Anesthetic Consideration for Peroral Endoscopic Myotomy

Invasive CO 2 monitoring with arterial line compared to end tidal CO 2 during peroral endoscopic myotomy

Background and study aims  Peroral endoscopic myotomy (POEM) has become a recognized treatment for achalasia. The technique requires CO 2 insufflation. It is estimated that the partial pressure of CO 2 (PaCO 2 ) is 2 to 5 mm Hg higher than the end tidal CO 2 (etCO 2 ), and etCO 2 is used as a surrogate for PaCO 2 because PaCO 2 requires an arterial line. However, no study has compared invasive and noninvasive CO 2 monitoring during POEM. Patients and methods  Seventy-one patients who underwent POEM were included in a prospective comparative study. PaCO 2 plus etCO 2 was measured in 32 patients (invasive group) and etCO 2 only in 39 matched patients (noninvasive group). Pearson correlation coefficient (PCC) and Spearman's Rho were used to calculate the correlation between PaCO 2 and ETCO 2 . Results  PaCO 2 and ETCO 2 were strongly correlated: PCC R value: 0.8787 P  ≤ 0.00001, Spearman's Rho R value: 0.8775, P  ≤ 0.00001. Within the invasive group, the average difference between PaCO 2 and ETCO 2 was 3.39 mm Hg (median 3, standard deviation 3.5), within the 2- to 5-mm Hg range. The average procedure time (scope in to scope out) was increased 17.7 minutes ( P  = 0.044) and anesthesia duration was 46.3 minutes. Adverse events (AEs) included three hematomas and one nerve injury in the invasive group and one pneumothorax in the noninvasive group. There were no differences in AE rates between the groups (13 % vs 3 % P  = 0.24). Conclusions  Universal PaCO 2 monitoring contributes to increased procedure and anesthesia times without any decrease in AEs in patients undergoing POEM. CO 2 monitoring with an arterial line should only be performed in patients with major cardiovascular comorbidities; in all other patients, ETCO 2 is an appropriate tool.

Effect of Drinking Warm Water on Esophageal Preparation Before Peroral Endoscopic Myotomy in Patients With Achalasia

Background/Aims

Food retention, which is a characteristic observed in patients with achalasia, can interfere with peroral endoscopic myotomy (POEM). However, there is no established guideline for esophageal preparation for POEM. A previous study has shown that drinking warm water may reduce the lower esophageal sphincter pressure in patients with achalasia. This study aims to evaluate the possibility of proper preparation of POEM by instructing the patient to drink warm water.

Methods

The warm water preparation was performed in 29 patients with achalasia who underwent POEM. The patients drank 1 L of warm water (60oC) the night before POEM. We evaluated the esophageal clearness and determined the preparation quality. Twentynine patients were prospectively recruited and compared to control group. The control cohort comprised achalasia patients whose endoscopic image was available from the achalasia database of our institution. A 1:2 propensity score-matched control cohort was established from the database of achalasia subjects (n = 155) to compare the outcome of the preparation.

Results

In the warm water preparation group, only 1 patient (3.4%) had some solid retention, but it did not interfere with the POEM procedure. The grade of clearness (P = 0.016) and quality of preparation (P < 0.001) were significantly better in the warm water preparation group than in the matched control group. There was no any adverse event at all related to warm water preparation protocol.

Conclusions

Drinking warm water dramatically reduces esophageal food retention and significantly improves the quality of esophageal preparation. This simple protocol is quite useful, safe, and cost-effective in the preparation of achalasia patients for POEM.

Anesthesia for Advanced Endoscopic Procedures

The gastrointestinal endoscopy paradigm is rapidly changing, and technological advancements are largely responsible. In tandem, anesthesia providers are adapting to the changing needs and demands. The challenges are unique. Complications arising from the procedures are both routine, such as aspiration and hypoxia, and procedure specific, such as bleeding, pneumothorax, pneumopericardium, and pneumoperitoneum. It is crucial for the anesthesia provider to have a good understanding of the techniques employed by the endoscopist. A higher index of suspicion is also essential to diagnose and appropriately manage many of the complications. In this review, an effort is made to discuss both procedural aspects and anesthesia challenges. We hope that both endoscopists and anesthesia providers will benefit from this review.

Anesthesia for Per-oral endoscopic myotomy (POEM) – not so poetic!

Peroral endoscopic myotomy (POEM) is a promising natural orifice transluminal endoscopic procedure for the treatment of esophageal motility disorders, with similar effectiveness as of Heller myotomy. It is performed under general anesthesia in endoscopy suite. Creation of submucosal tunnel in the esophageal wall is a key component. The continuous insufflation of CO₂ inadvertently tracks into surrounding tissues and leads to capno mediastinum, capno thorax, capno peritoneum, and subcutaneous emphysema. Thus, the challenges, for an anesthesiologist are not only providing remote location anesthesia, increased risk of aspiration during induction, but also early detection of these complications and specific emergency management. Though a therapeutic innovation, POEM remains an interdisciplinary challenge with no specific anesthesia care algorithms and evidence-based recommendations. The purpose of this review is to outline the anesthesia and periprocedural practices based on existing evidence.

Challenges in Anesthesia Management for Peroral Endoscopic Myotomy: A Retrospective Analysis

BACKGROUND

Peroral endoscopic myotomy (POEM) is used to treat achalasia with efficacy and reliability. However, during the procedure potential complications require attention in terms of anesthesia. This study aimed to investigate complications of the POEM procedure and its effects on arterial blood gas (ABG) parameters, peak airway pressures (PIP), hemodynamics, and postoperative analgesia requirements.

METHODS

Data from 220 patients who underwent POEM between 2014 and 2017 were retrospectively assessed. During the procedure, ABG samples, PIP, mean arterial pressure, and heart rate were recorded. The effects of the procedure and paracentesis on ABG, PIP, mean arterial pressure, heart rate, perioperative complications, and postoperative analgesia requirements were assessed.

RESULTS

Data from 220 POEM patients were analyzed. During the procedure, the mean PaCO2 was 48.27±6.34 mm Hg, which was significantly higher than the PaCO2 values before and after the procedure. The mean increase in maximum PIP was 5.90±3.49 cmH2O during the procedure. However, there was a significant decrease in PaCO2 and PIP values in cases with paracentesis compared with those without paracentesis. With regards to complications, subcutaneous emphysema (48, 21.8%), pneumoperitoneum requiring decompression (66, 30%), pneumothorax (1, 0.5%), aspiration pneumonia (1, 0.5%), and bronchospasm (5, 2.2%) were observed during the procedure. In the postoperative period, 58 patients (26%) had additional analgesia requirements because of visual analog scale values >3.

CONCLUSION

Periprocedural abdominal decompression with veress needle led to a reduction in arterial PaCO2 and PIP, and improved postoperative analgesia. Serious complications because of perioperative aspiration and CO2 insufflation were observed during the POEM procedure.

Acquiring new complex endoscopic skills: Experience from the development of peroral endoscopic myotomy (POEM) in Malaysia

Peroral endoscopic myotomy (POEM) has rapidly gained popularity as an effective treatment modality for achalasia. However, POEM services in the South East Asian region are not widely available due to either a lack of expertise or interest. In this article, we describe how a POEM service can be developed through a combination of networking with regional experts, having prior experience of endoscopic submucosal dissection (ESD), attending animal model workshops, collaborating with upper gastrointestinal surgeons, and working together in a multidisciplinary team. A total of 68 POEM procedures have been performed since 2015, with a 94.1% technical and 93.4% clinical success rate, and a 21.5% minor complication rate. We believe that our model may be useful for other Endoscopy Units in the region, which are performing advanced therapeutic endoscopy, to develop a POEM service too.