The use of point-of-care blood gas analysis on a South African fixed wing jet air ambulance service
Date
2013-04-24
Authors
Lunt, Steven Edward
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Abstract
Background Point-of-care blood gas analysis is considered a standard of care in modern air
ambulance operations by many professional organisations for clinical assessment and
monitoring of patients. Instances where point-of-care blood gas analysis has identified clinically
significant abnormalities which then led to clinical intervention are well documented and have
been quantified previously in the air ambulance environment. However, results obtained from
point-of-care blood gas analysis are not always required for patient care, nor do they always
result in any clinical action on the part of the medical crew. Our question therefore related to the
data for a Johannesburg based jet air ambulance service.
Methods By means of retrospective case reviews over a one year period, we reviewed the
overall frequency of utilisation of point-of-care blood gas analysis on patient transportations
within a Johannesburg based jet air ambulance service. We established how often point-of-care
blood gas analysis yielded abnormal findings, and how frequently abnormalities detected by
point-of-care blood gas analysis resulted in clinical interventions.
Results Point-of-care blood gas analysis was undertaken in 266 of 334 patients
transported (79.6%). Abnormal findings were noted in 203 of the 338 blood gas analyses
undertaken (60.1%). Patient age (p=0.001) and intubation status (p=0.01) were significant
influences on number of analyses performed, while flight time was not significant (p=0.07).
Clinical intervention followed in 65.5% of instances where abnormalities on blood gas analysis
were noted and in 87.6% where clinical corrective intervention was assessed as being possible
under prevailing conditions. Of all patients transported, some form of clinical intervention was
undertaken following 39.3% of all blood gas analyses undertaken. This therapeutic yield
evidenced is equivalent to 2.54 samples analysed per corrective clinical action evidenced. A
costing analysis further revealed that this testing is relatively inexpensive per positive finding
yielded and subsequent clinical actions.
Conclusions Abnormalities detected and subsequent clinical intervention using point-of-care
blood gas analysis in this patient population was significant with a clinical yield of 39.3%. Since
the costs are also not very high this modality is rightfully considered a minimum standard of care
in air ambulance operations. These findings also support the notion that such testing should be
carried out routinely on all patients irrespective of clinician interpretation of indication or need