Term
| The standardized diameter of face mask or et tubes. |
|
Definition
|
|
Term
| What is the way of measuring out other gases? |
|
Definition
|
|
Term
| What are the 3 knobs of the gas-flow adjustment? |
|
Definition
| Oxygen O2, Nitrous oxide (N20), and air. |
|
|
Term
|
Definition
| The metal floar that moves within a calibrated column to measure your gas flow. |
|
|
Term
| What does the fail-safe valve do? |
|
Definition
| It protects the patient by stopping the flow of all gases if the oxygen fails. |
|
|
Term
| What does the gas analyzer do? |
|
Definition
| It confirms that the gas is what the patient is getting. |
|
|
Term
| How does the gas analyzer work? |
|
Definition
| It continually samples a small volume of gas (about 150ml/min) through a little tube connecting it to the breathing circuit. This sample of gas is analyzed by mass spectrometry or other techniques to determine what its contents are. |
|
|
Term
| What do you do if a valve breaks? |
|
Definition
| We push gas flow in the right direction somply by turning up thr fresh gas flows. |
|
|
Term
|
Definition
| Automatic pressure-limiting (APL) valve also known as the pop off valve releases pressure above a preset level into the gas scavenging system. When patients breath spontaneosuly we leave it open as they do not need positive pressure. When we are ventilating them by aqueezing the reservoir bag, we close the valve partway to allow positive pressure. |
|
|
Term
| When is pressure controlled ventilation handy? |
|
Definition
| During laparoscopic and prone surgery. Both of thwese surgeries tend to cause higher-than-normal airway pressures. |
|
|
Term
| When is CPAP used during surgery? |
|
Definition
| Sometimes it is used as the patient is starting to breathe again at the end of a case to counteract the resistance of breathing through an ET tube. |
|
|
Term
What does the pressure relief valve do? |
|
Definition
| It prevents the pressure from rising indefinitely. it is connected between the breathing circuit and the waste-gas scavenging system. |
|
|
Term
| When is the humidifier removed from the breathing circuit and why? |
|
Definition
| It is removed before letting the patient breathe spontaneously at the end of the case because it contributes significantly to resistance in the circuit. |
|
|
Term
| What leads do we monitor in surgery? |
|
Definition
| Leads II and V5 because it displays inferior, lateral or anterior walls. |
|
|
Term
| How does a pulse oximeter work? |
|
Definition
| A pulse oximter shines 2 frequencies of light into a finger- the 660 nm red light that deoxyhemoglobin absorbs best, and the 940 nm near-infrared light that oxyhemoglobin absorbs best. It then analyzes what % of each frequency is absorbed and uses its built-in algorithms to calculate the ratio of oxygenated to deoxygenated blood. |
|
|
Term
| How does volatile anesthetics contribute to hypothermia? |
|
Definition
| They cause peripheral vasodilation (sending warm blood to the extremities, as if the patient were in a warm room instead of a cold one) and also temporarily reset the body's internal thermostat to maintain a lower temperature. |
|
|
Term
| What is the degree that patients tend to plateau in surgery? |
|
Definition
| 34 degrees Celsius or 93 degrees Farhenheit. |
|
|
Term
| Hypothermia leads to what complications? |
|
Definition
| Coagulopathy and wound infection. |
|
|
Term
| What position does orthopedic and thoracic procedures mostly take place? |
|
Definition
| Left/right lateral decubitus |
|
|
Term
| How do you try to make a hypoxic drive? |
|
Definition
| Leaving the oxygen content on its minimum setting and turning up the nitrous oxide. |
|
|
Term
| How do you test the oxygen fail-safe valve? |
|
Definition
| Detaching the oxygen hose at its wall socket. |
|
|
Term
| What is benzoin (Mastisol)? |
|
Definition
|
|
Term
|
Definition
| Bispectral index monitoring measures brain acitivty in adult patients undergoing general anesthesia or sedation. |
|
|
Term
| Describe the Meyer-Overton Rule. |
|
Definition
| The more soluble medications are in lipids, the more effective they are as anesthetics. |
|
|
Term
| What are the four things that make up general anesthesia? |
|
Definition
Amnesia- lack of memory
Analgesia- lack of pain
Hypnosis- lack of response
Muscle relaxation |
|
|
Term
| What are the fours of anesthesia? |
|
Definition
1. Analgesia and amnesia
2. Delirium and unconsciousness
3. Surgical anesthesia
4. Overdose |
|
|
Term
| What stage of anesthesis do patients have the highest risk of laryngospasm? |
|
Definition
| Stage 2: Delirium and unconsciousness |
|
|
Term
| What is one characteristic that patient must do before extubation? |
|
Definition
| We must wait until patients are able to respond to commands. They have to prove they are in stage 1 before they can be extubated. |
|
|
Term
| Where is the cardiorespiratory centers located in the brain? |
|
Definition
|
|
Term
|
Definition
| Minimum alveolar concentration or effective dose for 50% of people is how much volatile agent it takes for 50 percent of people not to move during skin incision. Typically arouns 1.3 MAC. |
|
|
Term
| What is the number considered for surgical anesthesia according to BIS? |
|
Definition
|
|
Term
| Describe the solubility of anesthetics. |
|
Definition
| The less soluble they are in blood, the faster the act. This is because when an agent is very soluble in blood, the blood acts like a reservoir; the body is absorbing inhaled anesthetic, but the blood is holding onto it, so the brain takes awhile to see much of it. Conversely, for agents that are less soluble, the blood rapidly gets as saturated as it's going to get-as does the brain. |
|
|
Term
| Descrive the 5 basic ways to speed up your concentration of an anesthetic. |
|
Definition
1. Use a less soluble anesthetic.
2. Increase fresh gas flows.
3. Increase alveolar ventilation
4. Use the "overshoot technique"- going past the desired concentrations on the vaporizer dial for a few breaths, then back down to your original goal.
5. Use the "second gas phenomenon" by adding N20 helps the volatile agent concentraion increase more rapidly. |
|
|
Term
| What are the 2 fastest voltile anesthetics? |
|
Definition
| Sevoflurane and Desflurane |
|
|
Term
| What is the longest acting volatile anesthetic? |
|
Definition
|
|
Term
| What is a disadvantage of sevoflurane? |
|
Definition
| It can react with soda lime (carbon dioxide absorbent) to form a variety of substances, including something called Compound A which causes kidney problems. It is used with caution with patients with kidney problems. |
|
|
Term
| How do you prevent Compound A buildup? |
|
Definition
| By keeping the fresh gas flows at 2 LPM or higher. |
|
|
Term
| Which gas is the lease soluble and therefore the fastest? |
|
Definition
|
|
Term
| What kind of surgeries is desflurane used for and why? |
|
Definition
| It used for long surgeries, especially obese patients because the amount absorbed depends on both time and body mass. |
|
|
Term
| What is a disadvantage associated with desflurane? |
|
Definition
| Airway hyper-reactivity even when asleep related to the sympathetic stimulation when it is first administered. it is used in caution with smokers or asthmatics. It can cause laryngospasm so we don't use it for mask induction. |
|
|
Term
| What volatile gas can we use for mask induction of kids? |
|
Definition
| Sevoflurane. Desflurane causes laryngospasm. |
|
|
Term
|
Definition
| It used for patients who will remain intubated at the end of the case. |
|
|
Term
| How does isoflurane work on cerebral and coronary arteries? |
|
Definition
| It dilates the coronary and cerebral vessles more than the other agents, so we like to use it for heart surgeries and certain neuro-surgical work; as an additional benefit for heart surgery, it has been shown to protect the heart during ischemia. It is also the cheapest. |
|
|
Term
| What are some side effects from volatile anesthetics after surgery? |
|
Definition
| The volatile anesthetics don't provide any analgesia at all once they wear off and patients may feel nauseated. |
|
|
Term
|
Definition
| To induce anesthesia with volatile agents. Common in pediatrics. Sevoflurane and N20 or primarily used. |
|
|
Term
|
Definition
| It provides profound analgesia, although amnesia is not reliable. its MAC is 106%, which wouldn't leave much room for oxygen so we can't give a full MAC. N20 is the fastest agent of them all. |
|
|
Term
| Which gas predisposed the patient to nausea more than any other agent? |
|
Definition
|
|
Term
| What happens when you turn off N20? |
|
Definition
| It diffuses rapidly from the blood into the lungs. If you're giving the patient room air at that point enough N20 can enter the lungs to make the patient hypoxic. This is termed DIFFUSION HYPOXIA and we avoid this by giving patients high-flow oxygen at the end of the case. |
|
|
Term
| Why is N20 a poor choice during abdominal surgeries. |
|
Definition
| N20 is far more soluble in air than in blood it will difuse into any air filled space in the body which includes the GI tract or any area where air has been trapped. It is particulary dangerous around a pneumothorax or pneumocephalus. |
|
|
Term
| What is the advantage that N20 has over the volatile agents? |
|
Definition
| It's the only inhaled agent that is odorless. Because of this, when we do mask inductions in children, we like to start with N20 before adding sevoflurane. |
|
|
Term
| Why are induction agents so quick? |
|
Definition
| It is quick to get to the brain by crossing the blood-brain barrier therefore it can induce anesthesia quick. |
|
|
Term
|
Definition
1) Either the patient can metabolize the drug
2). The patient can redistribute the drug-meaning it is taken up onto other tissues such as muscle. Redistricution can occur at different speeds, but is usually faster than metabolism at getting a single dose of drug out of the brain. |
|
|
Term
| What are the four induction agents? |
|
Definition
| Propofol, Etomidate, Ketamine, Thiopental |
|
|
Term
|
Definition
| It works on the GABA receptors to induce anesthesia. |
|
|
Term
| What are some side effects of propofol? |
|
Definition
| It reduces SVR, cardiac contractility, depresses respiration in does used for sedation and produces apnea in induction doses, and causes a warm or burning sensation when first injected iv. Propofol has no preservatives and the fat emulsion supports bacterial growth-the vial is good for only 6 hours after you open it. |
|
|
Term
| What are some benefits of propofol? |
|
Definition
| It has excellent antiemetic properties. If patient recalls dreams they are pleasant ones. It is the only induction agent that can be used alone when placing an LMA. |
|
|
Term
| What are 2 easy ways to correct propofol's hypotensive effects? |
|
Definition
| Laryngoscopy and a little does of ephedrine. |
|
|
Term
|
Definition
| Like propofol is works ont he GABA receptors, but this time by increasing receptor sensitivity. |
|
|
Term
| What are some disadvantages associated with etomidate? |
|
Definition
| Unline propofol it makes PONV more likely. It can cause adrenal suppresion. It is associated with myclonus- which is centrally mediated, and thus increases cerebral oxygen usage. |
|
|
Term
| What type of surgeries is thiopental used for and why? |
|
Definition
| Neurosurgeruy because it induces a decrease in cerebral blood flow but more than compensates by cutting the cerebral oxygen requirements in half. It is a barbituate. |
|
|
Term
| How is thiopental cleared from the brain? |
|
Definition
|
|
Term
| Why does thiopental cause hypotension? |
|
Definition
| It is from the barbituate knocking out the medullary vasomotor center causing vasodilation. A fluid bolus helps. |
|
|
Term
| What kind of anesthetic is Ketamine? |
|
Definition
| A PCP derivative. It is a dissociative anesthetic. The patient appears awake and typically continues to breaths but can't process or respond to stimulation. You can think of this as temporarily disconnecting the cortex (which handles sensation) from the thalmus. |
|
|
Term
| What are the advantages of Ketamine? |
|
Definition
| It increases b/p and hr because of its sympathetic stimulation. It bronchodilates. It doesn't cause apnea. Its ability to block the neurotransmitter NMDA makes it a potent analgesic. |
|
|
Term
| What are disadvantages of Ketamine? |
|
Definition
| It can cause dysphoric hallucinations so we premedicate with versed. Ketamine can also cause nausea and increased secretions. The increased secretions can be addressed with anticholinergics like glycopyrrolate. |
|
|
Term
|
Definition
| It enhances the action of the inhibitory neurotransmitter GABA in the brain. |
|
|
Term
| What are disadvantages of versed? |
|
Definition
| It depresses respiration and causes hypotension. A small sedation dose of versed wears off more quickly than valium. |
|
|
Term
| Name the different receptors opiods work on. |
|
Definition
| Mu-1 which cause analgesia. Mu-2 which causes respiratory depression. Kappa receptors are responsible for the opiods sedative effects. |
|
|
Term
| When do you typically give fentanyl and morphine? |
|
Definition
| Fentanyl for intraoperative pain and Morphine for longer acting postoperative pain relief. |
|
|
Term
| Where is fentanyl metabolized? |
|
Definition
| The liver. It's highly lipid soluble so it crosses the blood-brain barrier quickly. |
|
|
Term
| Is morphine fast or short acting and why? |
|
Definition
| It is short acting because its not very lipid soluble so it crosses the blood-brain barrier slowly. |
|
|
Term
| What is a common side effect of Morphine? |
|
Definition
| Hypotension related to histamine release especially when given quickly. Patient frequently complain of pruitis after receiving it. |
|
|
Term
|
Definition
| Renally. A dose may last several days in renal failure. |
|
|
Term
| How is Remifentanil metobolized? |
|
Definition
| Like Sux, it's metabolized by plasma cholinesterases. This means that there is no buildup over time. In other words, it wears off quickly. |
|
|
Term
| What medication is a good answer for neurosurgeons who will want to do a neuro check immediately afterward? |
|
Definition
|
|
Term
| What is a disadvantage of Remifentanil? |
|
Definition
| It is associated with hyperalges (worsening of pain- as if it sensitizes the patient) when discontinued, but that quick wakeup is worth the disadvantages in certain circumstances. |
|
|
Term
| What compound is demerol metabolized to? |
|
Definition
|
|
Term
| Why is demerol not typically given anymore? |
|
Definition
| Because it accumulates with large or repeated doses and lowers the seizure threshold. |
|
|
Term
| Why is demerol given for shivering post op? |
|
Definition
| It activated the kappa (sedative) receptors more than other opiods. |
|
|
Term
| What type of pain is demerol good for and why? |
|
Definition
| It is godo for bile duct pain since it decerases sphincter of Oddi contraction. |
|
|
Term
| Where is demerol cleared from? |
|
Definition
| The kidneys. It is a bad choice for renail failure patients. |
|
|
Term
| What are some advantages of dilaudid? |
|
Definition
| It doesn't release histamine like morphine and is associated with less nausea and vomiting than other opioids. |
|
|
Term
| What classifications are the local anesthetics? |
|
Definition
|
|
Term
| Describe why the esters have been replaced. |
|
Definition
| They are metabolized to para-aminobenzoic acid, or PABA. Fromerly an active ingrefient in sunblock. These patients should also not receive ester local anesthetics. |
|
|
Term
| Which classification of local anesthetics is associated with the LEAST allergic reactions? |
|
Definition
|
|
Term
| Name some amide local anesthetics. Which are long acting? |
|
Definition
| Lidocaine, bupivacaine, and ropivacaine. Each has 2 I's in its name. Bupivicaine and Ropivicaine are long acting. |
|
|
Term
| What are some signs and symptoms of overdose with a local anesthetic via an epidural cathetier that has entered a vein? |
|
Definition
| Odd sensations, such as ringing in the ears, and a metallic taste in the mouth. |
|
|
Term
| What is a complication of LA overdose and what is the treatment? |
|
Definition
| Seizures and EKG changes leading to cardiac arrest. Intralipid or IV fat emulsion has been shown to be useful in LA overdose. Since LA are lipid souble, a lare dose of IV lipids is theorized to help by absorbing LA from the bloodstream. |
|
|
Term
| Explain how a muscle contraction happens. |
|
Definition
| A signal-an action potential, travels down a nerve toward muscle. When it reaches the end of the nerve, calcium ions are released into the cytoplasm, and the neurotransmitter acetylcholine is released from storage vesicles into the neuromuscular junction. The ACh then binds to receptors on the muscle cell. If enough receptors are bound, the action potential will propogate along with muscle, the cell membrane will depolarize by cation flow across open channels, and the muscle will contract. Acetylcholinesterase, an enzyme located on the muscle cell membrane next to ACh receptor, then breaks down the ACh; this allows the muscle to repolarize, preparing for the next action potential. |
|
|
Term
|
Definition
| Sux resembles ACh and bind to its receptors. As with any action potential, this depolarizes the muslce cell: since acetylcholinesterase in the synaptic cleft can't break succinycholine down, the muscle stays depoloarized (and incapable of a 2nd action potential). |
|
|
Term
|
Definition
| Sux consists of 2 ACh molecules joined together. It is given iv and its action stops with pseudocholinesterase splits the 2 ACh molecules. |
|
|
Term
| What type of patient will recover slowly from sux and what type of patient will recover very slowly? |
|
Definition
| A heterozygoes patient will recover slowly and a homozygous patient will recover very slowly as sureted over the course of several hours. |
|
|
Term
| Describe the change with the nerve stimulator after giving sux. |
|
Definition
| When we give a dose of Sux and check it with the nerve stimulator, the response to a train of four is constant but less than normal; it does not get stronger after a tetanic stimulus. This changes with a second dose. With a 2nd dose "fade" happens - meaning that the twitches grow progressively weaker but get stronger after a tetanic stimulus. We call those a phase I block and phase II block. Phase II block is unpredictable, long-lasting, and not pharmacologically reversible; we avoid it whenever possible. |
|
|
Term
| What are some side effects of Sux? |
|
Definition
First, since sux is simply 2 ACh molecules joined together, it can stimulate any ACh receptor in the ANS. The most frequent result is bradycardia, with the most susceptible groups being children and adults who get a second dose of Sex. Pretreating with atropine helps.
Hyperkalemia- caution is pts with massive trauma, burns, neuromuscular disorders. |
|
|
Term
| What medications trigger malignant hyperthermia? |
|
Definition
| Sux and volatile anesthetics |
|
|
Term
| What is the pathophysiology of malignant hyperthermia? |
|
Definition
| Inherited but related tyo excessive calcium release inside skeletal muscle. |
|
|
Term
| What are the signs and symptoms of malignant hyperthermia? |
|
Definition
| It is a sudden hypermetabolic state. Starts with hypercarbia, tachycardia, and masseter spasm (jaw rigidity), then proceeds to hypertension, then hypotension and circulatory collapse. Fever is not a consistent sign. |
|
|
Term
| What is a common complication after MH is treated? |
|
Definition
| Kidney failure related to massive myoglobin load |
|
|
Term
| What should you do to treat MH. |
|
Definition
1. Get help
2. Turn off all volatile agents
3. hyperventilate the patient with 100% oxygen
4. Give dantrolene (muscle relaxant)
5. Cool the patient actively
6. Start an a-line
7. Resume surgery with a nontriggering anesthetics such as propofol if needed
8. Redose dantrolene every 6 hrs for 24 hrs
9. Give lasix and/or mannitol for diuresis. |
|
|
Term
| What disease dramatically increases the risk of MH? |
|
Definition
| Duchenne's muscular dystrophy |
|
|
Term
| How do non-depolarizers work? |
|
Definition
| They bind the same ACh receptors as depolarizers but don't open the ion channels that depolarize the muscle. Since the receptors are bound, ACh can't biond and depolarize the muscle; no depolarization takes place, but the muscle is relaxed. They work by competitive antagonism. |
|
|
Term
| Describe the twitches seen with non-depolarizing medication. |
|
Definition
| It mirrors a phase II block: the twitches fade with repetitive stimulation, and get stronger after a "tetanus." |
|
|
Term
| What is the metabolism of non-depolarizing agents. |
|
Definition
| Mainly biliary, so take longer for patients in liver failure. |
|
|
Term
| Where is nimbex broken down? |
|
Definition
| Spontan. in the plasma. This nonenzymatic "hofmann reaction" means that we can use it effectively, even in the face of hepatic and renal failure! Hypothermia and acidosis slow down its metabolism; in fact, we keep it in a refrigerator until we're ready to use it. |
|
|
Term
| When is Pancuronium used? |
|
Definition
| It's used when we want to speed up the heart rate and support blood pressure. |
|
|
Term
| Where is pancuronium metabolized and excreted? |
|
Definition
| Metabolized by liver and excreted by the kidneys so compromise of either system will extend its action. |
|
|
Term
| How many twitches is mostly warn off? |
|
Definition
|
|
Term
| What reversal agents are typically used for paralytics? |
|
Definition
| A combination of cholinesterase inhibitor (neostigmine) and an anticholinergic (glycopyrrolate) to fix bradycardia and excessive oral secretions. Neostigmine acts to slow down ACh breakdown at the neuromuscular junction, increasing its concentration and helping it to outcompete the remaining bit of nondepolarizer for the muscle receptor's attention. |
|
|
Term
| Alcohol tolerance applies to what class of medications and what medication? |
|
Definition
| Benzodiazepines and propofol |
|
|
Term
| Opiod tolerance applies to what classification of drugs? |
|
Definition
|
|
Term
| What do you need to ask a smoker during preop eval? |
|
Definition
| If the cough has changed. |
|
|
Term
| During liver dysfunction how will you need to adjust the dosage of muscle relaxants? |
|
Definition
| Maintenance does of muscle relaxants will generally be lower than they otherwise would because of lower clearance; paradoxically, the initial dose may actually be higher than normal because of pharmacokinetic abnormalities related to the liver disease. |
|
|
Term
| What function is always depressed in uremic patients? |
|
Definition
|
|
Term
| What strategies do you address for patient who have uremia from renal failure during pre-op eval? |
|
Definition
1) Ensure that patients have had dialysis with a reasonable period of surgery.
2) Anticipate a higher-than-normal blood loss in the contect of a lower starting hematocrit. This pt may need a transfusion. |
|
|
Term
| Which paralytic is best for renal failure patients? |
|
Definition
| Nimbex because it is degraded in the plasma. Most other paralytics are metabolized in the biliary. |
|
|
Term
| How long should a patient be npo prior to surgery? |
|
Definition
|
|
Term
| What are risk factors for PONV? |
|
Definition
| Female; younger age; abdominal, breast, pelvic, eye, or ENT surgery; hx of motion sickness; not smoking; procedure that involved blood going into the gi tract; and hx of PONV. |
|
|
Term
| Why do you avoid regional anesthesia for a patient who has a hx of neuropathy in the area being anesthetized? |
|
Definition
| It could make the situation worse. These patients receive general anesthesia. |
|
|
Term
| What medication should patient not receive who have denervated muscles because it could cause hyperkalemia? |
|
Definition
|
|
Term
| Besides MH what other inherited disorder should we screen for? |
|
Definition
| Pseudocholinesterase deficiency, which causes patients to metabolize Sux very slowly and stay pharmacologically paralyzed for hours with a singel dose. |
|
|
Term
|
Definition
|
|
Term
| What is the thyromental distance? |
|
Definition
| The distance from the mandible to the thyroid notch. A distance of <4 finger breadths correlates with an increased risk of difficult intubation. |
|
|
Term
| What is the term for absence of teeth? |
|
Definition
|
|
Term
| What should patients over 55 with pulmonary disease have preop? |
|
Definition
|
|
Term
| What should a patient over 50 have in the case of cad or dysrhythmias? |
|
Definition
|
|
Term
| What is typically the maximum Fi02 of a NC? |
|
Definition
|
|
Term
| What is the maximum Fi02 of a simple face mask? |
|
Definition
|
|
Term
| How many cm do you want the ET tube to be above the carina? |
|
Definition
|
|
Term
| When would you use an LMA? |
|
Definition
| When the patient will be able to breath spontaneously. |
|
|
Term
| What medication is typically used for LMA placement because we want patients to recover their respiratory drive quickly once it's in place? |
|
Definition
| Propofol. Muscle relaxers aren't used |
|
|
Term
| Do we need to auscultate the abdomen after LMA placement and why? |
|
Definition
| No, because the LMA doesn't go into the stomach. |
|
|
Term
| When an LMA is in place do we breath fast or slow and why? |
|
Definition
| We ventilate patients only enough to prevent hypoxia-typically only a few breaths per minute. This causes them to build up C02 in their blood, strongly stimulating the respiratory drive. |
|
|
Term
| What type of breaths do volatile anesthetics cause? |
|
Definition
| Shallower, more rapid breaths |
|
|
Term
| Inhaled lidocaine numbs up what parts of the airway? |
|
Definition
|
|
Term
| Which side do we place the pulse oximeter on typically? |
|
Definition
| The same side as the IV and opposite of the b/p cuff. |
|
|
Term
| What is the rate of increase in PaC02 in awake adults with normal lungs who hold their breath without previous hyperventilation? |
|
Definition
7mmHg in the first 10 sec.
2mmHg in the next 10 sec.
6mmHg thereafter |
|
|
Term
| What is the rate of incrase in PaC02 in apneic anesthetized patients? |
|
Definition
12 mm Hg during the first minute
3.5 mm Hg for every subsequent minute |
|
|
Term
| What vital sign to we monitor to determine if we have given too much pain medication? |
|
Definition
| Respiratory rate. Titrate to keep rate around 12-16 |
|
|
Term
| How many twitches have to be present before we can reverse the muscle relaxant? |
|
Definition
| 1 twitch on the train of 4. Once the patient has 4 twitches (which happens within a minute or so after reversal is given) and a sustained tetanic muscle contraction for 5 seconds, he or she is strong enough to start breathing unassisted. |
|
|
Term
| Why doesn't the patient start to breath after turning off the ventilator? |
|
Definition
| Volatile anesthetics increase the level of C02 that the body tolerates; since we adjust the ventilator to maintain normal physiological parameters. We allos a moderate degree of hypercapnia (permissive hypercapnia) by hypoventilating the patient as we reverse muscle relaxation. |
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Term
| What are the End tidal ranges that patients typically begin to start to breath again? |
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Definition
| The EtC02 may reach the 40s or 50s before the patient starts to breathe but should come back down after he or she starts to breathe again. At this point the patient will typically be breathing with rapid, shallow breaths and you can start titrating in the opioids. |
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Term
| What medications can we give if we plan to extubate the patient at the end of the case while the surgeon is starting to close the incision? |
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Definition
| N20, propofol, or Desflurane |
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Term
| What stage is the patient in if they buck, gag, and not follow commands? |
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Definition
| The patient can buck and gag during stage II in which largngospasm is the highest. |
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Term
| What is a complication of larngospasm when the patient tries to breath? |
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Definition
| If an extubated patient goes into laryngospasm, he will try to inhale while his larynx is unable to pass air - and the result is a phenomenon called negative pressure pulmonary edema, or NPPE. In NPPE, the vacuum created in the lungs pulls fluid from the interstitial spaces into the alveoli. |
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Term
| How do we know that the tube can safely be removed? |
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Definition
1). All muscle relaxants are reversed
2). The patient must be breathing spontaneously and regulary without assistance except PEEP.
3). The Tidal Volume should be adequate to maintain a stable and normal or slightly elevated ETC02.
4). Patient must follow commands. |
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Term
| What is a common complication after extubation that you will need to watch for 1-2 minutes? |
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Definition
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Term
| What type of pressures does PONV increase? |
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Definition
| Intracranial and intraoccular pressure |
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Term
| What is the neurotransmitter 5-HT also called? |
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Definition
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Term
| Where is the subtype of 5-HT3 (serotonin) found mainly in? |
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Definition
| The brain's vomiting center |
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Term
| Name 3 5-HTs antagonists. |
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Definition
| Ondasteron, dolasetron, granisetron. All end in tron* They all act to suppress the brain's signal to feel nauseated and vomit. |
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Term
| What should be the first line antiemetic? |
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Definition
| zofran (5-HT3 antagonist) |
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Term
| Do we often give more than 1 drug for patients who are at high risk for PONV? |
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Definition
| Yes! Decadron is a corticosteroid and is most effective when combined with a 5-HT3 antagonist like ondasteron, dolasetron, granisetron. |
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Term
| What classification is compazine? |
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Definition
| It is a dopamine (D2) antagonist with antiemetic effects. |
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Term
| What classification is phenergan? |
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Definition
| H1 blocker that also antagonizes D2 and muscarinic receptors. |
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Term
| What are some anticholinergic side effects pf phenergan? |
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Definition
| dry mouth and urinary retention. |
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Term
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Definition
| Increases gastric motility and loosens the pyloric sphincter and tightens the lower esophageal sphincter. |
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Term
| What is a critical side effect of droperidol, which is in the same phenothiazine family as haloperidol? |
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Definition
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Term
| What should you do if you use Droperidol? |
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Definition
| Continuous EKG, avoided in patients with a long QTI, and given in smaller doses than were historically used. |
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Term
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Definition
| Mostly as a last resort in patient is intractable PONV. |
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Term
| What are some ways to prevent PONV? |
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Definition
1) Use regional anesthesia where possible.
2) Premedicate with zofran before going to the operating room
3) Induce anesthesia with propofol if able
4) Maintain anesthesia with propofol infusion and inhaled agents
5) Consider Dronabinol which is typically used for chemotherapy than PONV. Side effects include AMS and hunger
6) Consider alcohol swabs |
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Term
| What is the dose of propofol that can be given in awake patients to combat nausea? |
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Definition
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Term
| What is nausea associated with epidural and spinal anesthesia typically a result from? |
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Definition
| hypotension from sympathetic block and resulting peripheral vasodilation. It can be treated with iv fluids and ephedrine to raise the b/p |
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Term
| What button should you not press while the patient is on the ventilator? |
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Definition
| The oxygen flush button. This exposes the lungs to full oxygen line pressure (50 psi) and can easily cause a pneumothorax. |
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Term
| Which central line insertion site has the lowest risk of infection? |
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Definition
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Term
| What are the contraindications to epidural catheters? |
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Definition
| Coagulopathy (seen with preeclampsia), infection ( either systemic, in the form of sepsis, or at the intended puncture site). |
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Term
| What interspaces are epidural and spinals typically performed at? |
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Definition
| L3-L4 or L4-L5 to give youurself a good margin of safety, since the cauda equina (horse tail) at the bottom of the spinal cord generally terminated within one interspace of L1-L2 |
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Term
| How do you locate the L4-L5 interspace? |
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Definition
| Palpate the iliac crests; it lies directly between them. For L3-L4, simply go up one interspace. |
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Term
| What are the bony prominences in the midline above and below called? |
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Definition
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Term
| During an epidural insertion when should you attach the syringe? |
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Definition
| As soon as you encounter resistance, indicating you have reached the interspinous ligament. |
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Term
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Definition
| Is a dural puncture, also a spinal. Performed by accident during an epidural by going in too far. |
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Term
| What ligaments do you pass while performing an epidural? |
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Definition
| You pass through the interspinous ligament into the ligamentum flavum, just outside the epidural space. It has been described as a crunchy sensation. |
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Term
| How far should you advance the epidural catheter once in? |
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Definition
| At least 5 cm beyond the end of the needle. |
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Term
| What should you do after you insert the epidural? |
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Definition
| Attach a plunger and withdrawl back. You should not see CSF. |
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Term
| Will the dose of a spinal be higher or lower than an epidural? |
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Definition
| Lower. A full epidural dose would likely cause a total spinal which is a signal that goes so high that it causes apnea and severe hypotension |
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Term
| What should you tell the patient as you first inject medications through an epidural? |
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Definition
| Ask the patient to tell you immediately if she feels a racing heartbeat, ringing in the ears, or a metallic taste in her mouth, any of which would signal that the catheter is feeding into a vein- the tachycardia being from the epinephrine and the other symptoms from the local anesthetic. |
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Term
| What changes might be expect in vital signs after an epidrual? |
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Definition
| An epidural produces a sympathectomy in the anesthetized area- meaning that it removes that area's ability to vasoconstrict as directed by the SNS. We can expect the patient's legs to become vasodialted. Hypotension is therefore the number one side effect of epidural placement, nausea after an epidrual is often related to it, and both typically respond to a fluid bolus and a smaller dose of ephedrine. |
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Term
| What should the labor patient feel who has an epidural? |
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Definition
| Pressure, but not sharp pain |
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Term
| During an epidural, what happens if you keep advancing the needle but never feel loss of resistance? |
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Definition
| Make sure you are centered. Ask the patient if unsure. |
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Term
| What is the main concern with a wet tap? |
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Definition
| A spinal headache technically called a post-dural-puncture headache, or PDPH. |
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Term
| What makes a PDPH worse and better? |
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Definition
| Partially relieved by reclining but becoming severe with sitting or standing. It is often associated with dizziness and nausea. |
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Term
| What should you do if you do a wet tap by accident? |
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Definition
| Keep the catheter in. It can be dosed with small amounts of local anesthetic for analgesia, and for some reason unclear the catheter's temporary (24 hr) presence in the dural hole has been shown to make PDPH much less likely. |
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Term
| What are the 4 focus points for PDPH? |
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Definition
| Pain medication, fluids, caffeine, and if all else failes an epidrual blood patch (EBP). These all focus on pain relief and helping the body produce more CSF. |
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Term
| What surgeries do we usually perform spinal anesthesia in? |
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Definition
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Term
| What exactly is a spinal? |
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Definition
| When we put small amount of LA directly into the CSF near that part of the spinal cord. It's easier to put in than a spinal because we don't have to avoid a wet tap. |
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Term
| What amide LA are prepared prior to spinal insertion? |
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Definition
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Term
| How do you add a trace of epinephrine to make a spinal last longer? |
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Definition
| Draw up epinephrine in the syringe and squirt it out prior to drawing up the LA; a tiny bit of epinephrine will remain in the syringe. |
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Term
| What size needle do you use for a spinal and why? |
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Definition
| We puncture the dura with the smallest needle possible (to prevent dura leaks) which ranges from a 25 gauge all the way to a hairlike 29 gauge. Epidural needles are usually a 17 gauge. We also use a less sharp "pencil point" needle to push dural fibers aside instead of slicing through them. Since the needle is thin and comparatively blunt, it is difficult to pass it through the skin and SQ tissue; we therefore use a slightly larger needle as an introducer. |
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Term
| What type of sensation should be expected after medication is injected through a spinal? |
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Definition
| The patient's legs will rapidly start to feel awrm and heavy, then numb. Numbness will start to ascend through the dermatoms of the abdomen; test its level as you would with an epidural. As it approaches the T4 (nipple line), place the bed in reverse trendelenburg position so that gravity will prevent the anesthesia from progressing further cephalad. |
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Term
| Medications inserted through regional anesthesia are referred to as what? |
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Definition
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Term
| What type of patients are LMAs typically condraindicated in? |
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Definition
| Obese patients. They are more prone to increased intra-abdominal pressure which is one of the leading risk ractors for aspiration, which can be prevented by choosing an endotracheal tube over an LMA. |
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Term
| What is the formula for fluid replacement? |
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Definition
4ml/kg for the first 10kg
2ml/kg for the second 10kg
1ml/kg afterwards
For adults this means 60ml for the first 20kg of weight and 10ml for every 10kg beyond that.
Multiple this number of hours the patient has been npo to establish the fluid deficit. Half of this is given over the first hour of surgery and 1/4 over each of the next 2 hrs. |
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Term
| How much crystalloid and colloid do we give for each cc of blood lose? |
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Definition
| 3ml of cystalloid or 1ml of colloid. |
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Term
| What should be the dose for the low flow rate of oxygen? |
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Definition
| Average patient needs around 300ml/min. The gas samplers go through 150ml/min. |
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Term
| Why should be keep a low flow rate instead of 2l/min of oxygen and 2l/min of air? |
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Definition
1) Warmth. Using fresh gases below body temp with no moisture (causing further evaporative losses) doesn't help. Low flow techniques maintain the patient's own exhaled humidity in the system; in fact, they do it so efficiently that on long 6-8 hr cases, you may need to drain water from the breathing circuit. They also let the patient gradualy warm his own inspired gas mixture, further reducing heat loss.
2) Cost
3) Environment. Anesthetic pollution in the OR is becoming an issue. |
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Term
| What will low flow of gases do to you C02 absorber? |
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Definition
| It will exhaust it more quickly |
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Term
| What is the main advantage of low-flow anesthetic? |
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Definition
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Term
| What are the advantages of a non-low-flow anesthetic? |
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Definition
| Vaporizer settings become inaccurate (for technical reasons) at very low flow rates, and the margin of safety is lower. |
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