Pleural decompression procedural safety for traumatic pneumothorax and haemothorax: Kelly clamps versus fine artery forceps.

OBJECTIVE: The present study aimed to determine the difference in force required to puncture simulated pleura comparing Kelly clamps to fine artery forceps. The treatment of symptomatic traumatic pneumothorax and haemothorax involves puncture of the parietal pleura to allow decompression. This is usually performed using Kelly clamps or fine artery forceps. Over-puncture pulmonary injury risk increases with the force used. METHODS: An experienced single operator performed puncturing of simulated parietal pleura on a thoracic mannequin while wearing a force sensor under gloves. The force imparted at the device tip onto the parietal pleura was estimated by subtracting the force required to hold the device from the total force. Outcome variables were the total maximum force and force imparted by the device. RESULTS: There were 11 simulated procedures completed, seven using Kelly clamps and four using fine artery forceps. After subtracting the force required to hold the chosen forceps, the median value of pleural puncture force using Kelly clamps was 52.91 N (IQR 36.68-63.56) and 10.70 N (IQR 7.64-26.56) using fine artery forceps (P = 0.006). CONCLUSION: A significantly increased force was required to puncture simulated parietal pleura using Kelly clamps compared to fine artery forceps. This higher puncture force will be associated with increased instrument acceleration at the time of pleural puncture, which may result in an increased risk of injury to the underlying lung. Based on these data, clinicians may reduce the risk of pulmonary injury by using fine artery forceps rather than Kelly clamps when performing pleural decompression.

Pneumoperitoneum Does Not Influence Spread of Local Anesthetics in Midaxillary Approach Transversus Abdominis Plane Block: A Descriptive Cadaver Study.

BACKGROUND AND OBJECTIVES: The transversus abdominis plane (TAP) block can be used as part of a multimodal analgesia protocol after abdominal surgery. This study investigated whether a pneumoperitoneum during abdominal surgery influences the spread of local anesthetics. METHODS: Nine fresh frozen cadavers were used for the study. Using an ultrasound-guided midaxillary technique, a unilateral TAP block-like injection with 20 mL of methylene blue dye was performed. After the injection, a pneumoperitoneum was immediately installed for 1 hour. After desufflation, this ipsilateral side was dissected, and a TAP block-like injection was performed on the contralateral side. One hour after injection, the contralateral side was also dissected. The anatomical dissection was used to determine the extent of dye spread and the nerves stained by the dye. RESULTS: In none of the specimens did the dye reach the posterior origin of the transverse abdominal muscle. There was no statistically significant difference in the number of stained nerves and spread of the dye in the insufflated side compared with the noninsufflated side. In 4 of 9 cadavers, we found a variant course of a nerve preventing staining of that nerve. CONCLUSIONS: The stretch of the abdominal wall caused by the insufflation of the abdomen does not influence the spread of dye in the abdominal wall. Because of the absence of posterior spread, regardless of the timing of a midaxillary ultrasound-guided approach, we believe that a posterior approach should be chosen if posterior spread is desired.