Consciousness during active resuscitation
Consciousness may occur during cardiopulmonary resuscitation (CPR) despite the absence of a palpable pulse. The phenomenon, known as CPR-induced consciousness (CPR-IC), was first described over three decades ago and there has been an increase in case reports describing it. However, there remains limited evidence in relation to the incidence of CPR-IC and to practitioners' experiences of it.
This mixed-methods cross sectional survey of UK paramedics sought to establish if paramedics had experienced CPR-IC during their career and to provide further description of any such event. The researchers were also interested in whether the CPR-IC interfered with the resuscitation attempt and, if so, what actually caused the interference.
Of the 276 eligible participants who completed the survey, 57% had experienced CPR-IC, with the majority of those having experienced it on more than one occasion. The most commonly described signs of consciousness were eye opening and active looking, intelligible and unintelligible sounds, and physical movements such as purposeful arm movements, interfering with airways and resisting CPR.
Patient resistance was the most commonly cited source of interference but a number of other themes emerged including increased rhythm checks, distress or nervousness of the paramedic, confusion and distraction, and concerns from bystander.
One of the most interesting take-home messages was that the responses in this study were remarkably similar between those who felt that the CPR-IC was interfering and those who did not. The study determined that many who experienced the phenomenon for the first time considered simple eye opening to be interfering due to the disconcerting effect it had upon them; whereas in other reports, purposeful motor movement and vocalisation that could be presumed to be interfering were deemed to be non-interfering by the attending paramedics. This suggests that interfering and non-interfering CPR-IC may be on a spectrum related more to the exposure of the clinician to CPR-IC than to any specific characteristic of the phenomenon itself.
Use of ketamine in severely agitated patients
The use of ketamine as a sedative is not common practice for the majority of UK paramedics but it has been used for a number of years in some regions of Australia. In Victoria, paramedics have administered 4 mg/kg of Intramuscular (IM) ketamine for severe agitation since mid-2015. When administered IM, ketamine has a rapid onset while maintaining airway reflexes, spontaneous respiration and haemodynamic stability. However, it may also lead to excessive salivation, hypertension, emergence reactions and laryngospasm. This retrospective review aimed to examine the prehospital characteristics and emergency department outcomes of patients with severe agitation following administration of IM ketamine over a 2-year period.
There were 358 prehospital cases transported to 32 hospitals included with ultimate outcome data available for 305 patients (21 hospitals). Over 71% of the patients were male, with a median age of 31 years (IQR 23–40). The primary outcome of the study was time to adequate sedation, which was defined as the time between administration of the first IM dose of ketamine and the time when physical restraint was no longer needed, and the patient was able to receive oxygen administration and undergo vital sign assessment. Adequate sedation was achieved in nearly 97% of cases in a median time of 5 minutes (IQR 3.0–7.0; range 1–31 minutes). Adverse events were transient hypoxia (5.0%), hyper-salivation (4.2%) and emergence reactions (0.8%). A total of 45 (14.8%) patients were intubated in hospital and two (0.6%) prehospitally. Notably, there was a significant but unexplained difference between the rates of intubation in hospitals that received >20 patients. The rate of intubation ranged from 0% at one hospital to 52% at another.
The authors concluded that ketamine may be an effective pharmacological agent for managing patients with severe agitation in the prehospital setting but recognised the need for a prospective randomised controlled trial (RCT) to confirm.