Effects of Serratus Anterior Plane Block on Early Recovery from Thoracoscopic Lung Resection: A Randomized, Blinded, Placebo-Controlled Trial.

BACKGROUND: The efficacy of serratus anterior plane block (SAPB) for treatment of pain after minimally invasive thoracic surgery remains unclear. This trial assesses the impact of SAPB on postoperative opioid consumption and on measures of early recovery after thoracoscopic lung resection. METHODS: Patients undergoing minimally invasive anatomic lung resection at a single center were randomized to undergo SAPB with 40 mL of injectate containing bupivacaine 0.25%, clonidine 100 mcg, and dexamethasone 4 mg (SAPB group) or sham block with 40 mL of normal saline (placebo group) at the conclusion of surgery. The primary outcome was cumulative intravenous morphine equivalents during the first 24 h postoperatively. Secondary outcomes were intravenous morphine equivalents, pain scores at rest and with cough, inspiratory volume on incentive spirometry, and incidence of nausea/vomiting during the first 48 h postoperatively; Quality of Recovery-15 score on postoperative day 7; and length of stay. RESULTS: Using the protocol-specified intention-to-treat analysis, the median (interquartile range, IQR) intravenous morphine equivalents was 10.6 (5.0 to 27.1) mg in SAPB patients (n=46) versus 18.8 (9.9 to 29.6) mg in placebo patients (n=46) (32% reduction; ratio=0.68 [95% CI, 0.44 to 1.06]; P=0.085). Of the secondary outcomes, only the composite pain with cough scores differed significantly in the SAPB group by a coefficient of -0.41 (95% CI, -0.81 to -0.01; P=0.044). A sensitivity as-treated analysis reported median (IQR) intravenous morphine equivalents of 10.0 (5.0 to 27.2) mg in SAPB patients (n=44) versus 19.9 (10.4 to 29.0) mg in placebo patients (n=48) (36% reduction; ratio=0.64 [95% CI, 0.41 to 1.00]; P=0.048). CONCLUSIONS: The protocol-specified intention-to-treat analysis demonstrated that SAPB did not result in a significant reduction in opioid consumption when added to a multimodal analgesic regimen after thoracoscopic anatomic lung resection. The sensitivity as-treated analysis showed a significant and modest clinical reduction in the primary outcome that warrants further investigation.

Amiodarone with or without N-Acetylcysteine for the Prevention of Atrial Fibrillation after Thoracic Surgery: A Double-blind, Randomized Trial.

BACKGROUND: Postoperative atrial fibrillation may identify patients at risk of subsequent atrial fibrillation, with its greater risk of stroke. This study hypothesized that N-acetylcysteine mitigates inflammation and oxidative stress to reduce the incidence of postoperative atrial fibrillation. METHODS: In this double-blind, placebo-controlled trial, patients at high risk of postoperative atrial fibrillation scheduled to undergo major thoracic surgery were randomized to N-acetylcysteine plus amiodarone or placebo plus amiodarone. On arrival to the postanesthesia care unit, N-acetylcysteine or placebo intravenous bolus (50 mg/kg) and then continuous infusion (100 mg/kg over the course of 48 h) was administered plus intravenous amiodarone (bolus of 150 mg and then continuous infusion of 2 g over the course of 48 h). The primary outcome was sustained atrial fibrillation longer than 30 s by telemetry (first 72 h) or symptoms requiring intervention and confirmed by electrocardiography within 7 days of surgery. Systemic markers of inflammation (interleukin-6, interleukin-8, tumor necrosis factor α, C-reactive protein) and oxidative stress (F2-isoprostane prostaglandin F2α; isofuran) were assessed immediately after surgery and on postoperative day 2. Patients were telephoned monthly to assess the occurrence of atrial fibrillation in the first year. RESULTS: Among 154 patients included, postoperative atrial fibrillation occurred in 15 of 78 who received N-acetylcysteine (19%) and 13 of 76 who received placebo (17%; odds ratio, 1.24; 95.1% CI, 0.53 to 2.88; P = 0.615). The trial was stopped at the interim analysis because of futility. Of the 28 patients with postoperative atrial fibrillation, 3 (11%) were discharged in atrial fibrillation. Regardless of treatment at 1 yr, 7 of 28 patients with postoperative atrial fibrillation (25%) had recurrent episodes of atrial fibrillation. Inflammatory and oxidative stress markers were similar between groups. CONCLUSIONS: Dual therapy comprising N-acetylcysteine plus amiodarone did not reduce the incidence of postoperative atrial fibrillation or markers of inflammation and oxidative stress early after major thoracic surgery, compared with amiodarone alone. Recurrent atrial fibrillation episodes are common among patients with postoperative atrial fibrillation within 1 yr of major thoracic surgery.

Use of vasopressors during esophagectomy is not associated with increased risk of anastomotic leak.

Vasopressor use during esophagectomy has been reported to increase the risk of postoperative anastomotic leak and associated morbidity. We sought to assess the association between vasopressor use and fluid (crystalloid and colloid) administration and anastomotic leak following open esophagectomy. Patients who underwent open Ivor Lewis esophagectomy were identified from a prospective institutional database. The primary outcome was postoperative anastomotic leak (any grade) and analyzed using logistic regression models. Postoperative anastomotic leak developed in 52 of 327 consecutive patients (16%) and was not significantly associated with vasopressor use or fluid administered in either univariable or multivariable analyses. Increasing body mass index was the only significant characteristic of both univariable (P = 0.004) and multivariable analyses associated with anastomotic leak (odds ratio, 1.05; 95% confidence interval, 1.01-1.09; P = 0.007). Of the 52 patients that developed an anastomotic leak, 12 (23%) were grade 1, 21 (40%) were grade 2 and 19 (37%) were grade 3. In our cohort, only body mass index, and not intraoperative vasopressor use and fluid administration, was significantly associated with increased odds of postoperative anastomotic leak following open Ivor Lewis esophagectomy.

Protective Lung Ventilation and Morbidity After Pulmonary Resection: A Propensity Score-Matched Analysis.

BACKGROUND: Protective lung ventilation (PLV) during one-lung ventilation (OLV) for thoracic surgery is frequently recommended to reduce pulmonary complications. However, limited outcome data exist on whether PLV use during OLV is associated with less clinically relevant pulmonary morbidity after lung resection. METHODS: Intraoperative data were prospectively collected in 1080 patients undergoing pulmonary resection with OLV, intentional crystalloid restriction, and mechanical ventilation to maintain inspiratory peak airway pressure <30 cm H2O. Other ventilator settings and all aspects of anesthetic management were at the discretion of the anesthesia care team. We defined PLV and non-PLV as <8 or ≥8 mL/kg (predicted body weight) mean tidal volume. The primary outcome was the occurrence of pneumonia and/or acute respiratory distress syndrome (ARDS). Propensity score matching was used to generate PLV and non-PLV groups with comparable characteristics. Associations between outcomes and PLV status were analyzed by exact logistic regression, with matching as cluster in the anatomic and nonanatomic lung resection cohorts. RESULTS: In the propensity score-matched analysis, the incidence of pneumonia and/or ARDS among patients who had an anatomic lung resection was 9/172 (5.2%) in the non-PLV compared to the PLV group 7/172 (4.1%; odds ratio, 1.29; 95% confidence interval, 0.48-3.45, P= .62). The incidence of pneumonia and/or ARDS in patients who underwent nonanatomic resection was 3/118 (2.5%) in the non-PLV compared to the PLV group, 1/118 (0.9%; odds ratio, 3.00; 95% confidence interval, 0.31-28.84, P= .34). CONCLUSIONS: In this prospective observational study, we found no differences in the incidence of pneumonia and/or ARDS between patients undergoing lung resection with tidal volumes <8 or ≥8 mL/kg. Our data suggest that when fluid restriction and peak airway pressures are limited, the clinical impact of PLV in this patient population is small. Future randomized trials are needed to better understand the benefits of a small tidal volume strategy during OLV on clinically important outcomes.

Hemodynamic Instability Following Airway Spray Cryotherapy.

BACKGROUND: Spray cryotherapy (SCT) of airway lesions is used to effectively palliate respiratory symptoms related to airway obstruction, but significant intraoperative hemodynamic complications have been noted. We reviewed the experience at a single institution using SCT for the treatment of obstructive airway tumors. METHODS: A retrospective review of a single institution experience with intraoperative and postoperative hemodynamic complications associated with SCT was performed. Descriptive statistics were performed. RESULTS: Between June 2009 and April 2010, 34 treatment sessions were performed on 28 patients. Median age was 60 years (range, 15-88 years). Tumor characteristics were as follows: 13 primary lung cancers (43%), 11 pulmonary metastases (50%), 1 direct extension of an esophageal cancer (3%), and 2 benign pulmonary lesions (7%). Twenty-one tumors (75%) were distal to the carina; 14 (50%) were >95% occlusive. Median procedure length was 78 minutes (range, 15-176 minutes). Eleven sessions (31%) led to severe hypotension and/or bradycardia, with 2 patients requiring cardiopulmonary resuscitation. One patient died intraoperatively after cardiac arrest; a second patient was stable intraoperatively but died within 24 hours of SCT. Four patients required reintubation and short-term mechanical ventilation. CONCLUSIONS: Unpredictable life-threatening hemodynamic instability can follow endobronchial SCT. We propose that the most likely cause is pulmonary venous gaseous emboli entering the right heart, the coronary arteries, and the systemic circulation. Although SCT may offer advantages over airway laser therapy (such as no risk of fire and rapid hemostasis), further study is needed to delineate the relative likelihood of therapeutic benefit versus catastrophic complications.

Practice patterns in choice of left double-lumen tube size for thoracic surgery.

BACKGROUND: Some anesthesiologists choose smaller than body size-appropriate left sided double-lumen tubes (DLTs) ("down-size") for lung isolation in an attempt to limit the risk of airway trauma. There are few data on the effects of DLT size on intraoperative outcome measures. METHODS: In 300 adults undergoing thoracic surgery requiring lung isolation, we conducted a prospective pilot study to evaluate whether the use of 35 FR DLT, regardless of gender and/or height (care standard of two investigators), was associated with a similar incidence of intraoperative hypoxemia, lung isolation failure, or need for DLT repositioning during surgery (noninferiority) than with the conventional goal of inserting the largest possible DLT (care standard of two other investigators). DLT insertion position was immediately confirmed with fiberoptic bronchoscopy after direct laryngoscopic placement and after lateral positioning. RESULTS: The combined incidence of transient hypoxemia, inadequate lung isolation, or need for DLT repositioning during surgery did not differ among patients receiving 35, 37, or 39 FR DLT, regardless of gender or height. Despite the high frequency of 35 FR DLT use, 2% of patients required further down-sizing due to the inability to introduce the DLT into the left mainstem bronchus or when no inflation of the bronchial cuff was needed for lung isolation. CONCLUSIONS: Under the conditions of this pilot study, the use of smaller than conventionally sized DLT was not associated with any differences in clinical intraoperative outcomes.

Case Report: Transection of Radial Arterial Catheter Requiring Surgical Intervention.

We report a case in which a radial arterial line was placed prior to induction of general anaesthesia in a 76 year old male with prostate cancer and multiple co-morbidities who presented for thoracoscopic resection of a right lower lobe carcinoid lung tumor. The patient's intra-operative course was complicated by acute blood loss requiring conversion to an open procedure. A subsequent injury to the superior vena cava resulted in the need for immediate re-exploration at the conclusion of surgery. While the arterial line was still indicated in this patient's postoperative course in the ICU, malfunction on post-operative day one resulted in removal of the catheter. The catheter was secured by stay sutures and during the attempt to cut these sutures, the arterial catheter was inadvertently severed and a fragment remained within the patient's radial artery. Surgical intervention was required to remove the retained catheter and the patient recovered without evidence of residual injury or deficit to the artery and extremity. Literature review reveals only one other case report of a retained catheter in a radial artery caused by accidental transection during removal. We review indications for arterial line placement, complications, as well as methods for securing arterial catheters.