Hypertension after coronary operation. Can it be prevented by pulsatile perfusion?

Nonpulsatile perfusion during cardiopulmonary bypass (CPB) has been implicated as a causative factor of postoperative hypertension. In a consecutive series, patients undergoing coronary bypass were selected for perfusion with either nonpulsatile flow (American Optical roller pump) or pulsatile flow (Desjardin's modification of the roller pump). The incidence of postoperative hypertension and the levels of peripheral renin were noted. No differences could be observed in renin activity, with either modality of perfusion, before CPB, after 30 minutes of stable CPB, or 2 hours postoperatively. Hypertension, necessitating treatment, occurred in 60% of the patients having pulsatile and 68% of those having nonpulsatile perfusion (p less than 0.05). Although pulsatile CPB would appear to be more physiological than nonpulsatile perfusion, this method of creating pulsatile flow does not appear to eliminate postoperative hypertension.

Hemolysis during pulsatile perfusion: clinical evaluation of a new device.

The degree of hemolysis occurring during cardiopulmonary bypass was evaluated in two groups of patients undergoing pulsatile and nonpulsatile perfusion. Results indicate that, with a newly developed method of creating pulsatile flow, both groups of patients compared favorably and had approximately the same degree of hemolysis. Because of its simplicity, low cost, reliability, and limited hemolytic activity, this pulsatile device warrants further clinical evaluation.

Relationship of the proinflammatory cytokines to myocardial ischemia and dysfunction after uncomplicated coronary revascularization.

The proinflammatory cytokines have been implicated in mediating myocardial dysfunction associated with myocardial infarction, severe congestive heart failure, and sepsis. We tested the hypothesis that cytokine levels are elevated after uncomplicated coronary artery bypass grafting and associated with episodes of postoperative myocardial ischemia and dysfunction. Coronary artery bypass grafting was performed under general anesthesia with moderate systemic hypothermia and cold-blood potassium cardioplegic solution. Tumor necrosis factor-alpha and interleukin-6 levels were determined by bioassays, and interleukin-8 levels were measured by a sandwich enzyme-linked immunosorbent assay. Myocardial function and ischemic episodes were assessed by intraoperative transesophageal echocardiography and perioperative 12-channel Holter monitoring. A total of 22 patients were studied, with no deaths or complications. Arterial tumor necrosis factor-alpha rose in a bimodal distribution, peaking at 2 and 18 to 24 hours after the operation (at 20.2 +/- 6.4 pg/ml, [mean +/- standard error of the mean]) and 5.8 +/- 1.6 pg/ml, respectively; before cardiopulmonary bypass: 0.90 +/- 0.20 pg/ml, p < 0.001 for both peaks) then progressively declined to levels before bypass. Arterial interleukin-6 was maximally elevated immediately on termination of cardiopulmonary bypass and peaked again 12 to 18 hours after cardiopulmonary bypass (at 7520 +/- 2439 pg/ml and 6216 +/- 1928 pg/ml, respectively; before bypass: 746 +/- 187 pg/ml, p < 0.0001 for both peaks). Arterial interleukin-8 levels were more variable but followed a similar pattern, peaking in the early period after cardiopulmonary bypass and again at 16 to 18 hours after the operation (at 4110 +/- 1403 pg/ml and 1760 +/- 1145 pg/ml, respectively; before bypass: 461 +/- 158, p < 0.05 for both peaks). By multivariate analysis, the aortic crossclamp time was independently predictive of postoperative cytokine levels. Left ventricular wall motion abnormalities were associated with both interleukin-6 and interleukin-8 levels, worsening scores being associated with increasing levels (for interleukin-6, p = 0.003; for interleukin-8, p = 0.05). Postoperative myocardial ischemic episodes were associated with interleukin-6 levels, six of seven (85%) patients with episodes of myocardial ischemia after a peak in interleukin-6 concentrations (p < 0.01). We conclude that proinflammatory cytokines are elevated after uncomplicated coronary revascularization and may contribute to postoperative myocardial ischemia and segmental wall motion abnormalities.

Multicenter experience with the thoratec ventricular assist device in children and adolescents.

BACKGROUND: Patient size is 1 determinant in selecting a mechanical circulatory support device. The current pulsatile ventricular assist devices (VADs) were designed primarily for average-sized adults. The flexibility of the Thoratec VAD, however, has encouraged physicians to use it in a significant number of intermediate-sized older children and adolescents. METHODS: We conducted a retrospective study in 58 children and adolescents <18 years (41 boys, 17 girls) who had been supported with the Thoratec VAD in 27 centers worldwide as of December 1999. Mean patient age was 13.8 years (range, 7 to 17 years), and mean patient weight and body surface area were 51.6 kg (range, 17 to 93 kg) and 1.5 m(2) (range, 0.7 to 2.1 m(2)), respectively. RESULTS: Thirty-five patients (60%) survived to transplantation and 6 (10%) to recovery of the native heart, respectively; 38 were discharged from the hospital (66%). In the transplanted group, post-transplantation survival was 97%. Patient age and size were not associated with significantly increased risk for death or adverse events. Fifteen patients (27%) had 18 neurologic events during support, and 6 of these were fatal. Left atrial cannulation proved a risk factor for neurologic complications. CONCLUSIONS: The Thoratec VAD has successfully been used in a large number of children and adolescents with similar morbidity and mortality results as with adults. The risk of neurologic complications may be increased, particularly in patients cannulated in the left atria.

Measurement of fibroblast proliferative activity in bronchoalveolar lavage fluid in the analysis of obliterative bronchiolitis among lung transplant recipients.

BACKGROUND: Bronchiolitis obliterans occurs in 30% to 80% of lung-transplant recipients and is a direct cause of death in more than 40% of patients with this complication. This study assessed the potential utility of measuring fibroblast-proliferative activity in bronchoalveolar lavage fluid from lung-transplant recipients to better understand the pathogenesis of this process. METHODS: The capacity of bronchoalveolar lavage fluid obtained from transplant recipients, during routine surveillance bronchoscopy, to stimulate the proliferation of human lung fibroblasts in vitro was assessed retrospectively and compared to that of control subjects. For each recipient, a correlation was made between the fibroblast-proliferative activity in serial lavage samples over time and the other modalities employed for detecting post-transplant complications including spirometry, transbronchial lung biopsy, and high-resolution computed tomography. RESULTS: There was a significant difference in fibroblast-proliferative activity between volunteer and transplant recipient groups (p = 0.002). Further, for each transplant recipient, the decline in the forced expired flow rate between 25% and 75% of expired volume (FEF(25%-75%)) was correlated with the mean fibroblast-proliferative activity during the period of this study (r = 0.83; p = 0.04). CONCLUSIONS: A sustained increase in fibroblast-proliferative activity in lavage supernatant precedes both histologic and physiologic evidence of bronchiolitis obliterans. Relative to an increase in fibroblast-proliferative activity or abnormalities in FEF25%-75%, a decrease in forced expiratory volume in 1 second is a late finding.

Prevention of early postoperative renal dysfunction in cardiac transplantation.

Fifty six patients undergoing cardiac transplantation were immunosuppressed with a multi-drug induction regimen in which Cs administration was delayed postoperatively until satisfactory hemodynamics and renal function were achieved. The advantage of this approach is the absence of acute renal dysfunction in the early postoperative period. This immunosuppressive regimen was well tolerated and without significant detrimental effects on patient survival, graft rejection, or infection.

Ventricular dysrhythmias in patients undergoing coronary artery bypass graft surgery: incidence, characteristics, and prognostic importance. Study of Perioperative Ischemia (SPI) Research Group.

To determine the incidence and characteristics of ventricular dysrhythmias (premature ventricular contractions greater than 30/min, ventricular tachycardia greater than or equal to 3 beats, and ventricular fibrillation) and whether a relationship exists between ventricular tachycardia and myocardial ischemia in patients undergoing coronary artery bypass graft surgery, we continuously monitored 50 patients for 10 perioperative days using two-lead electrocardiography. Electrocardiographic changes consistent with ischemia were defined as a reversible ST depression greater than or equal to 1.0 mm, or ST elevation greater than or equal to 2.0 mm from baseline, lasting at least 1 minute. Ventricular dysrhythmias developed in 10% of patients preoperatively and in 16% intraoperatively before bypass surgery. The highest incidence occurred postoperatively, with ventricular dysrhythmias developing in 66% of patients (22% to 44% of patients on any postoperative day 0 to 7). Premature ventricular contractions were greater than 30/hr in 6% of patients preoperatively, in 8% intraoperatively before bypass, and in 34% postoperatively (6% to 23% of patients on any postoperative day). Twenty-nine patients (58%) developed 76 verified episodes of greater than or equal to 3 beats of ventricular tachycardia. Ventricular tachycardia occurred in 6% of patients preoperatively (four episodes), in 8% of patients intraoperatively prior to bypass (four episodes), and 54% of patients postoperatively (5% to 21% on any postoperative day). No patient developed ventricular fibrillation. All postoperative ventricular tachycardia episodes (after tracheal extubation) were asymptomatic. Postoperatively, 48% of patients developed ischemia, compared with 12% preoperatively and 10% intraoperatively before bypass surgery. Only 5 of 68 (7%) postoperative ventricular tachycardia episodes occurred within 3 hours of an ischemia episode.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhalation of foreign bodies by children: a continuing challege in management.

In a review of 19 years' experience with inhalation of foreign bodies by children the 33 patients (mean age 28 months) were found to have presented most frequently with wheezing or coughing, or both, of recent onset, and to have decreased air entry, rhonchi or respiratory stridor, or a combination of these signs. Eighteen children had inhaled a nut, a pea or a bean. The other 15 had inhaled various organic and inorganic objects. All the children underwent bronchoscopy, and the foreign body was completely removed in 19 during the first procedure; the remainder required repeated bronchoscopy or direct surgical removal of the foreign body, or both. Permanent disability or death was not encountered. The findingsof the study indicate that early bronchoscopic removal is the preferred treatment when a child inhales a foreign body.

Minnesota ALG. Safe and effective immunosuppression for cardiac transplantation.

Fifty-six patients undergoing orthotopic cardiac transplantation were given Minnesota ALG prophylactically or therapeutically for acute cardiac rejection. During a follow-up period of 0-28 months (mean follow-up period, 11.9 months), the actuarial survival for the entire group was 96% and 86% at 30 days and 1 year, respectively. Actuarial freedom from rejection was 60% and 28% at 30 days and 1 year, respectively. All but seven rejection episodes responded to initial steroid pulses or a modification of a maintenance cyclosporine and azathioprine regimen. The seven failures were rescued with further Minnesota ALG therapy. Few serious hematologic or allergic reactions to Minnesota ALG were observed, and no new malignancies occurred during the follow-up period. We conclude that Minnesota ALG is safe and effective in cardiac transplantation.

Early bronchiolitis obliterans following lung transplantation: accuracy of expiratory thin-section CT for diagnosis.

PURPOSE: To evaluate the accuracy of thin-section computed tomography (CT) with expiratory scans in diagnosing early bronchiolitis obliterans after lung transplantation. MATERIALS AND METHODS: Thin-section CT scans were reviewed by two observers blinded to the diagnoses in seven consecutive lung transplant recipients with histopathologically proved bronchiolitis obliterans (group A) and 21 with normal biopsy findings (group B). All patients had normal biopsy and stable pulmonary function test (PFT) results 2-36 weeks prior to CT. Patients with normal biopsy results were placed into subgroups based on abnormal (group B1) or stable (group B2) PFT results. Air-trapping extent on expiratory scans was scored on a 24-point scale. RESULTS: The mean air-trapping score in group A (6.6) was not significantly different from that in group B (4.5, P =. 17). The air-trapping score was significantly higher in groups A and B1 than in group B2 (6.2 and 2.6, respectively; P =.03). The frequency of an air-trapping score of 3 or more in groups A and B1 was significantly higher than that in group B2 (P =.03). By using a score of 3 or more to indicate air trapping, the sensitivity of expiratory CT was 74%, specificity was 67%, and accuracy was 71%. CONCLUSION: Thin-section CT, including expiratory scans, is of limited accuracy in diagnosing early bronchiolitis obliterans after lung transplantation.

Acute rejection following lung transplantation: limitations in accuracy of thin-section CT for diagnosis.

PURPOSE: To evaluate the sensitivity, specificity, predictive values, and accuracy of thin-section computed tomography (CT) for the diagnosis of acute rejection following lung transplantation and to determine whether any individual CT abnormalities are associated with histopathologically proved acute rejection. MATERIALS AND METHODS: Thin-section CT studies from 64 lung transplant recipients were retrospectively reviewed. CT studies were temporally correlated with various grades of biopsy-proved acute rejection (n = 34); 30 other CT studies were from a control group with no histopathologic evidence of acute rejection. Acute rejection was diagnosed as present or absent, and the diagnostic was calculated. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT for the diagnosis of acute rejection were as follows: 35%, 73%, 60%, 50%, 53%, respectively. No individual CT finding was significantly associated with acute rejection. The sensitivity of CT for the detection of various grades of acute rejection was 17% for grade A1, 50% for grade A2, and 20% for grade A3. The combination of volume loss and septal thickening, with or without pleural effusion, was never seen in the absence of acute rejection. CONCLUSION: Thin-section CT has limited accuracy for the diagnosis of acute rejection following lung transplantation, and no individual CT finding is significantly associated with this diagnosis.