Subclause 6.1.2 – ALARM CONDITION priority

ü ALARM CONDITIONS should be prioritized based on the urgency of the required OPERATOR response or awareness of the situation that triggered the ALARM CONDITION. Priority is assigned through RISK ANALYSIS, either by the writer(s) of a particular standard or by the MANUFACTURER.

ü NOTE Some ALARM SYSTEMS have OPERATOR-configured or RESPONSIBLE ORGANIZATION-configured priorities.

ü MANUFACTURERS assign ALARM CONDITION priorities based on RISK ANALYSIS. This RISK ANALYSIS should primarily consider the severity and rapidity of onset of HARM if the ALARM CONDITION is not corrected. It should also consider other factors such as the sensitivity and specificity of the ALARM CONDITION for the actual event in the PATIENT or the equipment. The level of the priority of ALARM SIGNAL only suggests to the OPERATOR the speed at which the OPERATOR should respond to, or be aware of, an ALARM CONDITION. The actual speed of response or awareness required is ultimately based on the assessment by the OPERATOR.

ü “Immediate” category problems are those that are likely to cause PATIENT injury or death within seconds to several minutes if uncorrected. Few problems fall into the “immediate” category.

EXAMPLE 1 Asystole

EXAMPLE 2 Ventricular fibrillation

EXAMPLE 3 Failure of a cardiac support device (intra-aortic balloon pump, cardiopulmonary bypass machine)

EXAMPLE 4 Sustained high airway pressure

EXAMPLE 5 Extreme hypoxemia

EXAMPLE 6 Sustained high-energy radiation beam

ü “Prompt” category problems, on the other hand, do not cause PATIENT injury or death until at least several to many minutes have elapsed.

EXAMPLE 7 Many cardiac arrhythmias

NOTE Most cardiac arrhythmias would be prompt or delayed.

EXAMPLE 8 High or low blood pressure

EXAMPLE 9 Apnea (unless prolonged or associated with extreme hypoxia)

EXAMPLE 10 Mild hypoxemia

EXAMPLE 11 High or low pCO2

ü “Delayed” category problems cause PATIENT injury only after many minutes to hours have passed.

EXAMPLE 12 Failure of an infusion pump for maintenance of intravenous fluids

EXAMPLE 13 Failure of an enteral feeding pump

EXAMPLE 14 Failure of a PATIENT weighing system

The choice of priority should be based upon RISK ANALYSIS.

? In general, the lowest priority compatible with the RISK ANALYSIS should be selected.

ü In particular, HIGH PRIORITY ALARM SIGNALS should be reserved for those few ALARM CONDITIONS that truly require immediate response for PATIENT safety—that is, a response within seconds to a couple of minutes. Many types of equipment will not require any HIGH PRIORITY ALARM SIGNALS.

ü ME EQUIPMENT ALARM SYSTEMS are a protective measure used to minimize risks to PATIENT, personnel, and equipment. In certain therapeutic ME EQUIPMENT, a HAZARDOUS SITUATION could develop so rapidly, and cause injury or damage so rapidly, that OPERATOR response to even a well-designed ALARM SYSTEM would be too slow. In such ME EQUIPMENT, an automatic system of mitigating the HAZARDOUS SITUATION is highly desirable, if not essential. The general standard and many particular standards require such safety mechanisms.

ü It is recognized, however, that no ME EQUIPMENT could have protection against every possible HAZARD, or in the presence of multiple fault conditions.

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