Advanced | Co-existing Diseases or Disease States Part I Flashcards
A 30-year-old patient with Fibrodysplasia Ossificans Progressiva (FOP) requires a surgical procedure under general anesthesia. Which of the following would be the most appropriate approach for airway management in this patient?
A) Awake nasal fiberoptic intubation, as it avoids trauma to the airway and minimizes the risk of heterotopic ossification.
B) Orotracheal intubation without fiberoptic assistance, as it is the quickest and most effective method.
C) General anesthesia with muscle relaxants to facilitate intubation, as there is no significant risk of heterotopic ossification in the airway.
D) Intramuscular injection of a local anesthetic for airway management, since regional anesthesia is not an option.
A) Awake nasal fiberoptic intubation, as it avoids trauma to the airway and minimizes the risk of heterotopic ossification
A 30 year old female is scheduled for removal of thymoma. She is a known case of Myasthenia Gravis for a year now and she’s on immuno-suppressant medications. Post-operatively, which of the predictors will require this patient for prolonged intubation?
A. Duration of disease less than or equal 24 months
B. History of a smoking
C. Pyridostigmine dose of > 750 mg/day
D. Vital capacity 3.5L or more
C. Pyridostigmine dose of > 750 mg/day
The predictors of a prolonged mech vent post-operatively are the following:
Duration of disease ≥ 72 months (≥ 6 years)**greatest value
History of a chronic respiratory disease (e.g. asthma and COPD)
Pyridostigmine dose of > 750 mg/day
Vital capacity < 2.9 liters
Prader Willi patient will most likely have which of the following intraoperative issue?
A. Hypoglycaemia
B. Hypocalcaemia
C. Neuroleptic malignant syndrome
D. Malignant Hyperthermia
E. Hypothermia
A. Hypoglycemia
Hypoglycaemia
—
- Adrenal insufficiency occurs in up to 60%, which can lead to hypoglycemia
However in older age they may have diabetes which predisposes to hyperglycemia
TRUE or FALSE
Patients with MG are very sensitive to succinylcholine.
FALSE
In fact, patients with MG are highly resistant to depolarizing muscular blocking agents.
Mg patients are resistant to SUX, sensitive to nondepolarizing blockers. In addition, patients being treated with cholinesterase inhibitors will also have a prolonged response to succinylcholine (prolonged phase I blockade) due to impaired plasma cholinesterase function.
Plasma half-time of which of following is prolonged in patients with end stage cirrhotic liver disease?
A. Diazepam
B. Pancuronium
C. Fentanyl
D. All of the above
D. All of the above
Malignant Hyperthermia is believed to involve a generalized disorder of membrane permeability to
A. Sodium
B. Potassium
C. Calcium
D. Mg
E. Phosphate
C. Calcium
A 46-year-old man is scheduled for repair of an inguinal hernia. Six years ago, he had an episode of malignant hyperthermia during cholecystectomy. Which of the following is the most appropriate perioperative management?
A. Administration of a regional anesthetic
B. Administration of dantrolene orally for two days prior to surgery
C. Avoidance of all inhalational anesthetics except isoflurane
D. Avoidance of ester local anesthetics
E. Flushing the anesthesia machine with oxygen 10 L/min for a minimum of 12 hours
A. Administration of a regional anesthetic
Drugs suitable for patients with MH include all of the following except:
A. Etomidate
B. Nitrous oxide
C. Calcium chloride
D. Ketamine
E. All of the above
E. All of the above
Which of the following statements concerning myasthenia gravis is TRUE?
(A) Neostigmine is inappropriate for antagonism of neuromuscular blockade
(B) The number of acetylcholine receptors is decreased
(C) Plasma cholinesterase concentration is decreased
(D) The risk for malignant hyperthermia is increased
(E) Succinylcholine is contraindicated
(B) The number of acetylcholine receptors is decreased
Which of the following is a known effect of propofol?
(A) Decreased amplitude of somatosensory evoked potentials
(B) Induction of malignant hyperthermia
(C) Inhibition of cytochrome P450
(D) Initiation of porphyria
(E) Suppression of adrenocortical function
(A) Decreased amplitude of somatosensory evoked potentials
*INCREASED Latency
*DECREASED Amplitude
A 27-month-old, 14-kg infant with intestinal obstruction is anesthetized with nitrous oxide at 1 L/min, oxygen at 0.4 L/min, and halothane at 0.8% using a Bain circuit. Ventilation is controlled at a rate of 30/min. The child’s temperature is 39°C, and the PaCO2 is 65 mmHg. Which of the following is most likely?
(A) Malignant hyperthermia
(B) Low gas inflow rate
(C) Low respiratory rate
(D) Pulmonary aspiration of gastric contents
(E) Inaccurate flowmeters
(B) Low gas inflow rate
Most common ECG among Myotonic Dystrophy Type - 1?
Prolonged PR interval and QRS duration
this is a progressive multisystem disorder characterized by the DELAYED relaxation of skeletal muscle after voluntary contraction.
MYOTONIC DYSTROPHY
2 types
DM-1 is the more COMMON and SEVERE form, with a wide phenotype ranging from
asymptomatic to life threatening.
FEATURES of Myotonic Dystrophy Type 1:
- A trinucleotide expansion (CTG) on chromosome 19q
- Effects on virtually any organ system, but most seriously the musculoskeletal, cardiovascular, gastrointestinal, respiratory, central nervous, and endocrine systems
- dystrophic process, begins DISTALLY and
progressing proximally - The Myotonic grip often precedes weakness
A patient with Myotonic Dystrophy is at risk of aspiration due to:
Gastric ATONY and pharyngeal muscle weakness
True of False
(Myotonic Dystrophy) DM-2 commonly complain of myalgia and fatigue, and weakness is usually MILD.
True
- DM-2 is caused by a quadnucleotide expansion (CCTG) on chromosome 3q.
Overall, the clinical course of DM-2 is milder than DM-1.
Most commonly, patients present with mild proximal muscle weakness in the third decade of life or later.
TRUE or FALSE
Annual ECG are recommended among Myotonic patients?
TRUE
High yield tip | Anesthesia Technique:
Is succinylcholine indicated for Myotonic Dystrophy?
NO. Sux should be AVOIDED
Succinylcholine should be avoided, as patients have an exaggerated contracture response to succinylcholine that can potentially make ventilation and tracheal intubation difficult.
If NMB is needed, short acting NMB is preferred, and dosage of NMB should be adjusted in proportion to the degree of muscle wasting.
Is Neuromuscular monitoring reliable intraoperatively in Myotonic Dystrophy?
YES however myotonic response to stimulation can mimic sustained tetany, hence the degree of block could be UNDERESTIMATED.
- Neostigmine and Sugammadex is SAFE
TRUE or FALSE
Shorter-acting opiates and sedatives are preferred to reduce the need for postoperative ventilation.
TRUE
Disorder NOT typically associated with Malignant Hyperthermia:
A. Central core disease
B. Duchenne muscular dystrophy
C. King-Denborough Syndrome
D. Evans Myopathy
B. Duchenne muscular dystrophy
The effect of INHALATION anesthesia on patients with DMD is now thought to be a form of anesthesia-induced rhabdomyolysis
One of the following is evidently one of the earliest SIGNS of malignant hyperthermia:
A. Fever
B. Hematuria
C. Elevated ETCO2
D. Metabolic acidosis
C. Elevated ETCO2
TRUE of Malignant Hyperthermia:
A. Hypercarbia that is resistant to increases in minute ventilation.
B. After confirming adequate ventilation, hypercarbia resistant to increases in minute ventilation should prompt a suspicion of MH
C. The initial dose of dantrolene is 2.5mg/kg. Repeat as frequently as needed until there is a decrease in EtCO2 and muscle rigidity
D. All are TRUE
ALL OF THESE ARE TRUE statement
Hypercarbia that is resistant to increases in minute ventilation. After confirming adequate ventilation, hypercarbia resistant to increases in minute ventilation should prompt a suspicion of MH.
The initial dose of dantrolene is 2.5mg/kg. Repeat as frequently as needed until there is a decrease in EtCO2 and muscle rigidity
Differential diagnosis of MH includes the following EXCEPT:
A. Serotonin Syndrome
B. Fat Embolism Syndrome
C. Thyroid storm
D. Central anticholinergic syndrome
E. Hypokalemic Periodic Paralysis
E. Hypokalemic Periodic Paralysis
Which of the following findings is NOT consistent with a diagnosis of malignant hyperthermia?
a. PaCO2 150 mm Hg
b. MVO2 50 mm Hg
c. pH 6.9
d. Onset of symptoms an hour after end of operation
b. MVO2 50 mm Hg
MH reflects a hypermetabolic state. Clinical signs include tachycardia, tachypnea, arterial hypoxemia, hypercarbia, metabolic acidosis, hyperkalemia, hypotension, muscle rigidity, trismus after succinylcholine administration, and increased temperature.
- Mixed venous oxygen tension would
be very low (normal MVO2 is 30-35, so an elevated MVO2 of 50 would not be consistent with MH).
What type of channelopathy is the main culprit in Hyperkalemic periodic paralysis:
A. Na+ channel myopathy
B. K+ channel myopathy
C. Ca+ channel myopathy
D. Cl- channel myopathy
A. Na+ channel myopathy
It is an autosomal dominant channelo-pathy caused by a mutation of the sodium channel.
The muscles responsible for respiration are usually
spared
The use of potassium-wasting drugs such as thiazide diuretics or carbonic anhydrase inhibitors, along with maintaining a diet of carbohydrate-rich meals, can help prevent episodes.
What type of channelopathy is the main culprit in Hypokalemic periodic paralysis:
A. Na+ channel myopathy
B. K+ channel myopathy
C. Ca+ channel myopathy
D. Cl- channel myopathy
C. Ca+ channel myopathy
Hypokalemic periodic paralysis (hypoPP) is also autosomal dominant and is the result of mutations in both calcium ion (most common) and sodium ion channels.
Patients begin having episodes of weakness, usually in their teenage years; these episodes last hours to days and are the result of a low serum potassium concentration. Proximal muscles are most often affected, while the diaphragm and muscles supplied by the cranial nerves are spared.
Which of the following DOES not present as periodic paralysis?
A. Hyperkalemic periodic paralysis
B. Andersen–Tawil syndrome
C. Myotonia congenita
D. Thyrotoxic periodic paralysis
C. Myotonia congenita
What type of channelopathy is the main culprit in Andersen–Tawil syndrome?
A. Na+ channel myopathy
B. K+ channel myopathy
C. Ca+ channel myopathy
D. Cl- channel myopathy
B. K+ channel myopathy
Anderen–Tawil syndrome (ATS) is caused by a mtation in the potassium ion channel of skeletal muscle.
This results in a periodic flaccid paralysis
similar in presentation to hypokalemic periodic paralysis.
Unlike other channelopathies, Andersen-Tawil Syndrome affects the smooth muscle such as the cardiac muscles. May present with arrhythmia.
Andersen-Tawil syndrome (ATS) is characterized by a triad of: episodic flaccid muscle weakness (i.e., periodic paralysis); ventricular arrhythmias and prolonged QT interval; and anomalies including low-set ears, widely spaced eyes, small mandible, fifth-digit clinodactyly, syndactyly, short stature, and scoliosis.
Affected individuals present in the first or second decade with either cardiac symptoms (palpitations and/or syncope) or weakness that occurs spontaneously following prolonged rest or following rest after exertion.
Atlantoaxial subluxation is diagnosed when the distance between the:
A. anterior arch of the atlas and the odontoid process is >3mm
B. posterior arch of the atlas and the odontoid process >5mm
C. posterior arch of the axis and the odontoid process is >3mm
D. anterior arch of the axis and the odontoid process is >5mm
A. anterior arch of the atlas and the odontoid process is >3mm
Atlantoaxial subluxation is diagnosed when the distance between the anterior arch of the atlas and the odontoid process is > 3 mm
A known epileptic 18 year old is scheduled for electrocorticography to map out the foci-source of her seizure. Which of the following drugs SHOULD be AVOIDED?
A. Midazolam
B. Propofol
C. Alfentanil
D. Rocuronium
A. Midazolam
Why?
A patient undergoing eCOG(electrocorticography) is at higher risk of developing “awareness”. To prevent this, which of the following drugs can be given?
A. Scopolamine
B. 1.5 MAC isoflurane
C. Atracurium
D. Midazolam
A. Scopolamine
A patient with long-standing epilepsy is scheduled for an elective surgery. Pre-operatively, should the maintenance anti-epileptics be DISCONTINUED?
NO.
Unless there is a need for foci-mapping, all anti-epileptics are continued on the day of surgery.
Which of the following medications needs dose up-titration peri-operatively if a patient is on anti-epileptic medications?
A. Dexmedetomidine
B. Fentanyl
C. Rocuronium
D. All of the above
E. A and B only
D. All of the above
All of the following conditions are associated with acromegaly EXCEPT
A. T2 DM
B. Hypertension
C. Cardiomyopathy
D. Obstructive Sleep Apnea
E. COPD
E. COPD
Associated conditions with Acromegaly:
- OSA (70%), larger airways with calcinosis of larynx (may actually need smaller tube), macroglossia, macrognathia, extubation issues common
- HTN (40%), Heart disease, cardiomyopathy, valvular disease, heart block
- Carpal tunnel, raised ICP and headache from 3rd ventricle obsruction
- T2DM
Other Arthritis, large Bowel polyps/tumours, erectile dysfunction / dysmenorrhoea
