Abstract
Malignant hyperthermia (MH) is a rare, life-threatening hypermetabolic reaction to volatile anaesthetics and succinylcholine. Management of MH-susceptible patients undergoing elective surgery has been reported; however, concurrent transplant surgeries involving two MH-susceptible patients pose unique challenges. This report describes the perioperative management for a living-related renal transplant involving a donorrecipient pair both at risk for MH, highlighting the perioperative considerations and logistical challenges of preparing for potential simultaneous MH crises in high-stakes surgical scenarios. A 49-year-old woman with end-stage renal disease and her 29-year-old daughter were scheduled for living-related kidney transplantation. Both patients had a family history of MH but declined confirmatory testing. Preoperative planning centered around multidisciplinary discussions, crisis simulation, and preparation of two sets of trigger-free anaesthesia workstations, MH kits, cooling supplies, and resuscitation equipment. A trigger-free anaesthesia technique was employed. Two anaesthetic teams coordinated between the donor nephrectomy and recipient transplant at critical time points during the surgery. The surgeries proceeded smoothly, and both patients were stable intraoperatively with an uneventful recovery in High Dependency. This case highlights the importance of comprehensive perioperative preparations, including contingency planning, team coordination, and resource allocation, to manage potential simultaneous MH crises in concurrent surgeries. Future efforts to develop standardized protocols for scenarios involving concurrent surgeries in MH-susceptible patients and improving access to MH confirmatory testing would improve outcomes and streamline perioperative care in similar cases.
Keywords
Introduction
Malignant hyperthermia (MH) is a rare, life-threatening hypermetabolic reaction triggered by volatile anaesthetics and succinylcholine. While most institutions have MH protocols and MH kits designed for a single case given its rarity, challenges arise when two MH-susceptible patients require concurrent elective surgeries. Managing two MH-susceptible patients requires extensive perioperative preparation for trigger-free anaesthesia and simultaneous MH crisis resource management. We describe a concurrent living-related renal transplant involving both MH-susceptible donor and recipient, highlighting the perioperative complexities of preparing for potential simultaneous MH crises in high-stakes surgeries.
Case Report
A 49-year-old female with diabetes, hypertension, and end-stage renal disease on haemodialysis was scheduled for a living-related renal transplant from her 29-year-old daughter, who had no medical history. Neither had prior anaesthetic history. However, the recipient’s brother had a confirmed MH reaction during an appendicectomy under general anaesthesia (GA) 20 years ago.
Both were counselled on MH risks and implications on the surgery. Confirmatory testing was declined due to financial constraints. Preoperative discussions among anaesthesiologists, urologists, renal physicians, and the ethics committee addressed timing of surgical phases, contingency plans, and logistics. Two experienced anaesthesia and nursing teams were assigned to the donor and recipient. One week before surgery, a crisis simulation was held to coordinate actions for simultaneous MH crises, with pre-calculated doses of dantrolene and resuscitative drugs printed for quick reference.
The evening before and on the morning of surgery, the anaesthetic machines (Avance CS2, GE Healthcare) were flushed according to the manufacturer’s recommendations 1 to ensure they were vapour-free. Two MH kits, cooling equipment, and resuscitation trolleys were prepared; triggering agents were removed from the operating theatres (OT).
The laparoscopic nephrectomy and renal transplant were performed as the first cases in adjacent OTs using a trigger-free, total intravenous anaesthesia (TIVA) technique. The donor was induced with propofol, fentanyl and atracurium. Controlled ventilation was initiated using a vapor-free machine (tidal volume 7 mL/kg, respiratory rate 12-15 per min, oxygen/air flow rate 1 L/min). Standard monitors according to the American Society of Anaesthesiologists (ASA) guidelines, bispectral index (BIS), and nasopharyngeal and rectal thermometers were used.
Anaesthesia was maintained with target-controlled infusion (TCI) propofol, morphine and atracurium. The donor’s vitals and end-tidal CO2 remained stable throughout. The highest recorded nasopharyngeal temperature was 36.6°C. Ligation of the donor renal vessels and kidney explantation was delayed until the recipient had been under anaesthesia for 45 minutes without signs of MH. After the donor kidney had been anastomosed and the recipient was haemodynamically stable for an hour, the donor was reversed from anaesthesia. The total operation time for the donor was 3 hours 15 minutes.
Anaesthesia for the recipient was induced using a similar technique. The recipient remained stable throughout. The highest recorded nasopharyngeal temperature was 36.8°C. Total operation time was 3 hours and 11 minutes and cold ischemia time was 60 minutes.
Both surgeries completed uneventfully. The patients were extubated and monitored in the post-anaesthesia care unit with continuous skin temperature monitoring. To minimize exposure to exhaled anaesthetic gases in the recovery area, a face mask was applied. Both patients were transferred to high dependency and recovered uneventfully.
Discussion
Preoperative preparation
Malignant hyperthermia (MH) is a life-threatening hypermetabolic response triggered by volatile anaesthetics and depolarizing neuromuscular blocking agents. Dysregulated calcium release leads to a hypermetabolic response, rhabdomyolysis, metabolic acidosis with hyperkalemia and arrhythmias. Monitoring of capnography, electrocardiography and core temperature is essential for detecting signs of MH. MH has no pathognomonic features but should be suspected in any anaesthetized patient who develops unexplained hypercapnia, tachycardia, and hyperthermia after receiving triggering agents.
Early recognition and prompt intervention are crucial for survival. Treatment consists of trigger removal, dantrolene administration, active cooling and complication management. Post-MH management, patients should be monitored in the intensive care unit due to risk of recrudescence. Despite dantrolene, mortality remains 4-10%. 2
MH susceptibility is inherited in an autosomal dominant pattern, and a family history of adverse reactions to anaesthesia raises suspicion. The prevalence of MH susceptibility is estimated at one in 200 to one in 3000.3–5 Patients at our hospital are assessed in the Preoperative Anaesthesia Clinic weeks before elective surgery. The gold standard for diagnosing MH susceptibility is the in vitro contracture test (IVCT), which is not available locally and requires a live muscle biopsy performed overseas. While genetic testing is available locally, negative results do not rule out MH susceptibility due to undefined mutations. 6 Patients are deemed MH susceptible if they have a personal or family history of suspected MH or test positive during genetic testing and IVCT. Financial and accessibility barriers leave many labelled with ‘presumptive MH susceptibility.’
Due to the MH reaction in the patient’s brother, it was deemed prudent to manage the patient and her daughter as being MH-susceptible. To avoid an MH crisis, a trigger-free anaesthetic was planned by removing succinylcholine and volatile anaesthetics, and using a ‘vapour free’ anaesthesia workstation with TIVA. Although there have been no reported MH crises occurring during trigger-free anaesthesia, 7 a theoretical risk remains if residual volatile anaesthetics are released from internal components during use. Ideally, an anaesthesia workstation with no prior exposure to volatiles should be used; however, procuring two may be challenging. Therefore, both workstations were flushed according to manufacturer’s instructions to reduce volatile concentration to below 5 ppm. 8
Coordination of surgery between donor and recipient
The donor kidney risks being wasted if the recipient develops an MH crisis after donor explantation, or if either the donor or recipient becomes unstable during the surgery. To ensure the stability of both patients and likelihood of a successful transplantation, close communication was maintained between the two anaesthetic teams and three key coordinated actions were taken.
Firstly, we ensured the donor was stable under GA for the first 45 minutes, before inducing the recipient. The onset of MH can be variable and unpredictable, with case reports indicating a delayed onset of up to 40 minutes. 9 We postulated the likelihood of an MH reaction would be highest within the first 45 minutes of anaesthesia. During this period, laparoscopic dissection of the donor kidney was commenced. This approach allowed for manpower and resources to be focused on resuscitating a single patient if an MH crisis occurred during this initial period.
Secondly, the donor kidney’s renal vessels were ligated and explantation performed only after the recipient had also been under anaesthesia for 45 minutes with no signs of MH. This strategy aimed to minimize the cold ischemia time and reduce the risk of unnecessarily harvesting the donor kidney if an MH crisis developed in the recipient.
Lastly, the donor was reversed from anaesthesia only after anastomosis of the transplanted kidney had started and an hour of haemodynamic stability was observed in the recipient. This allowed for the option of re-implanting the kidney in the donor if the recipient experienced an MH reaction and became too unstable to receive the donor kidney.
Resource management for concurrent MH crises
Availability and preparation of dantrolene
The MH kit in our institution contains 36 vials of dantrolene, dilution equipment, a dantrolene dosing table and crisis task cards as per international guidelines
10
(Figure 1). We prepared two MH kits in the urology OT complex in the event of two simultaneous MH crises. Staff in other OTs were aware of the location of the MH kits to avoid delays in requisition should an MH event occur elsewhere. We ensured additional dantrolene supply was available in the pharmacy. Malignant hyperthermia kit.
Cooling tools and resuscitation drugs
Additional cooled saline bags and ice packs were also readily available in the Urology OT’s fridge to manage hyperthermia expediently. Two resuscitation trolleys stocked with emergency drugs to manage hyperkalemia, acidosis, and tachyarrhythmias were readily available in both operating theatres.
Teamwork and task management
We ensured adequate manpower in the event of concurrent crises. Our institution’s Dantrolene (Dantrium) comes in 20 mg vials, each requiring 60 mL of water for reconstitution. Considerable manpower is needed to quickly dilute multiple vials for prompt administration. A newer dantrolene preparation (Ryanodex; Eagle Pharmaceuticals) requires less volume for dilution and is easier to administer but is not available locally.
We conducted a high-fidelity in situ simulations for team members involved in the actual case to rehearse team responses for maximal efficiency during crisis. Roles were pre-assigned to minimize task duplication and confusion. Task cards and pre-calculated dantrolene dosing tables were printed to expedite dantrolene preparation, ensuring administration readiness within recommended timeframes (Figure 2). Malignant hyperthermia crisis task cards.
Conclusion
The potential impact of two concurrent MH crises during high-stakes surgeries like renal transplantation requires thorough preparation. This includes trigger-free anaesthesia, clear contingency plans, and adequate resource and manpower planning to optimize patient outcomes. All institutions should develop guidelines for managing elective surgeries in MH-susceptible patients to ensure effective crisis preparedness. Future efforts should focus on improving access to MH susceptibility testing in Singapore and the region for better preoperative risk stratification. Standardized protocols for complex cases involving multiple MH-susceptible patients could further enhance outcomes and streamline perioperative care.
Footnotes
Acknowledgments
We would like to thank the primary surgeon, Dr Valerie Gan, for her valuable guidance on the surgical considerations of the case.
Author contributions
Monica Tan, Emma Du Wei and Leonard Loh Wei Wen drafted and revised the manuscript. All authors reviewed and approved the final version of the manuscript.
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Ethical statement
Data Availability Statement
Data sharing is not applicable to this article as no datasets were generated or analysed during the current study.