Michigan state university – pain relief for terminally ill patients electricity lesson plans 8th grade

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The World Health Organization “Analgesic Ladder” was developed to address inadequate pain relief decades ago. Whether it is still an appropriate model is controversial. wikipedia electricity generation Critics point out that the distinctions between Ste 2 and Step 3 opioids are artificial, based more on the opioid’s availability only in combination products rather than any actual pharmacologic properties

However, many patients use these numbers differently. For example, someone may have severe pain but rate it as “4” while another person might have mild pain rated as “9.” Clinical judgment is required, and it may be helpful to clarify the patient’s sense of the pain (without criticizing his/her choice of number): “I find that many people mean that the pain is pretty mild when they rate it as a “4” – is that true for you as well?”

Patients receiving no analgesic therapy, who have mild-to-moderate pain should be treated first with nonopioid analgesic drugs (Step 1). If a patient has mild-to-moderate pain despite taking a nonopioid analgesic, the dose of the nonopioid analgesic should be maximized and a step 2 opioid analgesic (a "mild" opioid such as codeine, hydrocodone or oxycodone) should be added. Patients who have moderate-to-severe pain (or pain unrelieved by maximal therapy with Step 2 opioids) require a change to a Step 3 opioid (a "major" opioid such as morphine, hydromorphone or fentanyl).

Patients with mild-to-moderate pain should be treated first with nonopioid analgesic drugs (Step 1). If a patient has mild-to-moderate pain despite taking a nonopioid analgesic, the dose of the nonopioid analgesic should be maximized and a step 2 opioid analgesic (a "mild" opioid such as codeine, hydrocodone or oxycodone) should be added. Patients who have moderate-to-severe pain (or pain unrelieved by maximal therapy with Step 2 opioids) require a change to a Step 3 opioid (a "major" opioid such as morphine, hydromorphone, oxycodone or fentanyl).

Acetaminophen is a useful analgesic whose mechanism of action is poorly understood (inhibition of a COX-3 enzyme has been proposed). Excessive doses can cause serious, even fatal, hepatic injury, and the incidence of such injury has been rising steeply in recent years. The maximum safe dose for chronic administration is currently considered to be 3-4 grams per day. Many experts recommend a maximum chronic dose of 3 grams, or even less, for elderly patients and those with hepatic impairment.

Acetaminophen does not have any significant anti-inflammatory action or any effect on platelet function. Use of alcohol with acetaminophen is a significant risk factor for hepatic injury – patients taking maximal doses of acetaminophen should be cautioned to avoid alcohol. An important although under-recognized interaction with warfarin is an additional concern with use of acetaminophen.

NSAIDs vary in their COX-2 selectivity. COX-2 is the enzyme produced in acute inflammation. Although COX-2 inhibitors had initially been thought to be safer than COX-1 agents, more recent studies have been demonstrated that all NSAIDs share the same significant adverse effects, though with differing frequency. These include effects in the following systems:

The frequency and potential seriousness of these effects is often under-estimated. In addition, hypersensitivity reactions are more common than most of us realize – about 1% in otherwise healthy adults and 10-25% in those with asthma, nasal polyps, or chronic urticaria. These reactions can range from simple vasomotor rhinitis all the way to anaphylaxis. static electricity sound effect Cross-reactivity is common, so patients who have had hypersensitivity reactions to one NSAID (most commonly aspirin) have a relative contraindication to trials of others.

Most also have pharmacologically active metabolites that are renally cleared but have longer half-lives than the medication itself. These metabolites vary in clinical significance. The neurotoxic active metabolite of meperidine was described first, but further work has made it clear that both morphine and hydromorphone also have active metabolites with CNS toxicity. Case reports suggest that this will probably uncovered for fentanyl and methadone as well (although the clinical impact is typically less).

Most patients need regular dosing of an opioid, preferably with a sustained release formulation that simplifies the patient’s regimen. In addition, they need access to "p.r.n." (as needed) or "breakthrough" doses along with their regularly scheduled doses. Few patients have pain that is completely stable and steady; most experience exacerbations that require additional breakthrough dosing at least occasionally.

• Sustained-release dosing: When a stable 24 hour dose has been achieved with good pain relief, sustained-release preparations should usually be introduced. electricity usage This will reduce the burden on the patient or caregiver to administer medication so frequently, and it will also provide more stable serum levels, reducing peak-related side effects and trough-related pain (see image).

• Breakthrough dosing: Breakthrough dosing is often confusing to clinicians. A standard and conservative rule-of-thumb for an initial breakthrough dose is 10% (up to15% is recommended in the literature) of the 24 hour total dose. Some patients will need higher doses, and checking with the patient about the effectiveness of the dose is very important. Adjustments in the dose, usually upwards, can be made based on patient feedback.

The intervals for breakthrough doses can be derived from the time to peak effect of the opioid and its route of administration, NOT from the usual interval for regular dosing (a common mistake), (See “a” above.) One to one-and-one-half hours is a quite conservative interval for repeat oral dosing for continued pain; and 15-20 minutes is a similarly conservative interval for repeated intravenous dosing. In the case of severe pain, clinical judgment should be used to shorten the intervals for repeat dosing, and the dose itself should be aggressively increased. In many cases, an ongoing need for dosing at short intervals suggests a need for dose increase. See Equianalgesic Table

A common mistake in the hospital setting is to increase the rate of a continuous infusion of an opioid without using a bolus dose. gas bijoux nolita Recalling the principle in pharmacokinetic that it takes 4-5 half-lives of a drug to reach a new steady state, we can readily see that simply increasing the infusion rate will take 10-15 hours to reach a new steady state. (e.g. the new level of analgesia). This is a seriously delayed response for most patients in the inpatient setting.

True allergic reactions to opioids are very rare. Patients often report “allergies” – they should be queried about the specific reaction they had. Many describe nausea and vomiting; others experienced CNS effects like hallucinations. (While this may be important information in the treatment plan, it does NOT constitute an allergy and should not be recorded as such.) Many side effects are often confused with allergic reactions, but they are actually adverse effects that are generally easily managed.

This group of opioids is considered “mild” because they are generally available as fixed-dose combination products with aspirin or acetaminophen. When using these products, the toxicity of the non-opioid limits the dose of the opioid that can be administered daily. Because of this, they are inadequate for moderate to severe pain. They are also limited by a short duration of action (no sustained-release forms available) and being available in oral forms only.

Codeine – Codeine is the least useful of this group of opioids. Codeine is a “pro-drug” that must be metabolized to morphine in order to have analgesic effect. (Interestingly, its cough-suppressing effect is independent of this metabolism.) Up to 10% of Caucasians do not have the required enzyme for this conversion, and more recent work has suggested that this deficiency may be even more common.

In addition, codeine is the most constipating of the opioids at equianalgesic doses, and many experts believe it also has the highest rate of nausea and vomiting. Finally, analgesic efficacy is quite low – most studies show a minimal increase in pain relief when a patient is given acetaminophen with codeine as compared to acetaminophen alone. Side effects however are considerably higher with the codeine. Consider just dropping codeine from your pain management options!

We have a strong tendency to feel more comfortable giving higher equianalgesic doses of more potent opioids (like hydromorphone) than less potent (like morphine) because the numbers are lower: 1.5 mg hydromorphone equals 10 mg morphine IV. physics c electricity and magnetism formula sheet This “comfort zone” is irrational and awareness of it can help us to overcome this inappropriate tendency.

• Morphine – is the most commonly used opioid because it is one of the oldest agents and none of the newer ones ever have been shown to be more effective. It is also available in multiple forms, making it easy to titrate and change routes of administration. Liquid morphine also provides the option for the lowest dosing of any opioid. Sustained release preparations are also available. In addition, the cost of morphine is the lowest of all the opioids recommended for general use.

It is available in a lower potency oral tablet/capsule form (5 mg) than morphine, which is often helpful in initial therapy for patients with less severe pain or those anticipated to be particularly vulnerable to the effects of dosing too high, such as the elderly. (Liquid morphine is also an option.) Sustained release preparations are available in a wide range of doses.

• Hydromorphone – is pharmacologically very similar to morphine. It is particularly useful in patients with idiosyncratic reactions or side effects from morphine. o goshi judo Unfortunately, no sustained-release form of hydromorphone is available yet in the U.S. Because of its potency (lower dose required to get the same effect relative to other opioids), it can be useful when very high dose treatment is needed, especially sub-cutaneously. See the warning about misunderstanding of potency above.

• Fentanyl – is most commonly used as a transdermal product (Duragesic) available in patches that are replaced q 72 hours. Transmucosal preparations are also available (lozenges) for breakthrough pain relief with more rapid onset of action than other non-parenteral opioids. Fentanyl is often used intravenously for procedures or for intensive care patients, when its rapid onset and relatively shorter duration of action can be an advantage. Fentanyl has a somewhat reduced risk for respiratory depression in the acute care setting. Its strong lipophilic quality is the reason it can be given transdermally and transmucosally.

Fentanyl patches are also not recommended for use in titrating opioids. There is a twelve to eighteen hour delay in onset of action, and the peak is not reached until 18-24 hours or more, so it is NOT an appropriate treatment for acute pain or acute exacerbations of pain. a gas has no volume Remember that there will also be a similar delay in discontinuing the drug after patch is removed because of the subcutaneous reservoir of the medication. Frequent increases in patch strength without titration by another route can produce dangerously high new peak levels on a delayed time frame.

Transdermal absorption varies considerably between patients, and, more importantly, over time in the same patient. Data are lacking about predicting variations in patients. Many experts believe that transdermal fentanyl is less effective in elderly patients. Evidence has recently shown that cachetic patients have lower serum levels of fentanyl from the same dose patch that patients of normal weight, presumably because a lack of subcutaneous fat affects the pharmacokinetics (lack of depot/reservoir site). Absorption may also vary with skin temperature; high fever theoretically risks toxicity.

Equianalgesia tables are used when switching from one opioid to another, or when switching routes of administration. This helps to reduce problems related to under-dosing or over-dosing. Remember, "equianalgesia" simply refers to how much of drug A is needed to provide the same pain relief as x amount of drug B (note that "potency" refers only to the amount of the drug needed to achieve a given effect, not to its overall ability to relieve pain).

IV values should mainly be used when converting from IV to other forms of administration. If starting IV use, always use small frequent doses and titrate up to clinical effect. This is particularly true when using IV administration because of poor pain control with oral administration (as poor absorption may have contributed to the problem).