CHAPTER 51 | Anesthesia For Orthopedic Surgery Flashcards
TRUE of FALSE
In a beach chair position during upper extremity orthopedic surgery, for every 20 cm of difference in height of the head from the heart, there is a 15-mmHg difference in mean arterial pressure.
TRUE
Most common joint deformity in RA(rheumatoid arthritis):
Atlantoaxial instability, with subluxation of the odontoid process
In spinal cord injury, Succinylcholine can be administered safely for the first:
A. 48 hours after spinal cord injury
B. 72 hours after spinal cord injury
C. The acuteness of the injury is irrelevant to the junctional receptors for depolarizing neuromuscular blocking agent
D. 1-3 days after the injury
A. 48 hours after spinal cord injury
Succinylcholine can be administered safely for the first 48 hours after spinal cord injury. After that time, a proliferation of acetylcholine receptors in the muscle can cause hypersensitivity to depolarizing
muscle relaxants leading to marked hyperkalemia
Maximal hyperkalemia risk from succinylcholine occurs:
A. between 4 weeks and 5 months after spinal injury
B. 72 hours after spinal cord injury
C. between 1 to 2 weeks after injury
D. 24 hours immediately after injury
A. between 4 weeks and 5 months after spinal injury
Maximal hyperkalemia risk from succinylcholine occurs between 4 weeks and 5 months after spinal injury. Serum potassium levels may rise as high as 14
mEq/L, causing ventricular fibrillation and cardiac arrest.
The following are TRUE of spinal cord injury EXCEPT:
A. Patients with spinal cord injury are poikilothermic thereby a subsequent loss of vasoconstriction below the level of injury is expected
B. 48 hours after spinal cord injury, a proliferation of acetylcholine receptors in the muscle can cause hypersensitivity to depolarizing muscle relaxants
C. Spinal shock can occur immediately after the injury and may lasts up to 3 weeks
D. Autonomic hyperreflexia is a syndrome
characterized by severe paroxysmal hypertension with bradycardia from the baroreceptor reflex, dysrhythmias, and cutaneous vasodilatation below and vasoconstriction above the level of the injury
D. Autonomic hyperreflexia is a syndrome characterized by severe paroxysmal hypertension with bradycardia from the baroreceptor reflex, dysrhythmias, and cutaneous vasodilatation above and vasoconstriction below the level of the injury - This statement is FALSE because in Autonomic hyperreflexia, cutaneous VASOCONSTRICTION is expected below the level of injury and VASODILATATION above the level of injury.
Treatment involves removal of the stimulus, deepening of anesthesia, and administration of direct-acting vasodilators.
A 17 year old male, ASA I came in to the ER with a suspected spinal cord injury after a fall from a 8 feet building. He was immediately brought to the OR for surgical procedure of the spine. Intraoperatively, he suddenly develops hypertension and bradycardia, subsequently followed by a seizure. The most likely underlying cause of the intraoperative crisis at this time is:
A. Light anesthesia
B. Myocardial infarction
C. Autonomic Hyperreflexia
D. Malignant hyperthermia
E. Thyroid storm
C. Autonomic Hyperreflexia
With complete cord transection above T5, following recovery from spinal shock, 85% of patients go on to exhibit autonomic hyperreflexia. The syndrome can also occur with injuries at lower levels and is characterized by severe paroxysmal hypertension with bradycardia from the baroreceptor reflex, dysrhythmias, and cutaneous vasoconstriction below and vasodilation above the level of the injury.
Episodes are typically precipitated by distention of the bladder or rectum but can be induced by any noxious stimulus including surgery. Treatment involves removal of the stimulus, deepening of anesthesia, and administration of direct-acting vasodilators. Untreated, the hypertensive crisis may progress to seizures, intracranial hemorrhage, or myocardial infarction.
In scoliosis, surgery is considered
when the Cobb angle exceeds:
50 degrees in the thoracic or 40 degrees in the lumbar spine
5 is higher than 4 so as THORACIC is higher than LUMBAR hence:
50 - Thoracic
40 - Lumbar
Pathologic changes caused by Scoliosis are the following EXCEPT:
A. Hypoxia
B. Hypocapnia
C. Pulmonary vascular constriction resulting in irreversible pulmonary vascular changes.
D. Pulmonary hypertension
E. Cor pulmonale
B. Hypocapnia
Scoliosis can cause chronic hypoxia, hypercapnia, and pulmonary vascular constriction resulting in irreversible pulmonary vascular changes, pulmonary hypertension, and eventually right ventricular hypertrophy and cor pulmonale.
TRUE or FALSE
Post scoliosis repair, the pulmonary function acutely deteriorates for 7 to 10 days after surgery
TRUE
Although the long-term effect of scoliosis repair is to halt the decline in respiratory function, pulmonary function acutely deteriorates for 7 to 10 days after surgery. Preoperative vital capacity is a reliable prognostic indicator of respiratory reserve, and postoperative ventilator support is likely to be required for patients with a vital capacity less than 40% of predicted.
ASRA guideline when to stop WARFARIN prior to NEURAXIAL BLOCK
3-5 DAYS
ASRA guideline when to stop TICLODIPINE prior to NEURAXIAL BLOCK
14 DAYS
Thrombin and Xa Inhibitors
DABIGATRAN hold 5 DAYS prior to neuraxial block
APIXABAN hold 3 DAYS prior to neuraxial block
RIVORAXABAN hold 3 DAYS prior to neuraxial block
ASRA guideline when to stop LOW MOLECULAR WEIGHT HEPARIN prior to NEURAXIAL BLOCK
10-12 hours after prophylactic dose
24 hours after treatment dose
GURD’s minor criteria for FAT EMBOLUS SYNDROME except:
A. Thrombocytopenia
B. Subconjunctival Petechiae
C. Fever
D. Anemia
B. Subconjuctival petechiae
Petechiae in the subconjunctiva or extremities is a major criteria. All others are minor criteria.
In order to diagnose FAT EMBOLISM, 1 major criteria plus 4 minor or laboratory criteria is warranted.
TRUE of FAT EMBOLUS SYNDROME except:
A. surgery involving long-bone fractures and bilateral arthroplasty are predisposing factors
B. mortality rate is 10% to 20%
C. Early corticosteroid use in long-bone fracture patients have no benefit in preventing the syndrome
D. symptom occur 12 to 40 hours after the injury and can range from mild dyspnea to frank coma
C. Early corticosteroid use in long-bone fracture patients have no benefit in preventing the syndrome
Early corticosteroid use in long-bone fracture patients may be beneficial in preventing the syndrome. All the other choices hold TRUE.
GURD’s FAT EMBOLUS SYNDROME Criteria
SCHNOFELD FAT EMBOLISM Index
