Postoperative Cardiac Surgery Patients Research Articles

Intraoperative and postoperative effects of vancomycin administration in cardiac surgery patients

In response to an increased frequency of Staphylococcus epidermidis infections in postoperative cardiac surgery patients, antibiotic prophylaxis was changed to include both vancomycin and cefazolin pre- and intraoperatively. Subsequent to the addition of vancomycin prophylaxis, clinical impression and retrospective analysis supported a correlation between vancomycin administration and post-cardiopulmonary bypass norepinephrine use. A prospective, double-blind, randomized study. Tertiary care center in a university hospital. A total of 58 patients undergoing elective coronary artery bypass surgery under high-dose fentanyl anesthesia. Patients were randomized to receive cefazolin and either vancomycin or normal saline pre-, intra-, and postoperatively in a double-blinded protocol. Hemodynamic profiles and doses of administered vasoactive agents were calculated and recorded for all patients for both intra- and postoperative time periods. Hypotension consistent with vasodilation was treated with a norepinephrine infusion. The rate and frequency of norepinephrine infusions were tabulated for both groups. Hemodynamic profiles that were obtained after the administration of the initial dose of vancomycin or normal saline and before the induction of general anesthesia and those profiles obtained after the induction of general anesthesia until the initiation of cardiopulmonary bypass showed no difference between groups and no evidence of vasodilation secondary to vancomycin administration. However, subsequent doses of vancomycin in the intra- and postoperative periods were associated with a significantly greater frequency of norepinephrine infusions to maintain normal hemodynamic indices. In the vancomycin group, 50% of patients received a norepinephrine infusion in the intra- and/or postoperative period as compared with 14% in the normal saline group (p < .01). Furthermore, the group of patients who received vancomycin and subsequently required a norepinephrine infusion had significantly lower mean systolic arterial pressure, mean arterial pressure, and systemic vascular resistance as compared with all other groups. There were no differences between groups in the use of vasopressors (other than norepinephrine) or fluid balance. The results show that a significantly greater number of patients who received vancomycin required a norepinephrine infusion and that, despite norepinephrine infusion therapy, systemic vascular resistance was not normalized in this group of patients. The study supports the conclusion that perioperative administration of vancomycin in cardiac surgery patients may result in hypotension requiring the use of a vasopressor in an attempt to normalize hemodynamic indices.

Complications of epicardial pacing wire removal

Epicardial pacing wire removal (EPWR) is a procedure performed on postoperative cardiac surgery patients. Nurses who assist with or perform this procedure need to be aware of its possible complications; these include bleeding, pericardial or mediastinal tamponade, ventricular dysrhythmias, wire fragment migration, and infection secondary to retained wire fragments. Patients undergoing EPWR should be monitored for signs of complications; appropriate emergency equipment should be readily available, and nurses should educate patients on possible problems and interventions.

Infective endocarditis: a challenging diagnosis.

The critical care nurse plays a key role in the management and care of the patient with Infective Endocarditis. The nurse's sensitive assessment of post-operative cardiac surgery patients helps to identify this complication in the early stages so that early antibiotic therapy can improve outcomes for patients with this complication. Likewise, the nurse's assessment which uncovers a history of recent dental techniques or drug abuse helps identify this complication in newly-admitted patients. By administering and evaluating the success of antibiotic therapy the nurse helps the patient combat the Infective Endocarditis.

The Effects of Chest Physical Therapy Upon Percent Oxygen Saturation in Postoperative Cardiac Surgery Patients

The Effects of Chest Physical Therapy Upon Percent Oxygen Saturation in Postoperative Cardiac Surgery Patients

Estimating Left Ventricular Filling Pressure during Positive End-Expiratory Pressure in Humans

In the critically ill, accurate measurements of left ventricular (LV) filling pressure using pulmonary artery occlusion pressure (Ppao) are important for diagnostic and therapeutic purposes. In patients receiving positive end-expiratory pressure (PEEP), Ppao may not reflect LV filling pressure because of elevated pericardial pressure (Ppc). It has been proposed that in humans, Ppc and right atrial pressure (PRA) are equal, so that referencing Ppao to PRA may improve the assessment of LV filling pressure when Ppc is elevated. Similarly, it has also been shown in the dog that nadir Ppao immediately after airway disconnection from PEEP (nadir Ppao), accurately reflects LV filling pressure when LV filling pressure is greater than or equal to 10 mm Hg. We examined methods of estimating LV filling pressure using Ppao measurements under conditions in which increases in Ppc were the primary determinants of differences in the two measurements. Using left atrial pressure (PLA) relative to Ppc, called transmural PLA (PLAtm), as LV filling pressure, we compared the accuracy of Ppao, nadir Ppao, and Ppao relative to PRA to reflect PLAtm in 15 postoperative cardiac surgery patients in whom an air-filled pericardial balloon catheter and a left atrial catheter were inserted during surgery. PEEP was sequentially increased from zero to 15 cm H2O. We found that PRA always exceeded Ppc (p less than 0.01) and increased less with PEEP than did Ppc (p less than 0.05). At less than or equal to 5 cm H2O PEEP, both Ppao and nadir Ppao were similar to each other and to PLAtm.(ABSTRACT TRUNCATED AT 250 WORDS)

Stability of arterial to end-tidal carbon dioxide gradients during postoperative cardiorespiratory support

The changes in the arterial to end-tidal carbon dioxide gradient. P(a-ET)CO2, were studied in postoperative cardiac surgery patients from the time of admission to the intensive care unit, during changing cardiorespiratory support, up to the time of tracheal extubation. Individual factors evaluated for their effects on P(a-ET)CO2 included rate of mechanical ventilation, infusion of vasoactive agents (nitroglycerin, nitroprusside, dopamine, dobutamine, and metariminol), and associated changes in haemodynamic pathophysiology (cardiac index, pulmonary artery pressure, pulmonary vascular resistance index, systemic vascular resistance index, and pulmonary capillary wedge pressure). After approval by the Clinical Investigation Committee, 59 patients, age 63 +/- 9 (41 to 75) yr, were studied and 382 individual gradient determinations made. Mean P(a-ET)CO2 was 5.47 +/- 5.21 mmHg, with the mean PaCO2, 36.51 +/- 5.89 mmHg and mean ETCO2, 31.04 +/- 6.44 mmHg. For the population as a whole, the correlation between PaCO2 and ETCO2 determined by regression analysis was maintained (R = 0.644, P less than 0.001). Comparison of the individual and population correlation coefficients by Student's t test showed no significant difference, but a normal population distribution of the gradients (P less than 0.05). None of the variables assessed could be determined to influence P(a-ET)CO2 significantly. For many of the individual patients, however, the relationship between PaCO2 and ETCO2 did not maintain a significant correlation throughout the study period. In the postoperative cardiac surgery patient population P(a-ET)CO2 follows a normal distribution and PaCO2 and ETCO2 maintain a statistically significant correlation. However, when evaluating individual patients, this relationship has wide variability.

Continuous radionuclide monitoring of left ventricular systolic performance in postoperative cardiac surgery patients: Validation of the capintec vest

Continuous radionuclide monitoring of left ventricular systolic performance in postoperative cardiac surgery patients: Validation of the capintec vest

Calcium attenuates epinephrine's beta-adrenergic effects in postoperative heart surgery patients.

Epinephrine and calcium possess both cardiac inotropic and vasopressor activity. In addition, epinephrine's cardiovascular effects are mediated via increases in intracellular calcium. As a result, many clinicians administer the two agents together in an attempt to augment their effects. Although this approach seems rational, it has never been proven effective. We evaluated the cardiovascular and hyperglycemic actions of epinephrine (10 and 30 ng/kg/min), with and without calcium chloride administration (10 mg/kg bolus followed by 2 mg/kg/hr infusion), in a prospective, randomized, blinded, crossover designed study. Twelve adult patients were studied 1 day after aortocoronary bypass surgery. Calcium chloride raised ionized calcium levels from 1.06 +/- 0.03 (mean +/- SEM) to 1.44 +/- 0.05 mM (p less than 0.05). Calcium raised mean arterial pressure from 85 +/- 1 to 94 +/- 2 mm Hg (p less than 0.05) but had no significant effect on cardiac index. Epinephrine alone at 10 and 30 ng/kg/min significantly raised cardiac index from 2.7 +/- 0.2 to 3.0 +/- 0.2 (p less than 0.05) and 3.6 +/- 0.3 (p less than 0.05) l/min/m2. After calcium, epinephrine failed to significantly increase cardiac index. Epinephrine at 30 ng/kg/min significantly increased mean arterial pressure from 87 +/- 1 to 95 +/- 2 mm Hg (p less than 0.05). After calcium, epinephrine had no significant effect on blood pressure. In addition, epinephrine's hyperglycemic effect was blunted by calcium. Plasma epinephrine levels were similar during control and calcium infusions. We conclude that calcium blunts epinephrine's beta-adrenergic actions in postoperative cardiac surgery patients.

Thermal gradients and shivering following open heart surgery.

Critical care nurses caring for postoperative cardiac surgery patients are confronted, on a regular basis, with care issues related to thermal gradients and shivering. Thermal gradients are defined as temperature differences between two body parts. Monitoring the central and peripheral temperatures, evaluating the thermal gradients, and measuring shivering with reliable means are the prerequisites for the prediction of shivering. The detrimental physiologic effect of shivering necessitates additional clinical research to further define causative factors of shivering.

Acute respiratory failure after cardiac surgery: clinical experience with the application of continuous arteriovenous hemofiltration.

Hemodynamic and oxygen measurements were obtained before and during 24 h of continuous arteriovenous hemofiltration (CAVH) in 36 postoperative cardiac surgery patients with severe acute pulmonary failure. During the first 6 h, the low mean arterial pressure averaged only 50 +/- 7 mm Hg; PaO2 was 90 torr on an inspired oxygen fraction of 0.86 +/- 0.03; and lactic acid was 10.5 +/- 6 mmol/L. Of the 34 patients recovering from shock within 12 h, only 24 (67%) were hospital survivors. Cardiac index, oxygen availability index, oxygen consumption, and PaO2 increased during CAVH. This treatment decreased serum levels of the myocardial depressant factor, thus allowing catecholamine support to be reduced. We conclude that CAVH eliminates cardiopulmonary toxic substances partly responsible for shock. Our patients' improved hemodynamic and respiratory function suggests that CAVH may be useful in postoperative cardiac surgery patients with respiratory and hemodynamic failure.

Antiarrhythmic actions of lidocaine.

anesthesiologist s for this purpose. In 1963, lidocaine's electro physiologic and clini­ cal effects were studied in postoperative cardiac surgery patients, with the conclu­ sion that it was effective in abolishing ventricular arrhythmias when given intravenously, and that it produced less circulatory depression than procainamide when given intravenously to this group of patients (2). With the development of coronary care units, the frequency of ventricular ar­ rhythmias in the early post infarction period was recognized. Lidocaine was then introduced for the treatment of ventricular tachycardia, and the concept docu­ mented that frequent ventricular premature beats often heralded more serious ven­ tricular tachycardia and fibrillation (3-5). Thus, lidocaine was administered continuously to patients with premonitory dysrhythmias, with the idea of prevent­ ing more serious abnormalities. This concept has not been fully verified, but in a controlled study, Morgenson (5) showed a lower incidence of arrhythmias and death

Mean Circulatory Filling Pressure Measured Immediately After Cessation of Heart Pumping

Mean Circulatory Filling Pressure Measured Immediately After Cessation of Heart Pumping