Memory Master Test 4 Flashcards
3 major concerns related to anesthetizing Down’s patients?
1) Intubation may be difficult owing to LARGE TONGUE, SHORT NECK, SMALL MOUTH, AND SUBGLOTTIC STENOSIS. 1 ETT size smaller
2) Neck flexion during laryngoscopy and intubation may result in atlanto-occipital dislocation because of congenitally weak ligaments (consider getting cervical-spine films)
3) CONGENITAL HEART DISEASE is present in 40% of patients.
VATER syndrome
Vertebral anomalies Anal or intestinal atresia Cardiac Anomalies Tracheo- Esophageal fistula Renal Malformations Limb abnormalities
At what age is cleft palate usually repaired?
12-18 months
What are eleven clinical manifestations of MH?
1) Tachycardia
2) Tachypnea
3) Hypercarbia
4) Hyperthermia
5) Hypertension
6) Hyperkalemia
7) Hypoxemia
8) Acidosis (metabolic)
9) Myoglobinuria
10) Cardiac dysrhythmias
11) Skeletal muscle rigidity
MATTCHHHHHS
Earliest Sign of MH?
Increased ETCO2
How fast does temp increase during MH?
1-2 C q 5min
Diagnostic test for MH?
Halothane-caffeine contracture test is standard
How is MH diagnostic test done? Is it sensitive?
Skeletal muscle biopsy is placed in solution of halothane. Sustained contraction of muscle in response to halothane is diagnostic.
Test is not very sensitive. Many false +’s
Identify the anesthetic agents that are absolutely contraindicated in the patient with family history of MH?
Volatile inhalation agents and succs
8 actions for initial MH management
1) D/C inhaled volatiles and succs
2) Hyperventilate with 100% O2
3) Dantrolene (Ryanodex or Dantrium)
4) Treat acidosis with bicarb (1-2 mM/kg)
5) Lower body temp to 38C with ice packs/gastric lavage
6) place CHARCOAL filters, new anesthetic circuit, new CO2 absorber
7) monitor with capnography and blood gas
8) if necessary, treat hyperkalemia and dysrhythmias.
A patient just experienced masseter muscle rigidity from succinylcholine. What lab confirms diagnosis of MH?
Increased in creatine phosphokinase (CPK> 20,000)
How and where does dantrolene work?
Dantrolene acts at the ryanodine receptor to decrease the calcium level in the skeletal muscle cell by decreasing the release of calcium from Sarcoplasmic Reticulum.
Skeletal muscle relaxes when the supply of Ca to the contractile proteins is impaired.
List 4 ways to actively cool the patient during an acute episode of MH
1) Lavage (orogastric, urinary bladder, open cavities)
2) Administration of chilled IV NS
3) Cardiopulmonary bypass in severe cases
4) Surface cooling (icepacks to groin, axilla, neck, forced air)
What body temp should cooling of MH patient be stopped? Why?
Core temp 38C to prevent deleterious effects of hypothermia
Once the initial episode of MH is controlled, the patient will remain at risk for what 5 complications?
1) Reoccurence
2) DIC
3) Myoglobinuric renal failure
4) Skeletal muscle weakness
5) Electrolyte abnormalities
DREMS
A patient with MH crisis has PVCs. What is drug of choice?
Procainamide 15mg/kg IV
Lidocaine also acceptable
A woman in labor is identified as being susceptible to MH. What anesthetic techniques are acceptable?
Epidural without dantrolene pretreatment for routine labor. If general anesthesia is selected administer dantrolene prophylactically and use non-triggering agents.
During preop assessment of the patient you discover a + family history of MH. What six steps need to be taken to manage this patient? Are non depolarizers safe for the patient?
1) Anesthesia and premedication should be designed to produce low normal HR. Opioids benzos barbs antihistamines anticholinergics do not cause problems in MH
2) anesthesia machine has volatile vaporizers removed and changing CO2 absorbant and flush O2 at 10L/min for >10min
3) Measure ETCO2
4) Body core temp (Nasal, rectal, esophageal) If not possible IV induction follwed by N2O O2 and non depolarizers with opioids. Versed, precedex, diazepam, droperidol, and propofol are safe in MH
5) Art and CVL recommended only as dictated by surgical procedures
6) Observe patient closely Post OP
Why might 2.5 mg/kg dantrolene be administered to patient preoperatively?
Prevent MH
What syndrome mimics MH?
Neuroleptic Malignant Syndrome
NMS develops over 24-72 hrs / MH acutely develops
NMS presents as hypermetabolic episode consisting of hyperthermia, autonomic nervous system instability, muscle rigidity, and rhabdomyolysis
Child undergoing surgery with halothane develops tachycardia, increased temp, skeletal muscle rigidity. Drug of choice?
Dantrolene2.5 mg/kg
Halothane-caffeine contracture test. Good for MH? Why or why not?
No good. Too many false +’s
Which drugs should be avoided in the patient with a family history of MH?
Succinylcholine and volatile agents
Patients treated with what drugs are susceptible to neuroleptic malignant syndrome (NMS)?
NMS results from treatment with antipsychotic agents, (like phenothiazines, haldol, etc).
NMS following antipsychotic drug therapy presumably reflects dopamine depletion in the CNS
