Increasing EtCO2 (double or triple), over min. to hrs., or requiring increasing minute vent (or tachypnea) to maintain normal EtCO2
Masseter Muscle Rigidity (Trismus)
*2 or more of these signs greatly increases risk of MH
What is Masseter Muscle Rigidity?
Jaw muscle tightness with limb muscle flaccidity after admin of succhinylcholine.
Keeping in mind that incomplete relaxation or a tight jaw is different from MMR often described as Jaws of Steel.
Additionally myotonia can cause MMR.
What should you do if you're patient has masseter muscle rigidity?
Safest thing to do if MMR presents is to wake the pt up, as intubation will be unlikely as well.
Masseter muscle rigidity is preductive of MH in up to __% of cases, and is associated with myoglobinuria
After an episode of Masseter Muscle Rigidity, the patient should be observed carefully for a period of _____ hours.
What are the S/S of MH?
↑CO2, perspiration, hyperthermia, ↑HR, dysrhythmias, muscle rigidity, HOT CO2 exhauster, dark brown urine in foley catheter (myoglobinuria)
What lab abnormalities would you expect to see w/MH?
Pre-op ABCDs of MH
Ask about personal and family past history of Malignant Hyperthermia Adverse Anesthesia reactions (unexplained fever or death during anesthesia). Aware of clinical signs of MH.
Body temperature monitoring for all patients undergoing general anesthesia for other than brief procedures.
Capnographic monitoring for all patients undergoing general anesthesia.
Dantrolene: have dantrolene available wherever MH trigger anesthetics are used.
ABCDE of emergency treatment for MH
Ask for Help Ask for the MH cart and for dantrolene. Agents/Anesthesia: Stop anesthesia triggering agents and the surgery.
Breathing: hyperventilate with 100% oxygen.
Cooling, if the patient is hot (aggressively down to 38°C): insert large bore IV catheters. Cold intravenous fluids (NS) 15 cc/ kg IV 3 times. Irrigate the wound and stomach with cold saline. Call MH Hotline 1-800 MH HYPER
DANTROLENE: give dantrolene IV, 2-2.5 mg/kg, and repeat the dose until the signs are controlled.
Electrolytes, check them, especially potassium.
What is the dose of dantrolene?
2-2.5mg/kg Q5min repeat until signs are controlled (more than 10 mg/kg may be given as dictated by clinical circumstances)
Continue 1mg/kg Q 6hrs x 24-48 hrs.
How much cold IVF should you give in MH?
15cc/kg IV x3
Where should cool for MH?
ice packs to the groin and axilla, gastric, wound, and rectal lavage– of these, gastric lavage is the quickest most practical means for rapid temperature control.
What are the ABCDEF of secondary steps in MH?
Acidosis? Assess initial and subsequent arterial or venous blood gases.
Bicarbonate? 1-2 mEq/kg guided by pH and base deficit.