Anesthesia and analgesia
-
Anesthesia and analgesia · Apr 2004
Clinical TrialThe influence of anthracycline therapy on cardiac function during anesthesia.
Cardiotoxicity is a well recognized complication of anthracycline (AC) therapy. Subtle abnormalities in myocardial function that become apparent only after exercise may exist in survivors of childhood cancer who have previously received AC, yet have normal resting cardiac function. To evaluate if anesthesia-induced changes in cardiac function differ in pediatric patients with previous AC therapy from healthy children and adolescents, we evaluated in a prospective study 43 patients, of whom 42 were analyzed. Twenty-one patients (AC-group), mean age 9.6 yr (range, 3-16 yr), who had received 193 (30-490) mg/m(2) of AC as a mean cumulative dose with normal resting cardiac function (shortening fraction [SF] 0.34, normal value > 0.30) underwent removal of a Hickman catheter under general anesthesia. Twenty-one patients, mean age 10.9 yr (range, 4-17 yr), who underwent placement of a Hickman catheter before chemotherapy served as the control. All children were premedicated with midazolam 0.5 mg/kg orally. Anesthesia was induced by sodium thiopental (5 mg/kg), fentanyl (3 micro g/kg), and rocuronium (0.6 mg/kg) and maintained with isoflurane (1 MAC) in N(2)O/O(2) (70/30). Before induction (baseline), 5 and 20 min after intubation (T1 and T2), and 20 min after extubation (control), cardiac function was assessed by transthoracic (baseline, control) and transesophageal (T1, T2) echocardiography. Compared with baseline (SF: 34.9 +/- 3.7 [AC], 34.1 +/- 3.7 [C] [not significant]; stroke volume index [SVI] 36 +/- 6 mL/m(2)[AC], 35 +/- 4 mL/m(2)[C] [not significant]; cardiac index [CI] 3.6 +/- 0.6 L/min/m(2)[AC], 3.2 +/- 0.5 L/min/m(2)[C] [not significant]), we found a significant decrease in SF and SVI in both groups at T1 (SF: 26.2 +/- 3.6 [AC] versus 28.6 +/- 3.6 [C] [P < 0.05]; SVI: 26 +/- 4 mL/m(2) [AC] versus 30 +/- 46 mL/m(2) [C] [P < 0.05]) and T2 (SF: 24.1 +/- 3.2 [AC] versus 28.2 +/- 2.5 [C] [P < 0.01], SVI: 26 +/- 6 mL/m(2) [AC] versus 31 +/- 5 mL/m(2) [C] [P < 0.01]), which was significantly greater in the AC group. There were no significant changes of variables of diastolic function (E/A ratio, isovolumetric relaxation time) between both groups. Previous treatment with AC may enhance the myocardial depressive effect of anesthetics even in patients with normal resting cardiac function. ⋯ Previous treatment with anthracylines, a group of chemotherapeutic drugs in use for childhood cancer, may enhance the myocardial depressive effect of anesthetics even in children and adolescents with normal resting cardiac function.
-
Anesthesia and analgesia · Apr 2004
Case ReportsProfound hypoxemia resulting from shunting across an inadvertent atrial septal tear after left ventricular assist device placement.
Defects within the interatrial septum (IAS) can be a source of significant right-to-left shunting and hypoxemia, particularly after placement of a left ventricular assist device (LVAD). We report a case of LVAD placement in which an unrecognized IAS tear occurred intraoperatively, leading to profound arterial desaturation. Transesophageal echocardiography (TEE) was instrumental in making the diagnosis. Certain intraoperative events increased the pressure gradient between the right and left atria, aggravating hypoxemia. We recommend that patients undergoing LVAD placement be screened intraoperatively with TEE for unrecognized IAS defects. Re-examination of the IAS should occur on weaning from cardiopulmonary bypass. ⋯ A traumatic atrial septal defect after atrial cannulation caused a right-to-left intracardiac shunt on initiation of left ventricular assist device support that was further aggravated by chest closure and pleural suction, culminating in severe hypoxemia.
-
Anesthesia and analgesia · Apr 2004
Are patients comfortable consenting to clinical anesthesia research trials on the day of surgery?
Consent for clinical anesthesia research trials is often sought on the day of surgery when patients are most anxious and have little privacy or time for reflection. We conducted a retrospective survey of patients' perceptions and concerns regarding consent for clinical anesthesia trials on the day of surgery. Questionnaires were mailed to 175 patients who had participated in 1 of 6 negligible- or minimal-risk clinical anesthesia trials within the preceding year. Seventy-six patients responded (43%). Most patients (80%) reported that they understood the purpose of their trial, did not feel obligated (61%) or pressured (67%) to participate, and were satisfied (mean visual analog scale: 71 mm) with the recruitment and consent process on the day of surgery. Few patients (7%) believed that their well-being was put at risk because of their participation in the trial. ⋯ This retrospective survey suggests that patient recruitment and consent for negligible- or minimal-risk clinical anesthesia research trials is appropriate when performed on the day of surgery.
-
Anesthesia and analgesia · Apr 2004
Case ReportsAn epidural hematoma in an adolescent patient after cardiac surgery.
An 18-yr-old patient had a thoracic epidural placed under general anesthesia preceding an uneventful aortic valve replacement with a bioprosthetic valve. On the second postoperative day, he was anticoagulated and also received an antithrombotic medication. While ambulating, he experienced pain in his back, and there was blood in his epidural catheter. The catheter was removed, and he developed motor and sensory loss. Rapid surgical decompression resulted in recovery of his lost neurological function. Management and strategies for preventing this problem are discussed. ⋯ Epidural hematoma is a rare complication of epidural anesthesia and has not been reported in pediatric patients undergoing cardiac surgery. The successful treatment of this complication requires swift recognition, diagnosis, and surgical intervention.