Incidence of Hyperoxia in Combat Wounded in Iraq and Afghanistan: A Potential Opportunity for Oxygen Conservation

An Analysis of Ketamine Doses Administrated to Nonintubated Casualties Prehospital

INTRODUCTION

Previous studies demonstrate that a significant proportion of casualties do not receive pain medication prehospital after traumatic injuries. To address possible reasons, the U.S. Military has sought to develop novel delivery methods to aid in administration of pain medications prehospital. We sought to describe the dose and route of ketamine administered prehospital to help inform materiel solutions.

MATERIALS AND METHODS

This is a secondary analysis of a previously described dataset focused on prehospital data within the Department of Defense Trauma Registry from 2007 to 2020. We isolated encounters in which ketamine was administered along with the amount dosed and the route of administration in nonintubated patients.

RESULTS

Within our dataset, 862 casualties met inclusion for this analysis. The median age was 28 and nearly all (98%) were male. Most were battle injuries (88%) caused by explosives (54%). The median injury severity score was 10 with the extremities accounting to the most frequent seriously injured body region (38%). The mean dose via intravenous route was 50.4 mg (n = 743, 95% CI 46.5-54.3), intramuscular was 66.7 mg (n = 234, 95% CI 60.3-73.1), intranasal was 56.5 mg (n = 10, 39.1-73.8), and intraosseous was 83.3 mg (n = 34, 66.3-100.4). Most had a medic or CLS in their chain of care (87%) with air evacuation as the primary mechanism of evacuation (86%).

CONCLUSIONS

The average doses administered were generally larger than the doses recommended by Tactical Combat Casualty Care guidelines. Currently, guidelines may underdose analgesia. Our data will help inform materiel solutions based on end-user requirements.

Benefits and harms of increased inspiratory oxygen concentrations

PURPOSE OF REVIEW

The topic of perioperative hyperoxia remains controversial, with valid arguments on both the 'pro' and 'con' side. On the 'pro' side, the prevention of surgical site infections was a strong argument, leading to the recommendation of the use of hyperoxia in the guidelines of the Center for Disease Control and the WHO. On the 'con' side, the pathophysiology of hyperoxia has increasingly been acknowledged, in particular the pulmonary side effects and aggravation of ischaemia/reperfusion injuries.

RECENT FINDINGS

Some 'pro' articles leading to the Center for Disease Control and WHO guidelines advocating perioperative hyperoxia have been retracted, and the recommendations were downgraded from 'strong' to 'conditional'. At the same time, evidence that supports a tailored, more restrictive use of oxygen, for example, in patients with myocardial infarction or following cardiac arrest, is accumulating.

SUMMARY

The change in recommendation exemplifies that despite much work performed on the field of hyperoxia recently, evidence on either side of the argument remains weak. Outcome-based research is needed for reaching a definite recommendation.