Intra-operative spinal cord monitoring in orthopaedics.

The surgical correction of spinal deformities carries a small but significant risk of injury to the spinal cord. To detect the onset and possibly reverse the effects of surgical complication, a variety of neurophysiological monitoring procedures can be employed. The purpose of this review is to provide information regarding the various methodologies available for monitoring spinal cord and nerve root function during orthopaedic procedures. Intra-operative monitoring of cortically recorded somatosensory evoked potentials (SEPs) by peripheral nerve stimulation is of value during orthopaedic surgery and is the state-of-the-art in terms of non-invasiveness, versatility, time requirement, lateral discrimination, and ease of electrode placement. Monitoring of motor evoked potentials (MEPs) is useful particularly in combination with SEPs but is still considered investigational. Root function monitoring has limited application and requires more clinical research.

Myeloprotective effect of early primary granulocyte-colony stimulating factor during six courses of intensified 5-fluorouracil, epirubicin and cyclophosphamide (120FEC) chemotherapy for advanced breast cancer. Cooperative Group of Study and Treatment of Breast Cancer.

AIMS AND BACKGROUND: The neutropenia induced by six courses of an intensified FEC regimen is expected to be checked by early primary administration of G-CSF which is stopped eight days before the next chemotherapy course. Less information is available about megakaryocytic and erythroid toxicity over six courses. METHODS AND STUDY DESIGN: Sixty-six consecutive patients with metastatic breast cancer completed six courses of a randomized treatment with two FEC regimens administered every 21 days, in which 600 mg/m2 of cyclophosphamide and 5-FUwas associated with 60 or 120 mg/m2 of epirubicin (60FEC, 35 patients, vs 120FEC, 31 patients). 120FEC was supported by early primary G-CSF (days 4 to 13). Blood counts were obtained seven times during each course. RESULTS: The non-hematologic toxicity over 364 courses was similar in 60FEC and 120FEC. No cumulative hematologic toxicity was observed for white blood cells (WBC) and platelets (PLT), while for hemoglobin (Hb) a somewhat higher cumulative toxicity was observed with 120FEC than with 60FEC. WBC, PLT and Hb grade III-IV toxicity occurred in 40.1% and 45.6% (P=ns), in 23.1% and 0.8% (P <.0001) and in 15.6% and 3.0% (P <.005) of the two regimens, respectively. There were no febrile or hemorrhagic episodes. The epirubicin relative dose intensity delivered was 1.95 in 120FEC with respect to 60FEC. CONCLUSIONS: Our G-CSF schedule permitted to deliver six courses of 120FEC without any clinically relevant side effects. Grade III-IV leukopenia was similar with 120FEC and 60FEC, while grade III-IV thrombocytopenia and anemia occurred more often with 120FEC than with 60FEC.

Comparison of intravenous nifedipine and sodium nitroprusside for treatment of acute hypertension after cardiac surgery.

BACKGROUND: The present study was designed to compare the hemodynamic effects of nifedipine and sodium nitroprusside, intravenously administered to control acute systemic hypertension in the immediate postoperative period after open heart surgery. METHODS: The study was carried out on 16 patients who developed acute systemic hypertension, defined as mean systemic arterial pressure (MAP) values above 90 mmHg, within the first hour after ICU admission, which followed cardiac surgery for valvular and coronary disease. After control measurements during the hypertensive status, each patient was treated by alternating infusions of sodium nitroprusside and nifedipine in order to obtain MAP values of about 80 mmHg with each administration. All patients had preoperative left ventricular ejection fraction above 45%. RESULTS: Nifedipine produced a superior and significant increase in cardiac index (CI) (+28%) and stroke volume index (SVI) (+30%), and a greater decrease in systemic vascular resistance index (SVRI) (-39%), when compared with sodium nitroprusside [CI (+5%), SVI (no change), SVRI (-27%)]. On the contrary the right and left ventricular filling pressures were reduced significantly by sodium nitroprusside [pulmonary capillary wedge pressure (-30%), central venous pressure (-20%)], while nifedipine induced small and not significant changes in the preload values. No ECG changes suggesting ischemic myocardial events were observed in any patient. CONCLUSIONS: On the basis of these results it has been concluded that nifedipine affects primarily the arteriolar resistance vessels without significant changes in venous tone, which is on the contrary markedly reduced by sodium nitroprusside. The better improvement in cardiac index and stroke volume index obtained with the administration of nifedipine, makes this drug a good alternative to sodium nitroprusside for treatment of acute hypertension after cardiac surgery in patients with a good preoperative left ventricular function.

Paclitaxel in anthracycline-treated breast cancer patients.

Between May 1995 and July 1997, paclitaxel (TX) (175 mg/m2 by 3 h i. v. infusion every 21 days) was administered to 70 consecutive patients (median age: 57 years) previously treated with the FEC regimen (cyclophosphamide and 5-fluorouracil, 600 mg/m2, plus epirubicin, 60 or 120 mg/m2) as an adjuvant setting or as a first-line therapy for metastatic disease. Sixty-eight patients were evaluable for response, while two died early. Patients received a median of 4.7 (3-12 course) of TX for a total of 211 courses. The overall response and stable disease rate was 54% in 11 patients, who relapsed following adjuvant FEC, and 60% in 57 patients, who received FEC as first treatment for their metastatic disease. No complete respose was obtained. In patients pretreated for metastatic disease, response and stable disease rates were similar irrespective of previous response to FEC. Main hematologic toxicity of TX was of short duration, grade II/III leukopenia (86% of patients) and non-hematologic toxicity was grade II/III peripheral neuropathy, related to the cumulative dose of TX. At this schedule, TX offers a significant rate of partial responses or disease stabilization in patients with metastatic breast cancer previously treated with FEC.

Effects on renal function of a continuous infusion of nifedipine during cardiopulmonary bypass.

OBJECTIVES: To evaluate the effects on renal function of continuously administered nifedipine during cardiopulmonary bypass (CPB) in patients undergoing cardiac surgery. DESIGN: The study was prospective, randomized, and controlled. SETTING: The study was performed in the Department of Anesthesia and intensive care unit of a regional hospital in Italy. PARTICIPANTS: Thirty-four patients scheduled for elective coronary artery surgery; all patients had preoperative renal and hemodynamic function within normal limits. INTERVENTIONS: The patients were randomly divided into two equal groups: nifedipine and control. Twenty patients were included in the study: 10 patients in the nifedipine group (group A) and 10 patients in the control group (group B). In group A, nifedipine was continuously administered during CPB at an infusion rate ranging from 0.24 to 0.59 micrograms/kg/min to maintain the mean systemic arterial pressure (MAP) between 60 and 70 mmHg. In group B, increases of MAP above 70 mmHg were treated with IV boluses of urapidil (5 mg). MEASUREMENTS AND MAIN RESULTS: Renal function was studied using creatinine clearance (CRCL), determined before, during, and after the operation, and the glomerular filtration rate (GFR) was measured the day before and after the operation by plasma and urine clearance of 51-chromium edetic acid (51Cr-EDTA). Hemodynamic monitoring was performed using a pulmonary artery catheter. In comparison with preoperative determinations, CRCL and GFR values increased significantly after CPB (p < 0.001) and after the operation (p < 0.01) in the patients treated with nifedipine, whereas the two parameters showed a small and not significant reduction at the same times in the control patients. Hemodynamic function was well maintained in all patients throughout the study. CONCLUSIONS: It is concluded that, besides the maintenance of adequate hemodynamics, a continuous infusion of nifedipine during CPB can be an additional therapeutic tool to protect renal function in cardiac surgical patients.

[Continuous monitoring of mixed venous oxygen saturation during mechanical circulatory support of the left ventricle in heart surgery patients. Pathophysiologic principles and personal experience]. / Monitoraggio continuo della saturazione venosa mista durante assistenza circolatoria meccanica del ventricolo sinistro, nel paziente cardiochirurgico. Presupposti fisiopathologici ed esperienza clinica personale.

The clinical use of mechanical supports for cardiocirculatory function assistance has permitted to treat a higher number of low output syndromes insensitive to pharmacological therapy. One of the most important problems arising during mechanical circulatory assistance, is the ability to know if the performance of the artificial device is adequate to match metabolic tissues demands. Continuous monitoring of mixed venous O2 saturation (MSvO2) has been proposed as the most complete and reliable tool to verify this correlation. The Authors analyse the problems connected with this kind of monitoring during left ventricular assistance with centrifugal pump in cardiosurgical patients and present 6 cases taken from their clinical experience.

[Peridural anesthesia and narcosis with propofol in thoracic surgery]. / Anestesia peridurale e narcosi con propofol in chirurgia toracica.

Twelve patients undergoing elective thoracic surgery because of lung cancer, have been studied. The anesthetic management included: continuous epidural anesthesia with bupivacaine (T6-T7), continuous infusion of propofol and vecuronium, mechanical ventilation with an oxygen/air mixture. We evaluated the perioperative analgesia and the cardiovascular side effects of two groups of patients differing for the position (supine or lateral) selected to administer the local anesthetic. We also analysed the most important characteristics of the recovery from anesthesia (degree of analgesia and consciousness, respiratory function and cooperation with physiotherapeutic manoeuvres). The authors conclude that, although the number of patients studied is limited, there are no significant differences between the two groups for intraoperative analgesia and hemodynamic imbalance; the anesthetic technique employed is a reliable alternative to classic balanced anesthesia, because seems to reply very well to the mayor purposes of thoracic surgery. Moreover it makes the operative room free from pollution caused by volatile anesthetics.