinical situations in which the result is unimportant.

Because meticulous measurement is time-consuming, it is often given low priority in the conflicting needs of increasingly busy and complex nursing duties.

Arterial carbon dioxide (PaCO₂) is usually measured for purposes other than identification of SIRS, and is for that reason frequently overlooked in the marshalling of evidence for or against infection.

4. Raised White Blood Cell Count (WBC) is a non-specific finding in many clinical situations so it may not be considered valuable in the differential diagnosis.

Some of the early signs of sepsis were identified after many senior physicians were in medical school.

Traditional medical school and textbook teaching previously focussed only on criteria 1a., 2, 4a. and possibly 3a of the above PRACTICE POINT, so older physicians in particular tend to disregard subnormal temperature, decreased PaCO₂ and both proportions of immature WBC and mildly depressed total WBC counts.

However, apprehension, hyperventilation and consequent respiratory alkalosis (decreased PaCO₂) are often the first indicators of sepsis in the Intensive Care Unit⁴.

A source of infection may or may not (primary bacteremia) be clinically evident.

Absence of a focus from which the infection might have spread is commoner in debilitated patients and those with compromise of the immune system.

In such cases, bowel germs predominate and the bowel itself is believed to be the usual origin of the generalised infection.

Once generalised infection is suspected, the appropriate medical response is

1. comprehensive history and (re-)examination,

2. investigations for nature of the germ, source and severity of complications, and

3. the empirical initiation of appropriate antimicrobial therapy, pending the results of laboratory investigations.

Medicolegal Implications

General practice office, emergency room and intensive care unit have different characteristic errors.

A common source of Actionable mis-diagnosis or delayed diagnosis is failure to take an adequate history or perform appropriate or thorough physical examination.

All too often, the indicators of sepsis are recorded but the symptoms or signs are mis-attributed after too cursory a clinical assessment.

Practice Point

Look for signs of sepsis

1.   not examined (general practice)
2.   inadequately diagnosed (emergency)
3.   insidious in onset (intensive care)

In the Emergency Department in particular, the working diagnosis may fail to account for the documented mild fever, rapid pulse, or increased respiratory rate.

By contrast, in the Intensive Care Unit, an unexpected deterioration may be insidious in onset and get lost in the clinical complexity, information overload and team approach to management.

General and family practitioners more characteristically do not make the measurements that would lead to suspicion of sepsis as the cause of unexplained symptoms.

General and family practitioners are the specialists most likely to skip the investigation stage and prescribe antibiotics that are an inappropriate choice for the probable germs and/or inadequate in dosage.

The problem that then arises is that bacterial growth is suppressed in subsequent laboratory tests but not in the body.

Initial empirical choice of antimicrobial agent(s) depends on a sufficiently thorough and comprehensive clinical assessment of the likely origin of infection.

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