[Critical care medicine: who should really care for the patient?].
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Adolescent↗
Biomedical subjects
E R de Vivie
Publications and source records attributed to E R de Vivie.
Transvalvular in vivo gradients of the new generation bileaflet heart valve prosthesis St. Jude Medical Regent in aortic position.
BACKGROUND: By changing the design of the St. Jude Medical Regent prosthesis in shifting both sewing cuff and retaining ring into a completely supra-annular position, the Regent valve has a greater geometric orifice for a given outer diameter. Accordingly, in vitro studies have shown increased effective orifice areas (EOAs) and lower transvalvular gradients. The aim of our study was to determine in vivo transvalvular gradients and EOAs in patients after aortic valve replacement (AVR). METHODS: We investigated 75 patients at 12 to 21 months follow-up after AVR using transthoracic echocardiography. We determined left ventricular systolic and diastolic function, EOA, and transvalvular peak gradient parameters at rest. Outcomes were assessed using the NYHA classification and functional status. RESULTS: No patient experienced cardiac failure. The majority reported good functional status and good quality of life. Five (6.7 %) late deaths were observed within the surveillance period. At follow-up, 92 % of the patients had improved by at least one NYHA class. Transvalvular peak gradients at rest for patients with Regent valves were 25.4 +/- 7.7 mmHg, 19.2 +/- 4.6 mmHg, 15.6 +/- 5.8 mmHg, 14.6 +/- 5.5 mmHg, and 8.5 +/- 2.5 mmHg; EOAs were 1.38 +/- 0.32 cm2, 1.62 +/- 0.49 cm2, 2.24 +/- 0.83 cm2, 2.63 +/- 0.70 cm2, and 3.28 +/- 0.34 cm2 for valve sizes 19 mm, 21 mm, 23 mm, 25 mm, and 27 mm, respectively. CONCLUSIONS: The SJM Regent valve shows excellent in vivo hemodynamics as confirmed by echocardiography. Clinically, 92 % of the patients improved by at least one NYHA class.
Aortic Valve↗
Impact of hematocrit value after coronary artery surgery on perioperative myocardial infarction rate.
BACKGROUND: The optimal hematocrit (HCT) value after coronary artery bypass grafting on cardiopulmonary bypass (CPB) has not yet been established. The purpose of our retrospective study was to investigate the association between HCr at the time of entry into the ICU and perioperative Ml rate. METHODS: We reviewed the charts of 500 consecutive coronary artery surgery patients with respect to biometric data, operative procedure, aprotinin or tranexamic acid use, perioperative drainage blood loss and transfusion requirements, perioperative Ml, ICU stay and hospital mortality. Perioperative Ml was defined as new Q-wave on ECG and CK-MB 250U/I. Patients were categorized into three groups depending on their HCr value at the time of entry into the ICU: low (HCTcu 27%): medium (HCr,cu 28% to 32%); high(HCTrcu > or =33%). RESULTS: Age, gender distribution, preoperative LV function, and previous Ml rate were similar between the three groups. Low HCT patients (n -133) received 3.1 +/- 1.0 (Mean + SD) grafts during 55 +/- 19 minutes aortic cross clamp time, 98 +/- 31 minutes on CPB (medium HCT: n = 257; 3.2 +/- 1.0 grafts, 51 +/- 20 min cross clamp time, 93 +/- 30 min CPB; p - 0.45 vs. low HCT; high HCT: n = 110: 3.3 +/- 1:0 grafts; 53 +/- 20 min cross clamp time; 104 +/- 38 min CPB; p = 0.02 vs. medium HCT). The perioperative Ml rate was 3.8% in the low, 4.3% in the medium, and 6.4% in the high-HCr group (p =0.59 ). Intraoperative red blood cell and fresh frozen plasma transfusions were similar between the groups. In the low-HCa group, 53.4% of the patients received aprotinin during the procedure (medium HCa: 65.4%; high HCT: 77.3%; p<0.001). Drainage blood loss during the first 24 hours on ICU was 834 +/- 453 ml in the low, 757 +/- 485 ml in the medium (p -0.44 vs. low), and 640 +/- 353 ml in the high-HCr group (p = 0.003 vs. low). Postoperative red blood cell and fresh frozen plasma transfusions were highest in the low-HCa group(p<0.001). ICU stay was similar between the groups. Hospital mortality was 0.75% in the low, 1.9% in the medium, and 4.5%in the high-HCa group (p = 0.12). CONCLUSIONS: In this retrospective analysis of 500 consecutive coronary artery surgery patients, we did not find any association between perioperative Ml rate and HCr value on entry into the ICU. These results do not support the recent suggestion that low HCT at the time of entry into the ICU protects against perioperative Ml.
Aged↗
[Risk stratification in heart surgery: do risk scores facilitate the determination of indications?].
Various risk scores have been developed for the assessment of operative risk in cardiac surgery. Although risk stratification has been acknowledged as a useful tool to analyze trends in therapy and changes in patient populations, its relevance in assessing the indication for surgery has been questioned. It was the goal of this prospective study to compare 6 common risk scores with regard to the predictive value for mortality in individual patients. Between September 1998 and February 1999 all adult patients undergoing heart surgery were prospectively scored according to the following scores: initial Parsonnet, Cleveland Clinic, French, Euro, Pons, and the Ontario Province Risk score. Early lethality was assessed within 30 days postoperatively. Follow-up was completed in 504 patients. With the exception of the Ontario Province Risk score, lethality in the high risk group was overestimated by all scores, whereas lethality in low to moderate risk groups was underestimated by several scores. Mean scores of surviving and deceased patients showed a broad overlap with high standard deviations. Preoperative risk scores are effective tools for stratification of patient populations and the analysis of surgical outcome. With the aid of risk scores, operative risk can be sufficiently predicted for patient populations or subpopulations. The Euro score best predicted the outcome of our patients. However, when the indication for surgery is to be determined in an individual patient, risk scores should be only considered as an orientation in the decision process.
Adult↗
Cardiac surgery in patients with end-stage renal disease: 10-year experience.
BACKGROUND: End-stage renal disease is known to be an important risk factor complex for cardiac operations performed with cardiopulmonary bypass. METHODS: To investigate the influence of preoperative status on perioperative mortality and morbidity, we retrospectively analyzed data from 65 patients (20 women and 45 men with a mean age of 58.8+/-10.0 years [+/-standard deviation]) with end-stage renal disease who were on dialysis and who underwent a cardiac surgical procedure between 1988 and 1998. RESULTS: Fifty-one percent of the patients had isolated coronary artery bypass grafting, 35% had replacement or reconstruction of one valve or two valves, and 14% underwent combined coronary artery bypass grafting and valve replacement. The perioperative mortality rate was 13.8% with 78% (7 of 9) of deaths occurring in patients having a valve procedure. Six of the 9 patients who died had compromised left ventricular function preoperatively, and all 9 were in New York Heart Association class III or IV. Mean preoperative duration of dialysis was longer (80+/-70 months) in the 9 patients who died compared with that in the surviving 56 patients (45+/-49 months) (p = 0.05). We found dyspnea at rest, duration of dialysis of 60 months or more, combined procedures (coronary artery bypass grafting and valve operation), and New York Heart Association class IV to be associated with a higher relative risk for perioperative death. Neither angina pectoris nor isolated coronary artery bypass grafting was associated with increased relative risk for perioperative death. However, after a cardiac operation, mortality in patients with end-stage renal disease was substantially higher than in those with normal renal function. CONCLUSIONS: These data are comparable with those in the literature and possibly suggest that both indications and referral for surgical intervention have been delayed in patients who have end-stage renal disease combined with coronary artery disease, valve disease, or both. The delay may contribute to the relatively high perioperative mortality.
Adult↗
Activation of myocardial constitutive nitric oxide synthase during coronary artery surgery.
OBJECTIVE: The role of nitric oxide (NO) in myocardial ischemia/reperfusion is controversial. While some studies have shown cardioprotective effects of NO, others suggested that increased myocardial NO release secondary to ischemia may contribute to reperfusion injury. However, the impact of cardioplegia-induced myocardial ischemia/reperfusion on the activity of the NO-producing enzyme constitutive NO-synthase (cNOS or NOS-III) has not been investigated. METHODS: Twenty elective CABG patients were randomized to receive myocardial protection using either intermittent cold blood cardioplegia with 'hot-shot' (CBC; n=10) or continuous warm blood enriched with the ultra-fast-acting beta-blocker esmolol (WBE; n=10). We collected transmural LV biopsies prior to cardiopulmonary bypass (CPB), at the end of the cross-clamp period, and at the end of CPB. Specimen were subjected to immunocytochemical staining against myocardial NOS-III and cGMP using polyclonal antibodies. NOS-III activity was determined using TV-densitometry (gray units) and cGMP content using a semiquantitative score. Global myocardial metabolism was assessed by arterio-coronary sinus lactate concentration difference (a-csD(LAC)). For LV function determination we measured the fractional area of contraction (FAC) using TEE. RESULTS: In CBC hearts a-csD(LAC) was significantly decreased following cross-clamp removal as compared to pre-CPB indicating global ischemia during cross-clamp. In contrast, a-csD(LAC) was unchanged in WBE hearts indicating absence of relevant ischemia in this group. In CBC hearts NOS-III activity did not change from pre-CPB (35.6+/-11.1 U) to the end of the cross-clamp period (38. 0+/-8.1 U; P=0.2), but increased significantly to 48.5+/-12.1 U at the end of CPB following initial warm blood reperfusion (P=0.026). In WBE hearts NOS-III activity remained unchanged throughout (29. 2+/-10.8, 35.1+/-11.8, and 32.2+/-14.7 U, respectively; 0.3). At the end of CPB, nine CBC hearts, but only one WBE heart showed increased cGMP content (P=0.002). Compared to pre-CPB, FAC in the CBC group was 109+/-25% following weaning off CPB (P=0.26), but was slightly decreased to 87+/-22% at 4 h post-CPB (P=0.03). In the WBE group FAC remained unchanged compared to pre-CPB throughout (103+/-21 and 96+/-37%, respectively; 0.5). CONCLUSIONS: Our data show that global myocardial ischemia and reperfusion induced by CBC is associated with myocardial NOS-III activation and increased cGMP content suggesting increased NO release. In contrast, avoidance of ischemia by use of WBE prevented NOS-III and c-GMP increase. As LV function was decreased at 4 h post-CPB in the CBC group, these data suggest that increased NO release secondary to NOS-III activation may have contributed to ischemia-reperfusion injury as has been shown experimentally.
Adrenergic beta-Antagonists↗
Risk stratification in heart surgery: comparison of six score systems.
OBJECTIVE: Risk scores have become an important tool in patient assessment, as age, severity of heart disease, and comorbidity in patients undergoing heart surgery have considerably increased. Various risk scores have been developed to predict mortality after heart surgery. However, there are significant differences between scores with regard to score design and the initial patient population on which score development was based. It was the purpose of our study to compare six commonly used risk scores with regard to their validity in our patient population. METHODS: Between September 1, 1998 and February 28, 1999, all adult patients undergoing heart surgery with cardiopulmonary bypass in our institution were preoperatively scored using the initial Parsonnet, Cleveland Clinic, French, Euro, Pons, and Ontario Province Risk (OPR) scores. Postoperatively, we registered 30-day mortality, use of mechanical assist devices, renal failure requiring hemodialysis or hemofiltration, stroke, myocardial infarction, and duration of ventilation and intensive care stay. Score validity was assessed by calculating the area under the ROC curve. Odds ratios were calculated to investigate the predictive relevance of risk factors. RESULTS: Follow-up was able to be completed in 504 prospectively scored patients. Receiver operating characteristics (ROC) curve analysis for mortality showed the best predictive value for the Euro score. Predictive values for morbidity were considerably lower than predictive values for mortality in all of the investigated score systems. For most risk factors, odds ratios for mortality were substantially different from ratios for morbidity. CONCLUSIONS: Among the investigated scores, the Euro score yielded the highest predictive value in our patient population. For most risk factors, predictive values for morbidity were substantially different from predictive values for mortality. Therefore, development of specific morbidity risk scores may improve prediction of outcome and hospital cost. Due to the heterogeneity of morbidity events, future score systems may have to generate separate predictions for mortality and major morbidity events.
Adult↗
Coronary oxygen persufflation combined with HTK cardioplegia prolongs the preservation time in heart transplantation.
BACKGROUND: One of the most restricting factors remaining in heart transplantation is the limited myocardial ischemia time. A new approach towards the prolongation of this time is the combination of primary cardioplegic arrest followed by continuous coronary oxygen persufflation (COP) with gaseous oxygen. METHODS: This technique was applied in pig hearts, which we transplanted orthotopically after cardioplegic arrest by original (n = 5) and modified (addition of hyaluronidase: n = 11) Bretschneider HTK solution and 14 h of hypothermic preservation. Depending on the different preservation techniques, we created four groups: (1), original HTK (HTK), n = 5; (2), modified HTK (mHTK), n = 5; (3), modified HTK solution plus COP (mHTK + COP), n = 6; and (4), as a control five hearts were transplanted after cardioplegic arrest by the original HTK solution and a cold ischemia time of 3 h comparable to clinical routine procedure. RESULTS: After 14 h of preservation and orthotopic transplantation, cardiac functional recovery in mHTK + COP hearts was similar to control hearts, and improved compared to hearts of both other groups. Hemodynamics were significantly better in hearts preserved by mHTK + COP and in the control group compared to the HTK-hearts (P < 0.05), not significant compared to mHTK hearts (dp/dt(max) in % of preoperative +/- standard error of mean (SEM): mHTK + COP, 85 +/- 9; control, 85 +/- 10.5; mHTK, 59 +/- 14; HTK, 50 +/- 4). The cardiac output (CO) in % of preoperative was: mHTK + COP, 68 +/- 5.4; control, 64 +/- 4; mHTK, 44 +/- 2.7; HTK, 25 +/- 11. The ATP of left ventricular myocardium in mHTK + COP hearts at 14.7 +/- 1 micromol/g dry weight (DW) and in the control at 14.59 +/- 1.8 was higher compared to that in mHTK at 12.2 +/- 2.8 (P is non-significant (n.s.) versus mHTK + COP and control) and in HTK-hearts at 7.0 +/- 0.5 (P < 0.05 versus mHTK + COP and control). CK-MB in percent of CK showed no increase in either group. CONCLUSIONS: These data show that COP combined with a mHTK solution represents a potential alternative to complement currently used cold storage techniques for prolonged preservation periods.
Animals↗
Absence of hemodynamic and ECG changes in a patient with traumatic left ventricular injury and puncture of the left anterior descending branch.
Patients with penetrating cardiac injury usually present with cardiac tamponade and shock upon hospital arrival. However, absence of hemodynamic depression does not exclude a potentially fatal injury of the heart. This article reports on a patient who developed neither hemodynamic depression nor ECG changes for several hours, despite two left ventricular lacerations with puncture of the LAD. Echocardiography is advocated as the diagnostic tool of choice, and it is emphasized that no penetrating objects should be removed from the wound before surgical access to the heart is established, as this may result in the sudden development of cardiac tamponade.
Coronary Vessels↗
Surgical repair of right-atrial aneurysm.
Atrial fibrillation and embolic events are the most common clinical symptoms of congenital right- or left-atrial aneurysms. We report an a case of righ-atrial aneurysm, in a patient with typical history of atrial fibrillation and history of stroke. The aneurysm was resected, but the patient suffered from acute embolic occlusion of the left anterior descending coronary artery on the fourth postoperative day despite of systemic heparinization with 300 IU/kg bw per 24 hours.
Anticoagulants↗
Single-channel activity and expression of atrial L-type Ca(2+) channels in patients with latent hyperthyroidism.
Patients with "latent hyperthyroidism" (suppressed thyroid-stimulating hormone and normal circulating thyroid hormones) are at risk to develop atrial fibrillation. In animal models, hyperthyroidism is associated with increased cardiac L-type Ca(2+) current. Therefore, we assessed L-type channel function and expression in right atria from patients undergoing cardiac surgery. Single L-type channels were studied in the cell-attached condition. Voltage dependence of gating was similar in patients with and without latent hyperthyroidism. With use of a pulse protocol leading to maximum channel availability, single-channel activity was further analyzed. Average peak current was significantly enhanced in latent hyperthyroidism, mainly because of an increased channel availability (P < 0.05). Protein expression was analyzed by Western blot. In latent hyperthyroidism, expression of Ca(2+) channel alpha(1)-subunits was increased more than threefold (P < 0.01). In contrast, sarco(endo)plasmic reticulum Ca(2+)-ATPase and phospholamban levels were not significantly changed. We only observed a trend toward increased sarco(endo)plasmic reticulum Ca(2+)-ATPase expression (P = 0.085). Function and expression of human atrial L-type Ca(2+) channels are increased in latent hyperthyroidism. These endocrine effects on the heart may be clinically relevant.
Blotting, Western↗
Cardiac myocytes of hearts from patients with end-stage dilated cardiomyopathy do not contain Borrelia burgdorferi DNA.
OBJECTIVE: To determine if end-stage dilated cardiomyopathy (DCM) is associated with the presence of Lyme disease causing spirochete Borrelia burgdorferi in the myocardium, we used nested polymerase chain reaction to detect B burgdorferi DNA in myocardial samples from explanted hearts of patients with end-stage DCM. Patients originated from endemic areas for Lyme disease (Bavaria, Lower Saxony, Germany). METHODS AND RESULTS: This was a retrospective study. Polymerase chain reaction was used to detect the specific B burgdorferi recombinant outer surface protein A (OspA) gene in myocardial tissue from 68 patients with end-stage DCM who had undergone heart transplantation. The clinical history of Lyme disease, the presence of Borrelia burgdorferi OspA, and antibodies against OspA in myocardial tissue and serum were investigated. B burgdorferi DNA was not detected in any of the 68 human hearts. Immunoglobulin G antibodies against specific B burgdorferi antigens were observed in 3 (12.5%) of 24 patients. In contrast, 4 hearts from rats experimentally infected with B burgdorferi were all positive for OspA DNA as measured by polymerase chain reaction. CONCLUSION: Our data show that cardiac myocytes of hearts obtained from subjects with end-stage DCM did not contain B burgdorferi DNA as investigated by polymerase chain reaction. However, B burgdorferi shows a high affinity for myocardial tissue as shown by the animal studies, indicating that myocardial infections are nevertheless possible.
Animals↗
30 years clinical intra-aortic balloon pumping: facts and figures.
Since its first clinical application 30 years ago, intra-aortic balloon pumping (IABP) has become the most widely applied mechanical circulatory assist method. Following disappointing initial results in patients with cardiogenic shock after acute myocardial infarction, IABP has been preferentially used for treatment of post cardiac surgery low output syndrome. However, in recent years IABP use appears to be changing mainly due to increased use in the setting of acute myocardial ischemia/infarction associated with interventional cardiology, as well as trends for both overall increasing perioperative IABP use and relatively increasing preoperative use in high risk patients undergoing cardiac surgery. Despite the superiority of ventricular assist devices (VADs) in terms of circulatory support, IABP remains the clinician's first choice in postcardiotomy low output syndrome either alone or in combination with VAD's. Although IABP-related mortality and complication rate are declining in recent years, it has to be emphasized that IABP is still associated with substantial mortality and morbidity. However, the available data suggest that early IABP use significantly reduces mortality and morbidity in both cardiac surgery and cardiology patients. In addition, studies have shown that aggressive IABP use is "cost-effective" at least in selected patients due to both shorter hospital stay and complication reduction. Thus, the available 30 years experience appears to justify a more liberal IABP use in both cardiac surgery and cardiology.
Cardiac Surgical Procedures↗
Simultaneous carotid and coronary artery surgery: indications and perioperative outcome.
BACKGROUND: A significant number of patients with coronary artery disease is diagnosed with additional carotid artery disease. This subset of patients has been identified as a high-risk group for cardiac and cerebral complications following surgical intervention. METHODS: In a retrospective analysis we investigated the perioperative outcome of combined single-stage carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG) in 63 patients operated between January 1989 and August 1998. In all of these patients, CEA was performed prior to CABG and before initiation of cardiopulmonary bypass. RESULTS: Perioperative mortality rate was 7.9% (5/63) for simultaneous CEA and CABG and was due to cardiac complications in all patients. Postoperative unilateral neurological symptoms were diagnosed in 1 patient (1.7%) and were completely reversible. No neurologic events suggestive for permanent cerebral damage were observed during the 30 d postoperative period. CONCLUSIONS: In our study combined single-stage CEA and CABG was associated with low cerebral morbidity and patient outcome was mainly determined by cardiac complications. In this subset of patients, simultaneous CEA and CABG appears to be a safe method.
Carotid Stenosis↗
Emergency coronary artery surgery after failed PTCA: myocardial protection with continuous coronary perfusion of beta-blocker-enriched blood.
BACKGROUND: Myocardial protection during cardiac surgery in patients with acute ischemia after failed PTCA remains a challenge. Our recent experimental work demonstrated that continuous coronary perfusion with warm beta-blocker-(Esmolol) enriched blood may be a useful alternative to current cardioplegia techniques, especially for compromised hearts. This technique was applied in our last 12 patients after failed PTCA (beta-B). The purpose of this retrospective study was to compare this alternative myocardial protection technique with our standard technique of cold crystalloid cardioplegia (CP). METHODS: Between January 1994 and January 1998 fifty-five patients (beta-B: n = 12; CP: n = 43) underwent emergency coronary artery bypass grafting within 24 hours after failed PTCA. The mean age in beta-B patients was 62+/-9 (SD) years, and 33% were female (CP: 59+/-9 years, 42% female, p = NS). In beta-B patients 67% had myocardial infarction (MI) prior to coronary angioplasty, 67% had an ejection fraction (EF) >55%, and coronary vessel involvement (VI) was 2.1+/-0.7. CP patients had the following findings: MI rate 42%, EF >55% in 84%, VI was 2.2+/-0.6; p = NS. Operation commenced within 25-980 min after failed PTCA. Beta-B patients received 2.7+/-0.8 grafts during 45+/-20 min continuous coronary perfusion with Esmolol enriched blood, whereas CP patients had 3.0+/-1.1 grafts in 42+/-17 min cross-clamp time, p = NS. RESULTS: The total hospital stay was significantly (p = 0.004) shorter for beta-B patients (18+/-8 days) compared to CP patients (27+/-12 days). 30-days mortality rate was 9% in CP patients, whereas none of the beta-B patients died. Postoperative low cardiac output occurred in only one patient (8%) of the beta-B group and was treated with an intra-aortic balloon pump (IABP). Eight (19%) of the CP patients required an IABP and in five (12%) patients an additional ventricular assist device was necessary (LVAD: n = 4; RVAD: n = 1). The need for circulatory support with inotropes was significantly lower in beta-B patients. Cumulative postoperative dosage of dopamine and dobutamine was 34516+/-40400 microg/kg and 16221+/-26678 microg/kg respectively in CP patients. Beta-B patients required only 12457+/-14738 microg/kg (p = 0.02) dopamine and 5112+/-7381 microg/kg (p = 0.01) dobutamine. Perioperative myocardial infarction occurred in 53% of the CP patients and 17% of beta-B patients (p = 0.046). Total CKmax was significantly (p = 0.003) higher in CP patients (812+/-531 U/L) than in beta-B patients (457+/-265 U/L). Four CP patients (9%) had acute postoperative renal failure requiring hemofiltration, and 11 CP patients (26%) had acute postoperative pneumonia. In beta-B patients one patient (8%) suffered from postoperative pneumonia (p = NS) and no patient had renal failure (p = NS). CONCLUSION: These clinical results appear to confirm our experimental data and suggest that continuous coronary perfusion with warm esmolol-enriched blood is superior to crystalloid cardioplegia in terms of in-hospital complications and mortality, especially for compromised hearts after failed PTCA.
Adrenergic beta-Antagonists↗
Alterations of neuropsychological function and cerebral glucose metabolism after cardiac surgery are not related only to intraoperative microembolic events.
BACKGROUND AND PURPOSE: High-intensity transient signals (HITS) during cardiac surgery are capable of causing encephalopathy and cognitive deficits. This study was undertaken to determine whether intraoperative HITS cause alterations of neuropsychological function (NPF) and/or cerebral glucose metabolism (CMRGlc), even in a low-risk patient group, and whether induced changes are interrelated. METHODS: Eighteen patients without signs of cerebrovascular disease underwent elective coronary artery bypass grafting (CABG), and two of these additionally underwent valve replacement in normothermia. Intraoperatively, HITS were recorded by means of transcranial Doppler ultrasonography (TCD). Perioperatively, NPF and CMRGlc were assessed using a standardized complex test battery and positron emission tomography with 18F-2-fluoro-2-deoxy-D-glucose (FDG-PET), respectively. RESULTS: Intraoperatively, the number of HITS ranged from 90 to 1710 per patient and hemisphere, more on the right side than on the left (P<.05). HITS occurred primarily during cardiopulmonary bypass (71.3%) and, to a lesser extent, during aortic manipulation (22.2%). Changes in global and regional CMRGlc between first (one day preoperatively) and second (8 to 12 days postoperatively) FDG-PET scans were mild. No correlations were found between the number of HITS, age of patient, duration of cardiac ischemia or cardiopulmonary bypass and the changes in CMRGlc. In patients with recorded HITS and a postoperative decrease of regional CMRGlc (n=11), the maximal decrease of rCMR Glc in each hemisphere below the individual global change of CMRGlc correlated with the number of HITS (r= -0.46, P<.05). Limitations in NPF occurred 8 to 12 days postoperatively, resolved within 3 months, and were not found to be correlated to the absolute number of HITS or changes in CMRGlc. CONCLUSIONS: HITS during cardiac surgery can cause alterations of both NPF and CMRGlc, even in a low-risk patient group. However, the number of HITS and changes in NPF and CMRGlc are not necessarily interrelated, which indicates that (1) the location of brain damage related to HITS is more important for the development of NPF than is the absolute number of HITS, and (2) factors in addition to HITS might contribute to surgery-related brain damage.
Adult↗
Cooling gradients and formation of gaseous microemboli with cardiopulmonary bypass: an echocardiographic study.
BACKGROUND: Previous studies demonstrated gas emboli formation during rewarming from hypothermia on cardiopulmonary bypass when the temperature gradient exceeded a critical threshold. It also has been suggested that formation of arterial gas emboli may occur during cooling on cardiopulmonary bypass when cooled oxygenated blood exiting the heat exchanger is warmed on mixture with the patient's blood. The purpose of this study was to determine under what circumstances gas emboli formation would occur during cooling on cardio-pulmonary bypass. METHODS: Eight anesthetized mongreal dogs were placed on cardiopulmonary bypass using a roller pump, membrane oxygenator, and arterial line filter. For emboli detection, we positioned a transesophageal echocardiographic probe at the aortic arch distal to the aortic cannula and Doppler probes at the common carotid artery and the arterial line. Cooling gradients between normothermic blood and cooled arterial perfusate of 5 degrees, 10 degrees, 15 degrees, 20 degrees, and 0 degree C (isothermal controls) were investigated. In addition to preestablished temperature gradients, we investigated the effect of rapid cooling (maximal flow through the heat exchanger at a water bath temperature of 4 degrees C) after the initiation of normothermic cardiopulmonary bypass. RESULTS: Minimal gas emboli were detected at the aortic arch at gradients of 10 degrees C or greater. The incidence of emboli was related directly to the magnitude of the temperature gradient (p < 0.01). No emboli were detected at the carotid artery. During rapid cooling, no emboli were observed either at the aorta or at the carotid artery. CONCLUSIONS: Cooling gradients of 10 degrees C or greater may be associated with gas emboli formation, but they may be of limited clinical significance because no emboli were detected distal to the aortic arch. During the application of rapid cooling, no emboli formation was observed.
Animals↗
Augmenting cardiac contractility hastens myocardial edema resolution after cardiopulmonary bypass and cardioplegic arrest.
UNLABELLED: Although myocardial edema is associated with cardiopulmonary bypass (CPB) and cardioplegic arrest (CPA), interventions to expedite edema removal have not been investigated. The primary mechanism for the removal of excess interstitial fluid in the heart is myocardial lymphatic drainage, but lymphatic function can be impaired by decreased contractility because of edema. The purpose of this study was to determine whether enhancing cardiac contractility would increase myocardial lymphatic function and hasten edema resolution after CPB. Sixteen dogs were subjected to CPB and 1 h of hypothermic CPA. After weaning from CPB, 10 dogs received an intravenous dobutamine infusion and 6 dogs received no inotropic support. We determined myocardial lymph driving pressure from the major cardiac lymphatic, myocardial water content by using microgravimetry, and the peak rate of left ventricular pressure increase (dP/dmax) by using micromanometry. Measurements were taken at baseline, during CPA, and 60 min after CPB. Compared with controls, dobutamine-treated dogs had an increased dP/dmax (P < 0.05), which was associated with higher lymph driving pressures (P < 0.05), resulting in lower myocardial water gain 1 h after CPB (P < 0.05). We conclude that the resolution of myocardial edema after CPB was hastened by dobutamine. Organized ventricular contraction and myocardial contractility seem to be important determinants of myocardial lymphatic function and myocardial edema removal. These findings suggest that the administration of inotropic drugs after CPB may hasten cardiac recovery. IMPLICATIONS: Myocardial edema, which develops during cardiopulmonary bypass and cardioplegic arrest, contributes to cardiac dysfunction after heart surgery. This study demonstrated that enhancement of cardiac contractility by the administration of dobutamine after cardiopulmonary bypass and cardioplegic arrest was associated with increased myocardial lymphatic function and hastened edema resolution in dogs.
Animals↗