Microemboli detection on extracorporeal bypass circuits.

Numerous authors have associated gaseous microembolization with adverse cerebral outcomes during cardiopulmonary bypass (CPB). The introduction to this review provides background on the connection between microemboli and adverse cerebral outcomes. This connection is often difficult to quantify, as outcomes depend on a number of factors, including the size of the bubble, where it passes through the patient, patient comorbidities and other factors. Nonetheless, numerous studies have shown statistically significant differences in the mean number of cerebral emboli detected in patients that stroked and those that did not, as well as for patients with major cardiac complications and patients with a longer length of hospital stay. Our introduction is followed by case reports and laboratory studies showing how monitoring for gaseous microemboli (GME) can be used to reduce the embolic load delivered to the patient through the bypass circuit. These methods include improved qualification of bypass circuit design prior to surgery, modification of priming procedures to reduce air in the circuit at the start of surgery, new methods for injecting drugs into the circuit during surgery, and better detection of removal of sources of air during surgery. The review concludes with background on the ultrasonic detection of GME, comparing through-transmission gross air detectors and Doppler ultrasound technology with fixed-beam ultrasonic imaging of emboli, a new ultrasonic technique that images moving emboli in the blood using a single ultrasound transducer element in a fixed position. This overview is meant to shed light on why different ultrasonic detection technologies report widely varying counts and emboli loads, and why fixed-beam ultrasonic imaging represents an improvement in the ability to monitor, measure and quantitate embolic load during CPB.

Perfusion services national process improvement benchmarking.

The Joint Commission on Accreditation of Health Care Organizations recommends national and regional benchmarking in the quality improvement process. Benchmarking is comparing your organization's patient care process outcomes to the best. This communication describes a national benchmarking process for peer comparison of indicators in perfusion patient services process improvement. A databasing communication aplet was designed to facilitate national benchmarking as part of a larger perfusion service management software application. When patient information is entered in the patient database post precedure, patient-specific numeric data and 'yes'/'no' queries are entered at the clinical site. At any time, the local perfusionist system manager may transmit their own data and receive national database group results by modem and a 1-800 phone number. Local indicator outcomes are compared to national results. Strategies are employed to assure that institution and patient name remain anonymous and institution specific data are stored at the clinical site. Participating institutions employ an e-mail aplet to discuss and decide which indicators to employ as a group. Nine institutions have contributed outcome data for more than 6,425 cardiopulmonary bypass (CPB) procedures to a national database for ten months. National and institutional means for six discrete CPB outcome parameters are compared. The percent 'yes' responses to four procedure-related questions are compared. Joint Commission recommended benchmarking is accomplished while patient care is improved by comparing outcomes.

A fax-back oxygenator-perfusionist clinical performance data collection and statistical analysis method.

A method to collect clinical oxygenator performance data daily is described. At the end of a bypass procedure, the perfusionist fills in a fax-back form designed to automatically input patient-oxygenator performance data into a computer spreadsheet. Multiple blood gases, FiO2, gas and blood flow data, venous oxygenator blood inlet conditions (hemoglobin, O2 saturation, hematocrit and temperature), time on bypass and device manufacturer information are collected at the end of each cardiopulmonary bypass procedure at multiple institutions. A large sample database is created that allows multi-parametric analyses in regard to clinical practice, device performance, manufacturing consistency and patient requirements. The database and analyses facilitate institutional, manufacturer, and clinician benchmarking. Monthly reports to the clinicians give valuable feedback to improve oxygenator use and patient blood gas control. Reports to the device manufacturer provide information used to evaluate the clinical consequences of small changes in the manufacturing process.

An under-occluded roller pump is less hemolytic than a centrifugal pump.

The purpose of this study is to measure and compare the hemolysis produced by roller pumps with varied occlusion settings and a centrifugal pump. The null hypothesis is that there is no difference in the Index of Hemolysis (IH = gm Hb/100 L pumped) produced by a roller pump (RP) at four different occlusion settings and a centrifugal pump (CP) at the same blood flow rate (4.5 L/min) and afterload (250 mmHg, +/-10 mmHg) over three hours. Five identical closed-loop circuits were assembled and primed with saline. The pumps were then calibrated and occlusions were set. In three circuits, the occlusion for the RP was opened at 5 RPMs to support 150, 225, or 300 mmHg (+/-10 mmHg) against a clamped line. In one circuit, a RP was adjusted to a barely non-occlusive setting (1 cm drop/30 inch gradient). The fifth circuit employed a CP. Prior to testing, the saline in each circuit was replaced with one liter of fresh bovine blood (Hct = 22 +/- 2%). The IH for each treatment was compared in six trials yielding a statistical power > 0.80. Analysis of variance with multiple comparison (p < or = 0.05) demonstrated that compared to the barely non-occlusive setting, the IH in the centrifugal pump was not significantly greater. Under-occluded RP settings yielded IHs significantly less than the CP. It appears that opening the occlusion on a roller pump allows a lower IH compared to traditional RP occlusion setting or centrifugal pumping.

Adding hetastarch to the adult cardiopulmonary bypass prime does not affect patient outcomes.

Hespan (hetastarch), a synthetic colloid, is often used in priming cardiopulmonary bypass circuits. The purpose of this study is to determine the efficacy of adding hetastarch to the prime compared to adding no hetastarch. Twenty-four adult patients undergoing cardiopulmonary bypass received Hespan in the prime, while twenty-nine patients did not. Outcomes were compared using paired t-test, analysis of variance, analysis of covariance, and descriptive statistics, where p < 0.05 was considered significant. There were no significant differences in change in lung compliance, weight gain, time on the ventilator, or length of stay in the intensive care unit. Adding colloids to the adult CPB prime does not improve patient outcomes over priming exclusively with crystalloids.

Nursing informatics in nursing education.

Full integration of nursing informatics education at all levels at academic institutions and in practice is critical to nursing as the profession faces the 21st century. Nursing informatics, which encompasses computer hardware, software, and network systems, supports the profession's goals of achieving computer literacy by the year 2000. Strategies for successful integration of nursing informatics into curricula are identified, and specific tactics that promote desired outcomes suggested. The benefits that nursing informatics brings to education, administration, research, and practice are stated and the role of professional nursing organizations in promoting nursing informatics' status as a recognized nursing specialty is noted, and the specialty's role in promoting the profession's future development described.

Comparison of three methods to estimate heparin loading dose for cardiopulmonary bypass.

Three available methods used to determine heparin loading dose were studied to determine the most reliable method for reaching a target pre-bypass activated clotting time (ACT) of 510 seconds. One hundred and seven patients were randomly assigned to one of three treatment methods: A) 300 units/kg; B) Hemostasis Management System (HMS); C) RX/DX. Five different lots of heparin were assigned to Groups A and B, and Group C had one heparin lot. Different lots were used to account for possible variations in heparin activity. Post-skin incision ACTs, post-heparin pre-bypass ACTs, and heparin loading doses were compared. The mean and standard deviation of the post-heparin pre-bypass ACTs were used to determine which method was most reliable to obtain a desired ACT. There was no statistical difference between different heparin lots. There was no difference in the post-heparin ACTs for the three methods (A:487 +/- 135 vs. B:474 +/- 105 vs. C:474 +/- 111 sec). There was a statistically significant difference between the standard deviation for the HMS and 300 u/kg standard deviations (p < 0.05). The HMS has the smallest deviation which makes it the most reliable predictor of heparin loading doses to reach a target ACT for cardiopulmonary bypass.