Anaphylaxis during anesthesia: results of a 12-year survey at a French pediatric center

Anaphylaxis mortality in the perioperative setting: Epidemiology, elicitors, risk factors and knowledge gaps

Perioperative anaphylaxis (PA) is a severe condition that can be fatal, but data on PA mortality are scarce. The aim of this article is to review the epidemiology, elicitors and risk factors for PA mortality and identify knowledge gaps and areas for improvement regarding the management of severe PA. PA affects about 100 cases per million procedures. Mortality is rare, estimated at 3 to 5 cases per million procedures, but the PA mortality rate is higher than for other anaphylaxis aetiologies, at 1.4% to 4.8%. However, the data are incomplete. Published data mention neuromuscular blocking agents and antibiotics, mainly penicillin and cefazolin, as the main causes of fatal PA. Reported risk factors for fatal PA vary in different countries. Most frequently occurring comorbidities are obesity, male gender, cardiovascular diseases and ongoing treatment with beta-blockers. However, there are no clues about how these factors interact and the impact of individual risk factors. The pathophysiology of fatal PA is still not completely known. Genetic factors such as deficiency in PAF-acetyl hydrolase and hereditary alpha-tryptasemia, have been reported as modulators of severe anaphylaxis and possible targets for specific treatments. Our review underlines unmet needs in the field of fatal PA. Although we confirmed the need for timely administration of an adequate dose of adrenaline and the proper infusion of fluids, there is no evidence-based data on the proper dose of intravenous titrated adrenaline and which clinical manifestations would flag the need for fluid therapy. There are no large clinical studies supporting the administration of alternative vasopressors, such as glucagon and methylene blue. Further research on pathophysiological mechanisms of PA and its severity may address these issues and help clinicians to define new therapeutic approaches.

Latex Allergy in Children

Notwithstanding the efforts made in the last decades to mitigate the consequences of natural rubber latex allergy, this disease continues to be a major health problem, especially in developing countries. The categories of patients with greater and frequent exposure to latex (such as health care professionals and, in the pediatric field, subjects who undergo repeated surgery, e.g., those suffering from spina bifida and urogenital malformations) have an increased risk of developing sensitization and allergy to latex. Herein we provide an overview of the current knowledge and practical recommendations with a focus on epidemiology, diagnostics, and management (including both prevention and therapy) in order to guide a correct recognition and containment of this potentially fatal condition.

Could Artificial Intelligence Prevent Intraoperative Anaphylaxis? Reference Review and Proof of Concept

Drugs and various medical substances have been used for many decades to diagnose or treat diseases. Procedures like surgery and anesthesia (either local or general) use different pharmacological products during these events. In most of the cases, the procedure is safe and the physician performs the technique without incidents. Although they are safe for use, these substances (including drugs) may have adverse effects, varying from mild ones to life-threatening reactions in a minority of patients. Artificial intelligence may be a useful tool in approximating the risk of anaphylaxis before undertaking a medical procedure. This material presents these undesirable responses produced by medical products from a multidisciplinary point of view. Moreover, we present a proof of concept for using artificial intelligence as a possible guardship against intraoperative anaphylaxis.

Secondary prevention of latex allergy

PURPOSE OF REVIEW

The present review addresses the secondary prevention in healthcare worker, healthcare setting, and in patients outside the healthcare setting.

RECENT FINDINGS

There is sufficient knowledge of the broad aetiology of latex allergy for secondary preventive programmes to be widely adopted. Currently, avoidance of latex-containing surgical products is mandatory in the care of sensitized patients. They should also have a list of occult sources of natural rubber latex exposure and cross-reacting fruits. During all health-care procedures latex allergic patients should be treated in a 'latex-free' environment. Specific sublingual immunotherapy has been suggested as a suitable therapeutic option. It can be offered, in addition to symptomatic treatment, to selected patients, when avoidance measures are not feasible or effective. The use of omalizumab could also be extended as an adjunct to latex immunotherapy.

SUMMARY

Despite of the progress made in the secondary prevention of latex allergy, the disease still continues to be a global health problem.

Perioperative hypersensitivity reactions during childhood and outcomes of subsequent anesthesia

BACKGROUND

Pediatric perioperative hypersensitivity reactions are rare, and possibly life-threatening. Identification of precise etiology is crucial to circumvent future re-exposures.

AIMS

We aim to evaluate the clinical features and triggers of perioperative hypersensitivity reactions in children, and determine the outcomes of subsequent general anesthesia.

METHODS

A retrospective study was performed with patients who underwent skin testing for general anesthesia between 2007 and 2019. We noted demographic features and skin tests (neuromuscular blocking agents, induction agents, and antibiotics). We also recorded specific immunoglobulin Es or provocation results of drugs or substances (latex, chlorhexidine, and ethylene oxide) that patients were exposed to antecedent to the reaction. Telephone interviews were performed to determine the current status of the participants and reconsider subsequent anesthesia.

RESULTS

We enrolled 50 children (58% male) with a suspected perioperative hypersensitivity reaction. The median age was 6.67 (4.4-11.5) years, and the median time between the reaction, and skin tests was 4 (1-36) months. The most common potential causative agents were neuromuscular blocking agents (n = 8), midazolam (n = 3), ketamine (n = 2), and propofol (n = 1). Three children exhibited hypersensitivity to more than one general anesthetics, and three patients were allergic to latex. Thirty-one patients received subsequent anesthesia, and only one patient had a hypersensitivity reaction. A previous history multiple of general anesthesia administration (≥2) increased the risk of reaction to neuromuscular blocking agents.

CONCLUSION

Data on perioperative hypersensitivity reactions during childhood are rare due to limited diagnostic procedures. Different preference of general anesthetics may change the causative agent. Meticulous evaluation is necessary to safely administer subsequent anesthesia.

Use and Interpretation of Acute and Baseline Tryptase in Perioperative Hypersensitivity and Anaphylaxis

Paired acute and baseline serum or plasma tryptase sampling and determination have recently been included as a mechanistic approach in the diagnostic and management guidelines of perioperative immediate hypersensitivity and anaphylaxis. The timing of this paired sampling is clearly defined in international consensus statements, with the optimal window for acute tryptase sampling between 30 minutes and 2 hours after the initiation of symptoms, whereas baseline tryptase should be measured in a sample collected before the event (preop) or at least 24 hours after all signs and symptoms have resolved. A transient elevation of the acute tryptase level greater than [2 + (1.2 × baseline tryptase level)] supports the involvement and activation of mast cells. Here, we provide the clinical, pathophysiological, and technical rationale for the procedure and interpretation of paired acute and baseline tryptase. Clinical examples, up-to-date knowledge of hereditary α-tryptasemia as a frequent cause of baseline tryptase of 7 μg/L and higher, mastocytosis, other clonal myeloid disorders, cardiovascular or renal failure, and technical improvements resulting in continued lowering of the 95th percentile value are discussed. Clues for improved management of perioperative immediate hypersensitivity and anaphylaxis include (1) sustained dissemination and implementation of updated guidelines; (2) preoperative sample storage for deferred analysis; (3) referral for thorough allergy investigation, screening for mast cell-related disorders, and recommendations for future anesthetic procedures; and (4) sustained collaboration between anesthesiologists, immunologists, and allergists.

Perioperative anaphylaxis: A five-year review in a tertiary paediatric hospital

Making a diagnosis of perioperative anaphylaxis and identifying culprit drugs are diagnostic challenges. The aim of this study is to describe the perioperative presentation of anaphylaxis and results of patients who underwent allergy evaluation. This is a retrospective review of perioperative anaphylaxis of severity Grade 2 and above based on the Australian and New Zealand Anaesthetic Allergy Group criteria from 2015 to 2019 in a tertiary paediatric hospital. Data collected were demographics, clinical features, investigations and management. Of the 35,361 cases of paediatric anaesthesia, there were 15 cases of perioperative anaphylaxis, giving an incidence of four in 10,000. The median age was seven years (interquartile range four-15 years) with a male predominance of 86.7% (13/15). The severity of anaphylaxis was Grade 2 in 33.3% (5/15) and Grade 3 in 66.7% (10/15). The commonest presenting feature was hypotension (13/15, 86.7%) while the earliest symptom was respiratory change (9/15, 60.0%). Dynamic tryptase was raised in 75% (6/8) of the patients with adequate tryptase samples. Eight patients (53.3%) completed allergy testing, of whom five patients (62.5%) had IgE-mediated anaphylaxis with skin test positive to cefazolin (n = 3), atracurium (n = 1) and rocuronium (n = 1). Three patients (25.0%) had non-IgE-mediated reactions with negative skin tests. Although only half the patients completed allergy evaluation, a culprit drug could be identified in 62.5%, with antibiotics being the commonest. This emphasises the need for appropriate evaluation in cases of suspected perioperative anaphylaxis.

Andrographolide inhibits secretagogue-induced pseudo-allergic reaction

Many kinds of drugs induce pseudo-allergic reactions due to activation of mast cells. We investigated the anti-pseudo-allergic effect of andrographolide (Andro). The effects of Andro on pseudo-allergic reactions were investigated in vivo and in vitro. Andro suppressed compound 48/80 (C48/80) induced pseudo-allergic reactions in mice in a dose-dependent manner. Andro also inhibited C48/80-induced local inflammatory reactions in mice. In vitro studies revealed that Andro reduced C48/80-induced mast cells degranulation. Human phospho-kinase array kit and western blotting showed that Andro could inhibit pseudo-allergic responses via the calcium signaling pathway.

Perioperative anaphylaxis in children: Etiology, time sequence, and patterns of clinical reactivity

BACKGROUND

Perioperative anaphylaxis (PA) in children is an uncommon but potentially life-threatening complication associated with anesthesia. Early identification and management of PA is essential to optimize clinical outcomes.

METHODS

We performed a retrospective study of anesthesia records from pediatric patients with PA from centers in the United Kingdom, France, and the United States over a period of 10 years. Time sequence of clinical signs and physiological variables during PA were collected, along with results of allergy testing.

RESULTS

Twenty-nine children with PA were included. Median age was 11 years. Based on the modified Ring and Messmer Grading Scale, severe reactions were seen in 25 (86%) members of this cohort, with 4 (14%) experiencing cardiac arrest. Life-threatening hypotension was the first clinical sign of PA in 59% of cases, followed by tachycardia and bronchospasm. In 16 (55%) cases, the initial signs of PA involved multiple organ systems. When the initial signs of PA were cardiovascular and/or respiratory, more epinephrine doses were administered. Average time from initial sign of PA to treatment with epinephrine was 6 minutes (SD: 6, range: 1-25). The causative allergen was identified in 15 patients.

CONCLUSION

Severe hypotension is the most common presenting sign of PA in children. Initial cardiovascular and/or respiratory signs are associated with the need for increased epinephrine doses. Further studies should optimize the prediction, identification, and early management of PA in children.

Suspected Anaphylactic Reaction to Ketamine in 3 Yucatan Swine (Sus scrofa)

This case series describes the clinical courses of 3 juvenile Yucatan miniature swine (Sus scrofa) that experienced a suspected anaphylactic reaction to ketamine hydrochloride during premedication for protocol-related surgery. All 3 swine rapidly developed diffuse erythema shortly after injection with ketamine-containing drug combinations. Clinical signs ranged from tachycardia and erythema alone to tachycardia and erythema followed by respiratory and cardiac arrest. Ketamine was considered the most likely cause of these reactions because it was the only agent in the premedication sedation combination that was used in all 3 swine. Subsequent intradermal skin testing confirmed this suspicion. With supportive care measures and standard medical interventions for anaphylaxis, all 3 animals recovered well and went on to be successful experimental subjects when an alternative anesthetic regimen that did not contain ketamine was used. To our knowledge, this report is the first description of a suspected adverse ketamine reaction of this type in swine despite the widespread use of the drug in this species. Ketamine anaphylaxis is rare in people, but the few cases described presented with symptoms similar to the clinical signs seen in the pigs in this report. In addition to highlighting a potential adverse drug reaction to ketamine in swine, this case series demonstrates the value of emergency preparedness for even the most routine of procedures.

Diagnosis and management of drug-induced anaphylaxis in children: An EAACI position paper

Drug hypersensitivity reactions (DHR) constitute a major and common public health problem, particularly in children. One of the most severe manifestations of DHR is anaphylaxis, which might be associated with a life-threatening risk. During those past decades, anaphylaxis has received particularly a lot of attention and international consensus guidelines have been recently published. Whilst drug-induced anaphylaxis is more commonly reported in adulthood, less is known about the role of drugs in pediatric anaphylaxis. Betalactam antibiotics and non-steroidal anti-inflammatory drugs are the most commonly involved drugs, probably related to high prescription rates. Diagnosis relies on the recognition of symptoms pattern and is based on complete allergic workup, particularly including skin tests and/or specific IgE. However, the real diagnostic value of those tests to diagnose immediate reactions in children remains not well defined for a significant number of the drugs. Generally, a drug provocation test is discussed to confirm or exclude an immediate-onset drug-induced hypersensitivity. Although avoidance of the incriminated drug (and related drug) is the rule, rapid desensitization is useful in selected subgroups of patients. There is a need for large, multicentric studies, to evaluate the real diagnostic value of the currently available skin tests. Moreover there is also a need to develop new diagnostic tests in the future to improve the management of these children.

Management of the child with allergy to non-antibiotic drugs

Non-steroidal anti-inflammatory drugs, perioperative drugs, radio contrast media and chemotherapeutics drugs are, after the non-antibiotic drugs, the drugs most commonly responsible for allergic reactions in children. Management is different depending on the drug involved.

Reclassifying Anaphylaxis to Neuromuscular Blocking Agents Based on the Presumed Patho-Mechanism: IgE-Mediated, Pharmacological Adverse Reaction or "Innate Hypersensitivity"?

Approximately 60% of perioperative anaphylactic reactions are thought to be immunoglobulin IgE mediated, whereas 40% are thought to be non-IgE mediated hypersensitivity reactions (both considered non-dose-related type B adverse drug reactions). In both cases, symptoms are elicited by mast cell degranulation. Also, pharmacological reactions to drugs (type A, dose-related) may sometimes mimic symptoms triggered by mast cell degranulation. In case of hypotension, bronchospasm, or urticarial rash due to mast cell degranulation, identification of the responsible mechanism is complicated. However, determination of the type of the underlying adverse drug reaction is of paramount interest for the decision of whether the culprit drug may be re-administered. Neuromuscular blocking agents (NMBA) are among the most frequent cause of perioperative anaphylaxis. Recently, it has been shown that NMBA may activate mast cells independently from IgE antibodies via the human Mas-related G-protein-coupled receptor member X2 (MRGPRX2). In light of this new insight into the patho-mechanism of pseudo-allergic adverse drug reactions, in which as drug-receptor interaction results in anaphylaxis like symptoms, we critically reviewed the literature on NMBA-induced perioperative anaphylaxis. We challenge the dogma that NMBA mainly cause IgE-mediated anaphylaxis via an IgE-mediated mechanism, which is based on studies that consider positive skin test to be specific for IgE-mediated hypersensitivity. Finally, we discuss the question whether MRGPRX2 mediated pseudo-allergic reactions should be re-classified as type A adverse reactions.

Low prevalence of latex allergy in children with spinal dysraphism in non-latex-free environment

BACKGROUND

Studies in the past have shown that children with spinal dysraphism have highly prevalent latex allergy. These children have a spectrum of congenital spinal anomalies, caused by defects in neural tube closure, with an incidence of 1 in 1000 births. Proposed risk factors for latex allergy include multiple surgeries since birth, including an insertion of a ventriculoperitoneal shunt, elevated IgE titers, repeat multiple catheterizations, and atopy. In the 1990 s, studies published in the United States and Europe showed a latex allergy prevalence of over 70% in these patients. On the other hand, studies published years later in other countries showed a declining prevalence of no more than 17%.

OBJECTIVE

Our goal was to prospectively assess the prevalence of latex allergy in children with spinal dysraphism in our non-latex free environment center compared with a control group.

STUDY DESIGN

The study group included 58 children with spinal dysraphism attending our center between 2010 and 2013. Findings were compared to 65 children referred for evaluation of allergic diseases. The parents completed questionnaires assessing personal and familial history of allergic diseases. All children were tested for blood latex IgE-specific antibodies (IMMULITE 2000).

RESULTS

The mean age was 120.9 (67.6) months in the study group and 129.5 (68.5) months in the control group (p = 0.27). The corresponding median number of surgical procedures was 2 (range 0-10) and 0 (range 0-4), and mean duration of clean intermittent catheterization was 52 (72.2) months in the study group. Positive IgE antibodies and clinical allergic reactions were low with very similar prevalence in both groups (Figure).

DISCUSSION

Our results show considerable lower latex allergy and sensitization than studies published in the United States and Europe in the past, despite the fact that our center utilizes minimal avoidance measures for latex allergy. Study limitations include the relatively small number of patients in our single-center study. Moreover, our control group could not include normal volunteering healthy children due to institutional review board refusal.

CONCLUSIONS

Children with spinal dysraphism in our center have a low prevalence of latex allergy. Possible explanations include low latex protein content gloves and catheters used worldwide, including our center, lower number of surgeries, or a disease associated propensity for latex sensitization with a geographically variable genetic association. More studies are needed to validate our conclusion that using minimal avoidance measures, without maintaining a strict latex free environment, seems sufficient to prevent clinical latex allergy, at least in the Mediterranean region.

Drug hypersensitivity in children: report from the pediatric task force of the EAACI Drug Allergy Interest Group

When questioned, about 10% of the parents report suspected hypersensitivity to at least one drug in their children. However, only a few of these reactions can be confirmed as allergic after a diagnostic workup. There is still a lack of knowledge on drug hypersensitivity (DH) epidemiology, clinical spectrum, and appropriate diagnostic methods particularly in children. Meanwhile, the tools used for DH management in adults are applied also for children. Whereas this appears generally acceptable, some aspects of DH and management differ with age. Most reactions in children are still attributed to betalactams. Some manifestations, such as nonsteroidal anti-inflammatory drug-associated angioedema and serum sickness-like reactions, are more frequent among young patients as compared to adults. Risk factors such as viral infections are particularly frequent in children, making the diagnosis challenging. The practicability and validity of skin test and other diagnostic procedures need further assessment in children. This study presents an up-to-date review on epidemiology, clinical spectrum, diagnostic tools, and current management of DH in children. A new general algorithm for the study of these reactions in children is proposed. Data are presented focusing on reported differences between pediatric and adult patients, also identifying unmet needs to be addressed in further research.

Effects of anaesthesia techniques and drugs on pulmonary function

The primary task of the lungs is to maintain oxygenation of the blood and eliminate carbon dioxide through the network of capillaries alongside alveoli. This is maintained by utilising ventilatory reserve capacity and by changes in lung mechanics. Induction of anaesthesia impairs pulmonary functions by the loss of consciousness, depression of reflexes, changes in rib cage and haemodynamics. All drugs used during anaesthesia, including inhalational agents, affect pulmonary functions directly by acting on respiratory system or indirectly through their actions on other systems. Volatile anaesthetic agents have more pronounced effects on pulmonary functions compared to intravenous induction agents, leading to hypercarbia and hypoxia. The posture of the patient also leads to major changes in pulmonary functions. Anticholinergics and neuromuscular blocking agents have little effect. Analgesics and sedatives in combination with volatile anaesthetics and induction agents may exacerbate their effects. Since multiple agents are used during anaesthesia, ultimate effect may be different from when used in isolation. Literature search was done using MeSH key words ‘anesthesia’, ‘pulmonary function’, ‘respiratory system’ and ‘anesthesia drugs and lungs’ in combination in PubMed, Science Direct and Google Scholar filtered by review and research articles sorted by relevance.

Perioperative anaphylaxis: diagnosis, evaluation, and management

Perioperative anaphylaxis can occur during or after surgery and can have life-threatening consequences. As anesthesia protocols become more complex and incorporate multiple agents to regulate physiologic processes intraoperatively, perioperative anaphylaxis is becoming increasingly recognized. The allergist should obtain detailed records from the anesthesiologist in order to perform appropriate testing to identify the likely causative agents. Testing should ideally be performed 4 to 6 weeks after the reaction to account for a refractory period after mast cell activation. This article includes 2 cases of perioperative anaphylaxis and reviews the historical elements that must be considered after a reaction has occurred.

Anesthesia and ventilation strategies in children with asthma: part II - intraoperative management

PURPOSE OF REVIEW

As asthma is a frequent disease especially in children, anesthetists are increasingly providing anesthesia for children requiring elective surgery with well controlled asthma but also for those requiring urgent surgery with poorly controlled or undiagnosed asthma. This second part of this two-part review details the medical and ventilatory management throughout the perioperative period in general but also includes the perioperative management of acute bronchospasm and asthma exacerbations in children with asthma.

RECENT FINDINGS

Multiple observational trials assessing perioperative respiratory adverse events in healthy and asthmatic children provide the basis for identifying risk reduction strategies. Mainly, animal experiments and to a small extent clinical data have advanced our understanding of how anesthetic agents effect bronchial smooth muscle tone and blunt reflex bronchoconstriction. Asthma treatment outside anesthesia is well founded on a large body of evidence.Perioperative prevention strategies have increasingly been studied. However, evidence on the perioperative management, including mechanical ventilation strategies of asthmatic children, is still only fair, and further research is required.

SUMMARY

To minimize the considerable risk of perioperative respiratory adverse events in asthmatic children, perioperative management should be based on two main pillars: the preoperative optimization of asthma treatment (please refer to the first part of this two-part review) and - the focus of this second part of this review - the optimization of anesthesia management in order to optimize lung function and minimize bronchial hyperreactivity in the perioperative period.

Drug-induced anaphylactic reactions in Indian population: A systematic review

BACKGROUND

Epidemiological data on drug-induced anaphylactic reactions are limited in India and are largely depending on studies from developed countries.

AIM

The aim was to analyze the published studies of drug-induced anaphylaxis reported from India in relation with causative drugs and other clinical characteristics.

MATERIALS AND METHODS

The electronic databases were searched for Indian publications from 1998 to 2013 describing anaphylactic reactions. The information was collected for demographics, set up in which anaphylaxis occurred, causative drugs, incubation period, clinical features, associated allergic conditions, past reactions, co-morbid conditions, skin testing, IgE assays, therapeutic intervention and mortality. Reactions were analyzed for severity, causality, and preventability. Data were extracted and summarized by absolute numbers, mean (95% confidence interval [CI]), percentages and odds ratio (OR) (95% CI).

RESULTS

From 3839 retrieved references, 52 references describing 54 reactions were included. The mean age was 35.31 (95% CI: 30.52-40.10) years. Total female patients were 61.11%. Majority reactions were developed in perioperative conditions (53.70%), ward (20.37%) and home (11.11%). The major incriminated groups were antimicrobials (18.52%), nonsteroidal antiinflammatory drugs-(NSAIDs) (12.96%) and neuromuscular blockers (12.96%). Common causative drugs were diclofenac (11.11%), atracurium (7.41%) and β-lactams (5.96%). Cardiovascular (98.15%) and respiratory (81.48%) symptoms dominated the presentation. Skin tests and IgE assays were performed in 37.03% and 18.52% cases, respectively. The fatal cases were associated with complications (OR =5.04; 95% CI: 1.41-17.92), cerebral hypoxic damage (OR =6.80; 95% CI: 2.14-21.58) and preventable reactions (OR =14.33; 95% CI: 2.33-87.97).

CONCLUSION

Antimicrobials, NSAIDs, and neuromuscular blockers are common causative groups. The most fatal cases can be prevented by avoiding allergen drugs.

Perioperative anaphylaxis

Perioperative anaphylaxis is a life-threatening condition with an estimated prevalence of 1:3,500 to 1:20,000 procedures and a mortality rate of up to 9 %. Clinical presentation involves signs such as skin rash, urticaria, angioedema, bronchospasm, tachycardia, bradycardia, and hypotension. Prompt recognition and treatment is of utmost importance to the patient's prognosis, since clinical deterioration can develop rapidly. Epinephrine is the main treatment drug, and its use should not be postponed, since delayed administration is associated with increased mortality. Elevated levels of serum tryptase help to confirm the diagnosis. The main agents involved in IgE-mediated perioperative anaphylaxis are neuromuscular blocking agents, latex, antibiotics, hypnotics, opioids, and colloids. Specific investigation should be conducted 4 to 6 weeks after the reaction and relies on skin tests, serum-specific IgE, and challenge procedures. This review aims to discuss the main aspects of perioperative anaphylaxis: risk factors, diagnosis, treatment, culprit agents, specific investigation, and preventive measures.

Anaesthesia Management in Patients with Multiple Chemical Sensitivity Syndrome

Multiple Chemical Sensitivity (MCS) is characterised by the appearance of numerous and sometimes severe symptoms, when subjects are in contact with various chemicals and medicinal substances. Currently there are no useful guidelines for managing clinical issues and, specifically, anaesthesia for patients with MCS. This case report describes anaesthesia management in a patient affected by clinically documented MCS and a latex allergy, a candidate for a laparoscopic cholecystectomy operation.

Recommendations for sepsis management in resource-limited settings

PURPOSE

To provide clinicians practicing in resource-limited settings with a framework to improve the diagnosis and treatment of pediatric and adult patients with sepsis.

METHODS

The medical literature on sepsis management was reviewed. Specific attention was paid to identify clinical evidence on sepsis management from resource-limited settings.

RESULTS

Recommendations are grouped into acute and post-acute interventions. Acute interventions include liberal fluid resuscitation to achieve adequate tissue perfusion, normal heart rate and arterial blood pressure, use of epinephrine or dopamine for inadequate tissue perfusion despite fluid resuscitation, frequent measurement of arterial blood pressure in hemodynamically unstable patients, administration of hydrocortisone or prednisolone to patients requiring catecholamines, oxygen administration to achieve an oxygen saturation >90%, semi-recumbent and/or lateral position, non-invasive ventilation for increased work of breathing or hypoxemia despite oxygen therapy, timely administration of adequate antimicrobials, thorough clinical investigation for infectious source identification, fluid/tissue sampling and microbiological work-up, removal, drainage or debridement of the infectious source. Post-acute interventions include regular re-assessment of antimicrobial therapy, administration of antimicrobials for an adequate but not prolonged duration, avoidance of hypoglycemia, pharmacological or mechanical deep vein thrombosis prophylaxis, resumption of oral food intake after resuscitation and regaining of consciousness, careful use of opioids and sedatives, early mobilization, and active weaning of invasive support. Specific considerations for malaria, puerperal sepsis and HIV/AIDS patients with sepsis are included.

CONCLUSION

Only scarce evidence exists for the management of pediatric and adult sepsis in resource-limited settings. The presented recommendations may help to improve sepsis management in middle- and low-income countries.

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.

Allergy to rocuronium: from clinical suspicion to correct diagnosis

BACKGROUND

Allergy to rocuronium can be life-threatening. Correct diagnosis is a prerequisite because of serious consequences of diagnostic error.

OBJECTIVE

To assess skin testing, quantification of specific IgE (sIgE) and flow-assisted activation of basophils [basophil activation test (BAT)] in the diagnosis of rocuronium allergy.

METHODS

This study comprises 104 curarized patients with a history of profound hypotension and severe bronchospasm immediately after induction of anaesthesia. All patients had skin tests, quantification of sIgE and BAT to rocuronium, together with investigations for all relevant compounds administered during anaesthesia that could have evoked the reaction. Diagnosis of rocuronium allergy was considered definite when the patient demonstrated a positive outcome for at least two of the three aforementioned tests.

RESULTS

The positive predictive value for skin testing, BAT and sIgE was 98% (CI 95%: 92-99%), 97% (CI 95%: 88-100%) and 83% (CI 95%: 74-89%), respectively. The negative predictive value for skin testing, BAT and sIgE was 96% (CI 95%: 86-99%), 75% (CI 95%: 67-75%) and 72% (CI 95%: 58-83%), respectively. Cross-reactivity with vecuronium was documented in 69% of the patients.

CONCLUSION

Skin testing merits the status of primary diagnostic investigation to document rocuronium allergy and cannot be substituted by quantification of sIgE or BAT. SIgE can offer a diagnostic advantage in cases where skin tests yield negative results. However, additional tests (e.g. BAT) are of capital importance in patients with negative skin tests and positive sIgE results to help in interpreting the clinical significance of a positive sIgE result. Optimal assessment of cross-reactivity between rocuronium and vecuronium implies both skin testing and BAT.

Perioperative Anaphylaxis: Epidemiology

The clinical diagnosis of an anesthesia-related immediate hypersensitivity reaction is a difficult task for clinicians. Anaphylaxis may present as cardiovascular collapse or airway obstruction, associated or not with cutaneous manifestations. Drug hypersensitivity reactions that occur during anesthesia are responsible for significant morbidity and mortality and socio-economic costs. Perioperative anaphylaxis is becoming more common, probably because of the more frequent use of anesthesia and the increasing complexity of the drugs used. However, despite increased awareness of anaphylactic reactions to drugs and compounds used in anesthesia, their incidence remains poorly defined. Moreover, current epidemiological data should be carefully evaluated since the various studies published concerned non-homogeneous populations and gave differing definitions of drug hypersensitivity.

Perioperative Allergy: Risk Factors

Perioperative anaphylactic as well as anaphylactoid reactions can be elicited by drugs, diagnostic agents, antiseptics, disinfectants and latex. In some individuals, allergic reactions occur in the absence of any evident risk factor. Previous history of specific safe exposure to a product does not permit to exclude the risk of having a reaction. We have systematically reviewed characteristics in the patient's history or clinical parameters that affect the risk of developing reactions during anesthesia. Evidence shows that patients with previous unexplained reaction during anesthesia are at risk for perioperative allergic reactions. An allergic reaction to an agent is associated with previous reaction to a product that is related with the culprit agent. Multiple surgery procedures, professional exposure to latex and allergy to fruit are associated with an increased frequency of latex allergy. It has been shown that in some instances, allergic perioperative reactions may be more common in atopic patients and in female.

Perioperative Allergy: Clinical Manifestations

Adverse drug reactions or side effects are usually expected, dose dependent, and occur at therapeutic doses. Anaphylactic and anaphylactoid reactions are unexpected and dose independent and can occur at the first exposure to drugs used during anesthesia. Perioperative anaphylaxis is a severe and rapid clinical condition that can be lethal even in previously healthy patients. The initial diagnosis of anaphylaxis is presumptive. A precise identification of the drug responsible for the adverse reaction is more difficult to establish in the case of anaphylactoid reaction because the adverse reaction could result from additive side effects of different drugs injected simultaneously. The timing of the reaction in relation to events, e.g. induction, start of surgery, administration of other drugs, i.v. fluids, is essential for the diagnosis. Generally, reactions are predominant in the induction and recovery phases, and manifested mainly as cutaneous symptoms. Reactions to drugs coincide with the phases when they are administered. Reactions to antibiotics are more frequent in the induction phase, to neuromuscular agents in the initiation and maintenance phases and to non-steroidal anti-inflammatory agents in the recovery phase. The differential diagnosis of any adverse reaction during or following anesthesia should include the possibility of anaphylaxis.

Drug allergy: an updated practice parameter

Adverse drug reactions (ADRs) result in major health problems in the United States in both the inpatient and outpatient setting. ADRs are broadly categorized into predictable (type A and unpredictable (type B) reactions. Predictable reactions are usually dose dependent, are related to the known pharmacologic actions of the drug, and occur in otherwise healthy individuals, They are estimated to comprise approximately 80% of all ADRs. Unpredictable are generally dose independent, are unrelated to the pharmacologic actions of the drug, and occur only in susceptible individuals. Unpredictable reactions are subdivided into drug intolerance, drug idiosyncrasy, drug allergy, and pseudoallergic reactions. Both type A and B reactions may be influenced by genetic predisposition of the patient

Perioperative anaphylaxis

The incidence of immune-mediated anaphylaxis during anesthesia ranges from 1 in 10,000 to 1 in 20,000. Neuromuscular blocking agents are most frequently incriminated, followed by latex and antibiotics, although any drug or substance used may be a culprit. Diagnosis relies on tryptase measurements at the time of the reaction and skin tests, specific immunoglobulin E, or basophil activation assays. Treatment consists of rapid volume expansion and epinephrine administration titrated to symptom severity.

[Mastocytosis. A challenge in anaesthesiology]

Mastocytosis is a general term for a heterogeneous group of rare disorders. Many agents used in anaesthesia can trigger mast cell degranulation with release of histamine, prostaglandin, tryptase and heparin. Therefore, patients with mastocytosis are high-risk patients when undergoing anaesthesia. The management of these patients in anaesthesia will be discussed on the basis of the literature and illustrated with the discussion of three case reports. A premedication with antihistamines and a glucocorticoid is recommended. For induction of general anaesthesia propofol, etomidate, ketamine, a fentanyl-type opioid, cis-atracurium or pancuronium are recommended. Anaesthesia can be maintained either by a total intravenous technique or with a volatile anaesthetic such as sevoflurane.

Human mast cells express androgen receptors but treatment with testosterone exerts no influence on IgE-independent mast cell degranulation elicited by neuromuscular blocking agents

Women predominate in the anaphylactic reactions to neuromuscular blocking agents (NMBA). The expression of oestrogen receptors has been demonstrated in mast cells and oestrogen treatment can enhance mast cell degranulation, but the influence of androgens remains largely unclear. Our immunocytochemical study showed the expression of androgen receptor (AR) in mast cells isolated from human foreskin as well as in two human mast cell lines, HMC-1 and LAD2. The amount of AR was most abundant in human skin mast cells as determined by real-time polymerase chain reaction analysis. Treatment of the HMC-1 mast cells with testosterone or 17beta-oestradiol, alone or in combination with different NMBA, did not affect mast cell degranulation as measured by the release of beta-hexosaminidase. Our study shows for the first time the expression of AR in human skin mast cells. Further studies using primary human mast cell cultures are needed to understand whether and how sex hormones can influence mast cell activation.

General anesthetic allergy testing

Anaphylaxis in the setting of general anesthesia is a rare but potentially lethal event. The investigation of severe reactions is important for confirming the clinical diagnosis and identifying likely causative agents and safe agents that may be used in the future. Many comprehensive reports have described the testing protocol of individual specialized units, whereas there has been no standardization of testing techniques or formal assessment of these tests' diagnostic accuracy. We review the literature with reference to the recently published standards for reporting of diagnostic accuracy (STARD) and make recommendations for future studies of diagnostic accuracy in the field.

Latex allergy in children: modalities and prevention

Allergic or immediate hypersensitivity reactions to latex have been reported in children with increasing frequency in the past. The reported prevalence varies greatly depending upon the population studied and the methods used to detect sensitization. Children's subpopulations at particular risk include: atopics, individuals with spina bifida, children undergoing surgical procedure during the neonatal period and individuals who required frequent surgical instrumentations. Latex allergy is also an important medical issue, particularly for healthcare personnel. Sensitization mainly occurs by wound or mucosal contact with latex devices during surgery or by inhalation of airborne allergens released from powdered latex gloves. Regarding diagnosis, the medical history, skin prick test and search for specific serum IgE are crucial but cost effective. The development of a guide listing latex-containing drugs is essential for the primary prevention of allergic reactions. Immunotherapy or specific premedication seems not effective in preventing the risk of anaphylaxis during the perioperative course. The most effective strategy to decrease the incidence of latex sensitization is complete avoidance. This strategy is efficient in patients and also in health care workers and has been applied since 2002 in our pediatric surgical hospital. One of major problem with the latex-free gloves was that surgeons find them considerably more difficult to work with. But today, manufacturers made considerable effort and free-latex gloves with an equal tactile sensation than the latex-gloves are now available. The extra cost of free latex gloves is well counterbalanced as allergen test, long stay hospital for allergic reaction, and worker's compensation are no longer needed. Since the introduction of this program in our institution, no allergic reaction to latex has been reported in 25000 anesthetized children or with the health care workers.