A Study of Prior Cases

Transcription

1 A Study of Prior Cases Clinical theme Sub theme Clinical situation/problem Clinical approach Outcome/Lesson Searchable Key word(s) 1 Cannulation Cannulae insertion The surgeon was trying to cannulate for an A-V femfem bypass case. Both cannula were placed without difficulty. However, the surgeon was rushing and forgot to tie in the arterial cannula. The line pressure suddenly fell and blood began running on the floor. The cannula had errantly become dislodged. The ist must pay strict attention to all elements of the bypass circuit so that a swift response is possible. Failure to do so could result in exsanguinations of the patient. The ist simultaneously clamped both the arterial and venous lines as he was informing the surgeon. The cannula was reinserted and properly sutured in. Cannulae; femoral

2 2 Cannulation Sizing The surgeon insisted on using a 17 F femoral arterial cannula and a single stage 29 F femoral cannula. The BSA of the patient was 2.0. The ist noticed that line pressure was in excess of 300 mmhg at an index of 2.4. The surgeon was complaining that the patient was still full. There was an obvious mis- match of patient size and cannula choice. The ist informed the surgeon of the line pressure and proceeded to take the following measures: 1) Dropped blood flow to an index of The ist was 1.8. Venous sats unable to increase flows remained above 65%. 2) above an index of 1.8. The ist added Although oxygenation VAVD to the circuit to was adequate, though increase venous drainage marginal, the lower 3) At an appropriate time, blood flows required the ist rewarming to begin recommended that a vent earlier than usual. be placed to help Patient was weaned decompress the heart successfully from CPB Cannulae; VAVD; svo2 3 cerebral Circuit ascending/transverse aortic root replacement. The surgeon used arterial femoral cannulation and single staged IVC/SCV venous cannula. He wanted to do RCP. The nurses were given sterile tubing and 2 3/8 Y connectors and were instructed to cut in a bridge between the arterial and venous lines. When RCP was desired, the arterial cannula and IVC were clamped and the bridge was unclamped. The arterial pump directed Blood flow was noted at blood across the bridge up about 80 cc/min and the venous line and blood was seen coming through the SVC cannula. back into the aorta. RCP

3 4 cerebral Circuit ascending/transverse aortic root replacement. The surgeon used arterial femoral cannulation and single staged IVC/SCV venous cannula. He wanted to do RCP. The ist suggested that the SCV cannula be connected to the venous tubing with a luer lock connector. At the time for RCP, one arm of the Medtronic "Octopus" multiple cannula was connected to the luer port. The venous line was clamped below this point as was the IVC and arterial cannula. Straight, cold, oxygenated blood was pumped through the cardioplegia system, directing blood into the venous system and retrograde through the brain. The surgeon like the simplicity of the system and remarked that it worked very effectively. RCP; cannulae

4 5 cerebral Circuit ascending/transverse aortic root replacement. The surgeon used arterial and venous femoral cannulation. He wanted to do RCP. The ist used a 3/8 luer connector to connect the arterial cannula and arterial line. The ist also directed the nurse to use a piece of sterile 1/4" line with 1/4"/leur slip connectors on both ends. The surgeon place a retrograde coronary cannulae in the SVC. The retrograde cannula and the arterial lines were connected with the 1/4 line. The arterial cannula itself was clamped. RCP flow was directed from the arterial pump, through the arterial line, up the 1/4" line and into the retrograde cannulae. The system effectively delivered blood in a retrograde fashion to the brain but the surgeon refused to use the pressure monitoring port of the retrograde cannula. Therefore, flow had to be regulated solely on cc/min rather than pressure parameters. It would be better to monitor delivery pressure. RCP

5 6 Deep hypothermic circulatory arrest Method The case was a complicated aortic dissection and a redo operation. DHCA was required because systemic flow was impossible to maintain during the distal anastomosis. The surgeon asked the ist to drift to a temperature of 34 degrees during the initial portion of CPB. At the appropriate time, the ist as instructed to cool to a temperature of 18 degrees C. The surgeon also requested that cardioplegia be given during the cooling phase to initiate a diastolic arrest. the inflow temperature so that the patient did not get too cool and fibrillate prior to the deep cooling period. At the appointed time, the ist set the heater/cooler on the coldest setting and crash cooled. Meanwhile, 1000 cc of 4 degree high potassium cardioplegia was given through handheld ostial cannula. Cardiac arrest quickly ensued and cooling continued. The main heater/cooler needed to be filled twice with additional ice. The ist also suggested to anesthesia that the head be packed in ice and tympanic membrane be measured to monitor the patient's brain temperature. The target temperature of 18 degrees was obtained after 20 minutes of active cooling. The surgeon was informed and the ist thereby It is important to carefully monitor temperatures during DHCA cases: arterial, venous, bladder, tympanic and/or esophageal. Carefully regulating the temperature allows the appropriate control of blood gases, metabolic rates, hemostatic changes and neuroprotective measures. In this case, the patient was cooled appropriately with this method, allowing the surgical procedure to advance. Consider the quantity of ice that is required for these cases. Ice machines outside the OR may need to be used, meaning that there needs to be additional personnel available to acquire the ice. DHCA

6 7 Deep hypothermic circulatory arrest Blood gas management ascending/transverse aortic root replacement. The surgeon used arterial and venous femoral cannulation. The surgeon asks to take the patient to 13 degrees C. The patient has significant left and right carotid stenoses. The ist decides to use alpha stat blood gas management in the normothermic periods in the rewarmin phase once the core temperature gets to 28 degrees. However, in the rapid cooling and deep hypothermic phases, he decides to use ph stat to facilitate increased cerebral. The use of ph stat required the sweep rate to be dramatically lowered. However, this still did not allow for sufficient increases in pco2. Therefore, CO2 was titrated in through the blender to facilitate sufficient pco2 levels DHCA; blood gas management; alpha stat; ph stat 8 CPB Adequacy of AVR/root replacement. The ist was rewarming the patient and had gone from 32 degrees to 35 degrees. During this period, the svo2 fell to 74% to 55% and the pump flow was at an index of 2.4. The BIS reading went from 42 to 71. The ist turned up the pump flow to an index of 2.8. He also asked anesthesia to increase the level of paralysis and increase the isoflurane from 0.5% t0 1.5%. After a period of approximately five minutes, the svo2 rose to 68%. The ist had recognized that falling venous saturations and increasing levels of consciousness was one indication of inadequate. svo2; BIS; adequacy of

7 9 cardioplegia Administration technique The ist was asked to give retrograde cardioplegia. The surgeon refused to monitor the pressure with the available port on the cannulae. The cannulae was inserted by the surgeon and the command to give 750 cc was given. The ist turned on the cardioplegia pump to a flow of 90 cc/min, which would be normal for this surgeon. He noticed that the line pressure on his heart-lung machine was running at 356 mmhg. He turned the flow down and reported the line pressure to the surgeon. In order to It was discovered that keep pressure under 300, the coronary sinus flow was decreased to 10 ruptured with the high cc/ minute. The surgeon pressure. It took insisted that the flow be extensive time to repair turned up. Suddenly, the the damage. However, line pressure went to 30 the patient suffered no and the flow increased long-term negative substantially. outcome cardioplegia; line pressure, coronary sinus

8 10 Antegrade cardioplegia Administration technique The case was a CABG/AVR. The patient had aortic insufficiency. The surgeon told the ist that he wanted to open the aorta and give the initial cardioplegia dose through the coronary ostia to arrest. He asked the ist to give him the means to do so. The ist pulled a multiple cannula as well as 2- ostial lighthouse tip hand-held cannula. The ist instructed the scrub nurse to attach the cardioplegia line from the pump to the multiple cannula and then two of those "arms" to each of the hand-helds. After de-airing the system, the cardioplegia was able to be delivered through the ostia and cardiac arrest accomplished. However, initial attempts to deliver the cardioplegia where futile as the cardioplegia pump shut down due to overpressurization. Although cardioplegia delivery is accomplished, the ist had to be keenly aware of line pressure and blood flow. The initial problem was a result of all of the Roberts clamps being closed on the 4 arms of the multiple cardioplegia cannulae. The ist need to ask the surgeon to check the clamps, at which time it was recognized that they were all closed. Antegrade cardioplegia; ostial cannula