Perfusion Error Cause Removal: The Perfusion Case Conference

Prevention of accidents is one of the fundamental elements of perfusion quality. Unfortunately, errors and accidents frequently occur during cardiopulmonary bypass. A recent retrospective survey of perfusionists identified some common accidents. We have previously reported a method of developing protocols to prevent and treat the ten most common perfusion related problems. Until we reach the day when perfusion accidents no longer occur, we need to be able to systematically evaluate failures and prevent their recurrence. We have developed a non-judgmental forum to discuss, analyze, and prevent variances or unusual circumstances that occur during cardiopulmonary bypass. We hold a monthly case conference where we discuss all cases from which we can learn something–interesting cases and cases during which there was a departure from protocol. The purpose of this paper is to discuss the development of a case conference and to outline the format and benefits of such an Error Cause Removal program

The Biomedical Technology/Information Explosion: Find Yourself A Foxhole

Approximately 5500 biomedical papers are published every day and the half-life of this information is currently only 3-4 years. Therefore, it is not only important but nearly impossible to keep up-to-date on the literature relating to one's field. This paper will propose a Journal Club (JC) format designed for perfusionists. Our experience with JC the last three years encourages us to share what we have learned about design, scheduling, benefits, pitfalls, and the evolution of a JC. We will suggest a list of 50+ journals that represent a cross section of the literature from disciplines affecting perfusionists. We will discuss techniques for surveying the literature, reporting at JC, recording participation, and creating a database for reference. JC is the best way to stay current with new information in our field and the benefits justify the effort required

An Experimental Evaluation of the Capiox 1.6 and 5.4M

Membrane oxygenators do not create bubbles but most will transmit the bubbles which are common in venous reservoir bags. We previously reported the elimination of arterial micro-air in the 0.8m2 Capiox when operated in the inverted position with an open purge line. This same lung failed to eliminate micro-air when operated in the conventional orientation. The purpose of this study was to test the effectiveness of the Capiox as a bubble trap in lungs with a larger surface area (subgroup a-1.6m2) (subgroup b-5.4m2) and at higher flows. Two test circuits were constructed for each size lung (Group 1—conventional orientation) (Group 11—inverted). The circuits were primed with dilute, outdated human blood (Hct. 20 ± 2%). Ten injections of air (5ml) were done for each lung in both test positions. A bubble counter on the outlet side of the lung was used to count bubbles passed through the membrane oxygenator following the air challenge. Thirty second counts were significantly higher (p<.001) in Group I than in Group II for both size lungs. The counts for both groups were: Group I(alb

Is Your Oxygenator Failing? Diagnosis and Suggested Treatment

(J. Extra-Corpor. Technol. 19[3] p. 330-337 Fall 1987, 3 ref.) Oxygenator failure during open heart surgery can be a serious complication but one with which perfusionists should be prepared to deal. We hypothesize that oxygenators are often replaced unnecessarily and when they are performing within the manufacturers' specifications. This suspicion was confirmed by surveying several oxygenator manufacturers. Discriminating between oxygenator and nonoxygenator problems is critical. In the face of the correct diagnosis of oxygenator failure a simple, safe, expedient, and familiar method of replacement is needed. By using the gas transfer equations one can determine if the oxygenator is transfering adequate gas, after other associated problems are considered and ruled out. After oxygenator failure has been diagnosed, a plan for replacement which has previously been established and practiced should be implemented. We studied 2 techniques for hollow fiber membrane oxygenation (HFMO) replacement and found the risk of micro-air, as a result of the changeout procedure, decreased when the new oxygenator was vacuumed. The purpose of this paper is to help identify when/if an oxygenator is failing and suggest a planned replacement drill to help minimize confusion, delay and possible complications. We will also present a technique for decreasing the risk of micro-air which may result from a quick oxygenator changeout

Micro-Prime Circuit Facilitating Minimal Blood Use during Infant Perfusion

(J. Extra-Corpor. Technol. 19[3] p. 352-357 Fall 1987, 24 ref.) There is considerable concern about the use of blood products during cardiac surgery on the part of adult patients and the parents of pediatric patients. It has been fairly easy to eliminate blood usage in most adult patients but difficult to impossible in infants and small children. Most infant perfusion circuits require a priming volume of 500-850cc which may be cut to 400cc with substantial effort. These volumes are far in excess of the blood volume of most newborns requiring cardiac surgery. We have developed and refined a circuit using commonly available components that can be primed with as little as 265cc. The circuit consists of a Capiox II 0.8m2 lung, with a Terumo 1 OOcc venous reservoir bag and 1/4″ lines. It incorporates a level sensor, bubble detector, recirculation line, arterial GasSTAT™ sensor, and sampling and pressure monitoring lines. A priming volume this low facilitates minimal blood usage in even the smallest infants. This circuit is especially applicable for use with children of Jehovah's Witness parents. It is unique from a safety standpoint in that it not only allows level sensing and bubble detection, but the lung is inverted so the inlet is at the top and the outlet is at the bottom. This configuration causes the lung to act as a bubble trap which may decrease gaseous microemboli. We will describe this “microprime” circuit allowing minimal or no blood usage in this age group, including a review of the literature concerning the safe limits of hemodilution

Intra-Aortic Balloon Counterpulsation for the Treatment of Ischemic Stroke

Colloid volume expansion has been shown to increase cerebral blood flow to ischemic brain in an animal stroke model and improve recovery in patients. It is, however, potentially hazardous to use in older patients because of frequently associated cardiovascular disease. Intra-Aortic Balloon Counterpulsation might reduce the risks of using volume expansion therapy in the elderly patient. This study was designed to see if Intra-Aortic Balloon Counterpulsation (without volume expansion), in an animal with a normal heart, would increase cerebral blood flow and EEG activity in the ischemic brain. Unilateral cerebral ischemia was produced in baboons (n = 9) after right middle cerebral artery occlusion. A 12 ml intra-aortic balloon catheter was introduced into the descending aorta via the femoral artery prior to middle cerebral artery occlusion. The balloon was positioned distal to the origin of the left subclavian artery and following middle cerebral artery occlusion was inflated with each R wave on the ECG. Cardiac output, cerebral blood flow (by Hydrogen wash-out), computer-mapped EEG, and hemodynamic data were collected prior to middle cerebral artery occlusion and following occlusion both before and during counterpulsation. Intra-Aortic Balloon Counterpulsation produced a significant increase in pulse pressure from 54.7 ± 21 to 70.6 ± 33 mmHg (p = .043). No significant change was seen in cardiac output, mean arterial pressure, or cerebral blood flow. Although the computer- mapped EEG improved and the right (ischemic) hemisphere cerebral blood flow did increase slightly from 16.9 ± 6.5 to 18.3 ± 8.3 ml/100 gm/min, the cerebral blood flow changes were not significant (p=.295). It is possible that the desired increase in cerebral blood flow was not achieved partly because the animals were only 3-4 years old and were difficult to stroke. We believe that there is merit to a follow-up study in older primates with colloid volume expansion where Intra-Aortic Balloon Counterpulsation is used to protect the heart from the deleterious effects of volume expansion and where the cardiac effects of volume expansion and counterpulsation are quantified. Perhaps volume expansion with Intra-Aortic Balloon Counterpulsation will be safer and more effective than either treatment modality alone. (All data reported as mean ± standard deviation

A Computer-Based Audio Challenge and Response Cardiopulmonary Bypass Checklist System

Comparisons continue to be made between perfusion and aviation. Although similarities exist there are important differences. One substantial dissimilarity is in the area of safety where commercial aviation has a dramatically lower accident rate than perfusion. Extensive safety systems, including the routine use of checklists, are a major factor in safe air travel. Experience with the use of a checklist for cardiopulmonary bypass has proven useful for managing risk and assuring quality. Recent publications on cardiopulmonary bypass standards and safety mandate the use of checklists. We borrowed from the aviation industry an audio checklist management system which employs digital speech technology. A small, mast-mounted, battery operated device with a lifelike voice challenges the perfusionist with a cardiopulmonary bypass checklist. After being challenged with a checklist item, the perfusionist responds verbally and advances to the next checklist item, by pressing a remote button. The device records the time that an item is checked and upon completion of the checklist prints a document for inclusion in the record. The audio checklist includes pre-bypass set-up, pre and post-initiation, cardioplegia, pre-termination, and post-bypass checklists. Emergency procedure checklists, for common perfusion incidents, may be called-up by the perfusionist. The computer may be programmed to generate custom checklists to meet an individual perfusionist's need. The audio checklist device assures consistency and frees the perfusionist from a more cumbersome paper checklist system. Use of the audio checklist device minimizes the diversion of the perfusionist's eyes and attention from cardiopulmonary bypass equipment and events

Ten Common Perfusion Problems: Prevention and Treatment Protocols

(J. Extra-Corpor. Technol. 19[3] p. 392-398 Fall 1987, 30 ref.) Research has been done regarding the unfortunate consequences of cardiopulmonary bypass (CPB) problems, but written recommendations for preventing these problems have not been addressed. There are few, if any, commonly accepted protocols (which may decrease morbidity and/or mortality) to deal with specific perfusion accidents. We studied reports dealing with the incidence and nature of perfusion complications and found the most common perfusion problems included: protamine reaction, hypoperfusion, oxygenator failure, blood clotting within the extracorporeal circuit, line separation, gross contamination, transfusion errors, drug errors, gas embolism, and electrical failure. The purpose of this paper is to identify the perfusion problems that are “most likely” to occur, to recommend preventive measures, and to give examples of emergency protocols for treatment of these events. It is felt that the risk of perfusion accidents can be decreased through the use and practice of written prevention and treatment protocols and we recommend that perfusionists, surgeons, and anesthesiologists together do a failure analysis of their own systems and develop prevention and treatment protocols designed for their own needs

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, 0 2 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

Lactic Acid Generation During Pediatric Cardiopulmonary Bypass: A Comparison of Blood and Crystalloid Primes

With the increasing concern over patient exposure to donor blood, we undertook a study to determine whether the exclusion of red blood cells from the pump prime for pediatric cardiopulmonary bypass surgical procedures would contribute to the development of metabolic acidosis by either decreasing O2 carrying capacity or diluting plasma buffers with a crystalloid solution. We compared a cellular (blood) prime (fresh-frozen plasma and red blood cells) and a non-cellular prime (Isolyte E and serum albumin). Lactic acid and venous saturation levels were used to evaluate the effects of the two types of priming solutions. Lactic acid samples were drawn two minutes after bypass was initiated, and two minutes after cross clamp removal (or two minutes after bypass was resumed on circulatory arrest cases) and two minutes before discontinuing bypass. Venous saturation samples were taken at random times during the procedures. For cases using the clear prime, we were more aggressive in our blood conservation techniques. Two-way analysis of variance revealed that there was a significant increase in lactic acid levels in both groups as a result of circulatory arrest (p = .0000000887, n = 13). There was not a significant difference in lactic acid levels between groups at any period during cardiopulmonary bypass (p =. 7756). The only differences between groups 1 (n = 15) and 2 were the bypass hematocrits, number of donor blood exposures and patient cooling times. The two-way ANOVA "Interaction" p value (p = .6117) strongly suggests that this was a clean study. These findings are supported by the comparability of the exsanguination times and venous saturations. Our study results indicate that an Isolyte E and serum albumin prime did not increase the pediatric patient's lactic acid levels compared to a blood prime, but it does reduce patient donor blood exposure