This content has been generated for SALG by Dr Amy Dodd and Dr Linda Nel on behalf of the Perioperative Allergy Network

CASE 1

A patient with a penicillin allergy label presented for transcatheter aortic valve implantation (TAVI) under conscious sedation. A dose of gentamicin was administered slowly and tolerated. This was followed by a test dose of teicoplanin, after which they were given an 800mg dose of teicoplanin. The patient immediately complained of feeling hot and nauseated. Their skin was noted to be erythematous and non-invasive blood pressure reading was low with a systolic reading of ~ 50mmHg.

Anaphylaxis was declared and the patient was given intravenous (IV) adrenaline in small incremental doses due to tachycardia on a background of aortic stenosis. Hydrocortisone 100mg, chlorphenamine 10mg and an IV fluid bolus of 250mls Hartmann's were also administered. The duty anaesthetist arrived and a dose of metaraminol 1.5mg was administered with good effect. A radial arterial line and a femoral line were quickly sited by the cardiology team to facilitate monitoring and medication. Blood samples for mast cell tryptase (MCT) were taken. Once stabilised, a decision was made to proceed with the TAVI under anaesthesia. The patient remained stable throughout the procedure on a low metaraminol infusion and was transferred post-operatively to ICU. The patient subsequently died.

CASE 2

A patient presented for bilateral gynaecomastia surgery. Following induction of anaesthesia with midazolam, remifentanil and propofol, 1.2g of co-amoxiclav was administered followed by rocuronium. Within 60 seconds of administering rocuronium redness of the arms, chest and face was noted as well as a tachycardia and a systolic blood pressure of 80mmHg. At this point an allergic reaction was suspected. IV metaraminol was administered and an endotracheal tube sited. There was no evident airway swelling or bronchospasm and oxygen saturations remained stable.

The rash spread to cover the rest of the patient’s body and a further dose of metaraminol was required. IV chlorpheniramine hydrocortisone and dexamethasone were administered with 1000mls Hartmann’s solution. An arterial line and central venous catheter were sited and samples for MCT were taken. Due to the ongoing need for metaraminol, boluses of IV adrenaline were administered prior to starting an adrenaline infusion.  The decision was made to wake the patient. Following extubation the patient’s adrenaline requirements reduced and the infusion was stopped. The patient was admitted overnight for observation on a short-term medical ward.

CASE 3

Ten minutes post induction of anaesthesia for breast surgery, the patient had a drop in blood pressure and end tidal carbon dioxide (EtCO₂).  Anaphylaxis was suspected and vasopressors were administered. Blood pressure initially improved however the EtCO₂ remained low. An emergency was declared. Following A-C assessment, the endotracheal tube was removed, the patient was re-intubated and tube position confirmed. Further vasopressors were required to treat hypotension and ongoing low EtCO₂. An adrenaline infusion was commenced via a central line to maintain haemodynamics stability. The patient was transferred to ICU.

CASE 4

Following the administration of IV antibiotics at the start of surgery, the patient suddenly deteriorated. Clinical features included: hypotension, tachycardia, raised airwave pressures and a red rash over the patient’s whole body.  Anaphylaxis to teicoplanin or gentamicin was suspected, and the emergency buzzer was pulled.  IV adrenaline was administered which resolved the symptoms. IV chlorphenamine and hydrocortisone were administered with 3L IV crystalloid. An adrenaline infusion started before the patient was transferred to critical care intubated and ventilated. The patient was extubated the same day and discharged the next day.

Commentary

Anaphylaxis should be considered whenever unexpected and significant cardiovascular or respiratory compromise occurs and treated promptly.¹ The Perioperative Allergy Network (PAN) in collaboration with the Resuscitation Council UK (RCUK) have published an algorithm for the emergency management of peri-operative anaphylaxis¹ which aligns with the Quick reference handbook.²  Emergency guidance should be used to improve outcomes in the management of infrequent challenging scenarios.³

A delay in the appropriate treatment of anaphylaxis is associated with poorer outcomes.^4,5 First-line treatment of peri-operative anaphylaxis is intravenous adrenaline (epinephrine). An initial dose of 50 micrograms (0.5 ml of 1 mg/ 10 ml [1:10,000]) is recommended in adults and children aged 12 years and over.¹ Adrenaline must be supported by intravenous crystalloid fluid. Multiple large volume fluid boluses may be required (up to 3-5L in adults).¹

Adrenaline is the first line treatment for anaphylaxis due to its ability to counteract the effects of anaphylaxis through its vasoconstrictor, bronchodilator, inotropic and mast cell stabilising effects, suppressing histamine and leukotriene release. Antihistamines and corticosteroids are not recommended in the immediate treatment of anaphylaxis. Do not prioritise these or other vasopressors (eg metaraminol) over adrenaline and fluid resuscitation¹.

If signs of anaphylaxis persist despite boluses of adrenaline, an adrenaline infusion should be initiated. A low-dose adrenaline infusion, given via a peripheral venous line, is an effective alternative if central venous access is not immediately available. If there is a poor clinical response to an adrenaline infusion and appropriate fluid resuscitation, a second-line vasopressor should be given, in addition to adrenaline.¹

Where there are signs of severe or persistent bronchospasm, patency of the airway and anaesthetic circuit must be checked and oesophageal intubation excluded.

NAP 6 identified antibiotics as the most common cause of perioperative anaphylaxis and as such recommended that antibiotics are given prior to induction of anaesthesia.⁶  If antibiotics are given after induction of anaesthesia, then it is sensible to leave a 15 minute gap before administering antibiotics where possible, so that in the event of anaphylaxis it is easier to investigate the reaction and identify the culprit agent.

Teicoplanin, which is commonly used as first line prophylaxis in patients with a penicillin allergy label, is 17 times more likely to cause anaphylaxis than alternative antimicrobials. If Teicoplanin is the antibiotic of choice, then it should be given by infusion or a slow bolus over 3-5 minutes. There is cross reactivity with vancomycin. Both can cause ‘red man’-type reactions that may mimic anaphylaxis, if given rapidly. It is important to note, however, that where teicoplanin is suspected to have caused anaphylaxis previously in a patient, that it should not be given again. There appears to be more than one pathophysiological mechanism for anaphylaxis in the case of teicoplanin. This means that just adjusting the dosage speed may not prevent a subsequent anaphylaxis.

NAP 6 identified several cases of anaphylaxis related to antibiotic ‘test doses’. Typically in the perioperative setting, test doses are not administered in doses consistent with allergy-clinic challenge testing, and there is no evidence that a test dose reduces the severity of anaphylaxis when it occurred.

We encourage anaesthetists to continue to report incidents of suspected or confirmed perioperative allergy and to ensure that the results of investigations are added to the report when available, to enable better understanding of these incidents.

References:

1. Dodd A, Turner PJ, Soar J, Savic L; representing the UK Perioperative Allergy Network. Emergency treatment of peri-operative anaphylaxis: Resuscitation Council UK algorithm for anaesthetists. Anaes 2024;79(5):535-41.
2. Association of Anaesthetists. Section 3.1 Anaphylaxis (v5). Quick Reference Handbook. 2022 (Accessed 10/4/25)
3. Simmons WR, Huang J. Operating Room Emergency Manuals Improve Patient Safety: A Systemic Review. Cureus 2019;11(6):e4888.
4. de Silva D, Singh C, Muraro A, et al. European Academy of Allergy and Clinical Immunology Food Allergy and Anaphylaxis Guidelines Group. Diagnosing, managing and preventing anaphylaxis: systematic review. Allergy 2020; 76(5): 1493-506
5. Ko B, Kim J, Seo DW, et al. Should adrenaline be used in patients with hemodynamically stable anaphylaxis? Incident case control study nested within a retrospective cohort study. Sci Rep 2016; 6:20168
6. Harper NJN, Cook TM, Garcez T, et al. Anaesthesia, surgery, and life-threatening allergic reactions: epidemiology and clinical features of perioperative anaphylaxis in the 6th National Audit Project (NAP6). Br J Anaesth 2018;121(1):159-71