Barbara Gold

Suppression of cautery-induced electromagnetic interference of cardiac implantable electrical devices by closely spaced bipolar sensing

BACKGROUND: Electromagnetic interference (EMI) induced by electrocautery during surgery in patients with cardiac pacemakers or implanted cardioverter-defibrillators (ICDs) may inhibit pacing and cause inappropriate tachyarrhythmia oversensing. In particular, susceptibility to EMI may be enhanced in ICDs by frequently used wide interelectrode sensing (i.e., integrated bipolar sensing). Consequently, ICD function is usually disabled preoperatively and restored later by noninvasive programming. Because sensing by closely spaced electrodes (i.e., true bipolar) may be less susceptible to EMI, preoperative programming to a true bipolar mode may minimize the need for perioperative programming while preserving device function. METHODS: Our study population consisted of 23 consecutive patients either receiving a new ICD or undergoing ICD pulse generator change. In each patient, electrocautery-induced EMI was initiated with the ICD in the closely spaced sensing configuration and again during widely spaced sensing. RESULTS: In comparing the 2 sensing modes, right ventricular electrogram amplitude was significantly greater and EMI noise amplitude tended to be greater with widely spaced bipolar sensing. Furthermore, widely spaced bipolar sensing was associated with ICD pacing inhibition in 22 of 23 patients and incorrect “ventricular fibrillation” detection in 17 of 23 patients. Conversely, closely spaced bipolar sensing was not accompanied by either pacing inhibition or incorrect ventricular fibrillation sensing. CONCLUSION: Closely spaced bipolar sensing (i.e., true bipolar) appropriately rejects electrocautery-induced EMI. Programming implanted devices to closely spaced bipolar sensing may minimize the need for perioperative reprogramming while preserving intraoperative device operation.

Anesthesiology and Competitive Strategy

Whether we like it or not, medicine is big business. The argument is sometimes made that standard management strategies from the business world do not apply to medicine because the economics and practice of medicine are unique--driven by science and rapid rates of change. But an exploding knowledge base, light-speed technological development, and ever-changing reimbursement schemes are not exclusive to medicine and health care. Some fundamental principles of finance, business management, and strategic development have evolved to deal with problems of rapid change. These principles do apply to modern medicine. The business side of anesthesia practice is off-putting to many clinicians. However, knowledge of the market forces at play can help enhance patient care, improve service, expand opportunities, and extend the perimeter of the discipline. The mission and current market position of anesthesiology practice are considered here.

Value-Based Care and Strategic Priorities

The anesthesia market continues to undergo disruption. Financial margins are shrinking, and buyers are demanding that anesthesia services be provided in an efficient, low-cost manner. To help anesthesiologists analyze their market, Drucker and Porters framework of buyers, suppliers, quality, barriers to entry, substitution, and strategic priorities allows for a structured analysis. Once this analysis is completed, anesthesiologists must articulate their value to other medical professionals and to hospitals. Anesthesiologists can survive and thrive in a value-based health care environment if they are capable of providing services differently and able to deliver cost-effective care.

Introduction to section 2: practice parameters.

The need for non-operating room (OR) anesthesia services continues to expand as technology improves and the scope of procedures performed by cardiologists, radiologists, gastroenterologists, and other physicians grows. Indeed, the range of procedures that can now be performed safely and comfortably outside the OR is facilitated by many factors, not the least of which are improvements in sedation and anesthesia care. However, each of these non-OR settings has different needs and limitations. Delivering anesthesia in an operating room is a consistently structured endeavor irrespective of the specialty; a given OR can accommodate a wide variety of cases ranging from urologic surgery to neurosurgery. This is not the case in the non-OR setting; delivering anesthesia in a GI suite is qualitatively different than doing so in a cardiac catheterization lab—equipment is highly specialized, patient comorbidities are often unique to the particular specialty, physical access to the patient may vary, and the ‘‘culture’’ of the venue may make integration and communication difficult. For example, in the cardiac catheterization or EP lab, imaging equipment is often permanently affixed at the head of the bed, precluding easy access to the patient’s airway. Given the myriad screens and equipment around patients, there may be inadequate space for anesthesia equipment, especially when tables move to permit fluoroscopy. There may also be confusion as to the handling of lab specimens as well as communication of lab results to anesthesiologists if there is no standard protocol. Again, coping with these situations may be straightforward in an OR setting; outside the OR, however, basic work processes cannot be assumed. Work spaces are frequently retrofitted to accommodate anesthesia providers (and associated equipment) because procedural areas were not constructed with anesthesia delivery in mind. This often produces less-than-ideal working conditions for the anesthesia team. For example, medical specialists often dim ambient lights to accommodate digital images, making it difficult for the anesthesiologist to see equipment or observe patients. In addition, moribund patients deemed too sick to undergo an operation are often scheduled for a more limited procedure that nevertheless requires an anesthetic. The mix of unfamiliar work environment and processes along with a moribund patient can be especially problematic. However, anesthesia providers can help improve their work environment by becoming involved in the design phase of procedural facilities and also establishing working relationships with the subspecialty physicians. Indeed, as facilities are remodeled to accommodate the growing number of complex procedures performed outside the traditional confines of the OR, subspecialists increasingly are seeking the input of anesthesia care providers.