1. A Case Report of Subcutaneous Emphysema and
Tension Pnuemothorax During Peroral Endoscopic
Myotomy Procedure
Jean Camille L. Mendoza, MD
2nd Year Resident
Department of Anesthesiolgy and Perioperative Medicine
Rizal Medical Center
August 2021
4. Peroral endoscopic myotomy (POEM) is a form of natural orifice transluminal endoscopic
surgery (NOTES) which is used by gastrointestinal endoscopists to treat esophageal
achalasia.
INTRODUCTION
Esophageal Achalasia
• Characterized by poor peristalsis of
the esophagus in combination with
increased muscle tone and
incomplete relaxation of the lower
esophageal sphincter (LES).
• Symptoms arising from impaired
entry to the stomach include:
• nausea and vomiting
• dysphagia
• odynophagia
5. The PEOM procedure is a minimally invasive procedure developed to correct achalasia by
endoscopically insufflating the esophagus with CO2 and then making an incision into the
mucosa from the mid esophagus to 2-3cm into the proximal stomach.
General anestheisa with an ETT is preferred to protect the patient from aspiration of gastric
contents and minimize effects of CO2 insufflation.
INTRODUCTION
6. This is a relatively safe and effective procedure,
with 1.2% risk of major adverse events and
31.1% of minor adverse events.
Adverse events include:
- Subcutaneous emphysema
- Pneumothorax
- Pneumoperitoneum
- Pneumomediastinum
- Gastroesophageal reflux
Occurence of adverse events are directly
correlated with prolonged procedural time.
INTRODUCTION
8. A 33-year-old previously healthy woman (height 145cm, weight 36 kgs, BMI
17kg/m2) with a 3 month history of progressive odynophagia and dyphagia to both solids
and liquids. Work-ups and EGD done led to a endoscopic diagnosis of esophageal
achalasia. The patient was referred to our service for an emergency peroral endoscopic
myotomy procedure + laparoscopic fundoplication and was admitted last July 20, 2021.
The patient has no known co morbidities, has no previous surgical procedures, is
a non-smoker, and is an occasional alcoholic bevarage drinker.
The patient's baseline laboratory tests and chest x-ray were all unremarkable.
Patient is classified as ASA Ie, Mallampati score 1, anesthesia plan was to do general
endotracheal anesthesia rapid sequence induction. The patient was held NPO for 8h.
CASE PRESENTATION
9. The initial viatal signs in the operating room were blood pressure of 110/7mmHg,
heart rate of 90 bpm, respiratory rate of 19 cpm, normothermic at 36.5C, and oxygen
saturation of 99%.
During induction of general anesthesia, preoxygenation with 100% oxygen via face
mask was done for 5 min following by intravenous fentanyl 50 mcg and propofol 100 mg.
Rapid sequence technique was applied with cricoid pressure after administration with
rocuronium 36 mg. Successful endotracheal intubation was achieved at first attempt.
The lung was ventilated at a tidal volume of 7 mL/kg and a rate of 14 breaths/min.
The patient was maintained in stable hemodynamics with sevoflurane. The initial plateau
pressure was 21 mmHg under PEEP 5 mm Hg. Initial ETCO2 at 26
CASE PRESENTATION
10. The endoscope was then inserted into the esophagus and a submucosal tunnel
created by mucosotomy with blunt air dissection was being made.
Around 30 minutes into the procedure, there was noted minimal subcutaneous
emphysema on the anterior neck to supraclavicular area of the patient. Vital signs
remained stable but with noted increasing heart rate up to 98 bpm. No increase in airway
pressure or end tidal CO2.
By 45 minutes in to the procedure, there was gradual elevation of peak
inspiratory airway pressure (from 12 mm Hg to 25 mm Hg) and end tidal CO2 32mmHg.
The surgeons were informed of the findings. At that time, the ventilator was set at volume
controlled ventilation, with a tidal volume of 250 ml, respiratory rate of 14 breaths/min,
and PEEP 4mmHg.
CASE PRESENTATION
11. CASE PRESENTATION
Subcutaneous emphysema was identified by the presence of the characteristic
crackling feel over the chest. Ausculation done, equal breath sounds. Vital signs with blood
pressure 90/60mmHg, heart rate of 109bpm, O2 saturation of 100%. No ECG changes. The
procedure was continued. Ventilator settings were adjusted, TV lowered to 6mL/kg, RR
12cpm, PEEP turned off.
By 1 hour and 45 minutes of the operation, the
POEM procedure was just about to finish when the heart
rate gradually increased to 115bpm and end tidal CO2 to
37mmHg. Distention of the left chest area noted along
with decreased tidal volume to 80-100mL. The surgeons
were informed.
12. After a few minutes, the peak inspiratory pressure rapidly rose up to 44 mm Hg,
accompanied by loss of breath sounds of both right and left lung and loss of chest wall
movement was detected. Chest percussion showed hyper-resonance. There was obvious
subcutaneous emphysema over her neck, chest, and epigastric area. Tachycardia with HR
132 bpm and hypotension with BP 90/55 mm Hg ensued.The patient's oxygen saturation
decreased from 100% to as low as 88% and end tidal CO2 to 47mmHg. Sevoflurane was
turned off and the patient was manually being ventilated with 100% O2.
CASE PRESENTATION
Manual ventilation recruitment maneuvers were not
effective at restoring the saturation and airway obstruction during
ventilation was evident.
Bilateral tension pneumothorax resulting from intraoperative
POEM complication was diagnosed immediately and prompt
emergency management was started
13. The main surgeon immediately used emergent needle decompression using a 18G
needle, 50cc syringe and PNSS, inserted at the right 2nd intercostal space along the
midclavicular line. Noted decrease in subcutaneous emphysema. Needle decompression was
repeatedly performed at the left 2nd intercostal space along the midclavicular line, also at
the right and left 4-5th intercostal space of anterior axillary line. O2 sat has improved to 94%
by this time with peak inspiratory pressure at 30mmHg. Difficulty in manual ventilation was
still evident. Subsequently, the surgical team were getting ready to do bilateral chest tube
thorocostomy.
Bilateral chest tubes placed and secured and viital signs improved. Blood pressure
at 90/55mHg, heart rate gradually decreased to 110bpm, O2 saturation at 97%, end tidal
CO2 at 35mmHg, peak inspiratory pressure at 24mmHg. Shifting to volume controlled
ventilation was tried but the patient still had decreased tidal volume.
CASE PRESENTATION
14. Manual ventilation was continued for 20 minutes until patient stabilized with improved
findings of Blood pressure 100/60mmHg, heart rate 105 bpm, O2 sat 100%, end tidal CO2 at 29, peak
inspiratory pressure at 14mmHg.
Once the patient was stable, the main service continued to proceed with inserting a trocar
into the abdomanl cavity to decompress the pneumoperitonuem noted, then proceeded to continue
with laparoscopic fundoplication with minimal intrabdominal pressure maintained at 8mmHg. Vital
signs and ventilation were closely monitored during the remaining duration of the procedure which
lasted for 45 minutes.
At the end of the procedure, the patient was still sedated, had spontaneous breathing but
with still with decreased tidal volume around 50-100mL, delayed extubation was planned, portable
chest xray study was done at the OR, and the patient was transferred to the PACU at the end of the
procedure for close monitoring.
CASE PRESENTATION
15. Repeat CBC, BUN, Crea, serum electrolyes, and ABG done 1 hour post hooking to
mechanical ventilator (MV) at the PACU. Correction of ABG and weaning done overnight with close
monitoring of the patient at the PACU.
The patient remained awake, intubated but comfortable, cooperative, and eager to converse through
hand signals and writing. Extubation was done on the 18th hour post op. Close monitoring continued
and the patient was transferred to the wards.
CASE PRESENTATION
Over the course of the hospitalization, there was
complete resolution of the pneumothoraces,
pneumomediastinum and pneumoperitoneum and
subcutaneous emphysema.
Incentive spirometry was started on hospital day
2. Upper GI series performed on hospital day 4 and the
biilateral chest tubes were removed in the evening. The
patient was sent home on hospital day 6.
16. CASE SUMMARY
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17. CXR 7/20/21
Portable chest xray: Post op
s/p Endotracheal tube and pigtail catheter
placement. Bilateral opacities may relate to
pneumonia and/or pulmonary edema.
Subcutaneous emphysema at cervical,
supraclavicular, right shoulder, and the
lateral and anterior chest wall.
18. CXR 7/21/21
Portable chest xray: Post extubation
Consider pneumoperitoneum; interval
development of bilateral small volume
pneumothorax; margical regression of
pulmonary edema and/or thickening,
bilateral; regression of subcutaneous
emphysema
19. CXR 7/23/21
Chest xray: Post op day 3
Non-delineation of
pneumomediastinum and bilateral
small volume pneumothorax. Partial
clearing of pulmonary edema and/or
pneumonia/ Minimal pleural effusion
and/or thickening, left. Resolution of
subcutaneous emphysema at bilateral
cervical, supraclavicular, right shoulder,
lateral and anterial chest wall areas.
20. CXR 7/24/21 Upper GI series
No gross evidence of contrast extravasation in the visualized gastrointestinal tract. Irregular
stomach contour, likely post-operative changes.
21. CXR 7/24/21
Chest xray: Post op day 4
Minimal pleural effusion, left. Clearing
of bilateral lung opacities ascribed to
pulmonary and/or pneumonia.
Cardiomegaly.
23. Intraoperative pneumothorax during POEM -> 2.5%
PE findings that may indicate pneumothorax:
(a) decreased breath sounds
(b) hyper-resonance in chest percussion, and
(c) jugular venous distension
Suspected tension pneumothorax -->
prompt decompression
Postoperative POEM complications:
(a) pneumothorax,
(b) pneumoperitonium,
(c) mediastinal emphysema, and
(d) subcutaneous emphysema
24. 40 patients undergoing POEM procedure
• 7 pateints (17.5 %) = pneumoperitoneum and 1 patient (2.5%) = bilateral pneumothoraces
• resolved with prompt needle decompression
Experience and mastery of the endoscopists directly correlates to length og procedure, minutes per
cm of myotomy, and incidence of adverse effects
Furthere protoring and close supervision is needed to shorten this learning curve
25. POEM under general anesthesia
- aspiration remains to be the greatest risk during
induction (GETA-RSI)
- comes with serious and life threatening complications
• high degree of suspicion and prompt
management of arising complications is essential
- complications relate to the proximity of the esophagus
to the mediastinum and lungs
Pneumothorax
- air collection between the parietal and visceral pleura
resulting to lung collapse.
- main mechanisn of injury:
• gas leakage via surgical tear of mediastinal pleura
during disection of the thoracic portion of the
esophagus.
- positive pressure ventilation
DISCUSSION
26. Subcutaneous emphysema
Clinical features seen in patients during POEM
procedure
• crepitus,
• insufflation problems (flow and pressure),
• hypercarbia (monitor the end tidal CO2),
• acidosis,
• changes in lung complicance,
• sinus tachycardia, other cardiac arrhythmias,
• hypertension, and
• intraoperative increase in partial pressure of
end tital CO2 >50 mmHg
DISCUSSION
Pneumomediastinum
Rarely significant or symptomatic
Clinical features suggestive of this:
• increasing EtCO2,
• falling SO2,
• and inability to attain appropriate tidal volume
even with aggressive manual ventilation
• signs of hemodynamic failure
• arrhythmias and hypotension
Stop procedure and evaluate
Do ABGs
Abdominal paracentesis for deaeration
**Rule of the differential diagnosis of Malignant Hyperthermia
27. DISCUSSION
In suspected Tension Penumothorax
• Do not delay treatment
• Diagnosed clinically (high index of suspicion)
• Do chest xrays after immediate intervention
• Intervention includes:
decompression needle thoracostomy followed by
chest tube thorocostomy,
portable chest x-ray
• ABGs: severe acidosis, hypercarbia, and hypoxia inspite of 100% O2
ventilation
29. POEM is still a promising endoscopic procedure performed under general
anesthesia for the treatment of esophageal achalasia.
Anesthesiologists must have a great understanding in the intraoperative and
postoperative complications of POEM and be ready to promptly diagnose and
apply immediate and correct managements.
Aspiration remains to be the greatest risk during induction, thus GETA
RSI is preferred
The major intraprocedural risk -> leakage of CO2 across various fascial
planes
Stopping the procedure, prompt management and stabilization intraoperatively ,
is necessary
Pneumothorax
CONCLUSION
30. The ability to timely diagnose a pneumothorax is an important skill for the
anesthesiologist.
Pneumothorax can occur from various causes:
• upper extremity blocks,
• subclavian or internal jugular vein central lines,
• mechanical ventilation barotrauma,
• surgical entry into the pleural space,
• or trauma patients with institution of positive-pressure ventilation.
CONCLUSION
31. SUMMARY
PE findings that may indicate pneumothorax:
(a) decreased breath sounds
(b) hyper-resonance in chest percussion, and
(c) jugular venous distension
Tension Pneumothorax is a life threatening condition which may quickly lead
to cardiovascular collapse and shock
Prompt diagnosis even without laboratory or radiologic evidence
Immediate intervention must be initiated without delay if there is a high
clinical suspicion of a tension penumothorax
Intervention includes: decompression needle thoracostomy followed by chest
tube thorocostomy insertion,
Portable chest x-ray post CTT insertion to confirm tube placement and re-
expansion of the collapsed lung fields
This form of surgery integrates the perspectives of endoscopic medicine and minimally invasive surgery.
The PEOM procedure is a minimally invasive procedure developed to correct achalasia by endoscopically insufflating the esophagus with CO2 and then making an incision into the mucosa from the mid esophagus (the the GE junction) to 2-3cm into the proximal stomach
During insufflation, patients may have an increase in ETCO2 that can be controlled using mechanical ventilation. Potential risks of insufflation range from subcutaneous emphysema to pneumothorax, pneumomediastinum, and pneumoperitoneum. This procedure commonly requires several hours and is best accomplished using general anesthesia with an endotracheal tube, which protects the patient from aspiration of gastric contents and allows the anesthesiologist to minimize the perils of CO2 insufflation.
As with all NORA procedures, vigilance, teamwork, and communication are vital to ensure not only the success of the procedure but the safety of the patient as well.
This form of surgery integrates the perspectives of endoscopic medicine and minimally invasive surgery. The PEOM procedure is a minimally invasive procedure developed to correct achalasia by endoscopically insufflating the esophagus with CO2 and then making an incision into the mucosa from the mid esophagus (the the GE junction) to 2-3cm into the proximal stomach
During insufflation, patients may have an increase in ETCO2 that can be controlled using mechanical ventilation. Potential risks of insufflation range from subcutaneous emphysema to pneumothorax, pneumomediastinum, and pneumoperitoneum. This procedure commonly requires several hours and is best accomplished using general anesthesia with an endotracheal tube, which protects the patient from aspiration of gastric contents and allows the anesthesiologist to minimize the perils of CO2 insufflation.
As with all NORA procedures, vigilance, teamwork, and communication are vital to ensure not only the success of the procedure but the safety of the patient as well.
This is a relatively safe and effective procedure, with 1.2% risk of major adverse events and 31.1% of minor adverse events.
Adverse events include: pneumoperitoneum, subcutaneous emphysema, pneumothorax, and gastroesophageal reflux.
However, the occurrence of bilateral pneumothoraces, pneumomediastinum, pneumoperitoneum,pneumoretroperitoneum with subcutaneous emphysema in the same patient is a rare occurence. Occurence of adverse events are directly correlated with prolonged procedural time.
The lung was ventilated at a tidal volume of 7 mL/kg (250) and a rate of 14 breaths/min. The patient was maintained in stable hemodynamics with sevoflurane.
The initial plateau pressure was 21 mm Hg under PEEP 5 mm Hg.
The lung was ventilated at a tidal volume of 7 mL/kg (250) and a rate of 14 breaths/min. The patient was maintained in stable hemodynamics with sevoflurane.
The initial plateau pressure was 21 mm Hg under PEEP 5 mm Hg.
peak inspiratory airway pressure (Ppeak) is used to monitor airway patency, progressive obstruction of the endotracheal tube (ETT) resulting from secretions can go undetected for a prolonged period.
Plateau pressure is thought to reflect pulmonary compliance and can be measured by applying a brief inspiratory pause after ventilation. High peak pressure with normal plateau pressures indicates increased resistance to flow, such as endotracheal tube obstruction or bronchospasm.
Is mean airway pressure the same as plateau pressure?
Paw is airway pressure, PIP is peak airway pressure, Pplat is plateau pressure. Some researchers have suggested that plateau pressures should be monitored as a means to prevent barotrauma in the patient with ARDS. Plateau pressures are measured at the end of the inspiratory phase of a ventilator-cycled tidal volume.
overall procedure time lasted for at least 3 hours
DRAFTTT
TSUNG SHIH LI ET AL 2015 described in this literature that the development of Intraoperative pneumothorax during POEM accounted for 2.5% of adverse effects and was actually uncommon. No scenario of tension pneumothorax during POEM has been published during the time of publication of this article.
They reported in a case of a 56yo previously healthy woman for scheduled POEM for esophageal achalasia, who developed right tension pneumothorax secondary to esophageal rupture most likely during blunt air dissection of the esophageal mucosa. This resulted to tension pneumothorax due to gas leakage via surgical tear of mediastinal pleura when dissecting thoracic portion of the esophagus.
Tsung Shih Li also described the effects of positive pressure ventilation under general anesthesia which facilitates the development of pneumothorax. That's another factor why tension pneumothorax occurred in their patient following 2h of surgery.
Abnormal findings in physical examination such as decreased breath sounds, hyper-resonance in chest percussion and jugular venous distension may indicate the formation of pneumothorax. Once tension pneumothorax or pneumothorax with compromised vital signs is considered, prompt decompression should be done without any image evidence for the reason of immediate rescue of unstable hemodynamics. Post-operative complications of POEM associated with gas insufflation and gas leakage via minor esophageal tear include pneumothorax, pneumoperitonium, mediastinal emphysema, and subcutaneous emphysema.
------ using CO2 and Air for the proceudre, wherein CO2 is less
Comparing to carbon dioxide, air is less absorbable for pleural cavity. Evidence supported that the use of air had a higher rate in gas-insufflation related complications than the use of carbon dioxide.
In a study done by Kurian et al 2013 which involved the 40 consecutive patients undergoing the POEM procedure, their findings included seven of their patients developing capnoperitoneum and another bilateral capnothoraces. These adverse events were associated with hemodynamic instability, but were resolved by needle decompression
In this study, mastery of operative technique in POEM directly correlated to a decrease in length of procedure, variability of minutes per centimeter of myotomy, and incidence of adverse events in about 20 cases for experienced endoscopists
The learning curve can be shortened with very close supervision and/or proctoring.
Kurian AA, Dunst CM, Sharata A, Bhayani NH, Reavis KM, Swanström LL. Peroral endoscopic esophageal myotomy: defining the learning curve. Gastrointest Endosc. 2013 May;77(5):719-25. doi: 10.1016/j.gie.2012.12.006. Epub 2013 Feb 5. PMID: 23394838.
POEM UNDER GENERAL ANESTHESIA
Aspiration remains to be the greatest risk during induction thus GETA RSI is preferred Serious and life threatening complications are reported in patients undergoing POEM under general anesthesia. Both a high degree of suspicion and a plan of management is essential. Some of the complications include those earlier mentioned (pneumothorax, mediastinal emphysema, subcutaneous emphysema, and pneumoperitoneum) Again, these complications relate to the proximity of the esophagus to the mediastinum and lungs Pneumothorax
Air collection between the parietal and visceral pleura resulting to lung collapse.
Tsung Shih Li also noted that the likely cause or mechanisn of injury in their patient who developed pneumothorax intraop during POEM was the gas leakage via surgical tear of mediastinal pleura during disection of the thoracic portion of the esophagus.
Tsung Shih Li also described the effects of positive pressure ventilation under general anesthesia which facilitates the development of pneumothorax. That's another factor why tension pneumothorax occurred in their patient following 2h of surgery. Whereas the development of adverse effects during POEM is directly proportional to the length of the procedure
--------------------------------------------------- Use of air as insufflation gas provides better distension with better manipulative space, but is not advised. As compared to CO2, air is less absorbable in pleural cavity.
Positive airway pressure under general anesthesia may also facilitate the development of pneumothorax. Use of air is associated with a higher rate of gas-insufflation related complications than the use of CO2. The esophageal wall is thinly separated from or directly exposed to surrounding structures during the procedure.
Subcutaneous emphysema
- in pateints undergoing POEM, features of subcutaneous emphysema include: crepitus, insufflation problems (flow and pressure), hypercarbia (monitor the end tidal CO2), acidosis, changes in lung complicance, sinus tachycardia, other cardiac arrhythmias, hypertension, and intraoperative increase in partial pressure of end tital CO2 >50 mmHg
** Percutaneous needle decompression by insertion of a G16 angiocatheter cannula at the point of the Right Upper abdominal quadrant at least 5cm below the rib cage
Pneumomediastinum
- symptomatic or clinically significant pneumomediastinum during POEM is rare and often occurs in association with subcutaneous emphysema.
- Suggestive of pneumomediastinum: increasing EtCO2, falling SO2, and inability to attain appropriate tidal volume even with aggressive manual ventilation. Signs of hemodynamic failure, arrhythmias and hypotension are possible
What to do in this situation?
- it's necessary to stop the procedure and do a prompt evaluation
- ABG would show: severe acidosis inspite of 100% O2 ventilation
-- Abdominal paracentesis at another location may be necessary to deaeration.
- Continuation of positive pressure ventilation with appropriate ventilator settings
*** must rule out MH due to difficulty to ventilate and absence of hyperthermia
The ability to timely diagnose a pneumothorax is an important skill for the anesthesiologist. So In suspected development of Tension Penumothorax: Do not delay treatment of a suspected tension pneumothorax.
Remember!! The diagnosis of pneumothorax is made clinically when one has high index of suspicion.
Chest xrays may be done in the OR can be taken as confirmatory measures after immediate intervention has beend one
Intervention includes decompression needle thoracostomy followed by chest tube thorocostomy, followed by a portable chest x-ray to confirm tube placement and re-expansion of the collapsed lung fields
ABGs: Often seen in tension pneumothorax is a varying degree of acidemia, hypercarbia, and hypoxia inspite of 100% O2 ventilation AGAINNNNN, Laboratory and diagnostics may confirm the diagnosis of a tension pneumothorax (like. ABG, CXR) however the diagnosis lies predominantly on clinical presenting symptoms
Conclusions
POEM is still a promising endoscopic procedure performed under general anesthesia for the treatment of esophageal achalasia.
Anesthesiologists must have a great understanding in the intraoperative and postoperative complications of POEM (such as tension pneumothorax) and be ready to promptly diagnose and apply immediate and correct managements.
1) Aspiration remains to be the greatest risk during induction, thus GETA RSI is preferred
anesthesiologists must have a clear concept about this risk when they perform general anesthesia to these patients and provide good prevention.
2) The major intraprocedural risk involved in this procedure still remains to be the leakage of CO2 across various fascial planes
Stopping the procedure, prompt management and stabilization intraop, is necessary.
Conclusion
Pneumothorax can occur from various causes thus it's timely identification and diagnosis is an important skill for us anesthesiologists upper extremity blocks,
subclavian or internal jugular vein central lines,
mechanical ventilation barotrauma,
surgical entry into the pleural space,
or trauma patients who develop pneumothorax with institution of positive-pressure ventilation. https://www.sciencedirect.com/science/article/pii/S0104001415001220#bbib0075
