Postanesthetic Management Flashcards
What are the elements of a post anesthesia assessment?
- Respiratory Function
- Cardiovascular Function
- Neuromuscular Function
- Mental Status
- Core Temperature
- Pain
- Post operative nausea and vomiting (PONV)
- •Hydration, bleeding, drainage, urine output
What is the origin of the Aldrete Scoring System?
First described in 1970, although not originally designed for ambulatory patients – later modified with the advent of pulse oximetry
What isthe scoring for Aldrete Scoring System?
Assigns a score of 0, 1 or 2 to activity, respiration, circulation, neurologic status, and oxygen saturation with a maximal score of 10
What is the Aldrete Scoring System needed for transfer?
A score of 9 indicates sufficient recovery for transfer
What are the components of the Aldrete Scoring System?
- Activity
- Respiration
- Circulation
- Consciousness
- Oxygen saturation as determined by pulse oximetry
Review the Aldrete Scoring System.
Review N&P.
Box 55.4
What is true about Activity/Consciousness?
A patient’s intra-operative course may affect post-operative activity
What can affect Activity/Consciousness?
- Type of surgery
- Neuromuscular function
- Pain/Opioid therapy
What is something that can affect activity sfter surgery?
- Dressings/Splints/Casts Regional Anesthesia
What can affect neuromuscular function?
- Beware of patients who have been paralyzed intra-operatively.
- Sedation/amnesic properties of the anesthetic may be wearing off.
What is true about patients who are not moving?
Just because patients are not moving, does not mean they won’t hear what is being said around them.
What can occur if patients are not adequately reversed?
Residual muscle relaxation if not adequately reversed:
- Muscle weakness
- Respiratory distress
- Aspiration
How can pain be managed?
Pain can be managed with intrathecal, epidural, regional or intravenous medication
What is important to do with pain therapy?
- Always safer to titrate small amounts
- Be mindful of treating pain in the PACU and walking away (PACU nurse may be distracted with other patient, alarms on?)
Keep in mind patients are more sensitive to opioids within the ______ after GA
first hour
What is a safer approach to Pain/Opioid Therapy?
Consider a multi modal approach
What is the dose of Fentanyl?
For acute pain, usually 25-50 mcg with repeating doses for effect
What is the onset of Fentanyl?
2-5 minutes (peak effect at CNS 3.6 min)
When can maximum respiratory depression with Fentanyl seen?
Max respiratory depression usually not seen for about 20 minutes
When can delayed repiratory depression with Fentanyl be seen?
Delayed respiratory depression with epidural or spinal opioids seen approx 12-24 hrs after administration
What is the treatment for Pain and Narcotization?
- Time and supportive breathing measures
- T-piece, CPAP/BiPAP, etc.
What medication can be given pain medication overdose?
Narcan/Naloxone
What is the elimination half time of Narcan/Naloxone?
60-90 mins (Flood)
What is the duration of Narcan/Naloxone?
30-45 mins (Flood)
What is an effect of fentanyl?
first pass uptake into lungs (reservoir): can result in prolonged duration of analgesia and respiratory depression with repeated dosing Also undergoes a secondary peak of plasma level (up to 4 hours)
What is true with opioids with long half life?
If using opioids with a long half-life, narcan may metabolize before the opioid leading to re-narcotization
What is the respiratory/oxygen saturation complications? (9)
- Hypoventilation
- Obstruction (partial or complete)
- Laryngospasm
- Vocal cord paralysis
- Glottic edema
- Bronchospasm
- Negative Pressure Pulmonary Edema
- Aspiration
- Pulmonary embolus
What is the most common respiratory complication?
Hypoventilation - Most commonly caused by residual anesthetic agents effects on respiratory drive
What are causes of hypoventilation?
- Opioids
- Muscle relaxants or inadequate reversal
- Hypothermia
- Metabolic disorders
- Surgical issues (Pain/splinting)
Who is at the greatest risk of hypoventilation?
Large abdominal incision, thoracic procedure, underlying pulmonary disease, smoker, advanced age, obesity, length of anesthetic
What is the first stage of hypoventilation?
Stage 1: Initial tachycardia and hypertension with desaturation secondary to stimulation of the sympathetic nervous system
What is the 2nd stage of hypoventilation?
Stage 2: Bradycardia and hypotension ensue as the myocardium becomes depressed
What is the mental changes associated with hypoventilation?
- Initial agitation then somnolence
- PaCO2 >80mmHg causing a decrease in CSF pH
What is needed for hypoventilation?
- Action is needed immediately
- Address the cause, secure an airway, provide supplemental O2
What is a tissue obstruction?
Tongue falling back against the posterior pharynx when the patient is unable to protect their own airway
What are interventions for tissue obstruction?
- Jaw thrust
- Repositioning
- Nasal airway
What is laryngospasm?
An uncontrolled/involuntary muscular contraction of the vocal cords
What is causes of laryngospams?
Airway trauma, repeated instrumentation, stimulation to cords from secretions (blood or mucous)
What are interventions for laryngospasms?
- Jaw thrust
- Positive pressure ventilations in an attempt to open cords
- Succinylcholine +/- 20mg (Prepare to ventilate and possibly intubate)
What is the larson’s maneuver?
a jaw thrust with bilateral pressure on the body of the mandible anterior to the mastoid process
What surgeries can cause Vocal Cord Paralysis?
Thyroid surgery, Carotid endarterectomy, Spinal surgery in the neck (anterior cervical diskectomy), Mediastinoscopy, Esophagectomy, Cardiac surgery (especially aortic valve surgery), Lung surgery (usually only on the left), Repair of aortic aneurysms in the chest, Thymectomy, Brain surgery for aneurysm or tumor
What needs to be done with suspected Vocal Cord Paralysis prior to extubation?
Phonation after extubation
- “E”
- Consider reintubation quickly
What is Glottic Edema?
A swelling caused by fluid accumulation in the soft tissues of the larynx
What are causes of Glottic Edema?
The condition, usually inflammatory, may result from an infection, injury, allergy, or inhalation of toxic substances.
What are the s/s of Glottic Edema?
stridor, hoarseness, and dyspnea.
What is the treatment for Glottic Edema?
Nebulized racemic Epi 2.25% 0.5-0.75ml in 3ml NSS
Define bronchospasm.
Reversible narrowing of the medium and small airways because of smooth muscle contractions
What are causes of bronchospasm?
Vagal afferent stimulus in bronchi related to histamine, or noxious stimulation such as physical stimulation, cold air, inhaled irritants (e.g. inhalational anesthetics)
What are the s/s of bronchospasms?
Wheezing, hypoventilation, hypercarbia
What is the treatment of Bronchospasm?
FiO2 to 100%, remove stimulant, beta agonists, IV decadron & aminophylline
What is the occurence of Negative Pressure Pulmonary Edema?
9:1,000 Anesthetics
Where does Negative Pressure Pulmonary Edema most commonly occur?
Most common etiology in PACU
What are the causes of Negative Pressure Pulmonary Edema?
Can follow laryngospasm, biting on ETT, premature extubation followed by airway obstruction against a closed glottis
What occurs with Negative Pressure Pulmonary Edema?
- Dramatic increase in negative intrapleural pressure
- Creates a high negative hydrostatic pressure in the pulmonary interstitium
- Increases venous return and hydrostatic pressure within the pulmonary vasculature
- Causes fluid shifts and pulmonary edema
What is the treatment of Negative Pressure Pulmonary Edema?
- Continue or re-establish positive pressure ventilation
- Usually resolves within 24 hour
- AVOID airway obstructions!
What medications can be given for Negative Pressure Pulmonary Edema?
- Gentle diuresis with low dose furosemide
- Steroids may be beneficial
Define aspiration.
Inhalation of gastric content into the tracheobronchial tree
What are the causes of Aspiration?
Active vomiting, passive regurgitation, patient unable to protect their airway
What patients are at risk for Aspiration?
Altered LOC, anesthetized larynx, muscle weakness, full stomach, difficult intubation, patient positioning, supra glottic airways (LMAs)
What is the s/s of Aspiration?
Desaturation, coughing, laryngospasm, bronchospasm, dyspnea, evidence of bile.
What is the treatment of Aspiration?
- Establish a secure airway
- Positive pressure ventilation
- Serial chest x-rays
What medications should be given for Aspiration?
- Consider steroids and bronchial dilators
- Antibiotics
Define Pulmonary Embolus.
Partial or complete obstruction of the pulmonary circulation
What are some predisposing conditions Pulmonary Embolus?
hypercoagulable, smoking, cancer, obesity, DVT, pregnancy, immobility, estrogen therapy
What can cause a Pulmonary Embolus?
May be caused by blood clots, fat, air, and/or amniotic fluid
What are some s/s of Pulmonary Embolus?
- Desaturation, pleuritic chest pain, and hemoptysis
- Hypotension and tachycardia
What is the relationship between dead space and pulmonary embolus?
Increased dead space leading to increased PaCO2 (but a sudden drop in EtCO2 due to increase in deadspace ventilation)
What is the treatment of pulmonary embolus?
Adequate ventilation, supportive care, heparin
What is the extubation criteria?
- Sustained Head lift > 5 seconds (can occur at TOF < 0.6)
- NIF less than -25 cm H2O
- Tidal volume > 5 ml/kg
- Spontaneous ventilation
- Following commands, e.g. bilateral hand grasp
- TO4: 4:4 with sustained tetany
Key: for extubation criteria you must monitor ________
neuromuscular blockade
When is a no reversal agent needed?
*TOF ratio > 0.9 (obtained before you would consider no reversal agent)
When should you consider reversal dosing?
- Consider reversal dosing if last dose of relaxant within last 4 hrs despite clinical signs
What is the treatment for reversal?
- Neostigmine 25-75 mcg/kg
- Sugammadex
Where are electrodes for TOF placed?
Electrodes placed over the distal portion of a peripheral nerve
What is the goal of neuromuscular monitoring?
Contraction of the adductor muscle of the thumb via stimulation of the ulnar nerve is the preferred site for determining the level of blockade
What is the location of peripheral neuromuscular monitoring?
Distal electrode placed over the proximal flexor crease of the wrist and the other electrode placed over and parallel to the carpi ulnaris tendon
What are other sites for neuromuscular monitoring?
Other sites include the nerves of the foot and the facial nerve
What are characteristics of facial neuromuscular monitoring?
•Facial nerve monitoring generally involves stimulation of the temporal branch of the facial nerve that supplies the orbicularis oculi muscle (less resistant) around the eye or the corrugator supercilii (more resistant) that moves the eyebrow when frowning
What is the onset of muscle relaxant?
During onset of a relaxant, muscle group sensitivity follows a pattern:
- Eye muscles are the most sensitive and are the first group affected, followed by the extremities, the trunk of the body with the neck and chest first, then abdominal muscles, and lastly the diaphragm
What is the recovery of neuromuscular blockade?
- Eye muscles are the most sensitive and are the first group affected, followed by the extremities, the trunk of the body with the neck and chest first, then abdominal muscles, and lastly the diaphragm
- Recovery occurs in the opposite order
Where is blood flow greatest?
Blood flow is greatest to the head, neck and diaphragm so more of the drug is distributed to these areas upon initial distribution and onset
Where is recovery best measured? Why?
Recovery is best measured in the hand because hand muscles are more sensitive to relaxant than the diaphragm
What is characteristics of single twitch peripheral nerve stimulator?
Single Twitch = Single pulse of 0.1-1 hertz for 0.1-0.2 milliseconds
What does a single twitch peripheral nerve stimulator indicate?
Simply indicates whether 100% paralysis is present
What does it indicate if If a patient’s muscle moves when stimulated with a single twitch peripheral nerve stimulator?
less than 100% paralysis is present
Define TOF.
Four separate stimuli every 0.5 seconds at a frequency of 2 hertz for 2 seconds
What is the comparison made with the Train of Four?
A comparison is made of the four stimulated responses (T1 thru T4)
What is true about TOF and NDMB?
With NDMB there is a progressive diminution of twitch responses with visible fade (each successive twitch is smaller)
Train of four (T4 disappears) and percent of neuromuscular blockade
block of 75-80%
Train of four (T3 disappears) and percent of neuromuscular blockade
block of 80-85%
Train of four (T2 disappears) and percent of neuromuscular blockade
block of 90-95%
Train of four (No twitches) and percent of neuromuscular blockade
block of 100%
Train of four ratio is an assessment of the size of _____ compared with ____
T4; T1
Review Characteristic Train of Four Response During Onset of a NDMB
Review Characteristic Train of Four Response During Recovery of a NDMB.
Review TOF stimulation with nondepolarizinh block and depolarizing block.
Define Double Burst Stimulation.
Two bursts of 50 hertz tetanus separated by 0.75 seconds
What are the characteristics of Double Burst Stimulation?
- Improves the ability to detect residual paralysis during recovery
- Evaluating two (rather than four) twitches facilitates detection of fade
Review Double Burst Stimulation Graph.
Define tetanus.
Sustained stimulation of 50-100 hertz for 5 seconds
What is the result of no significant paralysis with the Tetanus?
If the muscle contraction produced is sustained for the entire 5 seconds without fade, significant paralysis is unlikely
What is the result of significant paralysis with the Tetanus?
If fade is present, clinically significant block remains
What is a characteristic of Tetanus?
Painful test so should not be repeated too often in order to avoid muscle fatigue
Define Post Tetanic Count.
50 hertz tetanic stimulation for 5 seconds, followed in 3 seconds by a series of single 1 hertz twitch stimulations
What is the characteristics of Post Tetanic Count?
When the 50 Hz stimulation is applied there is no response because the patient is completely blocked, but it does mobilize excess Ach so that after a 3 second pause a short series of single twitch responses in the hand can be elicited
What is the Post Tetanic Count?
The number of twitches is counted and the higher the count the less intense the block
What is counted in the Post Tetanic Count?
Usual count is between 0 (deep block) and 8 (less intense block where TOF response should return)
Review Peripheral Nerve Simulation.
What is the characteristic blocks?
- Phase I – Depolarizing Block
- Phase II- Nondepolarizing block
What medications are associated with Phase I – Depolarizing Block?
SCH
What precede onset of Phase I – Depolarizing Block?
Muscle fasiculations precede onset
What is the response of Phase I – Depolarizing Block?
Sustained response to tetanic stimulation
What is not a response of Phase I – Depolarizing Block?
- Absence of posttetanic potentiation, stimulation or facilitation
- Lack of fade to tetanus, TOF or double burst stimulation
What medications are associated with Phase II – Nondepolarizing Block?
NDMA
What is absence in Phase II – Nondepolarizing Block?
Absence of muscle fasciculation
What is absence of Phase II – Nondepolarizing Block?
Appearance of tetanic fade and posttetanic potentiation, stimulation or facilitation
What is neuromuscular monitoring for Phase II – Nondepolarizing Block?
TO4 and double burst fade
What reverses Phase II – Nondepolarizing Block?
Reversal with anticholinesterase drugs
What medication can cause a Phase II – Nondepolarizing Block?
In rare cases may be produced by an overdose and desensitization with succinylcholine at doses greater than 6mg/kg
What can still occur with TOF 4/4?
70-75% of receptors blocked
What can occur with Spontaneous Tidal Volume (5 mL/kg)?
Receptors may be as much as 80% blocked
What can occur with Vital Capacity 20 mL/kg?
Receptors may be as much as 75% blocked
What can occur with Negative inspiratory force of -40 cmH2O?
Receptors may be as much as 50% blocked
What can occur with Head lift 5 seconds?
Receptors may be as much as 50% blocked
Review N&P Table 12.3
Review Nagelhout Box factors that may prolong paralysis.
What is the circulation side effects that can occur post?
- Hypotension
- Hypertension
- Increased myocardial oxygen demand secondary to shivering
What are causes of hypotension?
- Decreased preload
- Decreased Contractility
- Decreased SVR
- Inadequate resuscitation
What are the charactersitcs of decreased preload?
- Intra operative blood loss
- Active bleeding
- Vasodilatation
What are the characteristics of decreased contractility?
CHF, cardiomyopathy, hypoxemia
What are the characteristics of decreased SVR?
- Vasodilatation
- Sepsis
- Anaphylaxis
What are the characteristics of inadequate resuscitation?
- Insensible losses during surgery
- Bleeding
- Preoperative fluid deficit
What are the s/s of hypotension?
- Weak peripheral pulses
- Difficulty obtaining a pulse oximeter tracing
- Decreased urine output
- Arrhythmias
What is the management of hypotension?
- FiO2 100%
- Stat H&H
- Expand circulating volume
- Consider inotropes or vasopressors
Define hypertension.
Increase of greater then 20% from baseline or an absolute reading of 160/110
What are causes of hypertension?
Pre-existing disease, acute withdrawal of medications, pain, volume overload, hypercarbia
What is the treatment hypertension?
•Investigate causes: Last dose of anti-hypertensive, Pain, Fluids
What are complications of hypertension?
MI, CHF, pulmonary edema, ICP
What does shivering produce?
Increases oxygen consumption by 400%
What is the relationship of shivering and inhalational anesthetics?
Inhalational anesthetics alter hypothalamic temperature control
What are causes of intra operative hypothermia?
- Room temperature (convection, conduction)
- Exposure (convection, evaporative)
- Vasodilatation secondary to anesthetic
What is the treatment for shivering?
Demerol 12.5mg x2
What is other treatments of shivering?
- Dexmedetomidine/Clonidine
- Butorphanol
- Ketamine
- Tramadol
What are other issues from post op surgery?
- Hypothermia
- N/V
- OSA (Assess, minimal sedation, CPAP)
- Emergence Delirium (assessing and treating underlying cause)
- Pain
What are examples of N/V?
dexamethasone, ondansetron, aprepitrant, (neurokinin, substance P antagonist), scopolamine, hydrations, diphenhydramine, TIVA with propofol
Who are at increased risk of Postoperative Nausea and Vomiting (PONV)?
- Female
- <50 years old
- Nonsmoker
- Hx of PONV
- Hx of motion sickness
- Use of volatile anesthetics
- Duration of anesthesia (inc. duration leads to inc. risk)
- Use of nitrous oxide
- Opioids
- Type of surgery: Laparoscopic, gynecologic, +/- cholecystectomy
Review anesthesia admission report?
When should facial nerves be assesed?
Facial nerves should be used when assessing relaxant onset as the facial muscles mirror distribution to the larynx and diaphragm
