The Influence of Airway Closure Technique for Right Pneumonectomy on Wall Tension During Positive Pressure Ventilation: An Experimental Study.

Bronchopleural fistula (BPF) remains a significant source of morbidity and mortality after right pneumonectomy (RPN). Postoperative mechanical ventilation represents a primary risk factor for BPF. We undertook an experiment to determine the influence of airway diameter on suture line tension during mechanical ventilation after RPN. RPN was performed in 6 fresh human adult cadavers. After initial standard bronchial stump closure (BSC), the airway suture lines were subjected to 5 cm H2O incremental increases in airway pressures beginning at 5-40 cm H2O. To minimize airway diameter, a carinal resection was then performed with trachea to left main bronchial anastomosis and the airway suture lines subjected to similar incremental airway pressures. Wall tension (N/m) at the suture lines was measured using piezoresistive sensors at each pressure point. As delivered airway pressure increased, there was a concomitant increase in wall tension after BSC and carinal resection. At every point of incremental positive pressure, wall tension was however significantly lower after carinal resection when compared to BSC (P < 0.05). Additionally the differences in airway tension became even more significant with higher delivered airway pressure (P < 0.001). Airway diverticulum after BSC leads to significantly increased tension on the bronchial closure with positive airway pressure as compared to a closure which minimize airway diameter after RPN. This supports the role of Laplacian Law where small increases in airway diameter result in significant increases on closure site tension. Techniques which reduce airway diameter at the airway closure will more reliably reduce the incidence of BPF following RPN.

Randomized Prospective Study Evaluating Single-Injection Paravertebral Block, Paravertebral Catheter, and Thoracic Epidural Catheter for Postoperative Regional Analgesia After Video-Assisted Thoracoscopic Surgery.

OBJECTIVE: Video-assisted thoracoscopic surgery (VATS) has improved patient outcomes; however, postoperative pain remains potentially severe. The objective of this study was to compare adjunct analgesic modalities for VATS, including paravertebral nerve blockade (PVB) and thoracic epidural anesthesia (TEA). DESIGN: Prospective, randomized trial. SETTING: Large academic hospital, single institution. PARTICIPANTS: Adult patients undergoing VATS. INTERVENTIONS: Ultrasound-guided PVB catheter, ultrasound-guided single-injection PVB, or TEA. MEASUREMENTS AND MAIN RESULTS: Postoperative visual analog scale pain scores (at rest and with knee flexion) and opioid usage were recorded. Pain scores (with movement) for the TEA group were lower than those for either PVB group at 24 hours (p ≤ 0.008) and for the PVB catheter group at 48 hours (p = 0.002). Opioid use in TEA group was lower than that for either PVB group at 24 and 48 hours (p < 0.001) and 72 hours (p < 0.05). Single-injection PVB was faster compared with PVB catheter placement (6 min v 12 min; p < 0.001) but similar to TEA (5 min). Patient satisfaction, nausea, sedation, and 6-month postsurgical pain did not differ between groups. CONCLUSIONS: TEA led to lower pain scores and opioid requirement for VATS procedures compared with PVB techniques. Single-injection PVB was faster and equally as effective as PVB catheter, and it led to similar patient satisfaction as TEA; therefore, it should be considered in patients who are not ideal candidates for TEA.

A randomized, controlled study of amiodarone for prevention of atrial fibrillation after transthoracic esophagectomy.

OBJECTIVE: Atrial fibrillation is common after esophagectomy. The objective of this study was to determine the efficacy and safety of amiodarone for prevention of atrial fibrillation after transthoracic esophagectomy. METHODS: Eighty patients undergoing transthoracic esophagectomy were randomly, prospectively assigned to receive amiodarone (n = 40) or no prophylaxis (control group, n = 40). Amiodarone-treated patients received the drug by continuous infusion, initiated at the time of induction of anesthesia, at a rate of 0.73 mg/min (43.75 mg/h), and continued for 96 hours (total dose 4200 mg). The primary end point was atrial fibrillation requiring treatment. Secondary end points included any atrial fibrillation lasting longer than 30 seconds and postoperative hospital and intensive care unit stays. RESULTS: There were no significant differences between the amiodarone and control groups in demographic characteristics, comorbid conditions, or preoperative or postoperative use of beta-blockers or calcium-channel blockers. The incidence of atrial fibrillation requiring treatment was lower in the amiodarone group than in the control group (15% vs 40%, P = .02, relative risk reduction 62.5%). There were no significant differences between the amiodarone and control groups in median hospital stay (11 days vs 12 days, P = .31) or median intensive care unit stay (68 hours vs 77 hours, p = .097). There were no significant difference between the groups in the incidences of adverse effects. CONCLUSIONS: Amiodarone prophylaxis significantly reduced the incidence of atrial fibrillation after transthoracic esophagectomy.

A randomized trial evaluating amiodarone for prevention of atrial fibrillation after pulmonary resection.

BACKGROUND: Atrial fibrillation (AF) occurs commonly after anatomic pulmonary resection. In this study, the efficacy of amiodarone for prevention of post-pulmonary resection AF was investigated. METHODS: One hundred thirty patients undergoing lobectomy, bilobectomy, or pneumonectomy were randomly assigned prospectively to receive amiodarone (n = 65) or no prophylaxis (control group, n = 65). The amiodarone group received 1,050 mg by continuous intravenous infusion over 24 hours, initiated at the time of anesthesia induction, followed by 400 mg orally twice daily until hospital discharge or for a maximum of 6 days. The primary endpoint was AF requiring treatment during hospitalization. Secondary endpoints included postoperative length of hospital and intensive care unit stays. RESULTS: There were no significant differences between the amiodarone and control groups in demographics, comorbid conditions, extent of pulmonary resection, or preoperative or postoperative use of beta-blockers or calcium-channel blockers. The incidence of AF was lower in the amiodarone group than in the control group (13.8% versus 32.3%, p = 0.02; relative risk reduction = 57%). There was no difference between the amiodarone and control groups in median length of hospital stay (7 versus 8 days, p = 0.79), but median length of intensive care unit stay was shorter in the amiodarone group (46 versus 84 hours, p = 0.03). There was no significant difference between the amiodarone and control groups in the incidence of pulmonary complications or other adverse effects. CONCLUSIONS: Amiodarone prophylaxis significantly reduces the incidence of AF after anatomic pulmonary resection, and is associated with a significant reduction in length of intensive care unit stay.

Prospective evaluation of serum amiodarone concentrations when administered via a nasogastric tube into the stomach conduit after transthoracic esophagectomy.

BACKGROUND: Atrial fibrillation occurs in up to 46% of patients following esophagectomy; amiodarone may be used for prophylaxis or treatment in these patients. There are few data regarding drug absorption following esophagectomy. OBJECTIVE: The aim of this study was to determine serum amiodarone concentrations when the drug is administered into the stomach conduit following esophagectomy. METHODS: Patients who underwent noncardiac thoracic surgery were enrolled in this prospective, controlled study. One group of patients underwent esophagectomy, and a second group of patients comprised a control group who underwent pulmonary resection (PR). A continuous IV amiodarone infusion (0.73 mg/min) was initiated at anesthesia induction and continued for 24 hours (total IV dose 1050 mg), followed by 400 mg via a nasogastric tube (in the esophagectomy group) or orally (in the PR group) every 12 hours for 6 days. Blood samples for determination of serum amiodarone concentrations were obtained at completion of the infusion (postoperative day [POD] 1), and before the third (POD 2) and seventh (POD 4) enteral doses. RESULTS: A total of 27 patients were enrolled (esophagectomy group, 13 patients; PR group, 14 patients). Patients in the 2 groups had statistically similar ages (mean [SD], 60 [10] vs 53 [10] years; P = 0.07) and proportions of men (12/13 [92%] vs 8/14 [57%]; P = 0.08). Patients in the 2 groups were statistically similar with respect to race (white, 13/13 [100%] vs 13/14 [93%]) and preoperative weight (mean [SD], 83.3 [11.5] vs 77.7 [18.6] kg). On POD 1, age-adjusted and sex-adjusted serum amiodarone concentrations were not significantly different in the esophagectomy group versus the PR group (mean [SD] 0.65 [0.22] vs 0.84 [0.20] microg/mL). Mean (SD) serum amiodarone concentrations were significantly lower in the esophagectomy group on POD 2 (0.35 [0.27] vs 0.60 [0.18] microg/mL; P = 0.02) and on POD 4 (0.30 [0.34] vs 0.87 [0.16] microg/mL; P < 0.001). Serum amiodarone concentrations were undetectable in 33% and 50% of patients in the esophagectomy group on PODs 2 and 4, respectively, compared with 0% in the PR group (both, P = 0.03). CONCLUSIONS: Serum amiodarone concentrations were significantly lower (and in some cases undetectable) when the drug was administered via a nasogastric tube into the stomach conduit in patients after esophagectomy compared with those concentrations after oral administration in a PR population. Nasogastric administration of amiodarone should probably be avoided for prophylaxis or treatment of postesophagectomy tachyarrhythmias.