Hemodynamic benefit of optimizing atrioventricular delay after cardiopulmonary bypass.

BACKGROUND: Shortening of atrioventricular delay (AVD) by sequential cardiac pacing has been proposed to improve hemodynamics in patients with end-stage heart failure. In addition, optimization of prolonged AVD may be associated with a decrease of presystolic mitral insufficiency. The aim of this study was to explore the incidence of prolonged AVD during the early postcardiopulmonary bypass (CPB) period and to evaluate the hemodynamic benefit of its shortening by using sequential cardiac pacing. METHODS: Fifty consecutive patients scheduled for coronary artery bypass grafting were prospectively screened. AVD was measured immediately after separation from CPB. Patients presenting with AVD greater than or equal to 200 ms entered the study. Sequential cardiac pacing was introduced with programmed AVD starting at 80 ms and randomly increased by steps of 20 ms until resumption of native anterograde atrioventricular node conduction. Cardiac index (CI) was derived from transesophageal echocardiographic data during each step of this procedure. RESULTS: Nineteen patients were included. Median native AVD was 220 ms. Median optimal AVD was 140 ms. Mean native CI (CI-nat) was 2.59 +/- 0.42 L/min/m2. Mean optimal CI (CI-opt) was 3.12 +/- 0.45 L/min/m2. CI-opt/CI-nat was 1.20 +/- 0.07. CI-opt/CI-nat was significantly inversely correlated with preoperative left ventricular ejection fraction (r = -0.83). CONCLUSIONS: Prolonged AVD is a common occurrence after CPB. Its artificial shortening by sequential cardiac pacing is always associated with a significant increase of CI. The magnitude of this hemodynamic improvement is inversely correlated with preoperative left ventricular ejection fraction.

Infected abdominal aortic aneurysm associated with a psoas abscess, aorto-duodenal and sigmoid fistulas. Case report and review of the literature.

A case of atherosclerotic abdominal aortic aneurysm, complicated by aortoenteric fistulizations and infected by Escherichia coli, is presented. Chronic contained rupture resulted in the formation of a huge left psoas abscess which was responsible for the symptoms. No similar case has been reported in the literature. Resection and extra-anatomic vascular reconstruction were curative.

Propofol-alfentanil versus fentanyl-midazolam in coronary artery surgery.

OBJECTIVE: To compare intraoperative hemodynamics profiles and recovery characteristics of propofol-alfentanil with fentanyl-midazolam anesthesia in elective coronary artery surgery. DESIGN: Prospective, randomized study. SETTING: University hospital. PARTICIPANTS: Fifty patients with impaired or good left ventricular function. INTERVENTIONS: In group 1, (n = 25) anesthesia was induced with an infusion of propofol, 3 to 4 mg/kg/h, alfentanil, 500 micrograms, and pancuronium 0.1 mg/kg, and maintained with propofol, 3 to 6 mg/kg/h (variable rate), and alfentanil infusions, 30 micrograms/kg/h (fixed rate). Additional boluses of alfentanil, 1 mg, were administered before noxious stimuli; group 2 (n = 25) received a loading dose of fentanyl, 25 micrograms/kg, midazolam, 1.5 to 3 mg, and pancuronium, 0.1 mg/kg for induction, followed by an infusion of fentanyl, 7 micrograms/kg/h, for maintenance. Additional boluses of midazolam (1.5 to 3 mg) and fentanyl (250 micrograms) were administered before noxious stimuli. MEASUREMENTS AND MAIN RESULTS. Cardiovascular parameters at eight intraoperative time points as well as time to extubation, morphine consumption, and pain scores were recorded. Induction of anesthesia was associated in both groups with a small but significant decrease in mean arterial pressure (1: 15 mmHg (15%); 2: 8 mmHg (8%) with significant decreases in cardiac index (1: 8%; 2: 8%) and left ventricular stroke work index (1: 24%; 2: 21%). Throughout surgery, hemodynamic profiles were comparable between groups except after intubation when the MAP was significantly lower in group 1 (75 +/- 12 mmHg) than in group 2 (89 +/- 17 mmHg). Group 1 required less inotropic support. Extubation was performed faster in group 1 (7.6 h) than in group 2 (18.0 h). Morphine requirements and pain scores were comparable between groups. CONCLUSIONS: Propofol-alfentanil anesthesia provides good intraoperative hemodynamics and allows early extubation after coronary artery surgery.

To control or to be controlled? From health locus of control to morphine control during patient-controlled analgesia.

We postulated that patients with an internal locus of control, i.e. those who like to control their health problems themselves, would adapt more adequately to the 'patient-controlled analgesia' technique as compared to patients with an external health locus of control, who do not believe in their own control. Since contradicting studies have been published on this matter, we investigated relations between the demand for analgesics, perceived pain in the postoperative phase, and the health locus of control in the postoperative context of cardiac surgery. Findings demonstrate distinct utilization patterns between subjects with internal or external locus of control concerning total morphine consumption, number of unsatisfied demands and reduction of perceived pain.

Safety of central venous catheter change over guidewire for suspected catheter-related sepsis. A prospective randomized trial.

We conducted a study to determine the safety of guidewire exchange of central venous catheters suspected of causing catheter-related sepsis (CRS). Out of a total of 146 patients studied prospectively 41 (28%) suspected of having CRS, were randomly allocated to have their catheters changed over a guidewire (group I) or replaced by a new contralateral venipuncture (group II). One hundred and five patients (group III) requiring only one catheterization served as a control group. Positive semiquantitative cultures (greater than or equal to 15 colonies per plate) of the catheter tip constituted a reliable index of CRS (positive and negative predictive value of 100%). No significant difference in catheter contamination rate and CRS rate was found between group I and II (p = 0.13) and between group I and II versus group III. Nevertheless, there were fewer problems of insertion in the guidewire group (p = 0.03). We conclude that changing a central venous catheter over a guidewire is as safe and has better patient acceptability than inserting a new one, as the proven CRS rate is low (2%) despite a high (27%) suspected rate.

Neuralgia following lumbar sympathectomy.

Between March and October 1986, 33 consecutive patients underwent unilateral lumbar sympathectomy in the Thoracic and Cardiovascular Surgical Unit of the Catholic University in Louvain, Belgium. Ten patients experienced postsympathectomy neuralgia. After a single epidural injection of fentanyl, 50 micrograms, and methylprednisolone 80 mg, pain disappeared completely in six patients. Neuralgia recurred in four patients requiring repeat epidural injection with relief of residual symptoms. Epidural infiltration is a reliable treatment for neuralgia after lumbar sympathectomy.

Intravenous infusion of propofol for induction and maintenance of anaesthesia during endoscopic carbon dioxide laser ENT procedures with high frequency jet ventilation.

Fourteen patients of ASA grades 1-3 were anaesthetised with continuous infusions of propofol and alfentanil for endoscopic carbon dioxide laser ENT microsurgery. Their lungs were ventilated with an oxygen-air mixture using a high frequency jet ventilator. Propofol was given at an initial rate of 120 micrograms/kg/minute for 10 minutes after a bolus dose of 2.6 mg/kg, and then at 80 micrograms/kg/minute. Alfentanil was given at a rate of 0.5 micrograms/kg/minute. Arterial pressure decreased significantly after the bolus dose. It increased significantly for a few minutes after laryngoscopy and returned to baseline values during maintenance of anaesthesia. Heart rate increased significantly during induction and until laryngoscopy was performed but it decreased below its initial value after 5 minutes of maintenance. Platelet count and the degree of aggregation did not change during infusion of propofol.

Cryoanalgesia for post-thoracotomy pain relief.

A randomized study comparing the postoperative requirements of narcotics of three groups of patients (Group I: no analgesia; Group II: internal intercostal nerve block; Group III: cryoanalgesia) was conducted. This study was performed in order to assess the efficiency of cryoanalgesia versus internal intercostal nerve block to obtain pain relief after thoracotomy. Regarding post-operative narcotic requirements (Piritramide-Dipidolor), there was no significant difference between Group I and Group II patients, but patients from Group III required a significantly lower amount of narcotics during the first 36 postoperative hours (p less than 0.01). We conclude that, although cryoanalgesia does not provide complete post-thoracotomy pain relief, it is however an easy and safe method and is more efficient than internal intercostal nerve block for pain relief after thoracotomy.

Halothane versus isoflurane for short ENT procedures with spontaneous respiration in children.

This study compares halothane with isoflurane for short ENT procedures performed under spontaneous breathing in 80 children. Monitoring included ECG, arterial pressure, PECO2 and respiratory rate. Induction, maintenance and recovery durations were recorded. Induction time was further subdivided into an initial phase followed by a plateau according to delivered halogen concentrations. Inhalation induction was possible with isoflurane without major side effects as long as the drug concentration was increased slowly. This precaution was not needed with halothane. No respiratory depression could be attributed to either of the tested drugs. Isoflurane elicited a significant drop in arterial pressure with a concomitant increase in heart rate. Recovery times were shorter in the isoflurane group.

Pulmonary edema following acute upper airway obstruction.

During recovery, our patient presented an acute upper airway occlusion. After the removal of the airway obstruction, he developed a massive bilateral pulmonary edema with an acute hypoxemia. Hemodynamic measures following this incident show that mean and wedged pulmonary pressures are in the normal ranges. Several cases, associating acute upper airway obstruction, massive bilateral pulmonary edema and low or normal filling pressures, have been reported in literature. Three mechanisms have been postulated to explain this phenomenon; a dramatic increase of the negativity of the interstitial pulmonary pressure, a significative augmentation of the after-load and the hypoxic pulmonary reflex vasoconstriction.