Rapacuronium and the risk of bronchospasm in pediatric patients

Perioperative Care of the Pediatric Patient and an Algorithm for the Treatment of Intraoperative Bronchospasm

Asthma remains a common comorbid condition in patients presenting for anesthetic care. As a chronic inflammatory disease of the airway, asthma is known to increase the risk of intraoperative bronchospasm. As the incidence and severity of asthma and other chronic respiratory conditions that alter airway reactivity is increasing, a greater number of patients at risk for perioperative bronchospasm are presenting for anesthetic care. As bronchospasm remains one of the more common intraoperative adverse events, recognizing and mitigating preoperative risk factors and having a pre-determined treatment algorithm for acute events are essential to ensuring effective resolution of this intraoperative emergency. The following article reviews the perioperative care of pediatric patients with asthma, discusses modifiable risk factors for intraoperative bronchospasm, and outlines the differential diagnosis of intraoperative wheezing. Additionally, a treatment algorithm for intraoperative bronchospasm is suggested.

Soft drugs in anesthesia: remifentanil as prototype to modern anesthetic drug development

PURPOSE OF REVIEW

The unique demands of modern anesthesia practice require that medications be effective, well tolerated, and efficient. These attributes are increasingly achieved with the soft drug approach, wherein novel active compounds are specifically designed to be susceptible to rapid biotransformation to inactive metabolites. The present review summarizes the historical background and recent trends in soft drug development in anesthesiology.

RECENT FINDINGS

Soft drug development programs for propranadid, etomidate, and benzodiazepine analogues have been undertaken in recent years. Although all three drugs advanced into human trials, neuro-excitatory adverse effects hampered the propranadid and etomidate analogue projects. Remimazolam, the soft benzodiazepine analogue, is at an advanced stage of development, having already received regulatory approval or review in several countries.

SUMMARY

With succinylcholine as the historical forerunner and remifentanil as the modern prototype, the soft drug paradigm continues to hold promise for the future of anesthesia drug development.

Paediatric airway management: What is new?

Airway management plays a pivotal role in Paediatric Anaesthesia. Over the last two decades many improvements in this area have helped us to overcome this final frontier. From an era where intubation with a conventional laryngoscope or blind nasal intubation was the only tool for airway management, we have come a long way. Today supraglottic airway devices have pride of place in the Operating Room and are becoming important airway devices used in routine procedures. Direct and indirect fibreoptic laryngoscopes and transtracheal devices help us overcome difficult and previously impossible airway situations. These developments mean that we need to update our knowledge on these devices. Also much of our basic understanding of the physiology and anatomy of the paediatric airway has changed. This article attempts to shed light on some of the most important advances/opinions in paediatric airway management like, cuffed endotracheal tubes, supraglottic airway devices, video laryngoscopes, rapid sequence intubation, the newly proposed algorithm for difficult airway management and the role of Ex Utero Intrapartum Treatment (EXIT) procedure in the management of the neonatal airway.

Muscle relaxants allergy

The most common agents that are responsible for intraoperative anaphylaxis are muscle relaxants. In fact, neuromuscular blocking agents (NMBAs) contribute to 50-70 percent of allergic reactions during anaesthesia. The main mechanism of hypersensitivity reactions to NMBAs is represented by acute type I allergic reactions and the most severe form is anaphylaxis. The rate of non IgE mediated immediate hypersensitivity reactions usually varies between 20 percent and 35 percent of the reported cases in most large series. In a recent report, non allergic suspected reactions to NMBAs occurred with almost the same frequency as did those with an allergic component. Although the precise mechanisms of these reactions remain difficult to ascertain, they usually result from direct non specific mast cell and basophil activation. After diagnostic procedures, regardless of the specific IgE results, NMBAs are contraindicated if the skin tests were positive. In view of the constantly evolving anesthesiologic practices, and of the complexity of allergy investigation, an active policy to identify patients at risk and to provide any necessary support to anaesthetists and allergologists should be promoted. The high frequency of IgE anaphylactic reactions and the feasibility of skin tests in children justify systematic allergy testing whenever hypersensitivity reaction occurs during general anaesthesia.

The undesirable effects of neuromuscular blocking drugs

Neuromuscular blocking drugs are designed to bind to the nicotinic receptor at the neuromuscular junction. However, they also interact with other acetylcholine receptors in the body. Binding to these receptors causes adverse effects that vary with the specificity for the cholinergic receptor in question. Moreover, all neuromuscular blocking drugs may cause hypersensitivity reactions. Often the symptoms are mild and self-limiting but massive histamine release can cause systematic reactions with circulatory and respiratory symptoms and signs. At the end of anaesthesia, no residual effect of a neuromuscular blocking drug should be present. However, the huge variability in response to neuromuscular blocking drugs makes it impossible to predict which patient will suffer postoperative residual curarization. This article discusses the undesirable effects of the currently available neuromuscular blocking drugs including the definitions, diagnosis and causes of hypersensitivity reactions and postoperative residual curarisation.

Evidence-based medicine in anesthesiology

PURPOSE OF REVIEW

The principles of evidence-based medicine are now being applied in anesthesiology and intensive care medicine. The purpose of this review is to acquaint practitioners with the fundamentals of evidence-based medicine and to provide examples of how these principles can be incorporated into clinicians' practice.

RECENT FINDINGS

Outcomes research utilizing evidence-based approaches are manifest in several areas of anesthesiology and intensive care medicine. Several examples are cited from various sub-specialty areas, including pediatric, obstetric, and general anesthesia, as well as intensive care medicine.

SUMMARY

Evidence-based medicine is the term used to describe a practice paradigm that emphasizes the use of the best evidence available in the medical literature in making treatment decisions about the care of patients. Evidence-based approaches to care integrate individual expertise with data from externally conducted systematic research. Although evidence-based medicine has its origins in the 'treating' and 'diagnosing' specialty of internal medicine, its tenets are applicable to 'non-therapeutic' specialties such as anesthesiology and intensive care medicine. This review illustrates how evidence-based principles can be incorporated into the practice of perioperative medicine.

Fosphenytoin may cause hemodynamically unstable bradydysrhythmias

The prodrug fosphenytoin (FOS) was recently introduced as an alternative to phenytoin (PTN) and has since become a first line therapy for status epilepticus. Unlike PTN, FOS generally has been considered to be safe from cardiac toxicity. To better characterize cardiac toxicity associated with FOS administration, we performed a review of the Food and Drug Administration's Adverse Event Reporting System databank for reports of possible FOS toxicity from 1997-2002. There were 29 applicable reports of adverse cardiac events likely related to FOS infusion, including 10 cardiac deaths. Among survivors, there were four cases of high-grade atrioventricular block, and five cases of transient sinus arrest. Our data suggest that FOS may produce more cardiac toxicity than previously thought. Clinicians should consider administering intravenous FOS in a monitored setting for selected high-risk patients.

Use of odds ratios on anaesthesia related studies

In line with other medical journals, odds ratios are increasingly being reported in anaesthesia literature. The frequency of the use of odds ratio and how well it relates to the relative risk when it is interpreted as relative risk remains unknown. We investigated the use of odds ratio, and its relationship to relative risk and the incidence of outcome in this study. We identified 60 meta-analyses and 87 original articles that reported odds ratios. While relative risk could have been reported in 79% of the studies, only a small proportion (3%) of these studies have estimated and reported the relative risk in addition to the odds ratio. There is a significant bias if odds ratio is interpreted as relative risk, especially so when the incidence of outcome is high. While odds ratio is a valid measure of treatment effect in its own right, anaesthetists and investigators should be careful not to interpret odds ratio as equivalent to relative risk.