Deep Neuromuscular Blockade Leads to a Larger Intraabdominal Volume During Laparoscopy

Summary

This article presents a method for measuring the working abdominal volume during laproscopic myomectomy using the surgical grasper, and applies this technique to obtain pilot data on whether deep neuromuscular blockade (NMB) can enable the use of lower insufflation pressure. Reduced insufflation pressure during laproscopic surgery has been shown to reduce post-operative pain, and thus the use of NMB during surgery may enable improved patient outcomes.

Abstract

Shoulder pain is a commonly reported symptom following laparoscopic procedures such as myomectomy or hysterectomy, and recent studies have shown that lowering the insufflation pressure during surgery may reduce the risk of post-operative pain. In this pilot study, a method is presented for measuring the intra-abdominal space available to the surgeon during laproscopy, in order to examine whether the relaxation produced by deep neuromuscular blockade can increase the working surgical space sufficiently to permit a reduction in the CO₂ insufflation pressure. Using the laproscopic grasper, the distance from the promontory to the skin is measured at two different insufflation pressures: 8 mm Hg and 12 mm Hg. After the initial measurements, a neuromuscular blocking agent (rocuronium) is administered to the patient and the intra-abdominal volume is measured again. Pilot data collected from 15 patients shows that the intra-abdominal space at 8 mm Hg with blockade is comparable to the intra-abdominal space measured at 12 mm Hg without blockade. The impact of neuromuscular blockade was not correlated with patient height, weight, BMI, and age. Thus, using neuromuscular blockade to maintain a steady volume while reducing insufflation pressure may produce improved patient outcomes.

Introduction

Neuromuscular blocking agents are commonly used to facilitate tracheal intubation, and, during anesthesia, to facilitate surgery. The use of pharmacological agents to achieve deep relaxation throughout the laparoscopic procedure allows the surgeons either to proceed at the same level of CO₂ insufflation while benefitting from better surgical conditions, or lowering the insufflating pressure to lower the risk of surgical complications. Several studies have shown the positive effect of lowering the working pressure ^5,6,7. One symptom that is often seen after laparoscopic hysterectomies is shoulder pain, which is often stated as a major problem and ....

Protocol

1. Case Presentation

1. The patient is set up for a visit at the gynecological clinic, often due to the occurrence of bleeding disorders. A physical examination is performed.
   1. If deemed appropriate, the patient is scheduled for a hysterectomy. The paperwork is prepared, and the patient is given the premedication for the day of surgery.
   2. Patients 60 years and older must first submit blood samples and monitored by electrocardiography (or ECG) prior to the procedure.
2. On the day of surgery, the patient is not allowed to consume anything by mouth for six hours prior to admittance.
   1. An exception is m....

Results

This pilot study of 15 patients was performed to assess the impact of deep neuromuscular blockade during laparoscopic surgery.

The method illustrated here was used to obtain measurements of intra-abdominal space in patients undergoing laparoscopic hysterectomy (Figure 1). In each patient, measurements of intra-abdominal space were taken under the following conditions: 12 mm Hg pressure without deep neuromuscular blockade, 12 mm Hg with blockade, 8 mm Hg without blockade, and .......

Discussion

Directly calculating the working volume available for laproscopic surgery is difficult, but the relationship between insufflating CO₂ pressure and abdominal volume is easier to measure⁹. Here, we present a method to use the surgical grasper to estimate the space within the abdomen during insufflation, as an alternative to the method of recording the volume of insufflated CO₂. These measurements have demonstrated that it is possible to maintain a steady volume when loweri.......