Errors in the administration of injected (parenteral) medication occur with alarming frequency, and are a serious safety problem in intensive care units, concludes a large study published on bmj.com today.

A previous study found that medication errors were frequent at the administration stage, so Dr Andreas Valentin and colleagues set out to examine this further on a multinational level. They monitored errors occurring at 113 intensive care units (ICUs) in 27 countries - 17 in the United Kingdom - over the same 24-hour period (January 17 or January 24 2007). All nurses and physicians on duty during the study period were asked to record errors using a questionnaire available at the bedside of each patient.

Errors were classified by type of error, type of drug administration and class of drug, and a detailed description of the error was recorded to allow assessment of contributing factors.

Further data were recorded to calculate occupancy rate, relative turnover, patient-nurse ratio, and patient-to physician ratio for each shift in ICU. The severity of illness in each patient and nursing workload were also assessed on the day of the study.

In a total of 1328 patients, 861 errors affecting 441 patients were reported over the 24-hour period. Just over two-thirds (67%) of patients experienced no error, 250 patients (19%) experienced only one error, and 191 patients (14%) experienced more than one error.

Although 71% of errors resulted in no change in the status of the patient, 12 patients (0.9% of the total study population) suffered permanent harm or death related to a total of 15 medication errors at the administration stage. Trainees were reported as being involved in eight of these errors.

The most frequent errors were related to wrong time of administration (386) and missed medication (259), followed by wrong dose (118), wrong drug (61), and wrong route (37).

Workload/stress/fatigue was reported by ICU staff as a contributing factor in 32% of all errors. Other contributing factors included a recently changed drug name (18%), communication - written (14%), communication-oral (10%), and violation of standard protocol (9%).

Odds for the occurrence of at least one medication error increased significantly with a higher severity of illness, a higher level of care, and a higher rate of parenteral drug administrations. This finding directly reflects the complexity of care of these patients and thus the increased opportunity for error, suggest the authors.

In contrast, odds decreased when a critical incident reporting system was in place and when there was an established routine of checks at nurses' shift change.

This study demonstrates that the administration of parenteral medication is a weak point in patient safety in ICUs, say the authors. And since the results are based on data from 113 participating ICUs worldwide, this problem represents a common pattern. With the increasing complexity of care in critically ill patients, organisational factors such as error reporting systems and routine checks at shift changes can reduce the risk of such errors in ICUs, they conclude.

"Research: Errors in administration of parenteral drugs in intensive care units: multinational prospective study"
BMJ online
http://www.bmj.com/cgi/doi/10.1136/bmj.b814

British Medical Journal
http://www.bmj.com