Collected from the EPEC Discussion Group provided by Growth House

On The Value of Meperidine for Treatment of Rigors

Use of "low dose" meperidine has long been a method of treating post-operative "rigors", "shaking chills", "shivering" in the recovery room [PACU]. These are poor choices of words since this is not a febrile condition nor is it isolated to patients with lowered core temp., but it is thought to be a hypothalamically mediated process, secondary to CNS actions of anesthetics, although, interestingly, it also occurs with 'regression' of regional anesthesia, such as epidural anesthesia for Caesarean Section). Decreasing shivering in the peri-op setting is important both for comfort and to reduce MVO2, oxygen utilization can be extreme with shivering; in cardiac patients, this can lead to ischemia, etc. The anesthesia literature on "shivering" is extensive. Also, meperidine is a particularly interesting opioid [beyond its toxic metabolites] insofar as it has an atropine-like configuration, although it does not have much in the way of evident peripheral autonomic (anti-cholinergic) effects, and has antispasmodic qualities. These (presumably) central effects may contribute to its efficacy for "shivering" in both perioperative and oncologic settings. Typically, parenteral doses of 0.2-0.5 mg/kg are effective, lasting 1-2 hours, and oftentimes, once shivering has been "short-circuited", it does not recur. This low dose and occasional use obviates concerns about normeperidine accumulation and toxicity. If meperidine is not available (we have all but eliminated it at our institution), fentanyl (like meperidine, a synthetic phenylpiperidine--in fact, fentanyl is the reverse ester of meperidine, although its primary metabolite, norfentanyl, does not seem to be neurotoxic) is a reasonable alternative since it has very similar structure-activity relationships. Other drugs that have been effective are propafol, chlorpromazine, and the other fentanyl congeners (e.g., alfentanil). To pursue this, the best keywords for a literature search would be "postoperative shivering" and a search of the cardiac anesthesia literature (or textbooks) for studies of this nature. Regards, and happy hunting,

Posted January 24, 2002

Reasons Not to Use Meperidine for Pain Management

Read a review of Meperidine

Control of Secretions

We use transdermal scopolamine often for treating death rattle and have been well pleased with pt response. This preparation works quite well. The death rattle is often experienced during the transition phase approaching death. I really haven't seen any obvious adverse reaction that would hasten death or cause suffering using transdermal scope. To the contrary, labored rattling respirations are often replaced with quiet unlabored respirations. In those refractory cases, we have used glycopyrrolate subq. 

We have used nebulized Atropine 1mg every 4 - 6 hours. This has produced good results for our end-stage COPD and CHF population. 

I work at a small hospice in NJ and we have had some good success with both the ScopTD patch and Levsin SL. There is some drying and for the families sake we have utilized these medications. There are also Atropine gtts that are effective and used by some hospices. The formation of mucus plugs can occur, but usually when the rattling starts things seem to occur much more quickly as far as the dying process. 

I have very good results using scopolamine patches for this purpose. I do find that one must use 2, however; one behind each ear. I have not had any untoward AE's. The other plus is ease of administration. I'd give it a try.

Posted February 11-19, 2002

Oxygen for Relief of Dyspnea & Post-Extubation Support

Initial Question

Several pulmonologists in our area are refusing to allow patients to be on oxygen after extubation for terminal care. Their reasoning seems to be that if we have made the decision to allow death to occur, then oxygen will only prolong the process and should not be used. I have considered oxygen to be a comfort measure, especially for patients who are quite hypoxic, and have continued it after extubation in most patients. We also use opioids and benzodiazepines for symptom control, of course. What is the standard practice in other regions? Are there studies to support the use of oxygen or no oxygen?

Responses

There are no studies I am aware of per se on oxygen after extubation. There are studies from the British that found that patients can not differentiate room air and oxygen if they are not hypoxic to start with. Therefore, oxygen really does not contribute anything but a placebo effect in the non-hypoxic. It may prolong the dying process. Hypoxia can stimulate endorphins which may ease symptoms also. Our policy is to first do pulse oximetry to document hypoxia. If present them we would titrate O2 to comfort, not a specific sat level. In the ICU setting, I think it depends on the level of consciousness. Not everyone who comes off a machine will die. This would certainly need to be done on a case by case basis.

I'm sure the practice of O2 or no O2 differs from place to place. I am aware of at least one published article that has a set of preprinted orders on ventilator withdrawal near the end of life, which states placing the patient on room air. Our pulmonologists would tend to agree with yours. Comfort can be provided with opiates and sedatives, as the patient who required a ventilator would like suffer dyspnea with or without the O2. Whether giving the O2 prolongs the dying process will probably never be determined. Check the article by Gordon Rubenfeld from Univ of WA in Respiratory Care 2000;45:1399. This journal published the results of a symposium on dying< held by the Amer Assoc of Respiratory Care (AARC). All the articles, including this one, appear in the November and December 2000 issues of Respiratory Care. They have a strong focus on pulmonary problems.

I imagine this is straightforward -- just go to the EPEC training, where it's clearly acknowledged that repeated anecdotal evidence suggests oxygen provides symptom relief often (and thus, there really is no reason not to use it for this purpose). Given the general principle of palliation, providing comfort comes first, even if the measure might prolong life -- which should also be a minimal effect, if the medical situation is analyzed well. As an aside, in two children with interstitial lung disease s/p marrow transplant, several years ago when the prognosis of this situation was zero, I chose to dial the FIO2 down fairly rapidly (with the patient heavily sedated and not paralyzed), which lead to death in a few minutes as expected. This avoided the fear of dyspnea after extubation and provided a very peaceful experience. This was not the "standard" approach, but it worked well.

Oxygen supplement in this case would be purely palliative. If we are treating patients perception of dyspnea, then I would recommend its use. I avoid using it only to treat a number, (i.e., hypoxia) especially if the patient is comatose. However, sometimes we have to palliate the family and provide for supplement. If we follow my hard and fast rule, guidelines are bendable: Everything we do should have a beneficial effect and everything we do should not have a negative effect. Although I am not aware of studies which try to demonstrate the value of oxygen therapy in terminal patients who have recently been extubated, in my opinion it is eminently sensible to minimize the sensations associated with asphyxia, even if such minimization may prolong slightly the ultimate demise of the patient. The decision to allow the patient to expire, and having extubated the patient does not justify causing any increased agony such as that caused by asphyxiation.

We use oxygen as a comfort measure as well regardless of their oximetry measure if the patient feels more comfortable on it. Also concur with the use of MSO4 and benzodiazepines. Example: a 55 yr old patient with emphysema from an alpha 1 deficiency who had been on a ventilator for 9 months and wanted to be taken off regardless of the consequences even to die. He came to our inpatient unit, He was short of breath on the ventilator despite what was considered an adequate volume. He was put on supplemental O2 and started on MSO4. The next day he was still on the ventilator O2 and MSO4 but comfortable and not short of breath. We weaned him off the ventilator over six hours and he did very well. At bed rest he was not short of breath and lived comfortably for six weeks until he died. He was grateful for the extra time and his comfort level. ( I'm a board certified pulmonary physician).

I agree with Dr. Allegretta and resonate with the way he answered. We also use oxygen therapy for comfort measures and have cared for several people who lived many days after being extubated. Withholding oxygen =sounds unethical to me... something perhaps your ethics committee might address. In my opinion, regardless of whether or not a study finds oxygen helps or not, if it provides comfort, or relieves the need to "feel air", then why not use it? (Or if it provides comfort for the family). However, I realize obtaining empirical evidence can be more convincing. Comfort for the patient is key and if the measures do not hurt the patient, why does the time of death matter?

There have been no studies to demonstrate that oxygen provides comfort to the dying patient. I do not give oxygen after extubation. I do provide opiates or benzos as needed but oxygen would be in the same category as IV fluids or antibiotics as far as we are concerned. Also gives false sense of therapy to family when death is the real expectation.

It has been my practice to reduce the amount of ventilatory support to a work level equivalent to that of spontaneous breathing with a room air FIO2 while titrating infusion of benzodiazepine and opiate to treat tachypnea or agitation. I then proceed to extubate or disconnect the ventilator while leaving the tube in place depending on preferences expressed by
patient/family. Patients with ventilatory insufficency will develop
significant hypercarbia which is usually a much more potent stimulus of respiratory drive than hypoxia. The more severe the oxygenation impairment, the more likely I will be to use room air ventilation. The profound hypoxemia which develops with transition to room air usually contributes to a rapid loss of consciousness and a brief duration of spontaneous ventilation. The use of high concentrations of supplemental oxygen may actually result in a longer survival period with initially better preserved CNS function as the pH falls and PCO2 rises leading to increased patient distress.
Although I do not usually specifically look for it, if an individual patient did manifest significant symptomatic relief with supplemental oxygen I would certainly administer it. It is my belief that in general high FIO2 post ventilator withdrawal probably does more harm than good from a palliative care perspective.

The recent publication "Managing Death in the Intensive Care Unit" Oxford University Press 2001 eds Curtis and Rubenfield includes a chapter on Withdrawal of Life-Sustaining Treatment (pp127-147) by Rubenfeld and Crawford. 'Withdrawing mechanical ventilation' is discussed on page 135 with the authors' practice described as "After adequate sedation is achieved, we reduce the inspired oxygen concentration to 0.21..."
Chapter 25 of the same publication deals with "Chronic Obstructive Pulmonary Disease" by Heffner (pp 319-328).
On page 324 he writes ' Among nonpharmacologic measures available to reduce dyspnea, supplemental oxygen provides marginal benefit. A recent controlled study failed to demonstrate reduced dyspnea in cancer patients who were given oxygen compared to patients managed with compressed air." Booth et al Am J Resp Crit Care Med 1996;153:1515-1518 is cited as evidence for this statement.

Here are two references. The first confirmed the subjective benefit of O2 in hypoxemic patients. The second found that non-hypoxic patients could not tell the difference in room air and O2.
Bruera E, Stoutz N, Velasco-Leiva A, Schoeller T, Hanson J: Effects of oxygen on dyspnea in hypoxemic terminal-cancer patients. Lancet 1993,342
Booth S, Kelly MJ et al: Does oxygen help dyspnea in patients with cancer. American Review of Respiratory and Critical Care Medicine 1996, 153:1515--1518.
In the comatose, clearly O2 is for families but education may work just as well.
We forget that O2 is not necessarily a benign intervention, particularly in those who are not bedbound. Lets not forget the dry nasal mucosa even with humidity, irritated nares from the plastic tubing, raw ears from the same and the need for gauze or something similar to ease that discomfort. Being tied to the wall or a heavy canister when you are already weak and want to get up is not insignificant. How many patients who really need O2 =keep taking it off? I do not find patients who have never had O2 demanding it if I explain that their dyspnea is on the basis of respiratory muscle weakness or effusions etc. We approach their comfort with medications instead.
We are approaching this discussion from emotion not science. They do not routinely use O2 is Britain, nor do they check oximetry. They have been doing it longer than we. Perhaps they have something to teach us.