Randomized, double-blind trial of simultaneous right and left atrial epicardial pacing for prevention of post-open heart surgery atrial fibrillation.

BACKGROUND: The purpose of this study was to assess simultaneous right and left atrial pacing as prophylaxis for postoperative atrial fibrillation. METHODS AND RESULTS: In a double-blind, randomized fashion, 118 patients who underwent open heart surgery were assigned to right atrial pacing at 45 bpm (RA-AAI; n=39), right atrial triggered pacing at a rate of >/=85 bpm (RA-AAT; n=38), or simultaneous right and left atrial triggered pacing at a rate of >/=85 bpm (Bi-AAT; n=41). Holter monitoring was performed for 4. 8+/-1.4 days after surgery to assess for episodes of atrial fibrillation lasting >5 minutes. The prevalence of postoperative atrial fibrillation was significantly less in the patients randomized to biatrial AAT pacing when compared with the other 2 pacing regimens (P=0.02). An episode of atrial fibrillation occurred in 4 (10%) of 41 patients in the Bi-AAT group compared with 11 (28%) of 39 patients in the RA-AAI group (P=0.03 versus Bi-AAT) and 12 (32%) of 38 patients in the RA-AAT group (P=0.01 versus Bi-AAT). There was no difference in the occurrence of atrial fibrillation between the right atrial AAI and AAT groups (P=0.8). There was no significant difference among the 3 groups with regard to the number of postoperative hospital days (7.3+/-4.2 days), morbidity (5.1%), or mortality rate (2.5%). CONCLUSIONS: Simultaneous right and left atrial triggered pacing is well tolerated and significantly reduces the prevalence of post-open heart surgery atrial fibrillation.

Intrathoracic tumors of the vagus nerve.

Two patients had resection of a middle mediastinal neurilemmoma of the vagus nerve. Twenty-seven other neurogenic tumors of the intrathoracic vagus are reviewed. These tumors are generally asymptomatic except for hoarseness in an occasional patient.

Does choice of anesthetic agent significantly affect outcome after coronary artery surgery?

A prospective study of 1094 consecutive adult patients undergoing coronary revascularization was undertaken to determine the effect of anesthetic technique on outcome. Patients received one of five primary techniques: high-dose fentanyl (greater than 50 micrograms/kg), moderate-dose fentanyl (less than 50 micrograms/kg), sufentanil (3-8 micrograms/kg), diazepam (0.4-1 mg/kg) with ketamine (3-6 mg/kg) or halothane (0.5-2.5% inspired concentration after thiopental induction). Supplemental inhalation anesthesia (enflurane, halothane, or isoflurane) was used in 60% of cases where the primary technique was intravenous based. Patients in the above anesthetic groupings had similar perioperative demographic and risk classifications. The overall incidence of postoperative myocardial infarction, postoperative low cardiac output state, and in-hospital death were 4.1, 5.6, and 3.1%, respectively. There were no significant differences in the incidence of these occurrences or in the incidence of serious pulmonary, renal, or neurologic morbidity or length of ICU stay among primary anesthetic techniques nor among supplemental inhalation agent groups. Multivariate discriminant analysis of this data suggests that a multitude of factors are significantly more important than anesthetic technique as determinants of outcome after coronary artery surgery.

Effect of pulmonary artery catheterization on outcome in patients undergoing coronary artery surgery.

Previous studies have suggested that low-risk cardiac surgical patients may be safely managed without pulmonary artery catheterization (PAC). However, no prospective studies have determined whether PAC improves outcome in higher risk patients compared with that following central venous pressure (CVP) monitoring alone. The authors prospectively examined the incidence of and factors related to perioperative morbidity and mortality in 1094 consecutive patients undergoing coronary artery surgery managed with elective PAC (n = 537) or with CVP (n = 557). Perioperative risk factors and demographics that predict morbidity and mortality after cardiac surgery were used to quantify risk classification. Outcome was judged by length of ICU stay, occurrence of postoperative myocardial infarction, in-hospital death, major hemodynamic aberrations, and significant noncardiac systemic complications. No significant differences in any outcome variables were noted in any group of patients with similar quantitative risk classification managed with or without PAC, including those in the highest risk class. In addition, there were no significant differences in outcome among the 39 patients who would have been managed with CVP monitoring only, but who subsequently developed a clinical need for PAC based on the occurrence of serious hemodynamic events compared to patients who had PAC performed electively. This study suggests that PAC does not play a major role in influencing outcome after cardiac surgery, that even high-risk cardiac surgical patients may be safely managed without routine PAC, and that delaying PAC until a clinical need develops does not significantly alter outcome, but may have an important impact on cost savings.

Mycotic disruption of aortic cannulation site.

Two cases of successful repair of leaking mycotic false aneurysms of the ascending aorta from the aortic cannulation site, secondary to mediastinal infection following open heart surgery are described. Institution of cardiopulmonary bypass via the femoral vessels, rapid sternotomy, and fingertip control of the aortic hemorrhage permitted primary repair of the disruption.

Drainage of pericardial effusions using the peritoneal and pericardial window technique.

We have treated nine patients with persistent pericardial effusions using the peritoneal and pericardial window technique, over the past four years, without surgical mortality and with effective results; reoperation was not necessary for reaccumulation of effusion.

A prospective trial comparing a silicone elastomer intravenous cannula (Visis) with a polytetrafluoroethylene cannula (Cathlon).

Post-infusion phlebitis remains one of the most frequent causes of hospital morbidity with an incidence varying between 13 and 39 per cent (1-4). A recent study indicated that a silicone elastomer cannula (Visis) had desirable properties (5). We have carried out a prospective trial comparing the value of such a cannula with a Teflon cannula (Cathlon) already in routine use.

Comparison of bupivacaine and prilocaine used in Bier block--a double blind trial.

The value of Bier blocks for the manipulation of fractures and for operations on the upper limb is well recognized. Two anaesthetic agents, bupivacaine and prilocaine, are widely used for this purpose. A prospective double blind trial of 200 patients has been carried out to compare the efficacy of each drug and the incidence of side effects. The study shows that bupivacaine was associated with a greater number of successful fracture reductions than prilocaine with little difference in their analgesic effects, but this was balanced by more minor side effects with bupivacaine. There was little difference in the time from injection to analgesia in the two groups. All intravenous regional analgesia procedures were carried out by junior orthopaedic or accident and emergency doctors. The overall success rate for analgesia was 91 per cent but marked cuff discomfort occurred in 9 per cent of patients. There was a clear association between failure of analgesia and two of the doctors carrying out the procedure.