Correspondence
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Propofol anaesthesia is safe in children with food allergy undergoing endoscopy A. E. Wiskin, J. Smith, S. K. Y. Wan, M. W. J. Nally and N. Shah* London, UK *E-mail:
[email protected]
Editor—Propofol is a commonly used anaesthetic agent. It is an emulsion containing soybean oil, and egg lecithin/phosphatide but despite these constituents there is a paucity of evidence regarding the use of Propofol in patients with egg and soy allergy;1 when surveyed more than 50% of paediatric anaesthetists would not give Propofol to children with egg and/or soy allergy.2 In our children’s hospital, Propofol is often the sole anaesthetic agent used during endoscopy because of its quick recovery time.3 We performed a retrospective analysis of patient records of children who underwent endoscopy between January 2011 and December 2012. Children were included if they had (i) documented egg, soy and/or nut allergy (IgE or non IgE mediated) (ii) received Propofol for anaesthesia (iii) complete records of anaesthesia, endoscopy and recovery. Children with incomplete records were excluded. A total of 149 procedures were performed in 131 children with allergies to egg soya or nuts (IgE or non IgE mediated). Of the 149 procedures, complete records for children who received Propofol were available for 76 procedures in 55 patients (30 male). 62% had a combination of egg and soy allergy; 38% of the children had single allergy, the majority of these children were allergic to soy. In total 28% of children had IgE mediated allergy. The median age at time of endoscopy was 6.2 yrs (range 1–17 yrs), the majority of patients had both oesophago-gastroduodenoscopy and Ileo-colonoscopy (62/76). Median duration of total anaesthesia was 30 min (range 10–80 min). Supplemental oxygen was given during 55 procedures, although this is now standard practice in our unit. Tracheal tube intubation was used during only 16 procedures; this was elective for 14 procedures but performed intra-operatively in two patients because of low oxygen saturations. In 62 procedures children received total IV anaesthesia with Propofol, the remaining 14 patients received gas induction and Propofol maintenance. Thirteen adverse events were reported (Table 1) none attributable to Propofol. The majority (7) were respiratory events. These were described as desaturations associated with coughing, recent upper respiratory tract infections and oral secretions. Five varied minor adverse reactions were seen, unrelated to
propofol or food allergy. A single allergy related incident was reported; the child developed facial swelling, flushing and periorbital oedema 3 h post procedure. This was attributed to coincidental and unexpected first presentation of latex allergy, later confirmed on further testing and probably caused by the patients’ name band. As a result of increasing numbers of food allergic patients in the UK, affecting up to 6% of children,4 an anaesthetist is likely to meet an allergic patient especially if regularly managing children. Propofol sedation is the drug of choice for paediatric endoscopy and is extensively used by many centres around the world.5 Despite common usage of Propofol there is scarce data upon which to inform its use or contraindication in food allergic children. In a study of 28 egg allergic children by Murphy and colleagues one child had a non-anaphylactic immediate allergic reaction attributed to Propofol. This seven yr old boy had a history of egg anaphylaxis and multiple IgE mediated food allergies. The authors concluded that Propofol is likely to be safe in the majority of egg allergic children who do not have a history of egg anaphylaxis.6 More recently a study retrospectively reviewed 60 patients with eosinophilic oesophagitis (52 sensitized to egg, soy or peanut, 18 with history of allergic reaction to these foods) who underwent endoscopy with Propofol and found no allergic adverse events.7 This retrospective evaluation suggests that it is probably safe to use Propofol in children with egg or soya allergy. This significantly adds to, and is in concordance with, the limited published data available.
Declaration of interest None declared.
Funding The study was supported by a grant from Great Ormond Street Children Charity Research grant.
Table 1 Adverse events found in 55 food allergic children who underwent 76 endoscopic procedures using Propofol anaesthesia Category
Number of procedures
Description
Respiratory Cardiovascular Metabolic Gastroenterology
7 1 1 2
Drug Allergy
1 1
Desaturations contributed by URTI, coughing, secretions Persistent hypertension post procedure Blood glucose 3.6 post procedure requiring dextrose administration Nausea and vomiting post procedure requiring i.v. cyclizine rescue Abdominal pain post procedure relieved with oral paracetemol Extravasation of i.v. propofol Latex allergy
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References 1. Harper NJ, Dixon T, Dugue P, et al. Suspected anaphylactic reactions associated with anaesthesia. Anaesthesia 2009; 64: 199–211 2. Villafana-Soto K, Campbell DE, Baines D, Mehr S. Perceptions of paediatric anaethetists on the use of propofol in egg/soy/ peanut allergy: Association of Anaethetists of Great Britain and Ireland, 2011 3. van Beek EJ, Leroy PL. Safe and effective procedural sedation for gastrointestinal endoscopy in children. J Pediatr Gastroenterol Nutr 2012; 54: 171–85 4. Sicherer SH, Sampson HA. Food allergy: Epidemiology, pathogenesis, diagnosis and treatment. J Allergy Clin Immunol 2014; 133: 291–307
5. Amornyotin S, Aanpreung P, Prakarnrattana U, Chalayonnavin W, Chatchawankitkul S, Srikureja W. Experience of intravenous sedation for pediatric gastrointestinal endoscopy in a large tertiary referral center in a developing country. Paediatr Anaesth 2009; 19: 784–91 6. Murphy A, Campbell DE, Baines D, Mehr S. Allergic reactions to propofol in egg-allergic children. Anesth Analg 2011; 113: 140–4 7. Molina-Infante J, Arias A, Vara-Brenes D, et al. Propofol administration is safe in adult eosinophilic esophagitis patients sensitized to egg, soy, or peanut. Allergy 2014; 69: 388–94
doi:10.1093/bja/aev177
Racemic ketamine 4.5-day infusion treatment of long-standing complex regional pain syndrome—a prospective service evaluation in five patients A. Goebel*, S. Jayaseelan, K. Sachane, M. Gupta and B. Frank Liverpool, UK *E-mail:
[email protected]
Editor—In the UK, S+ketamine (S+K) is not clinically available, instead racemic ketamine (RK) is used in anaesthetic practice. RK may be less potent and associated with more cognitive side effects than equianalgesic doses of S+K.1 Intravenous infusion of subanaesthetic doses of S+K over 4.5 days can substantially reduce pain in long-standing complex regional pain syndrome (CRPS) for several weeks,2 however, to our knowledge no report of 4.5-day RK treatment is available.3 We adapted the published S+K treatment protocol to RK and here report the results from a prospective service evaluation in five patients. We offered 4.5-day RK treatment to patients with refractory,4 severe, long-standing (>1-yr duration) CRPS (Budapest clinical criteria5). We registered our service evaluation with the Hospital Trust (for treatment details, see the web-appendix clinical protocol). We scheduled a data review to support a decision on continued provision of this service after five patients had completed treatment. We assumed half potency of RK vs S+K1). Patients were started on 150 μg kg−1 h−1 RK on Monday mornings and were up-titrated in regular intervals to a maximal 900 μg kg−1 h−1. Vital signs were monitored every 6 h. Where unacceptable side effects occurred, the infusion dose was decreased (for details, see the webappendix). Liver enzymes were tested at days 1 and 4. Patients were discharged on Friday afternoon. Patients recorded their present pain intensity in diaries every 2 h during the day and every 8 h at night; they also recorded any treatment side effects. At their first outpatient appointment after discharge they were asked to judge retrospectively the durations of both maximal and meaningful analgesia. Between June 2011 and March 2014, five patients were treated; one patient received repeat treatment after 6 months. Patient characteristics and treatment outcomes are detailed in Table 1. Patient 1, with no known medical history, felt fatigued during the
infusion and spent most of her time resting; developed shortness of breath on day 4; and independently her liver enzymes were mildly raised. The infusion was stopped and, following investigation, lower leg deep vein thrombosis (DVT) and pulmonary embolism (PE) were diagnosed. We treated her according to hospital protocol for PE and arranged a haematology assessment; she recovered without long-term sequelae. She was later diagnosed with a new presentation of CRPS-concomitant anti-phospholipid syndrome; her liver enzymes had normalized by 2 months after stopping the infusion. We consequently adapted the treatment protocol, including routine DVT prophylaxis. There were no additional serious adverse events or liver enzyme abnormalities. The treatment was well tolerated by three patients (patients 2, 3, and 5); patient 5 did not receive the highest infusion rate due to an administrative error. Patient 4 developed agitation that limited dose escalation and was discharged 72 h later, after she had fully recovered (Table 1). Three patients recorded substantial pain relief, which they considered meaningful ( patients 2, 3, and 5); this lasted 6 months in patient 2, who then received a repeat treatment, with again profound, but much shorter-lasting analgesia (Table 1); the patient then declined further ketamine treatment. Patient 3 experienced remarkable functional restoration lasting 10 days, with the ability to move his affected knee for the first time in a year. The median pain intensity in this group (excluding the second infusion in patient 2) reduced from NRS 8.5 at baseline to NRS 5 on the last treatment day, a 3.5 NRS point reduction. In conclusion, low-dose, 4.5-day RK infusion sometimes produced impressive analgesia with acceptable side effects in patients with otherwise refractory CRPS. With the exception of patient 2, beneficial effects were short-lived. Analgesia at 1 week was somewhat less than in the published S+K randomized controlled trial, where there was a mean of 4.5 points pain reduction with
