First Malignant Hyperthermia Laboratory in Africa Opens at Mediclinic Midstream
Posted on 5 February 2018
The MH laboratory identifies patients and families at risk for this life-threatening autosomal inherited abnormality.
While under general aneasthetic for a tonsillectomy at the age of four, Daniella Potgieter developed a high temperature, generalised muscle rigidity and cola-coloured urine. The anaesthetist suspected an acute Malignant Hyperthermia (MH) attack and immediately administered the antidote, dantrolene (Dantrium).
MH is an inherited autosomal dominant abnormality of skeletal muscle where anaesthetic vapours and certain muscle relaxants trigger a life-threatening hypermetabolic reaction, rhabdomyolysis and multi-organ failure.
Daniella survived this potentially fatal adverse anaesthetic event but, until recently, her parents remained uncertain about what caused the reaction that almost killed her in the operating theatre.
Case Study for First Malignant Hyperthermia Laboratory in Africa
In December last year, the plucky survivor had a muscle biopsy under trigger-free general anaesthetic and an IVCT (in vitro contracture test) was performed at the newly-established MH laboratory at Mediclinic Midstream. This is the only MH diagnostic laboratory in Africa and safely tests patients at risk of this potentially fatal pharmacogenetic disease before any elective surgery.
Daniella tested strongly positive for MH and now has a confirmed diagnosis. This meant she could get a Medic Alert bracelet to warn health care providers of her condition in case of trauma.
As Dr Hannah Brand, a specialist anaesthesiologist and MH expert at Mediclinic Midstream explains, MH is rare (1: 15 000 of the general population), but affects not only a patient, but their families too, due to its autosomal dominant inheritance pattern.
Interestingly, the MH reaction isn’t limited only to operating theatres. ‘Succinylcholine is a potential triggering agent that is sometimes used in emergency rooms, ICU, gastro units, interventional and cardiology suites and by paramedics on the road,’ Dr Brand explains. ‘Outside of theatre we also see the so-called “awake MH” in athletes, mineworkers and soldiers that trigger a MH-like reaction during exercise and heat. More evidence is seen that some MH patients and heat stroke patients share common causative mutations.’
The IVCT is the gold standard test for diagnosing MH and has a specifity of 97% and a sensitivity of 99%. ‘The IVCT laboratory at Mediclinic Midstream is equipped with the newest Hugo Sachs organ bath system,’ Dr Brand explains. ‘The IVCT is a highly specialised biophysical test performed on a muscle specimen submerged in Krebs Ringers solution and suspended in an organ bath. Muscle contraction is measured by an electrical transducer system after muscle has been exposed to incremental concentrations of anaesthetic vapour (halothane) and caffeine.’
For many years, family members of MH patient were treated as MH-susceptible because of the absence of a testing faciltiy to determine their real risk. ‘This has huge implications for children with MH relatives as they can’t receive inhalation anaesthesia,’ Dr Brand explains. Instead they are subjected to the Total Intravenous type of Anaesthesia (TIVA) technique with an awake intravenous needle insertion, which a lot of children find traumatic. Even a negative diagnosis in the MH laboratory has a huge implication for a patient and his/her family and their future anaesthetics.
This new MH laboratory clearly distinguishes Mediclinic as a leader in the healthcare industry. ‘It ensures that preventative medicine is integral to our patients’ care while simultaneously improving patient safety in theatres,’ Dr Brand asserts.
‘The MH lab highlights our commitment to patient safety – we now have the ability to diagnose the condition in at-risk individuals and prevent this potentially catastrophic complication,’ concludes Dr Shane Kotzé, Hospital General Manager at Mediclinic Midstream.