MALIGNANT MALIGNANT HYPERTHERMIA A CASE HYPERTHERMIA A CASE

REPORTREPORTBYBY

DR.K.RAVIKUMARDR.K.RAVIKUMARFELLOW PICUFELLOW PICU

APOLLO CHILDRENS HOSPITALAPOLLO CHILDRENS HOSPITAL

• 13 year old girl - admitted for posterior 13 year old girl - admitted for posterior scoliosis correction. scoliosis correction.

• History of recurrent respiratory tract History of recurrent respiratory tract infections.infections.

• Delayed motor milestones. Delayed motor milestones.

• Pre-operative pulmonary function testing Pre-operative pulmonary function testing showed restrictive lung diseaseshowed restrictive lung disease

CASE Contd.CASE Contd.

• NPO for 8 hoursNPO for 8 hours

• IV induction - atropine, fentanyl and IV induction - atropine, fentanyl and thiopentonethiopentone

• Intubated with 6.5 cuffed ET tubeIntubated with 6.5 cuffed ET tube

• Desflurane with nitrous oxide and Desflurane with nitrous oxide and atracurium was used for maintenanceatracurium was used for maintenance

CASE Contd.CASE Contd.• Baseline measurements Baseline measurements

SpOSpO22 at 99%, NIBP at 110/68, HR at 86/min, at 99%, NIBP at 110/68, HR at 86/min, ETCOETCO22 at 38 mmHg, skin temperature at at 38 mmHg, skin temperature at 35.5°C35.5°C

• 3 hours post induction3 hours post induction

HR-146/min, ETCO2-90, T-39.3 C, SpO2-83 %HR-146/min, ETCO2-90, T-39.3 C, SpO2-83 %

CASE Contd.CASE Contd.• What is your impression?What is your impression?

• DOPE ruled outDOPE ruled out

• 100% oxygen started100% oxygen started

• Pressure support & rate increased Pressure support & rate increased

CASE Contd.CASE Contd.

• ABG – 7.16/74/106/16/-4ABG – 7.16/74/106/16/-4

What is your interpretation?What is your interpretation?

• Combined metabolic & respiratory Combined metabolic & respiratory acidosis. acidosis.

CASE Contd.CASE Contd.

• Na-131, K-4.3, Cl-97, Ca-1.2(mmol),Na-131, K-4.3, Cl-97, Ca-1.2(mmol),

• Sugars- 132, lactate-2.4Sugars- 132, lactate-2.4

• ECG- sinus tachycardiaECG- sinus tachycardia

• What is the differential diagnosis?What is the differential diagnosis?

• Iatrogenic heatingIatrogenic heating

• sepsissepsis

• Thyroid stormThyroid storm

• PheochromocytomaPheochromocytoma

• Neuroleptic malignant syndromeNeuroleptic malignant syndrome

• What is the probable diagnosis? What is the probable diagnosis?

MALIGNANT HYPERTHERMIAMALIGNANT HYPERTHERMIA

• Most common drug implicated in MH?Most common drug implicated in MH?

ALL inhalational anaesthetics except ALL inhalational anaesthetics except nitrous oxide & Succinyl choline nitrous oxide & Succinyl choline

• Drugs safe in MH?Drugs safe in MH?

Nitrous oxide, local and IV anaestheticsNitrous oxide, local and IV anaesthetics

Non depolarising muscle relaxantsNon depolarising muscle relaxants

• Who are predisposed to develop MH?Who are predisposed to develop MH?

Children with myopathyChildren with myopathy

• Earliest clinical sign in MH?Earliest clinical sign in MH?

Rise in ETCORise in ETCO22

• What is the management plan?What is the management plan?

Cooling & controlled ventilationCooling & controlled ventilation

• What is the drug of choice?What is the drug of choice?

DANTROLENE SODIUMDANTROLENE SODIUM

CASE Contd.CASE Contd.

• Operative procedure abandonedOperative procedure abandoned

• NS bolus started NS bolus started

• Manual hyperventilation with 100% Manual hyperventilation with 100% oxygenoxygen

• Cooling – external/internalCooling – external/internal

CASE Contd.CASE Contd.• Patient shifted to PICUPatient shifted to PICU

• First dose of dantrolene sodium given First dose of dantrolene sodium given

• Skin temperature rapidly decreased to 37.5°C Skin temperature rapidly decreased to 37.5°C and EtCO2 decreased by approximately 30 and EtCO2 decreased by approximately 30 mmHg with dantrolenemmHg with dantrolene

• Controlled ventilation, central cooling and repeat Controlled ventilation, central cooling and repeat doses of dantrolene continued doses of dantrolene continued

CASE Contd.CASE Contd.• Skin temperature maintained between 36-36.5 CSkin temperature maintained between 36-36.5 C

• Fluid rate continued at one & half times Fluid rate continued at one & half times maintenance maintenance

• EtCO2 decreased to 38 and blood gas EtCO2 decreased to 38 and blood gas stabilized within two hours.stabilized within two hours.

• Patient remained stable and was extubated after Patient remained stable and was extubated after 14 hours. 14 hours.

CASE Contd.CASE Contd.

• CPK was elevated (852-7806-3426-1243-544-CPK was elevated (852-7806-3426-1243-544-78) 78)

• Urine myoglobin was negative Urine myoglobin was negative

• Renal and thyroid function tests were within Renal and thyroid function tests were within normal limitsnormal limits

• Muscle biopsy showed destructive myopathic Muscle biopsy showed destructive myopathic changes possibly secondary to malignant changes possibly secondary to malignant hyperthermiahyperthermia

MALIGNANT HYPERTHERMIA - MALIGNANT HYPERTHERMIA - DISCUSSIONDISCUSSION• Rare life-threatening condition Rare life-threatening condition

• Triggered by exposure to general anesthetics Triggered by exposure to general anesthetics (Inhalational anesthetic agents and depolarising (Inhalational anesthetic agents and depolarising muscle relaxants)muscle relaxants)

• Autosomal dominant disorderAutosomal dominant disorder

• Ryanodine receptor gene mutation – calcium Ryanodine receptor gene mutation – calcium channel receptor in sarcoplasmic reticulum.channel receptor in sarcoplasmic reticulum.

Increased calcium release Increased calcium release DANTROLENEDANTROLENE

sustained muscle contraction sustained muscle contraction

hypermetabolic statehypermetabolic state

cellular hypoxiacellular hypoxia

worsening acidosisworsening acidosis

MODSMODS

PATHOGENESIS

CLINICAL CRITERIACLINICAL CRITERIA• Respiratory acidosis (ETCO2 above 55 mmHg Respiratory acidosis (ETCO2 above 55 mmHg

or arterial pCO2 above 60 mmHg)or arterial pCO2 above 60 mmHg)

• Heart involvement (unexplained sinus Heart involvement (unexplained sinus tachycardia, VT/VF ) tachycardia, VT/VF )

• Metabolic acidosis (BE < -8, pH <7.25) Metabolic acidosis (BE < -8, pH <7.25)

• Muscle rigidity (generalized rigidity including Muscle rigidity (generalized rigidity including severe masseter muscle rigidity) severe masseter muscle rigidity)

CLINICAL CRITERIACLINICAL CRITERIA• Muscle breakdown (CK >20,000/L units, cola Muscle breakdown (CK >20,000/L units, cola

colored urine or excess myoglobin in urine or colored urine or excess myoglobin in urine or serum, potassium above 6 mmol/l) serum, potassium above 6 mmol/l)

• Temperature increase (rapidly increasing Temperature increase (rapidly increasing temperature, T >38.8°C) temperature, T >38.8°C)

• Other (rapid reversal of MH signs with dantrolene, Other (rapid reversal of MH signs with dantrolene, elevated resting serum CK levels)elevated resting serum CK levels)

• Family history (autosomal dominant pattern)Family history (autosomal dominant pattern)

COMPLICATIONSCOMPLICATIONS

• RhabdomyolysisRhabdomyolysis

• Compartment syndromeCompartment syndrome

• Renal failureRenal failure

• ArrhythmiasArrhythmias

• Coagulopathy (DIC)Coagulopathy (DIC)

• ARDSARDS

• MODSMODS

DIAGNOSISDIAGNOSIS• Score equal to or greater than 6 – more Score equal to or greater than 6 – more

likely MHlikely MH

• Susceptibility testingSusceptibility testing

• Muscle testing – caffeine halothane Muscle testing – caffeine halothane contracture testingcontracture testing

• Genetic testing – RYR mutationGenetic testing – RYR mutation

TREATMENTTREATMENT• Avoidance/discontinuation of trigger agentsAvoidance/discontinuation of trigger agents

• Dantrolene (Azumolene)/ fluids/ urine Dantrolene (Azumolene)/ fluids/ urine outputoutput

• CoolingCooling

• Treatment of complicationsTreatment of complications

TAKE HOME MESSAGETAKE HOME MESSAGE

• Suspect MH Suspect MH

• Availability of dantroleneAvailability of dantrolene

• Cooling/hyperventilationCooling/hyperventilation

• Testing of relativesTesting of relatives

THANK YOUTHANK YOU