Malignant hyperthermia: Difference between revisions
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==Work-Up== | ==Work-Up== | ||
*Core temperature | |||
*CBC | |||
*Chem 7 | |||
*Total CK | |||
*PT/PTT | |||
*ABG | |||
==Diagnosis== | ==Diagnosis== | ||
*Muscle contraction | |||
*Fever | |||
*First signs | |||
**Hypercarbia | |||
**Sinus tachycardia | |||
**Masseter spasm | |||
**Temperature abnormalities (may be early) | |||
*Most common pattern | |||
**Respiratory acidosis and muscular abnormalities | |||
===Presentations=== | ===Presentations=== | ||
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===Types=== | ===Types=== | ||
*Fulminant MH | |||
**muscle rigidity, high fever, increased HR shortly after induction of anesthesia | |||
*Masseter muscle rigidity | |||
**jaw muscle rigidity after succinylchoine | |||
**More common in children | |||
**Presages MH in 20-30% cases | |||
**All patients demonstrate elevated CK and often gross myoglobinuria | |||
**CK >20,000IU = high likelihood of MH | |||
* Late onset MH | |||
**Uncommon, may begin shortly after anesthesia termination (usually within first hour) | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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==Treatment== | ==Treatment== | ||
*Initial | |||
**Declare MH Emergency: (call OR for anesthesia to bring MH cart) | |||
** Discontinue Triggering Agents | |||
** 100% Oxygen at High Flow | |||
** Give Dantrolene | |||
***Designate 2 or 3 people to mix sterile water into Dantrolene \ | |||
****60ml sterile water into each vial of dantrolene; may need up to 36 vials | |||
****If using Dantrium® (20 mg/vial), each vial contains 3 g of mannitol (renal vasodilation); newer nanocrystalline dantrolene (250 mg/vial) has 250 mg mannitol per vial and requires mannitol supplementation | |||
*** '''2.5 mg/kg IV push''' | |||
*** Titrate to effect; may need more than 10 mg/kg | |||
**Bicarb for metabolic acidosis | |||
*** 1-2 mEQ/kg if blood gas values not yet available | |||
** Cool the patient if core temp >39 deg C (102.2 deg F) | |||
*** Stop cooling when temp reaches 100.4 | |||
** Dysrhythmias usually respond to treatment of acidosis and hyperkalemia | |||
*** Standard therapy EXCEPT NO CA CHANNEL BLOCKERS: | |||
****may cause hyperkalemia or cardiac arrest in presence of dantrolene | |||
** Treat hyperkalemia: standard treatment, remember to check glucose levels q1h after treatment with insulin/glucose | |||
** Call MHAUS Hotline if needed: 1-800-644-0737 | |||
*Continued Care | |||
**Dantrolene 1 mg/kg every 4-6 hours for 24–48 hours | |||
**Monitor for recrudescence (rate is 25%) | |||
**Follow electrolytes, blood gases, CK, core temperature, urine output and color, coagulation studies | |||
==Prognosis== | ==Prognosis== | ||
===Stable to Transfer Criteria=== | ===Stable to Transfer Criteria=== | ||
*ETCO2 is declining or normal | |||
*HR is stable or decreasing | |||
*No ominous dysrhythmias | |||
*Temperature is declining | |||
*Generalized muscular rigidity is resolving (if present) | |||
*IV dantrolene administration has begun | |||
===Complications=== | ===Complications=== | ||
*Consciousness Level Change/Coma | |||
*Cardiac Dysfunction | |||
*Pulmonary Edema | |||
*Renal Dysfunction | |||
*Disseminated Intravascular Coagulation | |||
*Hepatic Dysfunction | |||
*Relapse | |||
*Death | |||
==See Also== | ==See Also== | ||
Revision as of 18:46, 14 May 2015
Background
- Inherited disorder of skeletal muscles triggered most often by anesthesia inhalation agents and/or succinylcholine
- Results in hypermetabolism, skeletal muscle damage, hyperthermia, and death if not treated quickly
- GENERALIZED rigidity NOT always present; if it occurs, MH is almost certain
Likelihood of Complications
- Increased time from 1st sign to 1st dantrolene
- For every 30 minute increase in the interval, complication likelihood increases x 1.6
- Increased maximal temperature
- For every 2°C increase in max temp, complication likelihood increases x 2.9
Work-Up
- Core temperature
- CBC
- Chem 7
- Total CK
- PT/PTT
- ABG
Diagnosis
- Muscle contraction
- Fever
- First signs
- Hypercarbia
- Sinus tachycardia
- Masseter spasm
- Temperature abnormalities (may be early)
- Most common pattern
- Respiratory acidosis and muscular abnormalities
Presentations
- 99% Respiratory Acidosis
- 26% Metabolic Acidosis
- 80% Muscular Abnormalities
Watch for it with succinylcholine use.
Types
- Fulminant MH
- muscle rigidity, high fever, increased HR shortly after induction of anesthesia
- Masseter muscle rigidity
- jaw muscle rigidity after succinylchoine
- More common in children
- Presages MH in 20-30% cases
- All patients demonstrate elevated CK and often gross myoglobinuria
- CK >20,000IU = high likelihood of MH
- Late onset MH
- Uncommon, may begin shortly after anesthesia termination (usually within first hour)
Differential Diagnosis
Fever
Infectious
- Critical
- Sepsis
- PNA with respiratory failure
- Peritonitis
- Meningitis
- Cavernous Sinus Thrombosis
- Necrotizing Fasciitis
- Emergent
- PNA
- Peritonsillar Abscess
- Retropharyngeal Abscess
- Epiglottitis
- Endocarditis
- Pericarditis
- Appendicitis
- Cholecystitis
- Diverticulitis
- Intra-abdominal abscess
- Pyelonephritis
- Tubo-ovarian abscess
- Encephalitis
- Brain abscess
- Cellulitis
- Abscess
- Malaria
- Non-emergent
Non-infectious
- Critical
- Emergent
- CHF
- Dehydration
- Recent Seizure
- Sickle Cell Dz
- Transplant rejection
- Pancreatitis
- DVT
- Serotonin Syndrome
- Non-emergent
- Drug fever (except as in NMS and Serotonin Syndrome)
- Malignancy
- Gout
- Sarcoidosis
- Crohn's Disease
- Postmyocardiotomy syndrome
- Sweet's syndrome
Treatment
- Initial
- Declare MH Emergency: (call OR for anesthesia to bring MH cart)
- Discontinue Triggering Agents
- 100% Oxygen at High Flow
- Give Dantrolene
- Designate 2 or 3 people to mix sterile water into Dantrolene \
- 60ml sterile water into each vial of dantrolene; may need up to 36 vials
- If using Dantrium® (20 mg/vial), each vial contains 3 g of mannitol (renal vasodilation); newer nanocrystalline dantrolene (250 mg/vial) has 250 mg mannitol per vial and requires mannitol supplementation
- 2.5 mg/kg IV push
- Titrate to effect; may need more than 10 mg/kg
- Designate 2 or 3 people to mix sterile water into Dantrolene \
- Bicarb for metabolic acidosis
- 1-2 mEQ/kg if blood gas values not yet available
- Cool the patient if core temp >39 deg C (102.2 deg F)
- Stop cooling when temp reaches 100.4
- Dysrhythmias usually respond to treatment of acidosis and hyperkalemia
- Standard therapy EXCEPT NO CA CHANNEL BLOCKERS:
- may cause hyperkalemia or cardiac arrest in presence of dantrolene
- Standard therapy EXCEPT NO CA CHANNEL BLOCKERS:
- Treat hyperkalemia: standard treatment, remember to check glucose levels q1h after treatment with insulin/glucose
- Call MHAUS Hotline if needed: 1-800-644-0737
- Continued Care
- Dantrolene 1 mg/kg every 4-6 hours for 24–48 hours
- Monitor for recrudescence (rate is 25%)
- Follow electrolytes, blood gases, CK, core temperature, urine output and color, coagulation studies
Prognosis
Stable to Transfer Criteria
- ETCO2 is declining or normal
- HR is stable or decreasing
- No ominous dysrhythmias
- Temperature is declining
- Generalized muscular rigidity is resolving (if present)
- IV dantrolene administration has begun
Complications
- Consciousness Level Change/Coma
- Cardiac Dysfunction
- Pulmonary Edema
- Renal Dysfunction
- Disseminated Intravascular Coagulation
- Hepatic Dysfunction
- Relapse
- Death