Perianesthesia Flashcards
Pasero Opioid-Induced Sedation Scale (POSS)
S = sleep, easy to arouse; acceptable, no action necessary; may increase opioid dose if needed
1. Awake and alert; acceptable, no action necessary, may increase opioid dose if needed
2. Slightly drowsy, easily aroused: acceptable, no action necessary, may increase opioid dose if needed
3. Frequently drowsy, arousable, drifts off to sleep during conversation: unacceptable, monitor respiratory status and sedation level closely until sedation level is stable at less than 3. Decrease opioid dose 25% to 50% or notify doctor for orders for nonsedating, opioid-sparing nonopioid such as acetaminophen
4. Somnolent, minimal or no response to verbal or physical stimulation: unacceptable, stop opioid, consider administering naloxone
Mallampati airway classification score: grading system for anticipation of difficult intubation.
Exam conducted with patient’s head in neutral position and mouth is opened 50-60 mm
Class I: uvula, tonsillar pillars, soft and hard palate visualized
Class II: uvula, soft and hard palate visualized
Class III: portion of the uvula and hard palate visualized
Class IV: portion of hard palate visualized
Spinal Anesthesia
Order of Loss of Function
1. Autonomic or sympathetic functions (vasomotor, bladder control)
2. Sense of temperature
3. Pain
4. Touch
5. Movement
6. Proprioception (sense of body location)
Order of Return of Function
1. Proprioception
2. Movement
3. Touch
4. Pain
5. Temperature
6. Autonomic or sympathetic functions
Last blocked is first to recover
Blocks higher than T1 may cause severe cardiopulmonary collapse
Post Dural Postural Headache (PDPH)
Directly related to the size of the hole made in dura by spinal or epidural needle used
Symptoms: headache typically felt in frontal or occipital location or both (worsened by sitting or standing up); onset usually after 24-72 hours
Associated with neck ache or stiffness, backache, and nausea
Less common: shoulder pain, blurred vision, vomiting, tinnitus
Symptomatic treatment: hydration, analgesics, and caffeinated beverages
Definitive treatment: epidural blood patch that may be given 24 hours after PDPH develops
Drugs used to treat Malignant Hyperthermia
Dantrium: 36 vials with 60 ml sterile water or
Ryanodex: 3 vials with 5 ml sterile water
Initial dosing: dantrolene 2.5 mg/kg with a maximum dosing of 10 mg/kg
Sodium bicarbonate
Dextrose 50%: administer with insulin to prevent hypoglycemia
Regular insulin: to push K+ back into the cells
Lidocaine for injection: for cardiac arrhythmias
Refrigerated cold saline solution: minimum supply of 3 L
Lidocaine or procainamide should not be given if a wide-QRS complex is likely due to hyperkalemia, this may result in asystole
Medications for PONV
Droperidol: acts on dopamine receptors; can cause sedation, hypotension, EPS (extrapyramidal symptoms). Excessive dosing can cause QT prolongation (FDA black box warning)
Prochlorperazine: acts on dopamine receptors; can cause sedation, hypotension, EPS
Promethazine: acts on dopamine receptors; can cause sedation, hypotension, EPS. FDA black box warning: respiratory depression, severe tissue injury, gangrene with IV/IM administration
Diphenhydramine (antihistamine): causes sedation, dry mouth, blurred vision, urinary retention
Metoclopramide: acts on dopamine receptors; causes sedation, hypotension, EPS; increases gastric motility; reduce dose to 5 mg in renal impairment
Ondanestron: acts on serotonin receptors; causes headache, lightheadedness; much more effective for vomiting than nausea; at high doses or in patients with congenital ECG QT prolongation, can cause symptomatic QT prolongation and arrhythmias.
Scopolamine: transdermal patch; causes sedation, dry mouth, blurred vision, confusion; good for patients with motion sickness; apply 4 hours before exposure
Dexamethasone: monitor blood sugar levels in diabetic patients and fluid retention in cardiac patients
Brachial Plexus Block
Brachial Plexus is the major nerve bundle going to the shoulder and arm
For shoulder surgery, interscalene is the gold standard. Cervical paravertebral block above the shoulder is also used.
Block is contraindicated in patients with COPD due to risk of pneumothorax and blockage of phrenic nerve that innervates the diaphragm.
Femoral Nerve Block
Blocks sensation and motor function to the front of the thigh and knee. Commonly used for procedures that cover the knee.
Quadriceps weakness is a major downside, inhibiting early ambulation.
Sciatic and popliteal nerve block
Sciatic nerve provides sensation and motor function to the back of the thigh and most of the leg below the knee.
Popliteal block is a block of the sciatic nerve at the level of the popliteal fossa. Commonly used for surgeries on the knee, calf, Achilles tendon, ankle, and foot.
Adductor canal block
Pure sensory nerve block for post op analgesia following knee surgery. Advantage of preserving or minimally affecting quadriceps strength, facilitating ambulation and rehabilitation.
Isoflurane
Can lead to increased coronary blood flow, which can lead to coronary steal syndrome.
Prolonged use or high dosages of nitroprusside can lead to:
Cyanide toxicity
Fentanyl
Rapid IV injection of fentanyl may trigger bronchial constriction and chest wall rigidity, commonly called fixed chest syndrome. Can anticipate the need for succinylcholine to relieve chest wall rigidity and improve ventilation.
Ropivacaine
May have slightly less effect on motor nerves
SLE
Autoimmune disorder of connective tissues that is characterized by joint pain and swelling
