A report of no observed adverse events depends on which events were sought and how completely they were measured. A 2018 medication-use evaluation examined intramuscular olanzapine and lorazepam at a county psychiatric hospital.
The retrospective evaluation identified 91 instances in which both medications were administered within 24 hours. A subgroup of 41 instances involved administration within 60 minutes. Those exposure windows describe different degrees of temporal proximity and should accompany any summary of the findings.
Researchers extracted blood pressure, pulse, respiratory rate, and available pulse-oximetry measurements. The selected vital signs were those closest to the second injection. Seven patients declined vital-sign measurement, although staff documented an observed respiratory rate. Pulse oximetry was available for only 32 patients. No serious adverse events were reported in the evaluation.
The study used descriptive statistics and had no contemporaneous comparison group. A finding based on available charted measurements leaves uncertainty about unmeasured events, their timing, and uncommon complications. For forensic toxicologists reviewing a combination-exposure claim, the route, interval between doses, definition of an event, observation schedule, and completeness of each measurement all matter. This paper contributes a bounded retrospective observation. Estimating the probability of respiratory harm in another population requires evidence that addresses its monitoring and exposure circumstances. The article describes a historical study and its measurement limits.
Read the full scientific paper. DOI 10.9740/mhc.2018.09.208.