Transferring the critically ill patient: are we there yet?

Since the establishment of the first ICUs in the 1950s, the demand for intensive care
has grown exponentially. When demand exceeds supply, or when highly specialized care
is required, transfer of critically ill patients becomes necessary. In the United
Kingdom alone, more than 10,000 patients required secondary transfers in 1986 1]. In the USA 1 in 20 patients requiring ICU care is transferred to another hospital
2]. Similar transfer rates probably occur elsewhere.

The number of transfers is likely to increase because of supply-demand imbalances.
Recognition that centralization of specialist care is associated with reduced mortality
rates might generate a new stream of transfers 2]. A recent study conducted in the USA suggested that the lives of 4,000 patients might
have been saved in a year had they been transferred to another, better qualified hospital
3].

Interhospital transfers may save lives but they are expensive, logistically challenging,
and risky. The transport process itself is associated with a risk of physiological
deterioration and adverse events. The incidence of adverse events is proportional
to the duration of the transfer, to the pre-transfer severity of illness or injury
and to the inexperience of the medical escorts 4]-6].

Since the late 1970s, safety concerns have motivated several studies of when, how
and where to transfer critically ill patients. One of the first concluded that earlier
transfer, resuscitation before transfer, continuing medical care during the journey,
and hence a slower and smoother journey are beneficial to patients 7] and these conclusions apply to this day. In 1986 Ehrenwerth and colleagues 8] concluded that, with a specialized transport team and appropriate haemodynamic stabilization
and monitoring, severely ill patients can be transported safely. From then on, the
equipment improved, trolleys were modified and the first mobile ICU appeared 9].

Although transport guidelines appeared during the 1990s 10],11], a review published in 1999 still reported adverse events in up to 70% of transports.
This led the authors to urge intensivists to follow guidelines concerning logistical
organization, personnel, equipment and monitoring during transport 12]. Newer guidelines continued to emphasize the principles concerning personnel, organization
and equipment 13]-15]. Nonetheless, high rates of incidents continued to be published, many of which appeared
to be avoidable, and associated with non-adherence to the guidelines 16]-19].

In 2005, Haji-Michael 20] discussed two main reasons why, despite the existence of guidelines, interhospital
transfer of the critically ill patient is still associated with avoidable mishaps.
The first reason concerns sponsorship: those with responsibility and authority for
the care of the patients are simply not the ones doing the transfers. The second reason
is a lack of a motivation for change – we have always somehow managed 20]. A third reason might be the lack of evidence that the recommendations are of benefit.
The guidelines present clear recommendations but are based on weak evidence; cohort
studies, case series, and expert opinion.

In this review we evaluate the current literature on the organization and safety of
transfers of critically ill adult patients. We will also draw on the literature concerning
paediatric intensive care transfers, since these have already been well organized
for a long time.