Propofol-induced bronchoconstriction: two case reports

Propofol use in children with allergies to egg, peanut, soybean or other legumes

Propofol is the most commonly administered intravenous agent for anaesthesia in children. However, there are concerns that the emulsified preparation may not be safe in children with an allergy to egg, peanut, soybean or other legumes. We conducted a retrospective study of children with immunologically confirmed egg, peanut, soybean or legume allergy and who underwent general anaesthesia at Princess Margaret Hospital for Children between 2005 and 2015. We extracted details regarding allergy diagnosis, each anaesthetic administered and any adverse events or signs of an allergic reaction in the peri-operative period. A convenience sample of patients without any known food allergies was identified from our prospective anaesthesia research database and acted as a control group. We identified 304 food-allergic children and 649 procedures where propofol was administered. Of these, 201 (66%) had an egg allergy, 226 (74%) had a peanut allergy, 28 (9%) had a soybean allergy and 12 (4%) had a legume allergy. These were compared with 892 allergy-free patients who were exposed to propofol. In 10 (3%) allergy patients and 124 (14%) allergy-free patients, criteria for a possible allergic reaction were met. In nine of the food-allergic children and in all the controls valid non-allergic explanations for the clinical symptoms were found. One likely mild allergic reaction was experienced by a child with a previous history of intralipid allergy. We conclude that genuine serious allergic reaction to propofol is rare and is not reliably predicted by a history of food allergy.

Sedation With a Combination of Dexmedetomidine and Midazolam for Pediatric Dental Surgery

Intravenous sedation (IVS) is commonly used to complete dental treatment for uncooperative pediatric patients. Propofol (PRO) is widely used for IVS because of its short context sensitive half-time and amnestic effect. However, administering PRO to patients who have a history of egg anaphylaxis is still somewhat controversial. The evidence that supports the potential risks for allergic reactions following PRO use in patients with egg allergies is limited with some anesthesiologists recommending against its use in these patients. Alternative drug regimens for procedural sedation in this population are therefore desirable. Dexmedetomidine (DEX), a selective α-2 agonist, has antianxiety and sedative properties and has been widely used not only for procedural sedation with mild inhibitory effects on respiration but also during minor surgeries for its analgesic effect. In this paper, we describe the successful administration of a combination of DEX and low-dose midazolam (MDZ) for sedation in an uncooperative pediatric patient. Both DEX and MDZ have been reported as safe and useful sedatives for dental treatment, and their combination may provide a helpful option for IVS of pediatric patients for whom PRO is not preferred.

Bronchospasm During Induction of Anesthesia: A Case Report and Literature Review

Background:

Bronchospasm (spasm of bronchial muscles) in general anesthesia caused by many reasons. Untreated bronchospasm can cause hypoxia, hypotension and increased morbidity and mortality.

Case report:

A 28 years old female scheduled for tonsillectomy surgery. Immediately after induction of anesthesia patient developed with drop in oxygen saturation and difficulty in mechanical ventilation.

Conclusions:

Bronchospasm should be considered in differential diagnosis of oxygen saturation drop during general anesthesia. This situation is more common in patients without specific respiratory disorder. Tracheal irritants like sputum and blood can cause bronchospasm. Other causes include histamine or serotonin release.

The effect of tulobuterol patches on the respiratory system after endotracheal intubation

Background

Endotracheal intubation during anesthesia induction may increase airway resistance (R_aw) and decrease dynamic lung compliance (C_dyn). We hypothesized that prophylactic treatment with a transdermal β2-agonist tulobuterol patch (TP) would help to reduce the risk of bronchospasm after placement of the endotracheal tube.

Methods

Eighty-two American Society of Anesthesiologists (ASA) category I or II adult patients showing obstructive patterns were divided randomly into a control and a TP group (n = 41 each). The night before surgery, a 2-mg TP was applied to patients in the TP group. Standard monitors were recorded, and target controlled infusion (TCI) with propofol and remifentanil was used for anesthesia induction and maintenance. Simultaneously, end-tidal carbon dioxide, R_aw, and C_dyn were determined at 5, 10, and 15 min intervals after endotracheal intubation.

Results

There was no significant difference in demographic data between the two groups. The TP group was associated with a lower R_aw and a higher C_dyn, as compared to the control group. R_aw was significantly lower at 10 min (P < 0.05) and 15 min (P < 0.01), and C_dyn was significantly higher at 5 min (P < 0.05) and 15 min (P < 0.01) in the TP group. A trend towards a lower R_aw was observed showing a statistically significant difference 5 min after endotracheal intubation (P < 0.01) in each group.

Conclusions

Prophylactic treatment with TP showed a bronchodilatory effect through suppressing an increase in R_aw and a decrease in C_dyn after anesthesia induction without severe adverse effects.

Propofol Use in Pediatric Patients With Food Allergy and Eosinophilic Esophagitis

Propofol is a safe, well-tolerated anesthetic that is labeled as contraindicated in patients with egg or soy allergy. This contraindication has become increasingly problematic given the rising incidence of food allergy and eosinophilic esophagitis (EoE). To address this issue, we studied practice patterns of propofol use for esophagogastroduodenoscopies in children with EoE and food allergies at our institution. A retrospective observational study of 1365 esophagogastroduodenoscopies from January 2013 to June 2014 was performed. Data were analyzed using Student t tests, chi square tests, Fisher exact tests, and multivariable logistic regression. We found that propofol was used significantly less in patients with egg or soy allergy, and in patients with EoE, even after adjusting for the presence of food allergy. There was no difference in complication rates relative to propofol use. Propofol was used safely in pediatric patients with EoE and food allergy in this limited single-center review.

Administration of Esmolol in Microlaryngeal Surgery for Blunting the Hemodynamic Response during Laryngoscopy and Tracheal Intubation in Cigarette Smokers

Objectives:

Cigarette smokers constitute a group of patients with an increased hemodynamic response to tracheal intubation. We studied the dose-response and side effects of bolus administration of esmolol hydrochloride in cigarette smokers undergoing elective microlaryngeal surgery, when esmolol was used for reducing the intense hemodynamic response to laryngoscopy and tracheal intubation.

Methods:

We randomly allocated 165 patients (American Society of Anesthesiologists physical status classes I to III) to receive placebo (Eplac) or esmolol 1 mg/kg (E1) or 2 mg/kg (E2). The esmolol was given 2 minutes before laryngoscopy and tracheal intubation. The same anesthetic technique was used in all patients. Cardiovascular parameters were recorded every minute for the first 5 minutes and thereafter every 3 minutes. Bronchospasm, other side effects, and rescue esmolol treatment were noted during anesthesia.

Results:

In group Eplac, significant increases (p < .05) in arterial blood pressure and heart rate were observed in the first 3 minutes after tracheal intubation. In group E1, significant increases (p < .05) in diastolic blood pressure were observed in the first 2 minutes after intubation. In group E2, no significant fluctuations were recorded in cardiovascular parameters after intubation. During surgery, 17% of the patients in group Eplac showed an increase in blood pressure and tachycardia.

Conclusions:

We conclude that esmolol administration of 2 mg/kg during induction of anesthesia in smokers provides hemodynamic stability after laryngoscopy and tracheal intubation with no severe side effects.

No evidence for contraindications to the use of propofol in adults allergic to egg, soy or peanut†

BACKGROUND

Propofol is thought to be a potential cause of allergic reactions in patients allergic to egg, soy or peanut, since current formulations contain an emulsion that includes egg lecithin and soybean oil. However, other than six case reports lacking in confirmatory evidence of an allergic reaction, there is no evidence linking the two types of allergies. The aim of this study was to examine the frequency of propofol allergy and to investigate if patients with specific immunoglobulin E (IgE) to egg, soy or peanut tolerated propofol.

METHODS

Study A examined the frequency of propofol allergy in 273 patients systematically investigated for suspected perioperative allergic reactions. Of these, 153 had been exposed to propofol and underwent skin tests and intravenous provocation. Study B retrospectively investigated propofol exposure and tolerance in 520 adult patients with a positive specific IgE to egg, soy or peanut.

RESULTS

Four of the 153 propofol-exposed patients (2.6%) investigated in study A were diagnosed with propofol allergy. Of these, three tested positive only on intravenous provocation. None of the four had allergic symptoms when eating egg, soy or peanut and none had detectable levels of specific IgE to egg or soy in their serum. In study B we found no signs of allergic reactions towards propofol in 171 retrieved anaesthetic charts from 99 patients with specific IgE to egg, soy or peanut.

CONCLUSION

No connection between allergy to propofol and allergy to egg, soy or peanut was found. The present practice of choosing alternatives to propofol in patients with this kind of food allergy is not evidence based and should be reconsidered.

Effects of propofol or desflurane on post-operative spirometry in elderly after knee surgery: a double-blind randomised study

BACKGROUND

Intravenous or volatile agents reduce respiratory function, which can result in respiratory complications in geriatric patients. We hypothesised that there would be no differences in lung function between anaesthesia established using either drug.

METHODS

Elderly patients were randomly assigned to receive either propofol with remifentanil (n = 48) or desflurane (DES) with remifentanil (n = 52) for knee surgery. Spirometry tests including forced expiratory volume in 1 s (FEV1 ), forced vital capacity (FVC), forced mid-expiratory flow (FEF25-75), and FEV1 /FVC ratio were performed preoperatively, and 30 min, 60 min, and 24 h after awakening. Emergence time and post-operative pain scores were also measured.

RESULTS

Time to emergence was significantly longer in the propofol than in the DES group (17.0 vs. 12.5 min, P = 0.04). Post-operative FEV1 (1.6 or 1.4 l, P = 0.68 between groups) were significantly lower than preoperative values (2.1 or 2.0 l, P = 0.001 vs. post-operative values, respectively) in both groups. Reduced FEV1 lasted for 24 h after surgery (1.7 or 1.6 l, P = 0.001 vs. preoperative values, respectively). Post-operative FVC or FEF25-75 were lower than preoperative values. FEV1 /FVC ratio did not change during the study period in both groups. There was no difference in FEV1 , FVC, FEF25-75, FEV1 /FVC, and post-operative pain between the two anaesthetic techniques.

CONCLUSIONS

Although there is a delay in awakening when using propofol, the effects of propofol on post-operative spirometry parameters are similar to those of DES when anaesthesia duration is approximately 3 h. Decreased respiratory parameters persisted up to 24 h after anaesthesia, irrespective of the choice of anaesthetic.

Propofol: a review of its role in pediatric anesthesia and sedation

Propofol is an intravenous agent used commonly for the induction and maintenance of anesthesia, procedural, and critical care sedation in children. The mechanisms of action on the central nervous system involve interactions at various neurotransmitter receptors, especially the gamma-aminobutyric acid A receptor. Approved for use in the USA by the Food and Drug Administration in 1989, its use for induction of anesthesia in children less than 3 years of age still remains off-label. Despite its wide use in pediatric anesthesia, there is conflicting literature about its safety and serious adverse effects in particular subsets of children. Particularly as children are not "little adults", in this review, we emphasize the maturational aspects of propofol pharmacokinetics. Despite the myriad of propofol pharmacokinetic-pharmacodynamic studies and the ability to use allometrical scaling to smooth out differences due to size and age, there is no optimal model that can be used in target controlled infusion pumps for providing closed loop total intravenous anesthesia in children. As the commercial formulation of propofol is a nutrient-rich emulsion, the risk for bacterial contamination exists despite the Food and Drug Administration mandating addition of antimicrobial preservative, calling for manufacturers' directions to discard open vials after 6 h. While propofol has advantages over inhalation anesthesia such as less postoperative nausea and emergence delirium in children, pain on injection remains a problem even with newer formulations. Propofol is known to depress mitochondrial function by its action as an uncoupling agent in oxidative phosphorylation. This has implications for children with mitochondrial diseases and the occurrence of propofol-related infusion syndrome, a rare but seriously life-threatening complication of propofol. At the time of this review, there is no direct evidence in humans for propofol-induced neurotoxicity to the infant brain; however, current concerns of neuroapoptosis in developing brains induced by propofol persist and continue to be a focus of research.

Potential food allergens in medications

Excipients are substances in pharmaceuticals other than the active ingredients. Some excipients are foods or substances derived from foods, raising the possibility that these substances would pose a hazard to patients with food allergy. This review describes which food-derived substances are used as pharmaceutical excipients in which medications and reviews published data regarding the safety of the administration of these medications to recipients with food allergy. Such reactions are rare, usually because the amount of food protein is not present in a large enough quantity to elicit a reaction. When a food protein appears as an unintentional contaminant, the amount, if any, that is present might be variable and might elicit reactions only from some lots of medication or only in some patients. In most circumstances these medications should not be routinely withheld from patients who have particular food allergies because most will tolerate the medications uneventfully. However, if a particular patient has had an apparent allergic reaction to the medication, potential allergy to the food component should be investigated.

Propofol administration is safe in adult eosinophilic esophagitis patients sensitized to egg, soy, or peanut

BACKGROUND

Sedation might improve tolerability and adherence to endoscopic procedures in patients with eosinophilic esophagitis (EoE). Propofol administration is often contraindicated in patients with hypersensitivity to egg, soy, or peanut.

OBJECTIVE

To investigate the safety of propofol administration for procedural sedation in EoE patients sensitized/allergic to egg, soy, peanut.

METHODS

A retrospective observational study in adult EoE patients undergoing esophagogastroduodenoscopy with propofol sedation was conducted between January 2009 and March 2013. Food-specific serum IgE and skin prick tests for egg, soy, peanut, and cross-reactant foods were performed in all patients.

RESULTS

Sixty EoE adult patients, mostly on food elimination diets (91%), were evaluated (age: 28 years (14-56), male gender (90%)). Atopy was present in 88% of patients, being the most prevalent comorbidities rhinoconjunctivitis (78%) and asthma (67%). Fifty-two patients (86%) were sensitized to either egg, soy, or peanut. Eighteen patients (28%) had a history of allergic reactions to egg, legumes, and nuts and strictly avoided these foods. A total of 404 upper endoscopies were performed under propofol sedation. No allergic adverse events were reported, except a transient bronchospasm after orotracheal intubation in an asthmatic adolescent receiving multiple drugs for anesthesia, in whom no sensitization to either propofol or its lipid vehicle was confirmed.

CONCLUSIONS

Propofol was safely administered for procedural sedation in a large series of adult EoE patients multisensitized to egg, soy, peanut, showing one-third clinical allergy to these foods.

Update on perioperative management of the child with asthma

Asthma represents the leading cause of morbidity from a chronic disease among children. Dealing with this disease during the perioperative period of pediatric surgical procedures is, therefore, quite common for the anesthesiologist and other professionalities involved. Preoperative assessment has a key role in detecting children at increased risk of perioperative respiratory complications. For children without an optimal control of symptoms or with a recent respiratory tract infection elective surgery should be postponed, if possible, after the optimization of therapy. According to clinical setting, loco-regional anesthesia represents the desirable option since it allows to avoid airway instrumentation. Airway management goals are preventing the increase of airflow resistance during general anesthesia along with avoiding triggers of bronchospasm. When their use is possible, face mask ventilation and laringeal mask are considered more reliable than tracheal intubation for children with asthma. Sevoflurane is the most commonly used anesthetic for induction and manteinance. Salbutamol seems to be useful in preventing airflow resistance rise after endotracheal intubation. Mechanical ventilation should be tailored according to pathophysiology of asthma: an adequate expiratory time should be setted in order to avoid a positive end-expiratory pressure due to expiratory airflow obstruction. Pain should be prevented and promptly controlled with a loco-regional anesthesia technique when it is possible. Potential allergic reactions to drugs or latex should always be considered during the whole perioperative period. Creating a serene atmosphere should be adopted as an important component of interventions in order to guarantee the best care to the asthmatic child.

A critical incident report: Propofol triggered anaphylaxis

Although propofol is one of the most commonly used drugs for induction of anaesthesia, it is not devoid of anaphylactic potential. Early detection of any suspected anaphylactic reaction during anaesthesia, prompt management, identification of the offending agent and prevention of exposure to the offending agent in the future is the responsibility of the anaesthesiologist. This is a case report of anaphylaxis to propofol at the induction of anaesthesia in a previously non-allergic 56 year-old man, planned to undergo laparoscopic nephrectomy, who responded to epinephrine infusion.

Allergic reactions to propofol in egg-allergic children

BACKGROUND

Egg and/or soy allergy are often cited as contraindications to propofol administration. Our aim was to determine whether children with an immunoglobulin (Ig)E-mediated egg and/or soy allergy had an allergic reaction after propofol use.

METHODS

We performed a retrospective case review over an 11-year period (1999-2010) of children with IgE-mediated egg and/or soy allergy who had propofol administered to them at the Children's Hospital Westmead, Sydney.

RESULTS

Twenty-eight egg-allergic patients with 43 propofol administrations were identified. No child with a soy allergy who had propofol was identified. Twenty-one children (75%) were male, the median age at anesthesia was 2.4 years (range, 1-15 years), and the presence of other atopic disease was common (eczema 61%, asthma 32%, peanut allergy 43%). Most children (n = 19, 68%) had a history of an IgE-mediated clinical reaction to egg with evidence of a significantly positive egg white skin prick test (SPT) reaction (≥7 mm). Two of these had a history of egg anaphylaxis. The remaining children (n = 9, 32%) had never ingested egg because of significantly positive SPT (≥7 mm). All SPTs to egg were performed within 12 months of propofol administration. There was one nonanaphylactic immediate allergic reaction (n = 1 of 43, 2%) that occurred 15 minutes after propofol administration in a 7-year-old boy with a history of egg anaphylaxis and multiple other IgE-mediated food allergies (cow's milk, nut, and sesame). SPT to propofol was positive at 3 mm. No other egg-allergic child reacted to propofol.

CONCLUSIONS

Despite current Australian labeling warnings, propofol was frequently administered to egg-allergic children. Propofol is likely to be safe in the majority of egg-allergic children who do not have a history of egg anaphylaxis.

Analytic Reviews: Propofol Infusion Syndrome in the ICU

Propofol is an alkylphenol derivative named 2, 6, diisopropylphenol and is a potent intravenous short-acting hypnotic agent. It is commonly used as sedation, as well as an anesthetic agent in both pediatric and adult patient populations. There have been numerous case reports describing a constellation of findings including metabolic derangements and organ system failures known collectively as propofol infusion syndrome (PRIS). Although there is a high mortality associated with PRIS, the precise mechanism of action has yet to be determined. The best preventive measure for this syndrome is awareness and avoidance of clinical scenarios associated with development of PRIS. There is no established treatment for PRIS; care is primarily supportive in nature and may include the full array of advanced cardiopulmonary support, including extracorporeal membrane oxygenation (ECMO). This article reviews the reported cases of PRIS and describes the current understanding of the underlying pathophysiology and treatment options.

[Severe bronchospasm using Diprivan® in a patient allergic to peanut and birch]

Diprivan® is composed of propofol, refined soybean oil and purified egg phosphatide. One must eliminate any allergy to one of its components before use. We report the story of a child who underwent nevus surgery under general anesthesia which was associated with an hypersensitivity reaction. In fact, this child had asthma and allergy to peanuts, raising the problem of cross allergy between birch, peanut, soy and Diprivan®.

Recurrent attacks of post-intubation right upper lobe atelectasis

A 22-year-old woman with no history of asthma developed an acute recurrent attack of severe bronchoconstriction and right upper lobe atelectasis immediately after laryngoscopy and endotracheal intubation. The first attack had taken place 2 months earlier under identical circumstances. Induction of anesthesia for tracheal intubation was achieved using propofol, fentanyl, and rocuronium. Bronchial obstruction and bronchial intubation were excluded by bronchoscopy. The atelectasis was quickly resolved with mechanical ventilation and spasmolytic treatment on both occasions. The surgical procedure could proceed soon after resolution of the atelectasis.

Asthma, sedation, and the podiatric patient

Propofol is a common drug used for anesthetic induction of patients undergoing surgery. This popular drug has been around for many years and has been subjected to changes in formulation from its original patented formula. Once touted as safe, the newer propofol may possess hidden dangers, particularly for individuals suffering with hyperreactive airway disease.

Asthma, surgery, and general anesthesia: a review

Over 20 million Americans are affected with asthma. Many will require some type of surgical procedure during which their asthma management should be optimized. Preoperative assessment of asthma should include a specialized history and physical as well as pulmonary function testing. In many asthmatic patients, treatment with systemic corticosteroids and bronchodilators is indicated to prevent the inflammation and bronchoconstriction associated with endotracheal intubation. The use of corticosteroids has not been shown to adversely affect wound healing or increase the rate of infections postoperatively. Preoperative systemic corticosteroids may be used safely in the majority of patients to decrease asthma-related morbidity.

[Children with bronchial hyperreactivity: is it a problem for the anaesthetist?]

Identification of the patients with hyperreactivity and understanding the underlying physiopathological mechanisms are crucial to prevent the occurrence of peri-operative respiratory adverse events in these patients. Preoperative assessment and preparation is based on the maintenance of any long-term anti-inflammatory treatment, especially the inhaled steroids. Furthermore, premedication is based on the administration of a beta2-agonist, antihistamine and anticholinergic drugs that are able to prevent against lung constriction induced by either vagal stimuli or endogenous mediators such as histamine. Anaesthesia management is primarily based on the use of inhalation agents and especially, isoflurane, which has both a protective and a potent bronchodilation effect.

Anaesthetic considerations in patients with chronic pulmonary disease

PURPOSE OF REVIEW

Chronic pulmonary diseases are getting more important in daily anaesthetic practice, because prevalence is increasing and improved anaesthetic techniques have led to the abandonment of previous contraindications to anaesthesia. It is therefore essential for the anaesthetist to be up to date with current clinical concepts and their impact on the conduction of anaesthesia as well as new insights into how to anaesthetise these patients safely.

RECENT FINDINGS

If patients are treated adequately, open and minimally invasive operations can be safely performed under regional and general anaesthesia. The management of acute exacerbations remains challenging, and first-line medical treatment should be supported by non-invasive ventilation. In controlled mechanical ventilation, parameters should be set to avoid dynamic hyperinflation.

SUMMARY

Assessing the functional status of patients admitted for surgery remains a difficult task, and in patients identified as being at risk by clinical examination additional spirometry and blood gas measurements may be helpful. If there are flow limitations and signs of respiratory failure, the anaesthetist should be highly alarmed and monitor the patient closely and invasively, yet there is no reason to deny any patient a substantially beneficial operation.

Toxicity of intravenous anaesthetics

Intravenous anaesthetic agents are generally remarkably safe. However, it is clear that propofol infusion syndrome is a real, albeit rare, entity. This often lethal syndrome of metabolic acidosis, acute cardiomyopathy and skeletal myopathy is strongly associated with infusions of propofol at rates of 5 mg/kg/hour and greater for more than 48 hours. There is evidence to support the hypothesis that the syndrome is caused by the failure of free fatty acid metabolism due to inhibition of free fatty acid entry into the mitochondria and also specific sites in the mitochondrial respiratory chain. The syndrome therefore mimics the mitochondrial myopathies. Midazolam causes seizure-like activity in very-low-birthweight premature infants requiring the drug prior to tracheal intubation or during prolonged positive pressure ventilation. This can be successfully reversed with the specific benzodiazepine antagonist flumazenil. Midazolam can also cause paradoxical reactions, including increased agitation, poor co-operation and aggressive or violent behaviour, which has been successfully managed with flumazenil.