[Anesthetics responsible for anaphylactic shock. A French multicenter study]

Allergic Reactions to Sugammadex: A Case Series and Review of the Literature

Sugammadex is a novel agent for the reversal of neuromuscular blockade; it acts by encapsulating -rocuronium or vecuronium, eliminating the active compound from the circulation, thereby providing rapid and complete recovery even with profound or complete neuromuscular blockade. Clinical advantages, including reduced incidence of residual blockade, decreased nausea and vomiting, decreased dry mouth, less change in heart rate, and reduced pulmonary complications, have been demonstrated when comparing sugammadex to conventional agents, such as neostigmine, that inhibit acetylcholinesterase. Although generally safe and effective, anaphylactoid and allergic reactions have been reported with sugammadex. The potential for hypersensitivity reactions with sugammadex and previous reports from the literature, as well as diagnostic and treatment strategies, are presented in 3 pediatric cases.

What do we know about perioperative hypersensitivity reactions and what can we do to improve perioperative safety?

Hypersensitivity reactions are an important aspect of perioperative care and are a crucial interdisciplinary issue in anaesthesiological practice, as well as allergological and laboratory diagnostics. This phenomenon was observed as early as the 1980s and 1990s in Western European countries, and knowledge on this subject has grown significantly over time. Although hypersensitivity reactions are not frequent events (the incidence of perioperative hypersensitivity reactions ranges from 1:386 to 1:13 000 procedures, with higher frequency - 1 per 6500 general anaesthesias with neuromuscular blocking agents administrations), their courses are unfortunately serious and life-threatening. It should also be noted that there is no information regarding the occurrence of perioperative hypersensitivity reactions in many countries. Hence, global assessment of the problem is underestimated. The primary source of actual knowledge comes from epidemiological studies, which indicate an increasing frequency of hypersensitivity reaction occurrence and changes in aetiological factors. The first report from France (1984 to 1989) described two main causes - neuromuscular blocking agents and hypnotic agents. The following years confirmed an increase in perioperative hypersensitivity reactions associated with latex and antibiotics. The most recent data from the National Audit Project 6 indicated increased participation of antibiotics, chlorhexidine, and contrast agents. The results of epidemiological analyses are the basis of medical management guidelines and practice modification. Thanks to the activity of many organisations monitoring the intensity and nature of perioperative hypersensitivity reactions, guidelines for diagnostics and management have been developed. This article presents the results of numerous studies, including the first and the most recent, from various geographical regions. The clinical significance, pathogenesis mechanisms are also discussed. This publication also presents important directions for further scientific and epidemiological research on perioperative hypersensitivity reactions.Key messagesThe incidence of perioperative hypersensitivity reactions ranges from 1:386 to 1:13 000 procedures, with higher frequency - 1 per 6500 general anaesthesias with neuromuscular blocking agents administrations.Reactions may occur during the first episode of anaesthesia, most frequently in the induction of general anaesthesia, and much less frequently during postoperative follow-up.The first reports of perioperative hypersensitivity reaction come from the 1990s, and knowledge on this subject has grown significantly over time.In many countries, multidisciplinary teams and organisations have been established to identify, monitor the occurrence of this phenomenon, and have set the directions of medical activities and have changed the rules and recommendations.There is no information about the occurrence of perioperative hypersensitivity reactions in many countries, and global assessment of the problem is underestimated. Additionally, there is a great need to develop a system to monitor their occurrence in other countries.The long-term epidemiologic studies have demonstrated variability in pharmacologic triggers. However, the main pharmacological substances (antibiotics, muscle relaxants, disinfectans, contrast agents) are related to aspects of patient safety during anaesthesia.

Evaluation of Therapies for Peripheral and Neuraxial Opioid-induced Pruritus based on Molecular and Cellular Discoveries

Opioids are a mainstay of treatment for pain worldwide. Pruritus, a common side effect of opioids, is a patient dissatisfier that limits their use in many clinical settings. Both parenteral and neuraxial administration of opioids frequently evoke pruritus. The ability of opioids to suppress pain while causing itch continues to perplex clinicians and researchers alike. Several mechanisms have been proposed to explain how opioids can give rise to pruritus, but specific knowledge gaps perpetuate debate. This review summarizes the clinical burden of opioid-induced pruritus and emphasizes recent discoveries of peripheral and central mechanisms for opioid-induced pruritus, particularly with respect to scientific and conceptual advances in spinal cord circuitry and mast cell biology. The mechanisms and effectiveness of existing medications used for clinical management of pruritus will be evaluated, and we will highlight the emerging preclinical utility of selective κ-opioid receptor agonists, such as nalfurafine, for the management of opioid-induced pruritus.

Pilot study in France about the infiltration of local anaesthetics associated to oral surgery procedures performed under general anaesthesia

Introduction: Opinions differ regarding the combined use of local anaesthesia (LA) and general anaesthesia (GA) in oral surgery procedures. The aim of this study was to evaluate practices in France concerning intraoperative LA for oral surgery performed under GA. Practitioners and method: We conducted a prospective survey of 250 oral surgery practitioners (CNIL-2045135v0 e) and carried out a literature review with the MEDLINE search engine (PubMed) covering the period from January 2000 to September 2017. Results: Among the 77 practitioners who participated, 88.3% were dental practitioners, the majority of whom were in the 25–34-yr age group. More than half (59%) infiltrated the surgical site; 46% pre-operatively, 24% intraoperatively and 11% post-operatively. Discussion: LA under GA appears to have advantages for post-operative pain management, dissection of the first mucosal plane and bleeding management pre- and post-operatively. The contraindications remain the same as for patients in a vigilant state. In children, it should be used in moderation to limit the risk of self-inflicted lip or mouth trauma during recovery. Conclusion: The indications of LA under GA are operator-dependent and the analysis of the literature did not allow us to determine the interest or not of LA administered intraoperatively during oral surgery performed under GA.

An Unexpected Cause of an Acute Hypersensitivity Reaction during Recovery from Anaesthesia

Acute hypersensitivity reactions to chlorhexidine in the operating room are probably more likely to occur during the early phases of anaesthesia because chlorhexidine is often used for cleaning the surgical field or during placement of indwelling catheters. We report a case of an acute hypersensitivity reaction that occurred in the post anaesthetic care unit. Subsequent skin testing suggested sensitivity to chlorhexidine, which had been applied over the vaginal mucosa at the end of surgery. Relevant issues in the investigation of acute hypersensitivity reactions in the post anaesthetic period are discussed.

Perioperative anaphylaxis: what should be known?

Perioperative anaphylaxis is a unique condition as a result of the additive cardiovascular effects of anesthetics on the cardiovascular disturbances of anaphylaxis. It occurs mainly in adulthood, primarily follows anesthetic induction, and for the most part, is an IgE-mediated pathomechanism. Neuromuscular blocking agents (NMBAs) and antibiotics are the main culprit drugs, while latex is now infrequently involved. The Ring and Messmer scale is a useful tool for demonstrating the clinical severity of perioperative immediate hypersensitivity and guiding its management. Grades III and IV are life-threatening and are referred to as anaphylaxis. Three different clinical patterns of grade III may be observed, where cardiovascular collapse is the cardinal sign. Grade IV presents as cardiac arrest. The initial diagnosis is presumptive, whereas the etiological assessment is linked to the clinical presentation, tryptase levels, and skin test results. Since anaphylaxis presents with significant hypovolemia and vasoplegia, aggressive fluid therapy and epinephrine are the cornerstones of management. Whenever possible, anesthetic discontinuation is also recommended. Scientific evidence in favor of preemptive therapeutic strategies to prevent anaphylaxis in the operative setting is lacking.

Successful resuscitation in a case of sudden cardiac arrest in an epileptic patient posted for spinal surgery

A 17-year-old girl was posted for spinal surgery for traumatic spinal injury. The patient was a well-controlled epileptic with history of seizure since 8 years of her age. She was induced with thiopentone sodium and muscle relaxant atracurium was administered. Minutes after that, she had an episode of ventricular tachycardia, this converted to ventricular fibrillation despite of institution of cardiopulmonary resuscitation (CPR). CPR was continued for a prolonged period of 45 minutes and after 45 minutes, QRS complexes appeared and later sinus rhythm restored. Next 24 hours, she was kept on mechanical ventilation. Within 24 hours, Glasgow Coma Scale (GCS) improved and patient was conscious and extubated. We suggest that the neuromuscular blocking drug contributed to an anaphylactic reaction which might be the cause of cardiac arrest and highlight the importance of prolonged resuscitation and successful outcome in this scenario.

[Anaphylactic and anaphylactoid reactions occurring during anaesthesia in France. Seventh epidemiologic survey (January 2001-December 2002)]

OBJECTIVES

Hypersensitivity reactions IgE-mediated (anaphylaxis) or non-IgE-mediated (anaphylactoid) reactions occurring during anaesthesia remain a major cause of concern for anaesthesiologists, since these reactions remain usually unpredictable, may be potentially life-threatening even when appropriately treated. The authors report the results of the last 2-year survey (2001, 2002) of such reactions conducted in France by the GERAP (groupe d'etude des reactions anaphylactoides peranesthesiques), and compare these results with their previous published surveys.

METHODS

Between January 1, 2001 to December 31, 2002, 712 patients who experienced immune-mediated (anaphylaxis) or non-immune-mediated (anaphylactoid) reactions were referred to one of the 40 allergo-anaesthesia centres members of the GERAP. Anaphylaxis was diagnosed on the basis of clinical history, tryptase measurements during the adverse reaction, and skin tests and/or specific IgE assay.

RESULTS

Anaphylactic and anaphylactoid reactions were diagnosed in 491 cases (69%) and 221 cases (31%), respectively. The most common causes of anaphylaxis were neuromuscular blocking agents (NMBA) (n=271, 55%), latex (n=112, 22.3%), and antibiotics (n=74, 14.7%). Succinylcholine (n=102, 37.6%) and rocuronium (n=71, 26.2%) were the most frequently incriminated NMBAs. Cross-reactivity between NMBAs was observed in 63.4 % of cases of anaphylaxis to a NMBA. No difference was observed between anaphylactoid and anaphylactic reactions when the incidences of atopy, food, or drug intolerance were compared. However atopy, asthma and food allergy were significantly more frequent in case of latex allergy, when compared with NMBA allergy. Clinical manifestations were more severe in anaphylaxis. The positive predictive value of tryptase measurement for the diagnosis of anaphylaxis was 95.3%, the negative predictive value 49%. The diagnostic value of specific neuromuscular blocking agent IgE assays was confirmed.

CONCLUSION

Our results further corroborate the need for systematic screening in case of immediate hypersensitivity reaction during anaesthesia and for the constitution of allergo-anaesthesia centres to provide expert advice to anaesthesiologists and allergologists.

Opioid-induced mast cell activation and vascular responses is not mediated by mu-opioid receptors: an in vivo microdialysis study in human skin

Activation of mast cells and the systemic release of histamine is a common side effect of opioids. Nevertheless, fentanyl and its derivatives show only a slight activation of mast cells with a subsequent liberation of histamine and tryptase. In this study, we used intradermal microdialysis to assess whether this stimulatory effect of opioids on mast cells depends on the activation of opioid receptors. This new approach allowed us to measure the dose-dependent release of histamine and tryptase from mast cells and the subsequent vascular and sensory effect without systemic side effects in volunteers. The opiate codeine and the synthetic opioids meperidine, fentanyl, alfentanil, sufentanil, remifentanil, buprenorphine, and the opioid antagonist naloxone were tested. Only codeine and meperidine induced mast cell activation with the release of tryptase and histamine, leading to protein extravasation, flare reactions, and itch sensations. Because naloxone did not attenuate these effects, it is unlikely that mu-opioid receptors are involved in the activation of mast cells.

IMPLICATIONS

Opioid effects on mast cells were assessed using intradermal microdialysis. Mast cell activation was seen with codeine and meperidine; no other opioid induced degranulation. Therefore, histamine release seen at large concentrations of potent micro agonists is caused by an unspecific effect rather than an activation of opioid receptors.

Modification of mediators of immune reaction after general anaesthesia

The adverse reactions that may occur during a surgical intervention are of concern to anesthesiologists and allergists due to the civil responsibility they entail and the increased demand for healthcare in allergology units. The aim of the present study was to determine the prevalence of adverse reactions in our setting (Island of Lanzarote) and modifications to immune response mediators using three types of representative myorelaxants (succinylcholine, cisatracurium and vecuronium) in order to predict and prevent adverse reactions.

MATERIAL AND METHODS

We performed a prospective, cross sectional, observational study in a population of 201 patients scheduled to undergo surgery in the Surgery Department of the Lanzarote General Hospital from October 1998. Three groups were retrospectively selected: vecuronium (73 patients), cisatracurium (80 patients), and succinylcholine (48 patients). Blood was extracted from all patients before and after the intervention and the following in vitro variables were evaluated: histaminemia, eosinophil cationic protein, tryptase, IgE to latex, CD4/CD8 fractions, total lymphocytes, total IgE, C3 and C4, and also the histaminuria.

CONCLUSIONS

The mean age of the patients was 41 years with a predominance of women. Sixty percent had not previously undergone surgery. The mean operating time was 2 hours. Digestive surgery accounted for the greatest number of interventions (38.8 %) and most of the patients had no personal history of atopy (91.5 %). The greatest number of perioperative reactions was produced by cisatracurium (38.8 %), followed by succinylcholine (27.4 %) and vecuronium (20 %). The reactions observed were immediate type 1 and 2 reactions. All reactions were reversible without sequelae. Histaminuria levels were significantly decreased in the cisatracurium group. Histaminemia and eosinophil cationic protein showed no significant changes in any of the three groups. Tryptase concentrations in blood did not increase in the postoperative period in any of the three groups. On the contrary, concentrations were significantly lower than basal values. In the vecuronium and succinylcholine groups, CD4/CD8 fractions decreased in the postoperative period. Total lymphocytes decreased in all three groups. Total IgE tended to decrease in the cisatracurium and succinylcholine groups. IgE to latex was negative in the three groups. Specific IgE to succinylcholine was unmodified. C3 complement fraction was unmodified in all three groups and C4 fraction was reduced in the vecuronium group. In our setting and in our patients, the three myorelaxants produced immunosuppression of immune response mediators. The present study confirms that tests for allergy to myorelaxants are not indicated in the preoperative period.

Screening for mast cell tryptase and serum IgE antibodies in 18 patients with anaphylactic shock during general anaesthesia

BACKGROUND

In the perioperative setting multiple agents can cause anaphylaxis. Often the reactions are dramatic, and due to their lifethreatening potential it is crucial that the responsible agent is identified in order to avoid future adverse reactions. The aim of the present study was to measure the concentration of serum mast cell tryptase (MCT), to investigate the prevalence of serum IgE antibodies against ammonium groups, choline, morphine, suxamethonium, thiopentone and latex and to perform skin prick tests (SPTs) in 18 patients experiencing an anaphylactic reaction during induction of general anaesthesia.

METHODS

Serum samples from 18 patients with an anaphylactic reaction during general anaesthesia were analyzed for MCT and specific IgE against ammonium groups, choline, morphine, suxamethonium, thiopentone and latex. Skin prick tests were performed in 11 out of 18 patients.

RESULTS

Ten patients had elevated MCT levels and specific IgE against ammonium ion, morphine and (with the exception of patient nos 3, 9 and 10) suxamethonium. Seven of these patients had positive SPTs to suxamethonium. One of the patients tested positive to latex in addition to suxamethonium. Two patients showed elevated MCT, while specific IgE against the drugs tested was not detected. Three patients tested positive to ammonium ion, morphine and suxamethonium, but negative to MCT. Three patients tested negative to both MCT and specific IgE.

CONCLUSIONS

Fifteen out of 18 sera tested positive for MCT and/or specific IgE against neuromuscular blocking drugs (NMBDs). Ten of the 18 patients experienced an IgE-mediated anaphylactic reaction to NMBDs during anaesthesia, verified by detection of specific IgE and elevated levels of MCT.

Preventing and managing drug-induced anaphylaxis

Drug-induced anaphylaxis and anaphylactoid reactions have increased in frequency with more widespread use of pharmaceutical agents. Anaphylaxis is a systemic, severe immediate hypersensitivity reaction caused by immunoglobulin (Ig) E-mediated immunological release of mediators of mast cells and basophils. An anaphylactoid reaction is an event similar to anaphylaxis but is not mediated by IgE. The incidence of anaphylactic or anaphylactoid reactions differs amongst classes of medications. Antibacterials are the most usual offenders, and penicillins are the most studied. Other compounds commonly causing reactions include non-steroidal anti-inflammatory drugs, anaesthetics, muscle relaxants, latex and radiocontrast media. Prevention, if possible, is the purpose of detailed patient history taking and physical examination. Simple strategies can be employed to decrease the risk of anaphylaxis. These include consideration of the route of drug administration, identification of patients with known causes of anaphylaxis, and the knowledge that certain medications cross react and are contraindicated in those with known history of anaphylaxis. Tests are available, and include IgE-specific skin tests and radioallergosorbent tests. Penicillins are the only compounds whose antigenic determinants are well documented, it is therefore difficult to determine the negative predictive value of other compounds tested. Oral challenge remains an alternative, though entails risk. Desensitisation procedures, as well as gradual dose escalation protocols, are available and can be implemented based on patient history and diagnostic testing. The management of anaphylaxis is based on control of the airway, breathing and circulation. Treatment consists of epinephrine (adrenaline) and supportive measures. Rapid diagnosis and intervention are important in these life-threatening reactions. After stabilisation, all individuals with a documented history of anaphylaxis require a Medic-Alert bracelet or necklace, and an identification card for their wallet or purse.

Anaphylactoid reactions after cisatracurium administration in six patients

IMPLICATIONS

We report six cases of anaphylactoid reaction after the administration of the muscle relaxant cisatracurium. They include two first-time documented anaphylactoid reactions after a precurarising dose. These incidents challenge existing views of a substantially reduced anaphylactoid potential of cisatracurium relative to other muscle relaxants.

Anaphylactic reactions to isosulfan blue dye during sentinel lymph node biopsy for breast cancer

BACKGROUND

Sentinel lymph node biopsy (SLNB) is an alternative to axillary dissection for many breast cancer patients. Cases of anaphylactic reaction to the isosulfan blue dye used during SLNB have recently been reported. No study on the incidence of serious anaphylactic reactions during SLNB for breast cancer has been reported.

METHODS

We reviewed 639 consecutive SLNBs for breast cancer performed at our institution. Sentinel lymph node biopsy was performed using both isosulfan blue dye and technetium-99m sulfur colloid. Cases of anaphylaxis were reviewed in detail.

RESULTS

Overall, 1.1% of patients had severe anaphylactic reactions to isosulfan blue requiring vigorous resuscitation. No deaths or permanent disability occurred. In patients with anaphylaxis, hospital stay was prolonged by a mean of 1.6 days. In 1 patient, the anaphylactic reaction required termination of the operation.

CONCLUSIONS

Prompt recognition and aggressive treatment of anaphylactic reactions to isosulfan blue are critical to prevent an adverse outcome. Lymphatic mapping with blue dye should be performed in a setting where personnel are trained to recognize and treat anaphylaxis.

Rocuronium: high risk for anaphylaxis?

Patients suspected of anaphylaxis during anaesthesia have been referred to the senior author's clinic since 1974 for investigation. Since release of rocuronium on to the worldwide market, concern has been expressed about its propensity to cause anaphylaxis. We identified 24 patients who met clinical and laboratory (intradermal, mast cell tryptase and morphine radioimmunoassay) criteria for anaphylaxis to rocuronium. The incidence of rocuronium allergy in New South Wales, Australia has risen in parallel with sales, while there has been an associated fall in reactions to other neuromuscular blocking drugs. Data from intradermal testing suggested that rocuronium is intermediate in its propensity to cause allergy in known relaxant reactors compared with low-risk agents (e.g. pancuronium, vecuronium) and higher-risk agents (e.g. alcuronium, succinylcholine).

Cost identification analysis for succinylcholine

The cost of a dose of succinylcholine from society's perspective equals the acquisition cost of the drug plus the cost of its adverse outcomes. We hypothesized that although the acquisition cost of succinylcholine is minimal, the true cost would be much larger. We reviewed the medical literature to identify the total cost of a dose of succinylcholine when administered for nonemergency purposes according to manufacturers' guidelines (i.e., to adults only). We found that 88% of the cost per dose of succinylcholine was for the chance of dying or sustaining permanent brain injury from anaphylactic or anaphylactoid reactions to succinylcholine. Consequently, the estimated cost per dose of succinylcholine was sensitive to the incidence of anaphylactic or anaphylactoid reactions to succinylcholine, the risk of severe injury from anaphylactic or anaphylactoid reactions, and the financial value of unforeseen instant death or permanent brain injury. The range for the cost per dose of succinylcholine was thus large, $9 to $93. Our best estimate of the cost per dose was $37. We conclude that the true cost per dose of succinylcholine from society's perspective is more than 20 times the acquisition cost. However, a precise costing requires better knowledge of the incidence and consequences of anaphylactic or anaphylactoid reactions to succinylcholine.

IMPLICATIONS

The true cost of succinylcholine is more than 20 times the acquisition cost of the drug. The estimated cost is very sensitive to the risk and cost of patients dying or sustaining brain injury from anaphylactic or anaphylactoid reactions to succinylcholine.

Anaphylaxis caused by neostigmine

A patient developed anaphylaxis during anaesthesia, towards the end of surgery, 30 s after intravenous administration of neostigmine. Anaphylaxis to neostigmine was confirmed by demonstrating an elevated mast cell tryptase and a strongly/positive skin prick test, showing the presence of drug-specific IgE (skin prick tests to neostigmine were negative in normal subjects). This is a rare cause of anaphylaxis during anaesthesia.

Neuromuscular blocking drugs in pediatric patients

The most useful qualities of a NMBD for pediatric anesthesia are: rapid, reliable onset of laryngeal muscle block after IV or IM administration, duration of < or =20 min, and lack of side effects. Until recently, no nondepolarizer met all these criteria. However, 2 mg/kg rapacuronium produces rapid laryngeal block that can be easily reversed to restore neuromuscular function within 20 min in most pediatric patients.

Succinylcholine: adverse effects and alternatives in emergency medicine

Succinylcholine has long been the favored neuromuscular blocking agent for emergent airway management because of its rapid onset, dependable effect, and short duration. However, it has a plethora of undesirable side effects, ranging from the inconsequential to the catastrophic. When patients requiring tracheal intubation present with potential contraindications to succinylcholine use, the emergency physician will need to substitute a rapid-onset nondepolarizing neuromuscular blocking agent, such as rocuronium or mivacurium. An understanding of the pharmacology of these agents is essential.

Latex allergy in children: diagnosis and management

Latex allergy is an increasingly common condition, in both children and health care workers who provide care for them. Subpopulations at particular risk include children with spina bifida, children undergoing multiple surgical procedures, and health care workers in the operating theatre. Chemical additives in latex gloves can cause an irritant or allergic contact dermatitis. Latex proteins are responsible for most of the immediate IgE-mediated hypersensitivity allergic reactions. Symptoms range from rhinitis, conjunctivitis and urticaria to anaphylaxis and death. A latex-directed history is the primary method of identifying latex sensitivity, although both skin and serum testing is available and increasingly accurate. (Latex avoidance should be used in all individuals with a positive skin or blood test or a positive history). The most important preventive measure for patients with or at risk for latex allergy is minimizing direct patient exposure to latex products, most notably latex gloves. Recent operating room studies indicate simple preventive measures can dramatically reduce intraoperative reactions. Preoperative prophylaxis with antihistamines and steroids have not been shown to be necessary or effective. Treatment of an allergic reaction begins with immediate removal of any identified source of latex in direct patient contact. Treatment is similar to anaphylaxis from other causes, and may require the use of epinephrine. Everyone caring for the patient at risk for latex allergy must be involved in making their medical environment safe.

The effects of rapacuronium on histamine release and hemodynamics in adult patients undergoing general anesthesia

Neuromuscular blocking drugs may have variable effects on heart rate (HR) and blood pressure. Rapacuronium is a rapid-acting, steroidal-derived neuromuscular blocking drug whose hemodynamic effects have not been characterized. We studied the effects of 1, 2, and 3 mg/kg rapacuronium on histamine release, HR, and blood pressure in 47 ASA physical status II or III adult patients after the induction of anesthesia with etomidate/fentanyl/N2O. Plasma histamine concentrations were measured before induction and immediately before and 1, 3, and 5 min after the rapid administration of rapacuronium. Mean arterial pressure (MAP) decreased after rapacuronium administration, but there were no significant differences among the groups for changes in HR or MAP, and there was no correlation between changes in MAP or HR and increases in histamine levels. There were no changes in HR or MAP among five patients who had significant (> or = 1 ng/mL) increases in histamine from baselin. Seven patients had bronchospasm without increases in plasma histamine levels. Rapacuronium 2-3 mg/kg increased plasma histamine levels. However, clinically significant histamine-related sequelae did not occur in this population with 1- to 3-mg/kg doses of rapacuronium, and cardiovascular changes were not directly correlated with histamine release. Rapacuronium administration can produce hypotension via mechanisms that do not seem to be related to histamine release.

IMPLICATIONS

Rapacuronium, a new steroidal-derived muscle relaxant, may release histamine and produce slight changes in blood pressure and heart rate after administration.

[Epidemiology of anesthetic anaphylactoid reactions. Fourth multicenter survey (July 1994-December 1996)]

Since 1984 an epidemiological survey of anaphylactoid reactions occurring during anaesthesia has been obtained in France with regular repeated inquiries by the Perioperative Anaphylactoid Reactions Study Group (Gerap). The members of this group collected during the study period cases of patients having suffered from an anaphylactoid reaction and subsequently tested in their allergoanaesthetic outpatient clinic. The three previous surveys published in the Annales françaises d'anesthésie et de réanimation in 1990, 1993 (in English) and 1996 included 1,240, 1,585 and 1,730 patients respectively. The current survey concerned 1,648 patients, tested by the GERAP (38 diagnostic centres) from July 1994 to December 1996. The diagnostic tests for IgE anaphylaxis were cutaneous tests (prick tests and intradermal tests), which minimal dilutions for specific positive skin test were previously determined by comparison with control subjects. The cutaneous tests were performed by all the centres. These tests were associated, in 29 centres, with the detection of specific IgEs against quaternary ammonium compound and inhibition test, and detection of IgEs against propofol, thiopental and latex. Moreover, leukocyte histamine release test was performed in seven centres. The mechanism of the reaction was: anaphylaxis in 692 patients (characteristic clinical symptoms and positive allergological tests), anaphylactoid reactions in 611 patients (characteristic clinical symptoms and negative allergological tests), and other causes in 345 patients (unusual clinical symptoms and negative allergological tests). An immune mechanism was found in 53% of the reactions, with characteristic clinical symptoms occurring during anaesthesia. The 692 cases of anaphylaxis were due to 734 substances (double anaphylaxis in 42 patients): muscle relaxants (61.6%), latex (16.6%), antibiotics (8.3%), hypnotics (5.1%), colloids (3.1%), opioids (2.7%) and others (2.6%) among which aprotinin (four cases) ethylene oxide (five cases) local anaesthetics (two cases). The muscle relaxants implicated in anaphylactic reactions included: vecuronium (n = 130), atracurium (n = 107), suxamethonium (n = 106), pancuronium (n = 41), rocuronium (n = 41), mivacurium (n = 18), and gallamine (n = 9). These results reflected French anaesthetic practice, except for suxamethonium (5% of the French market share of curares). In 70% of the patients who were allergic to one muscle relaxant, cross-sensitivity was found with the other relaxants. The comparison with the three previous surveys confirms that the mechanism of about half of the anaphylatoid reactions occurring during anaesthesia is of immune origin, due to specific IgE antibodies. Muscle relaxants remain the most common cause of anaphylaxis, followed by latex whose incidence seems to decrease, whereas the incidence of anaphylaxis to antibiotics increases. Incidence of reactions to suxamethonium decreased, corresponding however to one quarter of all muscle relaxant anaphylaxis, similar with vecuronium and atracurium. For this survey, more clinical information was obtained in 583 patients, allowing the following conclusions: reactions were always more severe in case of anaphylaxis than nonspecific histamine release; reactions occurred more frequently in females (F/M = 2.5); 17% of patients allergic to a muscle relaxant were never anaesthetized beforehand; a history of reactions during previous anaesthetics was a risk factor for a reaction during subsequent anaesthetics; neither drug allergy nor atopy (except for latex allergy) were a predisposing factor for reactions with anaesthetic agents. Considering that in 1996, 8 million anaesthetics were administered in France, of which 2.5 million included the use of muscle relaxants, the overall incidence for anaphylactic reactions, all agents included, was evaluated as 1 in 13,000 anaesthetics, while the incidence of anaphylaxis to muscle relaxants was 1 in 6,500 anaesthetics.

[Rapid sequence anesthetic induction via prehospital tracheal intubation]

The choice of sedation for emergency intubation remains controversial. This lack of consensus has led to various sedation protocols used in French prehospital care setting. A review of data from the literature suggests that the association etomidate-suxamethonium is probable the best choice for rapid sequence intubations in the prehospital setting. Its benefits include protection against myocardial and cerebral ischaemia, decreased risk of pulmonary aspiration, and a stable haemodynamic profile. Randomized studies are needed to substantiate the advantages of the association etomidate-suxamethonium for rapid sequences intubation in the prehospital setting.

[Substances responsible for peranesthetic anaphylactic shock. A third French multicenter study (1992-94)]

Since 1989, the epidemiological survey of anaphylactoid reactions occurring during anaesthesia is obtained in France with repeated inquiries by the Perioperative Anaphylactic Reactions Study Group. The members of this group collect during the study period the cases of patients having suffered from an anaphylactoid reaction and tested in their allergo-anaesthetic outpatient clinic, their characteristics (age, gender), the results of the allergological tests (mechanism, agents responsible for the reactions). The two previous surveys published in the Annales françaises d'anesthesie et de réanimation in 1990 and 1993 included 1,240 and 1,585 patients respectively. The current survey concerned 1,750 patients tested in 27 diagnostic centres, from January 1992 to June 1994. The reactions occurred at all ages, predominantly between 10 and 50 years, the sex-ratio (F/M) was 2.4. Allergological tests carried out to diagnose an immune mechanism for the shock were cutaneous tests in all centres (prick-tests in 21 centres, intradermal tests in 27 centres) using the same dilutions for the tested agents and the same threshold for positivity. Specific IgE antibodies against muscle relaxants, thiopentone and propofol, were measured by radio immunoassays in 20 centres. The leucocyte histamine release test was used in 10 centres. The immune origin of the shock--IgE dependent anaphylaxis--was diagnosed in 1,000 patients (57.8%) and due to 1,030 agents muscle relaxants (59.2%), latex (19%), hypnotics (5.9%), benzodiazepines (2.1%), opioids (3.5%), plasma substitutes (5%), antibiotics (3.1%) and other drugs given during anaesthesia such as aprotinine and protamine (2.2%). Suxamethonium was responsible for 39.3% of muscle relaxant anaphylaxis, vecuronium for 36%, atracurium for 14.5%, pancuronium for 4.8%, gallamine for 3.1% and alcuronium for 2.3%. The latter has been withdrawn from the French market in 1993. These differences in the incidence of reactions are correlated with the clinical use of muscle relaxants in France for vecuronium and atracurium, however not for suxamethonium, responsible for 39% of the reactions but representing only 5% of the muscle relaxants sold in France. The comparison with the two previous surveys confirms that the mechanism of more than half of the anaphylactoid reactions occurring during anaesthesia is of immune origin, due to specific IgE antibodies. It is therefore essential to systematically carry out an allergologic assessment several weeks after the reaction, in order to discard for the subsequent anaesthetics the agent(s) responsible for anaphylaxis. If the muscle relaxants remain the first drugs involved in shock occurring at induction, there is a significant increase in latex shock, as demonstrated by the three epidemiological surveys (0.5%, 12.5% and now 19%). The incidence of other anaesthetic agents, antibiotics and plasma substitutes remains unchanged.

Anaphylactic shock following intravenous administration of lignocaine

A 26-year-old female, presenting for dental surgery, developed anaphylactic shock immediately after intravenous administration of lignocaine without preservative added to the propofol to alleviate pain during intravenous injection. We describe the clinical circumstances, the management and the investigations carried out to detect the cause.

Muscle relaxants and histamine release

Many anaesthetic drugs and adjuvants can cause the release of histamine by chemical (anaphylactoid) or immunologic (anaphylactic) mechanisms. While both types of reactions can be clinically indistinguishable, they are mechanistically different. In anaphylactoid reactions, only preformed mediators are released, of which histamine may be the most clinically important. In true immunologic reactions, mast cell degranulation occurs, and many vasoactive substances (including histamine) are released. Clinical signs and symptoms of both classes of reactions include hypotension (most common), tachycardia, bronchospasm, or cutaneous manifestations. Anaphylactoid reactions may occur commonly under anaesthesia in response to many drugs, including induction agents, some opiates, plasma expanders, and curariform relaxants. Anaphylactic reactions are far less common than anaphylactoid reactions, but they nevertheless represent more than half of the life-threatening reactions that occur in anaesthetic practice. Muscle relaxants are the most frequently implicated class of drugs; suxamethonium is the most common agent implicated in anaphylactic reactions during anaesthesia, but even drugs without apparent chemical histamine release (i.e., vecuronium) are frequently implicated in anaphylactic reactions.

Adverse effects of depolarising neuromuscular blocking agents. Incidence, prevention and management

Muscle relaxants block neuromuscular transmission, acting at nicotinic acetylcholine receptors of the neuromuscular junction. Suxamethonium (succinylcholine) is a depolarising agent, whereas all other relaxants in clinical use are nondepolarising. The desired neuromuscular block results from the structural similarity of muscle relaxants to acetylcholine, enabling the interaction with receptors at the neuromuscular junction. Adverse effects of suxamethonium are generally related to its agonist mode of action. Autonomic cardiovascular effects may result. Other adverse effects include anaphylactic or anaphylactoid reactions, and histamine release. Various disease states may present specific considerations in the use of muscle relaxants. Although many complications of muscle relaxants (such as prolonged block or resistance) are easily treated, others may require immediate intervention and vigorous therapy. Careful selection of appropriate relaxants for particular patients will usually prevent the occurrence of complications.

[Anaphylactoid reactions to colloid plasma substitutes: incidence, risk factors, mechanisms. A French multicenter prospective study]

Changes in transfusion behaviour induce a widespread use of colloid plasma substitutes, the range of which has recently been enlarged by the marketing of starch derivatives. The product chosen depends, at least in part, on its adverse effects, anaphylactoid reactions being a part of these. This study aimed to discover the frequency and severity of these reactions according to the type of substitute available in France, to look for possible risk factors, and determine the mechanisms involved. A prospective inquiry was carried out in 49 public and private hospitals spread throughout France. It lasted for 15 months, between June 1991 and October 1992. A data sheet was filled in for each patient who was given a plasma substitute, whether or not there was an incident. When a reaction did occur, an assessment was carried out in two stages: straightaway, with the measurement of the concentrations of serum tryptase, antigelatin antibodies, urinary methylhistamine; and four to six weeks later, with skin tests. A series of 19.593 patients was thus collected: 48.1% were given gelatins, 26.7% starches, 15.7% albumin, and 9.5% dextrans. 43 anaphylactoid reactions were recorded, giving an overall frequency of 0.219%, or 1 reaction for 456 patients. The frequency differed according to the substitute considered: 0.345% for gelatins, 0.273% for dextrans, 0.099% for albumin, and 0.058% for starches. These reactions (grades III and IV) were serious in 20% of cases. Multivariate analysis revealed four independent risk factors: giving gelatins (odds ratio: 4.81), giving dextrans (odds ratio: 3.83), a history of drug allergy (odds ratio: 3.16), and being male (odds ratio: 1.98). The relative risks of anaphylactoid reactions due to one type of substitute with respect to another were estimated to be 6 times less for starches with respect to gelatins, and 4.7 times less than with dextrans. The relative risk of albumin is 3.4 times less than that of gelatins, and almost identical to that of the starches. An immuno-allergological assessment was only carried out in 15 patients who had been given a gelatin (Plasmion). IgE-dependent anaphylaxis was proven in 7 of these. To conclude, it was shown that gelatins and dextrans should be avoided in patients with a known history of drug allergy. When a reaction does occur, an allergological assessment must be carried out, as this may be due to specific antibodies. Should this prove to be the case, that particular substitute would be contraindicated for the rest of the patient's life.