Pneumothorax associated with epidural anesthesia

Evaluation of a modified ultrasound-assisted technique for mid-thoracic epidural placement: a prospective observational study

BACKGROUND

Although mid-thoracic epidural analgesia benefits patients undergoing major surgery, technical difficulties often discourage its use. Improvements in technology are warranted to improve the success rate on first pass and patient comfort. The previously reported ultrasound-assisted technique using a generic needle insertion site failed to demonstrate superiority over conventional landmark techniques. A stratified needle insertion site based on sonoanatomic features may improve the technique.

METHODS

Patients who presented for elective abdominal or thoracic surgery requesting thoracic epidural analgesia for postoperative pain control were included in this observational study. A modified ultrasound-assisted technique using a stratified needle insertion site based on ultrasound images was adopted. The number of needle passes, needle skin punctures, procedure time, overall success rate, and incidence of procedure complications were recorded.

RESULTS

One hundred and twenty-eight subjects were included. The first-pass success and overall success rates were 75% (96/128) and 98% (126/128), respectively. In 95% (122/128) of patients, only one needle skin puncture was needed to access the epidural space. The median [IQR] time needed from needle insertion to access the epidural space was 59 [47-122] seconds. No complications were observed during the procedure.

CONCLUSIONS

This modified ultrasound-assisted mid-thoracic epidural technique has the potential to improve success rates and reduce the needling time. The data shown in our study may be a feasible basis for a prospective study comparing our ultrasound-assisted epidural placements to conventional landmark-based techniques.

Inadvertent Placement of Thoracic Epidural Catheter in Pleural Cavity: A Case Report and Review of Published Literature

Thoracic epidural placement is considered the gold standard for pain management for abdominal or thoracic surgery. It provides analgesia superior to that provided by opioids with a decreased risk of pulmonary complications. Insertion of a thoracic epidural catheter requires the knowledge and expertise of an anesthetist; epidural catheter insertion may be challenging especially when sited in the higher thoracic region, in patients with unusual neuraxial anatomy, patients unable to position adequately for insertion or morbidly obese patients. Postoperatively the anesthetic team is required to look after the patient and assess for any complications such as hypotension. Even though the incidence of complications may be low; however, some of these could have detrimental consequences for the patients such as epidural abscess, hematoma formation, and temporary or permanent neurological damage. In this case report, we will discuss a patient who underwent a three-stage esophagectomy for esophageal squamous cell carcinoma under general anesthesia with epidural analgesia. The epidural catheter (Portex® Epidural Minipack System with NRFit® connector, ICUmedical, USA) was found in the intrapleural space during video-assisted thoracoscopy for the thoracic part of esophagectomy. To facilitate surgical access, the catheter was removed immediately, and the patient was given patient-controlled analgesia with morphine for postoperative pain control.

Real-time ultrasound-guided versus anatomic landmark-based thoracic epidural placement: a prospective, randomized, superiority trial

Background

Thoracic epidural placement (TEP) using the conventional anatomic landmark-based technique is technically challenging, may require multiple attempts, and is associated with a high failure rate (12–40%). We hypothesized that real-time ultrasound guidance would be superior in the “first-pass” success rate of TEP, when compared with the conventional technique.

Methods

This prospective, randomized, superiority trial was conducted in a University hospital, and recruited 96 patients undergoing elective major abdominal or thoracic surgery and scheduled to receive a TEP for postoperative analgesia. Patients were randomly allocated to receive TEP using either the conventional technique (Gp-Conv, n = 48) or real-time ultrasound guidance (Gp-Usg, n = 48). The success of TEP was defined as eliciting loss of resistance technique and being able to insert the epidural catheter. The primary outcome variable was the “first-pass success rate” meaning the successful TEP at the first needle insertion without redirection or readvancement of the Tuohy needle. The secondary outcomes included the number of skin punctures, number of attempts, the overall success rate, TEP time, and total procedure time.

Results

The first-pass success rate of TEP was significantly higher (p = 0.002) in Gp-Usg (33/48 (68.8%); 95%CI 55.6 to 81.9) than in Gp-Conv (17/48 (35.4%); 95%CI 21.9 to 49.0). There was no statistically significant difference (p = 0.12) in the overall success rate of TEP between the 2 study groups (Gp-Usg; 48/48 (100%) vs. Gp-Conv; 44/48 (91.7%); 95%CI 83.9 to 99.5). Ultrasound guidance reduced the median number of skin punctures (Gp-Usg; 1 [1, 1] vs Gp-Conv; 2 [1, 2.2], p < 0.001) and attempts at TEP (Gp-Usg; 1 [1, 2] vs Gp-Conv; 3 [1, 7.2], p < 0.001) but the procedure took longer to perform (Gp-Usg; 15.5 [14, 20] min vs Gp-Conv; 10 [7, 14] min, p < 0.001).

Conclusions

This study indicates that real-time ultrasound guidance is superior to a conventional anatomic landmark-based technique for first-pass success during TEP although it is achieved at the expense of a marginally longer total procedure time. Future research is warranted to evaluate the role of real-time ultrasound guidance for TEP in other groups of patients.

Trial registration

Thai Clinical Trials Registry; http://www.thaiclinicaltrials.org/; Trial ID: TCTR20200522002, Registration date: 22/05/2020.

Intrapleural placement of a thoracic epidural catheter in a patient with spinal stenosis

Due to the close proximity of the thoracic epidural space and parietal pleura, pleural puncture with intrapleural catheter placement is a potential complication of thoracic epidural anesthesia. The authors present a case of an obese patient with a history of spinal stenosis that underwent thoracotomy. Repeated failed attempts at epidural anesthesia were complicated by intrapleural placement of the catheter. The patient subsequently developed clinical signs of pneumothorax and required urgent thoracostomy.

Epidural catheter misplaced into the thoracic cavity: Utilized to provide interpleural analgesia

Thoracic epidural analgesia is one of the most effective and time-tested modalities of providing postthoracotomy pain relief. It improves postoperative pulmonary outcome. Nevertheless, being a blind procedure several complications have been associated with the technique. Pleural puncture is one rare complication that might occur following thoracic epidural catheterization. We have discussed a patient who underwent a right thoracotomy for excision of emphysematous bulla of lung under general anesthesia with thoracic epidural. The epidural catheter was misplaced in the pleural cavity and was detected intraoperatively after thoracotomy. The catheter was left in situ and was successfully utilized to provide postoperative analgesia via the interpleural route.

Bilateral pneumothoraces following central venous cannulation

We report the occurrence of a bilateral pneumothoraces after unilateral central venous catheterization of the right subclavian vein in a 70-year-old patient. The patient had no history of pulmonary or pleural disease and no history of cardiothoracic surgery. Two days earlier, she had a median laparotomy under general and epidural anaesthesia. Prior to the procedure, the patient was hemodynamically stable and her transcutaneous oxygen saturation was 97% in room air. We punctured the right pleural space before cannulation of the right subclavian vein. After the procedure, the patient slowly became hemodynamically instable with respiratory distress. A chest radiograph revealed a complete left-side pneumothorax and a mild right-side pneumothorax. The right-side pneumothorax became under tension after left chest tube insertion. The symptoms finally resolved after insertion of a right chest tube. After a diagnostic work-up, we suspect a congenital “Buffalo chests” explaining bilateral pneumothoraces and a secondary tension pneumothorax.

Unrecognized contralateral intrapleural catheter: bilateral blockade may obscure detection of failed epidural catheterization

Thoracic epidural analgesia has been widely used to reduce both postoperative and posttraumatic pain. We describe a case of inadvertent right-sided interpleural catheter placement and pneumothorax during attempted epidural catheter placement for left-sided rib fractures that went unrecognized because of bilateral blockade and adequate analgesia.