Are the new resuscitation guidelines optimal?

PURPOSE OF REVIEW: The purpose of this review is to evaluate the 2005 guidelines on cardiopulmonary resuscitation. RECENT FINDINGS: International guidelines are based ideally on results from robust clinical trials. They are necessarily constrained in how far they can draw conclusions from experimental data, and have to pay regard to perceived safety and educational issues. Informed opinion can be more radical in drawing from compelling recent experimental findings, particularly when supported by unreplicated or indirect clinical evidence. Those already available cover a range of issues relevant to the guidelines; the most important ones are reviewed here. SUMMARY: The 2005 guidelines represent a major advance on those previously in use, but on the evidence already available they cannot be considered optimal. Deviations based on good evidence should not be discouraged provided they are approved and preferably monitored by authoritative bodies that should see this as a legitimate role in developing the science of resuscitation medicine. Guidelines for the most pressing of medical emergencies should not be set and inflexible over several years whilst the science behind them continues to advance.     

Are US informed consent requirements driving resuscitation research overseas?

Following a 2-year federally imposed moratorium on acute resuscitation research due to concern regarding the inability of patients in cardiac arrest to provide prospective, informed consent to participate in such research, the United States federal government in 1996 released regulations with provisions for exemption of prospective informed consent in certain types of emergency research. While very few acute resuscitation research studies have been attempted in the United States since that time, such research has continued overseas. We discuss one large multi-center, out-of-hospital trial of a device intended to improve the hemodynamics of cardiopulmonary resuscitation. After pilot implementation overseas, this trial could not be conducted in the United States, largely due to the difficulties and costs involved in implementing the requirements of the 1996 regulations. A recent European Union directive on the conduct of clinical trials may halt European research on patients who are unable to provide prospective, informed consent. The directive contains no provisions for exceptions or waiver of informed consent, and may hinder acute resuscitation research in Europe to an even greater degree than the 1996 regulations have in the United States.     

Vasopressin: improving resuscitation?

Historically, epinephrine has been used in the treatment of cardiac arrest for its alpha effects of peripheral vasoconstriction to promote vital organ perfusion. Unfortunately, epinephrine, like many other pharmacological agents, targets other receptor sites that can have a detrimental effect on the patient in cardiac arrest. Vasopressin is an endogenous hormone that may be an ideal alternative or adjunctive to epinephrine in the setting of cardiac arrest. Vasopressin, like epinephrine, promotes selective but potent vasoconstriction of smooth muscle, but unlike epinephrine, without the potentially harmful side effects of increasing myocardial workload, therefore increasing oxygen demand and subsequent worsening of cardiac function. The newest data on the impact of vasopressin in cardiac arrest is promising. Further studies are required to determine if vasopressin has a significantly positive impact in outcome as measured by discharge of the neurologically intact patient in the North American EMS model.     

New airways for resuscitation?

Over the last 15 years supraglottic airway devices (SADs), most notably the classic laryngeal mask airway (LMA) have revolutionised airway management in anaesthesia. In contrast for resuscitation, both in and outside hospital, facemask ventilation and tracheal intubation remain the mainstays of airway management. However there is evidence that both these techniques have complications and are often poorly performed by inexperienced personnel. Tracheal intubation also has the potential to cause serious harm or death through unrecognised oesophageal intubation. SADs may have a role in airway management for resuscitation as first responder devices, rescue devices or for use during patient extraction. In particular they may be beneficial as the level of skill required to use the device safely may be less than for the tracheal tube. Concerns have been expressed over the ability to ventilate the lungs successfully and also the risk of aspiration with SADs. The only SADs recommended by ILCOR in its current guidance are the classic LMA and combitube. Several SADs have recently been introduced with claims that ventilation and airway protection is improved. This pragmatic review examines recent developments in SAD technology and the relevance of this to the potential for using SADs during resuscitation. In addition to examining research directly related to resuscitation both on bench models and in patients the review also examines evidence from anaesthetic practice. SADS discussed include the classic, intubating and Proseal LMAs, the combitube, the laryngeal tube, laryngeal tube sonda mark I and II and single use laryngeal masks.     

The capacity of different infusion fluids to lower the prooxidant activity of plasma iron: an important factor in resuscitation?

BACKGROUND: Prooxidant activity of non-protein-bound iron (NPBI) is an important contributor to reactive oxygen species-induced injury after the resuscitation of critically ill patients. Plasma NPBI occurs in critically ill adults, children, and newborn babies, who often require resuscitation. The ability of the resuscitation fluids to bind iron and lower the patients' NPBI levels in vitro has not previously been studied. STUDY DESIGN AND METHODS: In an in vitro model, highly iron-saturated cord blood plasma from 10 preterm and 10 term babies was mixed with FFP, pasteurized plasma protein solution, and 0.9-percent saline. Plasma from 10 healthy adult volunteers was used as a control. Before and after the mixing with any resuscitation fluid, NPBI levels and ceruloplasmin iron-oxidizing and transferrin iron-binding antioxidant capacities were measured. RESULTS: After the in vitro mixing with FFP, the incidence and concentration of NPBI were markedly decreased and the iron-binding antioxidant capacity was increased in the plasma of the preterm and term babies. Being mixed with pasteurized plasma protein solution and 0.9-percent saline did not influence the iron-binding antioxidant capacity of newborn babies' plasma. In the control plasma, results were not changed after the mixing with any resuscitation fluid. In every group, the iron-oxidizing antioxidant capacity was not changed after the mixing with any fluid. CONCLUSION: Iron-induced oxidative tissue damage may be influenced by resuscitation fluids. In the ongoing debate over the choice of crystalloid or colloid resuscitation fluids, the influence of each fluid on the patient's antioxidant capacity warrants more attention.     

Can cardiopulmonary resuscitation injure the back?

Cardiopulmonary resuscitation (CPR) is performed frequently by nurses in general hospitals and often in compromised positions. This may induce injury to the rescuer's spine particularly if the CPR procedure is continued for a considerable time before medical staff arrive. Back pain as an occupational symptom in nurses has received considerable attention in the medical literature, but there is no report on the effect of CPR on back discomfort. This article reports a survey of the CPR experience of nurses in general hospitals and nursing homes and explores the difficulties encountered by nurses during the CPR procedure. A questionnaire was sent to nurses who had CPR experience in three general hospitals and 20 nursing homes through the nursing administrators of the respective units. Analysis of 205 completed questionnaires showed that the duration of the CPR procedure could last up to 27 min. While 86% of the nurses performed CPR on a bed, 70% of them had their legs hanging over the edge of the bed without support and 55% had to turn their head or back to look at the ECG monitor during the procedure. Over 80% experienced back discomfort during or after the CPR procedure and 56% considered their back discomfort was related to the duration of the procedure. Twenty percent of the nurses suffered back injury or prolapsed disc and over 40% of these 'injured' nurses considered their back injury was related to or aggravated by CPR. Results of this survey suggest there is a need to review the support given to nurses to ensure safe administration of the CPR procedure in the general ward environment.