DISEASE STATES: Obesity / Sleep Apnea - TOP

I am being besieged by the morbidly obese with diagnosed or suspected sleep apnea .  I am familiar with Dr. Benumof's ASA Refresher Course article and several letters to the editor.  I am also aware that this subject will be discussed at the upcoming SAMBA meeting.  I am having difficulty putting together a policy re: sleep apnea. Does anyone have anything that might help me?

-- From S.R., Dallas, TX

REPLY:

Unfortunately there is very little data available which helps us develop evidence-based protocols for the management of OSA patients. The vast majority of published information is either retrospective reviews, case reports, or opinion. We do know that the number of patients with OSA is expected to increase 5-10 fold over the next decade so this problem is not going away. It is estimated that 4% of middle-aged males and 2% of females have OSA and 80-90% of patients have not been diagnosed.

Patients with OSA are at increased risk for perioperative problems including difficult intubation, postoperative hypoxia, hypercarbia, ischemia and reintubation. There are 19 cases of patients with OSA in the ASA closed claims database. In 18/19 cases, the patient sustained brain damage or death related to adverse respiratory system events. There is a recent report in the Anesthesia Patient Safety Foundation Newsletter (Lofsky APSF Newsletter 2002; 17:24-5) describing 8 cases of "unexplained" postoperative cardiopulmonary arrests. All patients received parenteral narcotics and were ultimately diagnosed with OSA.

Treatment of OSA with nCPAP may dramatically improve BP control and symptoms of heart failure. None of the case reports of sudden death or cardiorespiratory arrest involved patients wearing nCPAP. One study (Rennotte et al Chest 1995;107:367-74) described 14 consecutive patients effectively treated with nCPAP for 3 weeks preop, nearly continuously postop for 24 hrs and then for all sleep periods. There were no major complications despite the use of opioid analgesics. This highlights the importance of screening patients for symptoms of OSA preoperatively so they can be studied and treated before surgery.

Although there is no data correlating severity of OSA with complications, most authors feel it is reasonable to consider severity of OSA when formulating a management plan. Similarly, the anesthetic technique has not been studied to determine its influence on complications. Regional anesthesia may have advantages by circumventing airway difficulties and limiting the need for sedative and analgesic medications. However, the type of surgery and need for postoperative opioid analgesics is probably more important than the type of anesthetic.

It is not known which OSA patients can safely undergo ambulatory surgery. The recent paper in A&A (Sabers et al Anesth Analg 2003;96:1328-35) found no difference in unexpected admission rates or complications between OSA and weight-matched controls. However, there are several problems with this retrospective study. There was a very high unanticipated admission rate (24%), the controls were obese and not screened for symptoms of OSA, the OSA group was a mixture of treated and untreated and there was no information about complications for patients who were sent home. There are several papers expressing opinions (Tung and Rock Curr Opin Anaesth 2001;14:671-678 and Benumof J Clin Anesth 2001;13:144-156) and one paper that proposes a protocol for management of OSA patients (Deutscher et al APSF Newsletter 2002; 17:58). Ultimately, each institution needs to develop guidelines for management of these patients. I think it is imperative that patients are screened preoperatively for symptoms of OSA and elective surgery postponed until they can be assessed and treated. Adequately treated OSA patients may be considered for ambulatory surgery if they are having minor surgery with minimal need for postoperative analgesics, are alert and are willing and able to use nCPAP themselves at home for all sleep periods.

-- From Janet van Vlymen, MD, FRCPC, Kingston, Ontario, Canada

REPLY:

Any discussion really depends on the type of facility you practice in. I would not allow surgery involving the airway in these patients if I worked in a free standing unit. I feel that these patients should be admitted over-night after general anesthesia and airway surgery. As you know they can be difficult intubations. Most are not. But when these patients are difficult intubations they can be very difficult. Our policy is to approach these patients very cautiously. When in doubt, admit overnight. Their recovery from general anesthesia is often stormy. Sitting them up immediately after extubation helps. Expect lower oxygen saturations early. They usually improve with time. These patients can die in the postoperative period. They are especially sensitive to morphine.

We do surgery on several of these patients every week. Most do well. However, some are challenging postop problems. If you don't want to get hung up in the PACU occasionally, don't do them.

-- From Grover R. Mims, MD, Winston-Salem, NC

The following two questions address similar issues and are therefore considered together.

Does anyone have specific guidelines/policies regarding Body Mass Index that would limit a potential patient candidate from undergoing a procedure at an ASC?

-- From M.T. Reichel, M.D., Beaufort, SC

I am a staff anesthesiologist at a small outpatient surgery center. We do not have the staff to provide pre-op visits. We frequently get morbidly obese patients for general anesthesia. Many have undiagnosed conditions (i.e. sleep apnea). Do you feel there should be an absolute cutoff regarding BMI for outpatient surgery, as waiting to evaluate patients on the day of surgery means a lot of last minute cancellations and unhappy patients and surgeons? I gave a GAET for a breast biopsy (difficult to reach area) in a 5'4", 420 pound patient yesterday. She had asthma, hypertension and diabetes and was 31. Arkansas is now the most obese state in the nation. I am guessing that around 20% of our patients are morbidly obese. A cutoff of 40 BMI seems unreasonable to our staff (because it is so common). Any ideas? If we develop a guideline we are being asked to back it up with "data". I can't seem to find much, except the OSA articles by Jonathan Benumof.

-- From Sandra L. Stolzy, M.D., Fayetteville, AK

REPLY:

This was discussed at the SAMBA Mid Year meeting and at panels, but I don't think there was a consensus. These are higher risk patients, but I don't believe there is an actual cut-off. The most important factor may be the weight limit on the equipment (OR tables). I don't think there is a lot of data out there on this one. Perhaps the answer is to develop a better working relationship with the surgeons so they get some pre-op information about the patient and give you a call - then you could ask more questions or make a decision.

-- From Alan P. Marco, M.D., M.M.M., Toledo, OH

REPLY:

One obvious consideration is your OR bed. OR beds have weight limits that should not be exceeded.

-- From Lance Lichtor, M.D., Iowa City, IA

REPLY:

In our Ambulatory Surgery Center (also small with 2 OR's), after some bad experiences with morbidly obese patients, we decided to set up a cutoff regarding BMI of 35. Since 2 months ago, a trained nurse is running a preoperative evaluation (1 - 2 weeks before the day of surgery) and she uses this cutoff to decide which patients can be done on an ambulatory basis. Anyway, we take the patient's height and weight again the day of surgery and if the BMI is > 35, the anesthesiologist can decide to go on or cancel, depending on the anesthetic technique to be used. If the anesthetic technique chosen is a general, we cancel. We can tolerate a BMI up to 36 or 38 with other techniques if the patient doesn't have an illness like Obstructive Sleep Apnea (OSA). To avoid unhappy surgeons with last minute cancellations we sometimes overbook the OR ("waiting list") to resolve the situation of patients not showing up.

-- From Germán Seckel von Unger, M.D., Anesthesiologist, Chile

Has SAMBA commented on the Canadian survey about BMI?  About 50% of the respondents stated they did ambulatory surgery on patients with a BMI of 45 or less with no other medical problems. Has SAMBA done a similar survey? If OR beds accommodate patients weighing 500 lbs., can we safely anesthetize patients with a BMI of 50 or greater if they are young and have no other medical problems? This issue is more of a problem at our ASC than the morbidly obese patient with concomitant medical problems. It is easier to convince the surgeons that these patients need to be done at the hospital. It is the "healthy" morbidly obese patients that we are constantly questioned about their suitability for ambulatory surgery.

-- From Nolana Bell, M.D., Auburn, WA.

REPLY:

Over the past two decades, the US has seen an upward trend in adult obesity, doubling from 15% of the population in 1980 to 31% in 2001 (NHANES: National Health and Nutrition Surveys Data). Body mass index (BMI), describes body weight relative to height and is strongly correlated with total body fat contents in adults. Obesity has been defined as > 30 BMI, and Morbid obesity (MO or Clinically Severe Obesity) as > 35 BMI. The rising prevalence in adults and children has created a national public health problem, and anesthesiologists will be faced with evaluated the eligibility of these patients for anesthesia.

At the last SAMBA Mid-year meeting, I presented information about eligibility of obese patients for ambulatory and office based surgery. No absolute cut-off was provided. In that discussion, the increased morbidity and mortality of obesity patients was linked to the presence of co-morbidities and BMI. Multisystemic effects on cardiovascular (e.g. CAD, HTN, CHF, Pulmonary HTN), respiratory (e.g. sleep apnea, restrictive lung disease, reduced FRC), endocrine (e.g. DM, thyroid disease), musculoskeletal, surgical wound healing and even psychiatric systems need to be considered. There are reported increase risks of premature and sudden death in BMI > 35 (2-13 times); Twice the risk of DVT for BMI > 30; 50-60% of obese patients have mild- moderate HTN; 5-10% have severe HTN, 3-4 times the risk of respiratory depression from sedative/analgesics with a BMI > 35 and a 5% risk of sleep apnea with BMI > 30. Patients having undergone bariatric procedures do not reverse their risks for at least 12 months. As such a proper preoperative evaluation would need to be conducted to identify these risks. Until proven otherwise, patients with BMI > 30 are at increased risk and likely to have any of the associated co-morbidities. In addition to the physiologic stability of the patient, technical considerations, such as appropriately sized equipment, IV access, airway management, and operating room table size influence whether these patients can be done in a non-hospital setting.

With the prevalence of obesity increasing worldwide, it is apparent that clear guidelines are needed. However, to date no evidenced-based guidelines have been formulated. Absent that, a recent publication entitled, Ambulatory Surgery Adult Patient Selection Criteria: A survey of Canadian Anesthesiologists http://www.cja-jca.org/cgi/content/abstract/51/5/437 tried to address controversial issues in ambulatory surgery patient selection using a short questionnaire. A response rate of 60% from among 1357 anesthesiologists reported that medical conditions with extreme grades of severity (mild or severe) are associated with majority opinion to proceed or not to proceed with surgery. Issues with 75% agreement reflect common practice. The specific conclusions regarding obesity are as follows:

Over 90% of anesthesiologist would include in their patient selection a patient with MO (BMI > 35-44) in the absence of cardiovascular or respiratory co-morbidities. 81.7% of responders would not include these MO patients with BMI > 35-44 in the presence of co-morbidities; and 95.2% of responders would not include severe MO (BMI > 45) with co-morbidities. When asked about severe MO (BMI > 45) without co-morbidities, the responders were split: 49.5% would and 50.1 % would not include them as ambulatory surgery patients. Lack of consensus under these circumstances begs for prospective outcome studies that could serve as a future guide for changing the practice of ambulatory anesthesia.

While the ambulatory surgery environment provides a reasonable alternative for many outpatient procedures, the surgical and anesthesia considerations associated with obesity including anatomic, physiologic, and pharmacologic implications must be seriously considered. The risks and benefits of proceeding in either a hospital, ASC or an office need to be appreciated and discussed with the patient and the surgeon

Selected Reading:

1. Twersky RS. Panel on office-based anesthesia: update on patient eligibility – obese patients ; SAMBA Mid-year meeting, October 22,2004, Las Vegas, NV.
2. U.S. Dept of Health and Human Services. The surgeon general's call to action to prevent and decrease overweight and obesity, 2001. www.cdc.gov/nccdphp/dnpa.obesity/recommendations.htm accessed Sept 2004
3. Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity among US adults, 1999-2000. JAMA 2002;288:1723-7.
4. Iverson RE, Lynch D. ASPS Task Force on Patient Safety in Office-Based Surgery Facilities. Patient safety in the office-based surgery facilities: II. Patient selection. Plast Reconstr Surg 2002; 110(7):1785-90; discussion 1791-2
5. DeJong, RH. Body mass index: risk predictor for cosmetic day surgery. Plast Reconstr Surg 2001;108(2):556-61
6. Adams JP, Murphy PG. Obesity in anesthesia and intensive care. Br J Anaesth 2000;85:91-108
7. Davies KE, Houghton K, Montgomery JE. Obesity and day-case surgery. Anaesthesia 2001; 56: 1112-5.
8. Atkins JP, White J, Ahmed K. Day surgery and body mass index: results of a national survey. Anaesthesia 2002; 57: 169-82.

-- From Rebecca Twersky, M.D., Brooklyn, NY

DISEASE STATES: Cardiac - TOP

Stent - TOP

I am the medical director of Canyon Surgery Center in Phoenix, AZ. During a recent State inspection we were told that a death had occurred in a patient with a stent in a local outpatient facility. They felt that we needed to formulate a policy for when patients post insertion of a coronary stent are candidates for outpatient surgery. I have been searching the cardiology literature only to find that the cardiologist do not agree with any specific time recommendation. Their literature says anything from ok to do in first 2 weeks after insertion of stent, but not ok after 8 weeks, to should wait 4-6 weeks for anticoagulant therapy, and one paper noted a 30% restenosis rate within the first 6 months.

I have asked several other medical directors in my area and we have all come up against the same problem of no real answer in the literature. I even contacted the American College of Cardiology who referred me to an article which didn't give a concrete answer either. In that article they basically took the position that cardiac clearance consists of "optimizing the patient", but didn't give any real guidelines either. I also contacted the ASA and was given the following response from Karen Williams, M.D., Chair of the Committee on Surgical Anesthesia:

"Your question regarding the timing of performing elective surgery following the recent placement of coronary stents was referred to me as Chair of ASA's Committee on Surgical Anesthesia. Your question was circulated to committee members who all agree with your research on the matter. The current literature is controversial regarding the timing of elective surgery after stenting. There are no prospective, definitive studies. Empirically, some institutions wait until the antiplatelet therapy is maximized, others wait for 4 weeks up to 12 months for some types of stents if there is a high restenosis rate within the first few months. It seems that your policy would be based on the multidisciplinary input with your cardiologists, based on your best judgment."

So, I am very interested to see if some sort of consensus can be reached and a standardized time agreed upon.

-- From Rebecca Dalmeida, M.D., Phoenix, AZ.

REPLY:

Cardiologists have added coronary stents to balloon angioplasty because they prolong patency. However, the downside is an early (~1 st three months) increase in stent thrombosis compared to angioplasty alone. For this reason, cardiologists employ aggressive antiplatelet therapy in the short-term (weeks to months) after stent placement.

Obviously, we would prefer not to anesthetize a patient in the midst of stent thrombosis, or just before, especially since hypercoagulability often follows surgery. On the other hand, surgery performed on a patient receiving aggressive antiplatelet therapy may increase bleeding. In the 2002 revision of AHA/ACC Guidelines for Perioperative Cardiovascular Evaluation For Noncardiac Surgery (Eagle KA et al. Circulation. 2002;105:1257-67), the following was recommended:

“There is uncertainty regarding how much time should pass between PCI (percutaneous coronary intervention) and noncardiac procedures. Delaying surgery for at least 1 week after balloon angioplasty to allow for healing of the vessel injury has theoretical benefits. If a coronary stent is used, a delay of at least 2 weeks and ideally 4 to 6 weeks should occur before noncardiac surgery to allow 4 full weeks of dual antiplatelet therapy and re-endothelialization of the stent to be completed, or nearly so.”

While several studies suggest that most patients who have had a stent do well, others suggest that surgery in the 6 weeks after stent placement may be associated with catastrophic events (Kaluza GL et al. J Am Coll Cardiol. 2000;35:1288-94). These include stent thrombosis if the antiplatelet therapy is stopped, and hemorrhagic complications if therapy is continued. However, this cohort of patients underwent major vascular surgery; the relevance to smaller out-patient procedures in unclear.

My recommendation, acknowledging a rapidly changing field and the absence of clear guidelines, is that elective surgery be postponed until at least 4 weeks of antiplatelet therapy are completed, followed by 1 week off of antiplatelet therapy. In some cases (especially carotid endarterectomy, cerebrovascular disease) cardiologists and/or surgeons may wish to continue therapy until the time of surgery, with the attendant bleeding risks. For patients who have an “old” stent (placed more than 2-3 years in the past), preoperative stress testing and/or cardiology consultation may be warranted if there are significant risk factors, symptoms, or exercise limitation because stents (and certainly angioplasty) are less durable revascularization than CABG.

-- From John E. Ellis, M.D., Chicago, IL

Automatic Defibrillators - TOP

We currently have a policy in place and do ambulatory procedures on patients with implanted automatic defibrillators . We turn them off if any form of electrocautery is to be used. We otherwise leave them on.

Is it appropriate to do such patients in a free standing center and should they always be turned off? We are somewhat concerned in that an AICD may simply be a marker of patients with enough cardiac pathology such that it may be best to simply exclude them.

-- From B. Evans, M.D.

REPLY:

Pacemakers and ICDs are complex implanted devices that have significant implications for perioperative care. Patients need these devices for various reasons and often have coexisting cardiac or other problems. Patients with ICDs may obviously have severe cardiac problems including ongoing ischemic cardiac disease (with previous myocardial infarctions) or severe cardiomyopathy. Only "minor" procedures would seem reasonable in a freestanding center for these type of ASA 3 and 4 patients. Your rapid access to cardiology assistance would also be a factor.

When you have a patient with cardiac devices you should consider:

• Why does the patient have the device? How long has it been there?
• Does the patient have a "Device ID Card"? (Make, model, serial number)
• When was the last time the device was checked? Battery status?
• Is the device near its replacement time? Replace it before an elective procedure!
• For pacemakers - is patient hemodynamically dependent on device? Underlying cardiac rhythm?
• For ICDs - what is the "shock" history?
• What is the hemodynamic response to electrical pacing? (Do all pacing "spikes" on ECG cause peripheral pulses?)
• What are the programming parameters? (Printout from interrogation)
• Does the device have "rate modulation" biosensors? What about battery saving auto-search routines? (Turn them off, usually)
• What will happen when a donut magnet is applied? Is the response programmable? (Ignored, fixed rate, shuts off, for how long?)
• Should the device be re-programmed prior to procedure?
• What heart rate will be appropriate to meet metabolic demands for the procedure?
• Are a defibrillator and an external pacing device available in your facility? (they should be)
• Have you consulted a knowledgeable Cardiologist and the device manufacturer concerning recommendations?
• ALWAYS consult with a Cardiologist if the patient has a device for Long Q-T or Cardiomyopathy, or is a pediatric patient.
• Re-interrogate device after the procedure to ensure proper functioning and battery life if electromagnetic interference (EMI) was present.

Preoperatively, you need to be sure the device is in good working order. Interrogation before the anesthetic is the only way to do this.

The following comments address ICDs. Pacemakers have an even longer set of issues (see Rozner reference).

Turning off the ICD is essential when EMI is anticipated. This prevents EMI induced ICD shocks. Turning it off with a programming device is the only way to do this with some ICDs. A donut magnet may elicit auditory (some Guidant) or no (Medtronic and others) indication of the active status of the ICD. With Medtronic ICDs, a Smart Magnet® is the only way to know if temporary magnet suspension of the device has been achieved. However, magnets may encroach on the surgical site, or slip off during the case.

Patients who have procedures performed without the use of electrosurgical units (ESU) or other EMI, may have an ICD left in the "active" mode. HOWEVER, if a shock is delivered by the device, the patient may move suddenly. If a sudden movement could cause surgical injury during a procedure (e.g. during an eye or middle ear operation), then this is a plan with some risk.

After any case with EMI exposure, cardiac devices should be checked to ensure proper functioning before the patient leaves the facility. Check with the device manufacture about any new information. This is a rapidly changing area of medicine. Don't assume.

These patients take much more time to care for in the perioperative period. Only you can decide if this is worth it in your practice.

References:

1. Heart Rhythm Society (NASPE): http://www.hrsonline.org
2. American College of Cardiology: http://www.acc.org
3. Rozner MA. Intrathoracic Gadgets: Pacemakers and Defibrillators in the New Millennium. ASA Refresher Course Lectures 2004
4. ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices. Circulation 2002; 106:2145-61

-- From Scott R. Springman, M.D., Madison, WI

DISEASE STATES - Upper Respiratory Tract Infections - TOP

What is the minimum time we need to wait before delivering anesthesia to pediatric patients after upper respiratory infections?

-- Anonymous

REPLY:

I recommend a month to the surgeons. However, I have broken my own rule, especially when other factors (social, repetitive illness, urgency of case) intervene. The data, as far as I know, say six weeks. However, I find that a very hard sell.

-- From Phil Morgan, MD, Cleveland, OH  

DISEASE STATES: Malignant Hyperthermia - TOP

Malignant Hyperthermia (MH) is an unusual event but dangerous when it happens. It can develop in any moment of an anesthetic procedure. Does someone have any experience with MH in ambulatory surgery? Is it possible that a patient can develop MH after being discharged to home? Knowing the higher safety of IV anesthetics, does anyone allow patients with known risks to develop MH, to be done on an ambulatory basis if only IV anesthetics are used?

-- From Germán Seckel V., M.D., Los Angeles, Chile

REPLY:

MH can and does occur in any setting where anesthesia trigger agents are administered, be it in a hospital, ambulatory center or office.

I do not believe that MH will occur if the patient has done well for four hours postoperatively and has had no unusual postoperative complaints. However, some rare patients may develop rhabdomyolysis after being discharged, but not the full blown syndrome.

MH susceptibles may have anesthesia in an ambulatory setting. Non trigger agents, local anesthesia, intravenous agents and nitrous oxide may be used without problem. Patients should be monitored for 2-4 hours postoperatively.

Dantrolene sodium should be available wherever MH trigger agents are employed.

-- From Henry Rosenberg, M.D., C.P.E., Livingston, NJ

Does SAMBA have any recommendations on performing surgery and anesthetics on patients at risk for Malignant Hyperthermia? For example, patients with a direct family history of MH or with a muscular disorder like Muscular Dystrophies?

I'm a medical director of a free standing surgicenter, and different anesthesiologists I've asked have differing opinions. What is your opinion?

-- From K. Ando, M.D., Phoenix, AZ

REPLY:

Patients who are MH susceptible or who suffer from muscular dystrophy or other myopathies may be anesthetized with regional or local techniques, with intravenous agents, with non-depolarizing neuromuscular blocking agents and nitrous oxide in combination with narcotics, sedative, hypnotics, etc. However, dantrolene should be available wherever such patients are cared for.

-- From Henry Rosenberg, M.D., C.P.E., Livingston, NJ

DISEASE STATES: Recent Pneumothorax - TOP

A 28 y/o male is status/post MVA 14 days ago. He was treated then for pneumothorax. How long after a pneumothorax should an elective procedure be done? (I have polled anesthesiologists and thoracic surgeons at my old home (Mass General), and folks here in Phoenix. The consensus seems to be three weeks.)

-- From Joshua A. Bloomstone, M.D., Phoenix, AZ

REPLY:

The chest surgeons at our institution feel that one should wait 4 to 6 weeks before exposing a patient to a general anesthetic. Their rationale is that it takes at least four weeks for the lung and pleura to fully heal.

-- From Grover R. Mims, M.D., Winston-Salem, N.C.

REPLY:

Elective surgical procedures can be performed once the pneumothorax is resolving (i.e., the lung is healing).  If the chest tube drainage is minimal and there are no bubbles, the hole in the lung should be healing and positive pressure ventilation should not reopen it.  One does not have to wait until the pneumothorax is completely gone.  In our hospital (a major trauma center), chest tubes are commonly removed (once the criteria for removal are achieved) while the patients are still on positive pressure ventilation in the ICU. This suggests that ventilation during anesthesia should not be deleterious.  Of course, we should have a high index of suspicion in case problems do occur intraoperatively.

As well, the patient's clinical status plays a major role in the decision making. The patient should be maintaining saturation and not in respiratory distress. A case I had today illustrates some of these points:

A 17 year old with a pelvic fracture 2 days ago was scheduled for repair of the fracture.  On admission after the MVC, the chest X-ray showed some fluid and a pneumothorax.  However, as the patient was comfortable, with no signs of distress and the pneumothorax was small, no chest drain was placed.   Now that the patient was going to have to be ventilated during surgery, there were discussions as to whether we should place a chest tube prophylactically.  However, we decided not to place one and just observe the patient closely, as the pneumothorax was resolving, suggesting that the lung injury was healing.  No problems were experienced intraoperatively.

A chest X-ray on the morning of surgery is also recommended, as illustrated by another case I had today:

A patient with secondaries in the lung was scheduled for brain tumor resection   A lung biopsy was done 10 days ago, after which a chest tube was placed.  The chest tube was removed 3 days ago.  A chest X-ray this morning showed that the pneuothorax had reaccumulated.  Thus, we decided to place a chest tube after the induction of general anesthesia.

-- From Girish Joshi, M.D., Dallas, TX

DISEASE STATES: Acid Reflux / Hiatal Hernia - TOP

Acid reflux is increasingly common in our patient population. Many patients have mild symptoms or in fact no symptoms at all while taking acid suppressive therapy. Is there evidence to suggest a higher risk of aspiration in these patients? What about the patient with an asymptomatic hiatal hernia? And is acid reflux a contraindication to the use of the laryngeal mask airway?"

-- Anonymous

REPLY:

The writer states that acid reflux is more prevalent than in the past. I am not sure that this is true. Is it really more prevalent, or are more patients being treated for it, in part due to the massive effort in direct-to-consumer marketing?

-- From Alan P. Marco, M.D., M.M.M., Toledo, OH

REPLY:

I haven't seen any evidence contraindicating an LMA when acid reflux is asymptomatic or controlled by medication. We will tell the patient to take their acid suppressive therapy the morning of surgery or we will pretreat with Pepcid and then we will place an LMA if it is indicated for the operation.

I think the central point is whether the acid reflux is symptomatic. If there are no symptoms, I don't believe there are is a contraindication.

The other point to consider is the diagnosis of acid reflux or hiatal hernia. I think this a very over diagnosed condition perhaps due to the frequency of television commercials. It has become an "in-vogue" disease for anyone with occasional or food-related heartburn. As these medicines become over the counter (and the volume of commercials increase), the problem will become even more prevalent.

-- From David S. Rapkin, M.D., Richmond Hts, OH

REPLY:

I agree that the increased "prevalence" is due to awareness, partly caused by marketing by drug companies.

It occurs to me that the use of other supraglottic airways that have greater "occlusivity" as evidenced by effective airway pressures before "leak" is noted and ex vivo gastric pressure testing might be more wise. The classic LMA is convenient, but more limited in that regard.

-- From Charles B. Watson, MD, FCCM, Bridgeport, CT

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