Wednesday, February 16, 2005

NEJM -- The Risk of Cesarean Delivery with Neuraxial Analgesia Given Early versus Late in Labor

NEJM --The Risk of Cesarean Delivery with Neuraxial Analgesia Given Early versus Late in Labor

" Analgesia was initiated in the intrathecal group by a combined spinal–epidural technique. Intrathecal fentanyl (25 µg) was injected, an epidural catheter placed, and an epidural test dose administered. At the second request for analgesia, the cervix was again examined. Epidural analgesia was then initiated as follows: if the cervix was less than 4.0 cm in diameter, a 15-ml epidural bolus of bupivacaine (0.625 mg per milliliter) with fentanyl (2 µg per milliliter) was given, and if the cervix was 4.0 cm or greater in diameter, a 15-ml epidural bolus of bupivacaine (1.25 mg per milliliter) was given (Figure 1). In both instances, patient-controlled epidural analgesia was then begun. "

Bottom Line: Intrathecal fentanyl in women not yet at 4 cm cervical dilation does not increase C-section rate when compared to systemic opioids. Lots of great information to digest over the next several days...



Sunday, February 13, 2005

Think CPAP Mask After Major Abdominal Surgery

JAMA just published Continuous positive airway pressure for treatment of postoperative hypoxemia: a randomized controlled trial and those of us giving anesthesia for open major abdominal surgery should take note. Here's the abstract:

" Results Patients who received oxygen plus continuous positive airway pressure had a lower intubation rate (1% vs 10%; P = .005; relative risk [RR], 0.099; 95% confidence interval [CI], 0.01-0.76) and had a lower occurrence rate of pneumonia (2% vs 10%, RR, 0.19; 95% CI, 0.04-0.88; P = .02), infection (3% vs 10%, RR, 0.27; 95% CI, 0.07-0.94; P = .03), and sepsis (2% vs 9%; RR, 0.22; 95% CI, 0.04-0.99; P = .03) than did patients treated with oxygen alone. Patients who received oxygen plus continuous positive airway pressure also spent fewer mean (SD) days in the intensive care unit (1.4 [1.6] vs 2.6 [4.2], P = .09) than patients treated with oxygen alone. The treatments did not affect the mean (SD) days that patients spent in the hospital (15 [13] vs 17 [15], respectively; P = .10). None of those treated with oxygen plus continuous positive airway pressure died in the hospital while 3 deaths occurred among those treated with oxygen alone (P = .12). "

I remember the first time someone suggested using CPAP for the struggling patient in the recovery room after major abdominal surgery. I snorted and mumbled something under my breath about how the patient needed an endotracheal tube and should have taken the offered thoracic epidural. I went back to bed, convinced that I'd be called in an hour or two to intubate the patient who would by then certainly be in extremis. You know what? They never called me that night and this paper helps me understand why.

I think I need to modify my internal algorithm for post-anesthesia management of these often difficult cases to reflect the option of CPAP as a middle ground between mask oxygen and endotracheal intubation.

Screening for AAA Recommended for Smokers Aged 65-75

The U.S. Preventive Services Task Force (part of AHRQ) now 'recommends one-time screening for abdominal aortic aneurysm (AAA) by ultrasonography in men aged 65 to 75 who have ever smoked.'

" Rationale: The USPSTF found good evidence that screening for AAA and surgical repair of large AAAs (5.5 cm or more) in men aged 65 to 75 who have ever smoked (current and former smokers) leads to decreased AAA-specific mortality. There is good evidence that abdominal ultrasonography, performed in a setting with adequate quality assurance (i.e., in an accredited facility with credentialed technologists), is an accurate screening test for AAA. There is also good evidence of important harms of screening and early treatment, including an increased number of surgeries with associated clinically-significant morbidity and mortality, and short-term psychological harms. Based on the moderate magnitude of net benefit, the USPSTF concluded that the benefits of screening for AAA in men aged 65 to 75 who have ever smoked outweigh the harms. "

Patients should also be made aware that there is an alternative to open AAA repairs known as 'endovascular repair.' NEJM recently published A Randomized Trial Comparing Conventional and Endovascular Repair of Abdominal Aortic Aneurysms which concluded:

" On the basis of the overall results of this trial, endovascular repair is preferable to open repair in patients who have an abdominal aortic aneurysm that is at least 5 cm in diameter. Long-term follow-up is needed to determine whether this advantage is sustained. "

As an aside, wouldn't it be nice to be able to query our electronic medical record for all patients in our primary care practice who meet this criteria? Oh wait. We don't have EMR's (for the most part).



Friday, December 10, 2004

Parenteral metoclopramide for acute migraine: meta-analysis of randomised controlled trials -- Colman et al. 329 (7479): 1369 -- BMJ

BMJ: Parenteral metoclopramide for acute migraine: meta-analysis of randomised controlled trials -- Colman et al. 329 (7479): 1369

""Conclusions: Metoclopramide is an effective treatment for migraine headache and may be effective when combined with other treatments. Given its non-narcotic and antiemetic properties, metoclopramide should be considered a primary agent in the treatment of acute migraines in emergency departments.""

This works well. I've been using metoclopramide (Reglan) for perioperative migraine for years, ever since learning about it from a Navy ER doc at Balboa. I don't use metoclopramide for post-operative nausea vomiting (prophylactic or treatment), but that's another blog post.



Friday, December 3, 2004

Simple steps nearly eliminate catheter-related blood infections

Eliminating catheter-related bloodstream infections in the intensive care unit :

""Intervention: To eliminate CR-BSIs, a quality improvement team implemented five interventions: educating the staff; creating a catheter insertion cart; asking providers daily whether catheters could be removed; implementing a checklist to ensure adherence to evidence-based guidelines for preventing CR-BSIs; and empowering nurses to stop the catheter insertion procedure if a violation of the guidelines was observed.""

Well, that last point right there explains the whole effect. In my experience, whenever I place a line in an ICU the nurse disappears. Poof. Gone. "Empowering nurses to stop the...procedure" is just a fancy way of saying "forcing them to stay in the room in case you need anything so you don't contaminate yourself by accident."

[Via Science Blog - Science News Stories]

Perioperative Pacemaker Management

There's an editorial in A&A titled Pacemaker Misinformation in the Perioperative Period: Programming Around the Problem by Marc Rozner. The editorial makes an important point: slapping a magnet on a pacemaker is NOT universally indicated because not ALL pacemakers will switch to continuous asynchronous mode.

In the editorial, Rozner points to the American College of Cardiology perioperative guidelines (pdf) on perioperative cardiac management. The guideline contains a section on pacemakers and AICD's. These guidelines nicely summarize why we worry about using elecrocautery in patients with implanted pacemakers or AICD's:

""The electrical current generated by electrocautery can cause a variety of responses by the implanted device, including the following: (1) temporary or permanent resetting to a backup, reset, or noise-reversion pacing mode (i.e., a dual-chamber pacemaker may be reset to VVI pacing at a fixed rate); (2) temporary or permanent inhibition of pacemaker output; (3) an increase in pacing rate due to activation of the rate-responsive sensor; (4) ICD firing due to activation by electrical noise; or (5) myocardial injury at the lead tip that may cause failure to sense and/or capture. ""

And their recommendations are as follows:

""However, under optimal circumstances, several general recommendations can be made. Patients with implanted ICDs or pacemakers should have their device evaluated before and after surgical procedures. This evaluation should include determination of the patient’s underlying rhythm and interrogation of the device to determine its programmed settings and battery status. If the pacemaker is programmed in a rate-responsive mode, this feature should be inactivated during surgery. If a patient is pacemaker dependent, pacing thresholds should be determined if the patient has not been evaluated recently in a pacemaker clinic. ICD devices should be programmed off immediately before surgery and then onagain postoperatively to prevent unwanted discharge due to spurious signals that the device might interpret as ventricular tachycardia or fibrillation. If QRS complexes cannot be seen during electrocautery, other methods of determining heart rate should be monitored to be certain device inhibition is not present.""

Kudos to the American College of Cardiology for making these guidelines available free of charge. The more I think about this the more sense it makes to require a pacemaker check within, say, six months of elective surgery and call the supporting company for specifics about any given pacemaker



Tuesday, November 9, 2004

Liberal Fluid Administration to Improves Recovery After Lap Chole

Liberal Versus Restrictive Fluid Administration to Improve Recovery:

""Results: Intraoperative administration of 40 mL/kg compared with 15 mL/kg LR led to significant improvements in postoperative pulmonary function and exercise capacity and a reduced stress response (aldosterone, antidiuretic hormone, and angiotensin II). Nausea, general well-being, thirst, dizziness, drowsiness, fatigue, and balance function were also significantly improved, as well as significantly more patients fulfilled discharge criteria and were discharged on the day of surgery with the high-volume fluid substitution.Conclusions: Intraoperative administration of 40 mL/kg compared with 15 mL/kg LR improves postoperative organ functions and recovery and shortens hospital stay after laparoscopic cholecystectomy.""

Yawn. This is a 'me too' study, but does provide yet more support to the idea more fluid is good during anesthesia. It's important to note that this is for a 'closed' procedure, not an open one. Insensible loses are minimal with this technique.

Anatomy of a Near Miss

Medical errors are insidious. Many, many errors occur that do not lead to a bad outcome, but they are errors nonetheless. Given a different patient or set of circumstances, those same errors could result in injury, death, or at the very least less than optimal care. The following example serves to reinforce this point.

A thin, elderly woman is admitted the morning of her planned multi-level spinal laminectomy, instrumentation, and fusion. She is healthy, active, and appears younger than her stated age. She meets her anesthesiologist for the first time twenty minutes before the case. Upon review of her records, she appears to be free of cardia or pulmonary disease, but he notes laboratory results on the chart which indicate a macrocytic anemia (blood count of 30--normal is greater than 35 or so). The patient does not recall being told this before. No mention is made of this finding in the surgeon's history and physical examination, or elsewhere in the chart. Someone did think to do serum B12 and folate levels, both of which were found to be normal but no note is present to indicate the differential or planned workup. The finding is discussed with the surgeon and the case proceeds.

Error number one: the abnormal laboratory value should have triggered further evaluation. Some evaluation was attempted, but there was nothing in the chart to indicate by whome, or what their conclusion was. Significant blood loss is likely in this case. Starting with a lower hematocrit means less blood can be lost before a transfusion becomes necessary.

Error number two: the anesthesiologist should have cancelled this case due to a new anemia of unknown etiology. The severity of the anemia is such that a blood transfusion will almost certainly be needed. If time had been taken to evaluate and treat the anemia, the blood count may have risen sufficiently to reduce the likelihood of needing a transfusion. Even if the blood count could not be improved, directed donation or intraopoerative blood salvage techniques could have been used. Why didn't the anesthesiologist cancel the case? No good reasons, just all the usual ones. He was afraid the surgeon would be angry. He kne w the patient had been dealing with severe pain and was holding out just for this surgery.

Intra-operative blood loss was approximately 700 cc. Euvolemia was maintained with Hespan and lactated Ringer's solution. The patient was warm, urine output was good, and both blood pressure and heart rate were stable. Her hemoglobin near the end of the case was now 7, and a unit of blood was ordered from the blood bank. When no blood arrived within 30 minutes, the blood bank was called to inquire if there was a problem. No blood sample from the patient was available in the blood bank to cross-match bank blood against. A sample was immediately drawn into a red-top vial and sent. The case ends, patient is extubated successfully, and transported to the recovery room where her vital signs remain stable and urine output good. The anesthesiologist continues with other scheduled cases after giving report and asking the recovery room nurse to administer one unit of blood when it become available.

After another thirty minutes pass, the blood bank calls the recovery room to inform them that the sample was received in the wrong vial. The blood bank used to require a red-topped vial, but now want a lavender-topped vile (the former contains no anticoagulant, the later does). A phlebotomist is called to draw the new sample and the patient received a blood transfusion fully two hours after the anesthesiologist made the decision to administer blood.

Error numbers three through ten: 'what we have here is a failure to communicate.' There was a failure to communicate:

  • that blood had not been drawn pre-operatively as ordered (even though the pre-op checklist indicated it had)
    As an interesting aside, this was the first morning the nurses in the pre-op area were asked to use a computerized nursing record rather than their preferred paper method of charting.
  • that the blood bank had no specimen to crossmatch blood against after receiving a call for blood.
  • that a change had been made in what kind of specimen was needed for crossmatch.
  • you can fill in the remainder.

    The only reason this patient did not suffer harm from this incident is that she was physiologically very healthy. Imagine a patient with stable but significant coronary disease. That patient would not have tolerated a hemoglobin of seven so well. Imagine a more significant blood loss. It's better to be lucky than good. It's even better to be both.

    This example demonstrates what is so often true of medical misadventures: it is a series of events in combination which conspire against the practitioner and the patient to cause harm.

    My response to this event is to draft a 'Go/No-Go' list. My personal decisions on whether to do a case is heavily influenced by what I know the surgeon reaction will be. I'm not saying that's the right reaction, mind you. It's just my reaction (in wanting to please people as I do). A Go/No-Go list is similar to what NASA uses to decide whether or not to launch a space craft. If any item is 'No-Go' the launch is scrubbed. On my anesthesia Go/No-Go list, if I discover an item in a patient chart that's on my list, launch is scrubbed and the case is rescheduled. New, unexplained anemia is certainly on that list, especially in light of a surgery likely to result in significant blood loss. I need to spend some serious time adding to this list. I'll post it as a work in progress.



    Saturday, October 30, 2004

    One Shot Eases Pain After Surgery

    It is well known that the injection of a small dose of morphine into the epidural space or cerebral spinal fluid can provide significant post-operative pain relief for as long as 24 hours. The FDA has approved a liposome formulation of morphine that can double that duration. DepoDur, a morphine sulfate extended-release liposome injection, was approved in May, 2004.

    ""The recommended dose is 10 mg for caesarean section, 10-15 mg for lower abdominal surgery and 15 mg for major orthopaedic surgery of the lower extremities. Some patients may benefit from a dose of 20 mg.
    ...[snip]...
    The most common adverse events reported during clinical trials were decreased oxygen saturation, hypotension, urinary retention, vomiting, constipation, nausea, pruritus, pyrexia, anemia, headache and dizziness.""

    More information at SkyePharma.

    [Via Yahoo! News: Health]



    Wednesday, October 27, 2004

    Yahoo! News - Anesthesiologists Vulnerable to Drug Abuse

    Yahoo! News - Anesthesiologists Vulnerable to Drug Abuse:

    ""Drug abuse among some anesthesiologists may be linked to exposure to low doses of powerful anesthetic drugs administered intravenously to surgery patients, according to a University of Florida study.

    Anesthesiologists who sit near a patient's head during surgery are subject to secondhand exposure to anesthetic drugs exhaled by the patient, explained Dr. Mark Gold, a distinguished professor with UF's McKnight Brain Institute.""

    and

    ""Easy access to drugs is a current theory that seems to offer a simple explanation for higher addiction rates among anesthesiologists, said Dr. Mark Aronson, a professor of medicine at Harvard Medical School (news - web sites). However, drug usage is monitored much more closely by hospitals now. That makes access to those drugs more difficult and the easy access addiction theory less plausible.""

    Wrong. (I love telling Harvard people that.) I have yet to meet a monitoring system I can't beat if I really want to divert drug.



    Tuesday, October 26, 2004

    Anesthesia Can Dim Elderly Patients' Minds (?)

    'Anesthesia Can Dim Elderly Patients' Minds' or
    Longitudinal Asssessment of Neurocognitive Function in Elderly Patient after Major, Noncardiac Surgery (pick your title):

    ""Conclusion: Elderly patients experience a high prevalence and persistence of cognitive decline after major, noncardiac surgery characterized by early improvement followed by a later decline. Cognitive impairment at hospital discharge predicts long-term cognitive impairment. Future investigations should evaluate the mechanisms responsible for postoperative cognitive decline and interventions to reduce this serious complication.""

    The actual scientific abstract is here.

    Though intriguing, it's only an abstract. There are so many confounding factors, it's really hard to know what to make of this on first blush. Where's the control group? Wouldn't it be better to have a control group that did NOT have surgery or anesthesia at all and see how they fared after two years?

    [Via Yahoo! News: Health]



    February, 2005
    Sun Mon Tue Wed Thu Fri Sat
      1 2 3 4 5
    6 7 8 9 10 11 12
    13 14 15 16 17 18 19
    20 21 22 23 24 25 26
    27 28  
    Dec  Mar

    Feeds and Categories

    Blog Roll

    Google Modules
       Body Mass Index
       Allowable Blood Loss

    Anesthesiology
       The Ether Way
       Westmead Anaesthesia Blog
       Anesthesioboist
       Book of Joe
       Anesthesiamania
       i'm so sleepy
       GASMAN

    Medicine
       Aggravated DocSurg
       Retired Doc
       Finger and Tubes
       Running A Hospital
       Medviews
       Doctor
       Chance To Cut
       Medlogs
       Medpundit
       RangelMD
       DB's Medical Rants
       EchoJournal
       Palmdoc Chronicles
       Blogborygmi
       The Well-Timed Period
       WebMD

    Journals
       NEJM
       JAMA
       A&A
       Anesthesiology

    Geeks Like Me
       Seth Dillingham
       Jonathan Greene