Remote Monitoring of Pulse Oximetry - Improving Patient Care -- MEDICA - World Forum for Medicine

Patient Care is Evolving

In today's medical environment, the definition of high quality patient care is evolving as hospitals react and respond to ongoing changes in patient population, healthcare delivery and reimbursement structures.

The aging of the population as a whole is contributing to an increase in medical treatment for age related illnesses. Chronic diseases such as congestive heart failure and degenerative autoimmune diseases such as diabetes are further exacerbated by the proclivity to gain weight with age. Bariatric adults are also more prone to undiagnosed sleep apnea and are at higher risk for sentinel events on the general floor. Older adults disproportionately increase the demand on healthcare facilities. According to the latest figures by the Centers for Disease Control and Prevention, individuals 65 years of age and older accounted for the single largest population pool of patients, accounting for every 38 out of 100 hospital discharges. By 2030, almost 20 percent of the population is projected to be 65 years and older, up from the current 12 percent, representing an almost doubling in yearly elderly admittances to the hospital in the next three decades.

Healthcare delivery as a whole has been significantly impacted by the change in third party reimbursement since the shift by Medicare to a prospective payment system in 1984. Under this system, hospitals are paid a predetermined amount for specific diagnosis related illnesses and treatment strategies. These payments are believed to represent the average patient cost and it is assumed that hospitals will recoup money lost for longer than average patient stays from those patients recovering in a shorter than average time frame. The rise of hospitals becoming operated as independent profit centers is a direct offshoot of these policies. Many hospitals, unable to compete within this infrastructure, have been forced to close or shift to specialized treatment centers.

Although the ongoing decline in hospitals has slowed in recent years, the number of patients per hospital has been on the rise and will continue to increase the ratio of patients treated per hospital in the future. As hospitals struggle to maintain quality patient care, another healthcare model is helping to offload the less critical patients from the system. Improvements in outpatient services, coupled with newer and more effective pharmaceutical solutions, is helping to shift patient care to ambulatory care centers, physician offices, clinics and home care. The downside to this shift is that the patients that seek hospital care are far more acute, requiring much more intensive care than in the past.

Patient Alarms May Not Suffice

While the acuity of patients increases, the healthcare industry is facing an inability to provide the traditional ratio of caregivers per patient due to a growing shortage of both physicians and nurses (particularly nursing care in the hospital environment). Although this trend is projected to continue in the foreseeable future, advances in technology are creating an evolution in health care services of the future.

Oxygen saturation is a critical measure in those patients experiencing respiratory depression whether it is the physiological result of cardiopulmonary or respiratory distress or the response from receiving an anesthetic or a commonly used pain management medication such as patient controlled narcotic or intrathecal morphine. Pulse oximetry provides a fast, accurate and non-invasive method to measure a patients' arterial oxygen level and is among the first patient vital signs to indicate physiological distress.

Pulse oximetry is monitored continuously in the operating room and post-operatively, in the intensive care and critical care wards, and in the intermediate care areas of the hospital. Patients in the general medical/surgical wards typically have their blood oxygenation levels monitored at specified intervals rather than monitored continuously.

The monitoring of pulse oximetry in patients has steadily advanced in recent years. Significant improvements have been made in the ability of pulse oximetry devices to measure oxygen saturation levels in patients that were flailing or in motion. Advanced systems such as Nellcor's Oxi-Max® N-595 Pulse Oximeters are also able to accurately measure oxygenation levels in patients with low blood perfusion such as neonates and wound victims. In addition, sophisticated algorithms have significantly reduced the number of false alarms, which were frequently the result of motion or low flow.

However, the search for the right equilibrium between technology and caregiver support continues to be an issue, particularly in crowded, hectic care areas. The inability to hear alarms in noisy situations and its potential for serious repercussions in patients experiencing desaturations and distressed respiratory conditions has in fact contributed to a recently released recommendation by the leading accreditation organization for hospitals, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO). As part of its National Patient Safety Goals for 2003, JCAHO is recommending that hospitals ensure the effective use of patient monitoring alarms through use of appropriate settings and make sure that the alarm is ‘sufficiently audible with respect to distances and competing noise within the unit'. If the alarm cannot be heard on the floor then some other alternative should be incorporated to ensure patient safety.

Oxinet® III Telemetry Solution

Nellcor introduced its earliest telemetry system in the mid-1990s and announced a remote pulse oximetry notification system in 2000, known as Intouch™. Targeted to critical care and pediatric units, nurses were provided with pagers, which allowed them to monitor critically ill patients remotely. In its quest to continue to improve patient care in the hospital, Nellcor has recently unveiled an even more comprehensive telemetry based, pulse oximetry system to allow physicians, nurses, respiratory therapists and other care givers the ability to maintain quality of patient care in noisy, hectic environments.

Nellcor's Oxinet® III Central Station and Paging System (shown in Figure 1) offers clinicians the ability to monitor up to 24 patients remotely, whether through a central station monitor or a handheld device such as a pager or PDA. Existing Nellcor bedside pulse oximeters can easily be connected, via cable, to a wireless client bridge that is attached to the wall, or to an ethernet port at the bedside in a traditional wired network. The client bridge translates and configures the data into packets for data transmission to a hub, which in turn forwards the data onto the Oxinet® CPU and monitor located at the central nursing station, by this means allowing the nursing staff to monitor the patients remotely.


Nellcor's advanced Oxi-Max® N-595 Pulse Oximeters and its N-395 connect, via cable, to a client bridge. The client bridge contains a wireless local area network (LAN) card. The Oxinet® III system is configured on the 802.11b wireless network protocol and operates in the 2.4 GHz ISM band or over WMTS bandwidths using the latest, most secure, frequency hopping spread spectrum (FHSS) modulation scheme. FHSS wireless transmissions offer better reliability, can be used in conjuction with multiple Oxinet® systems and do not interfere with the transmissions of other wireless devices in the vicinity.

Patient Monitoring Journal Article featuring Nellcor Oxinet III Oximetry

"Our telemetry based, pulse oximetry monitoring systems have been very well received and are already in hundreds of hospitals. They're being used throughout the hospital, everywhere from critical pulmonary care units to the general floor. The sophistication of computing power and economic, scalable networking hardware components makes this solution very affordable. Following the JCAHO recommendations on patient safety that came out last year we expect sales to surge in coming years," states Brian Earp, Market Manager for pulse oximetry devices at Nellcor, a division of Tyco Healthcare.

"The most common configurations adopted by the hospitals are for 8, 16 or 24 beds. Once hospitals start using the system and care givers see how convenient it is to keep track of at risk patients, while performing all of their other activities, they frequently expand their bed coverage within a short period of time. Being able to keep track of more patients is becoming critical now that the typical patient to nurse ratio is approaching 6 patients per nurse on the night shift," says Earp.

Reception in Intensive Care Wards

The adoption of Nellcor's Oxinet® III system has been very diverse. Initial adoption has been in post-surgical recovery units where time to response can often mean the difference between rapid recovery and a slow, possible decline.

Meadowlands Hospital Medical Center, part of the Liberty Healthcare System, in Secaucus, New Jersey has adopted Nellcor's pulse oximetry telemetry solution in its high-end, Acute Pulmonary Care unit, which specializes in hard-to-wean, ventilated patients. Meadowland's Acute Pulmonary Care unit provides an integrated healthcare delivery system to these high-risk patients including occupational therapy and all sorts of physical therapy, in addition to weaning the patient from ventilation.

"Prior to its adoption of the Oxinet® III system," says Matthew Hamilton, Pulmonary Unit Director, "the configuration of our previous system included an imprmptu workaround. We do advanced weaning of the most distressed and acute patients. Thus, we demanded greater functionality and ultimately decided to move away from our older system, where the pulse oximeter was routed along with the ventilator and then hooked into an antiquated central alarm system, located at the central nursing station."

"After hearing about the advantages of Nellcor's wireless solution, we decided to give it a chance. The new system is such an advantage. The pagers have shortened our response times and enable our certified respiratory therapists (CRT) to get more done. They can be doing a procedure anywhere on the ward and know immediately if a patient is in trouble without having to listen for the audible alarm on the central alarm system at the nurses station. The pagers also provide relevant patient information so that the CRT knows the patient's saturation levels before s/he gets to the patient giving them a head start on correcting the problem," says Hamilton.

"The central Oxinet® III monitor, located at the nurses station," Hamilton continued, "has a wonderful onscreen display. It has all of the significant rooms that have been assigned, tells you if there is motion going on with the patient, gives you the all of the patient vital signs and has an audible alarm to keep the nurses abreast of what is happening with the patients. The CRTs can also customize the alarm sensitivities for each individual patient depending upon the course of treatement prescribed by the attending physician. The telemetry system has really been advantageous and has helped us provide an even higher quality of care." The alarm sensitivities are adjusted at the Pulse Oximeter using Nellcor's SatSeconds tool.

New Applications on the General Floor

Demand for continuous pulse oximetery monitoring is also starting to increase on the general floors. A number of recent studies conducted by J. Paul Curry, a physician, with Hoag Memorial Hospital Presbyterian, Newport Beach, California have been aimed at correcting some popular misconceptions regarding the risk of post-operative patients receiving patient-controlled narcotic analgesia. This is particularly relevant for patients having major abdominal surgery or hip/knee replacement surgery.

In two abstracts presented at the recent annual meeting of the American Society of Anesthesiologists in October 2003, the researchers used Nellcor's Oxi-Net telemetry system to continuously monitor those post-operative patients receiving patient-controlled narcotic analgesia (PCA). These patients are thought to be at less risk for respiratory depression and postoperative hypoxemia than patients who receive intrathecal morphine (ITM). By monitoring the patient's blood oxygenation levels, Curry et al were able to determine that those patients receiving PCA were at as much risk as the ITM patients with both patient populations exhibiting extremely high prevalences of post-operative hypoxemia. Post-operative hypoxemia and respiratory depression can lead to death if not corrected in time.

The conclusion and recommendation was that all post-operative patients receiving narcotic analgesia should be continuously monitored on the general floor, preferably using a telemetry system such as Nellcor's Oxinet® III, in order to provide the most flexibility to the nursing staff while ensuring the highest quality patient care. Spot-checks alone do not offer healthcare workers sufficient warning in the event of a sudden decrease in a post-operative patient's oxygen saturation levels.


Significant improvements in pulse oximetry technology is improving patient care in hospitals throughout America. The sophisticated algorithms, reduced level of false alarms, ease-of-use and flexibility of the remote alarm management solutions, ability to adjust the alarm levels on a patient by patient basis and the easy to follow patient vital sign display at the central nursing station enables healthcare workers to provide better care with existing resources.

For further information please contact:

Katja Feick
Corporate Communications
+44 (0) 207 915 7856