A small study of 6 PICU patients requiring CPR for cardiac arrest due to primary cardiac disease showed that blood pressure as measured by an arterial line increased when the depth of chest compression was increased from one third to one half of the chest wall diameter (using the hand-encircling method). Systolic, mean, and pulse pressures increased significantly whereas diastolic blood pressure (a key determinant of coronary perfusion) did not.
Should the ILCOR guidelines be changed to recommend deeper chest compressions? More data are needed, but the take home message here may be that invasive arterial monitoring is a good guide to the effectiveness of CPR during cardiac arrest resuscitation.
A double blind randomised trial comparing amethocaine (Ametop) with EMLA was conducted on 679 kids in a New Zealand emergency department. No significant differences were seen in success rate of first-attempt cannulation, skin blanching, or pain scores. However the protocol required an unblinded triage nurse to remove the creams at 45 minutes for amethocaine and 90 minutes for EMLA. The faster acting amethocaine may therefore be more useful in acute care settings.
Ketamine lowered ICP in brain-injured kids
Ventilated children between the ages of 1 and 16 with traumatic brain injury and elevated intracranial pressure (ICP) were given ketamine and effect on cerebral perfusion pressure (CPP) and ICP was measured. Ketamine decreased ICP while maintaining blood pressure and CPP.
These results refute the notion that ketamine increases ICP. The authors conclude: “Ketamine is a safe and effective drug for patients with traumatic brain injury and intracranial hypertension, and it can possibly be used safely in trauma emergency situations”
During simulated cardiac arrest resuscitations, a comparision was made between those run by teams that had had time to form before the arrest, and those that had to be assembled ad hoc after the arrest occurred. 99 teams of three doctors, including GPs and hospital physicians were studied. ACLS algorithms were less closely followed in the ad hoc formed teams, with more delays to therapies such as defibrillation. Analysis of voice recordings revealed the ad hoc teams to make fewer leadership utterances (eg. ‘we should defibrillate’ or ‘the next countershock will be 360J’) and more reflective utterances (eg. ‘what should we do next?’). The authors suggest that team building is therefore to be regarded as an additional task imposed on teams formed ad hoc during CPR that may substantially impact on outcome. No surprise to those of us who banned ‘cardiac arrest teams’ from our emergency department resuscitation rooms many years ago!
Hands-on time during cardiopulmonary resuscitation is affected by the process of teambuilding: a prospective randomised simulator-based trial
An observational, prospective study comparing tibial and humeral intraosseous access using the EZ-IO
Emergency physicians at Singapore General Hospital found flow rates to be similar when comparing the tibia with the humerus as sites for adult IO access. The EZ-IO had a very high insertion success rate. It took about 12 minutes to infuse a litre of saline, which drops to about 6 minutes if a pressure bag is used.
Trauma scissors vs the Rescue Hook, exposing a simulated patient: a pilot study
American military investigators compared traditional trauma scissors with the ‘rescue hook’ (a hooked knife with the cutting edge on the inside of the hook) in rapidly removing the clothes from a simulated casualty. An army desert combat uniform and boots were removed more quickly with the rescue hook, which was favoured by the combat medics employed in the study. We don’t have data on how it would work on denim, leather, or belts, but it looks pretty good. I just want to know if it’ll go through a sternum before I trade in my trauma scissors.
Published flow rates for cannulae are derived from a test in which fluid runs through a perfectly straight cannula into an open receptacle. Laminar flow is expected in such a model in which the Hagen-Poisseuille formula tells us that flow is proportional to the fourth power of the radius. In this study manufacturers’ published flow rates were compared with an artifical vein model. Hartmann’s flowed faster than Gelofusine. For all cannulas flow was less than the manufacturers’ published rates. Although the radius was the biggest determinant of flow rate, the fourth power could not be used, suggesting a mixture of laminar and turbulent flow. The addition of pressurised infusions increased the flow rate with increasing pressure. Although the vein model used has limitations, and many other factors may influence flow rate in the clinical setting, the authors’ conclusions are helpful:
While the effect of radius is less than commonly believed, it is still important. However, clinicians should be aware of the limitations of increasing radius and use other strategies to increase flow when needed. These could include use of pressure, choice of fluid to be infused, and using multiple cannulae in parallel.
The presence and degree of compartment intrusion (from crash investigation data) was correlated with the likelihood of serious injury in 880 children from age 0-15 years, and odds for presence of serious injury increased for each centimetre of compartment intrusion.
The risk of apnoea in neonates requiring prostaglandin E1 infusions for duct-dependent congenital heart disease is well described and often results in the recommendation to intubate prior to transfer. An American study of 202 transported infants on PGE1 shows a higher rate of transport-related complications in those that had been intubated. None of the 73 (36%) unintubated patients required intubation for apneoa during transport. These data are in keeping with a previous Australian study of 300 infants receiving PGE1 in which only 2 of 78 unintubated patients experienced apnoea. To intubate or not to intubate? Transporting infants on prostaglandin E1 Pediatrics. 2009 Jan;123(1):e25-30
A prospective observational study of paediatric patients requiring pre-hospital intubation attended by a helicopter medical team (HMT) included 95 children with a GCS of 3-4. Fifty-four received bag-mask support by EMS paramedics until the HMT arrived and intubated them (survival 63%), and 41 were intubated by EMS paramedics. Of these, ‘correction of tube/ventilation’ was required in 37% and the survival was 5%. The authors conclude that bag-mask support should be the technique of choice by EMS paramedics, as the rate of complications of tracheal intubation in this patient group is unacceptably high. Hard to comment as I only have access to the abstract but one wonders if the EMS-intubation group were sicker patients requiring more aggressive early control of airway and breathing. http://www.ncbi.nlm.nih.gov/pubmed/18684547