How to manage isolated tension non-surgical pneumoperitonium during bronchoscopy? A case report

Abstract

BACKGROUND

Tension pneumoperitonium is a rare complication during bronchoscopy that can cause acute respiratory and hemodynamic failure, with fatal consequences. Isolated pneumoperitonium during bronchoscopy usually results from ruptures of the abdominal viscera that need surgical repair. Non-surgical pneumoperitoneum (NSP) refers to some pneumoperitoneum that could be relieved without surgery and only by conservative therapy. However, the clinical experience of managing tension pneumoperitonium during bronchoscopy is limited and controversial.

CASE SUMMARY

A 51-year-old female was admitted to our hospital for cough with bloody sputum of seven days. On the 8^th day of her admission, a bronchoscopy was arranged for bronchial-alveolar lavage to detect possible pathogens in the lower respiratory tract, as oxygen was delivered via a 12 F nasopharyngeal cannula, approximately 5-6 cm from the tip of the catheter, with a flow rate of 5-10 L/min. After four minutes of bronchoscopy, the patient suddenly vomited 20 mL of water, followed by severe abdominal pain, while physical examination revealed obvious abdominal distension, as well as hardness and tenderness of the whole abdomen, which was considered pneumoperitonium, and the bronchoscopy was terminated immediately. A computer tomography scan indicated isolated tension pneumoperitonium, and abdominal decompression was performed with a drainage tube, after which her symptoms were relieved. A multidisciplinary expert consultation discussed her situation and a laparotomy was suggested, but finally refused by her family. She had no signs of peritonitis and was finally discharged 5 d after bronchoscopy with a good recovery.

CONCLUSION

The possibility of tension pneumoperitonium during bronchoscopy should be guarded against, and given its serious clinical consequences, cardiopulmonary instability should be treated immediately. Varied strategies could be adopted according to whether it is complicated with pneumothorax or pneumomediastinum, and the presence of peritonitis. When considering NSP, conservative therapy maybe a reasonable option with good recovery. An algorithm for the management of pneumoperitonium during bronchoscopy is proposed, based on the features of the case series reviewed and our case reported.

Key Words: Pneumoperitonium, Tension, Isolated, Non-surgical, Bronchoscopy, Case report

Core Tip: Tension pneumoperitonium is a rare complication during bronchoscopy that can cause serious consequences. Isolated pneumoperitonium during bronchoscopy usually results from ruptures of the abdominal viscera that need surgical repair. Nonsurgical pneumoperitoneum (NSP) refers to some pneumoperitonium that could be relieved without surgery and only by conservative therapy. However, the clinical experience of managing tension pneumoperitonium during bronchoscopy is limited and controversial. Herein, we describe a rare case of isolated tension pneumoperitonium during bronchoscopy, which was recovered with no signs of peritonitis by conservative therapy. An algorithm for the management of pneumoperitonium during bronchoscopy is proposed.

INTRODUCTION

Pneumoperitonium is a rare complication during bronchoscopy[1,2]. Tension pneumoperitonium may cause acute respiratory and hemodynamic failure[1,2], and can give rise to fatal consequences[3,4]. When pneumoperitonium is complicated with pneumothorax or pneumomediastinum, it is usually due to high positive pressure ventilation or airway/alveolar rupture[2,5]. Isolated pneumoperitonium during bronchoscopy is usually caused by ruptures of the abdominal viscera that need surgical repair[3,6]. Some pneumoperitonium could be relieved without surgery and only by conservative therapy, which is known as non-surgical pneumoperitoneum (NSP)[6]. When tension pneumoperitonium occurs during bronchoscopy, prompt diagnosis and life support should be performed, and whether it is an NSP should be confirmed, which may help the patient avoid surgical procedures and get a good recovery with conservative treatment[7]. However, given the limited and controversial clinical experience in the management of tension pneumoperitonium during bronchoscopy, we recount a rare case of isolated tension pneumoperitonium during bronchoscopy that was relieved by conservative therapy.

CASE PRESENTATION

Chief complaints

A 51-year-old female was admitted to our hospital for cough with bloody sputum of seven days.

History of present illness

A 51-year-old female was admitted to our hospital for cough with bloody sputum for 7 d, with chest pain, dyspnea after exercise, and with no fever.

History of past illness

Her past medical history includes right knee arthroplasty one month before admission, and tubal ligation for twenty-seven years.

Personal and family history

She had no trauma history, no other special diseases, or family genetic history.

Physical examination

Vital signs at admission: Temperature 36.3 ℃, Pulse 98 bpm, respiratory rate (RR) 20 bpm, blood pressure (BP) 131/96 mmHg, pulse oxygen saturation (SPO₂) 81% (at room air), body mass index 28. She was alert, with moist rales in both lower lobe.

Laboratory examinations

At admission, her C reactive protein was 189.66 mg/L, Arterial Blood Gas showed pH 7.44, PaCO₂ 32.2 mmHg, PaO₂ 45 mmHg; Fibrinogen 5.59 g/L, D-dimer 2.41 mg/L. Her blood cell count, procalcitonin and brain natriuretic peptide were in normal range.

Imaging examinations

Her chest computer tomography (CT) showed infiltrates in the bilateral pulmonary lobes, localized consolidation in the right lower pulmonary lobe, and bilateral basal pleural effusions (Figure 1A and B).

Figure 1 Chest and abdomenal computed tomography scan of the patient on day 1, day 8, and day 9. A and B: Thoracic enhanced computed tomography (CT)-scan on admission showed infiltration and fibrotic foci were scattered in the bilateral pulmonary lobe, with localized consolidation of the right lower lobe, and bilateral pleural effusions; C-F: Thoracic and abdominal CT-scan on day 8 taken after needle decompression demonstrating the presence of a large anterior pneumoperitoneum without fluid collections and pneumothorax or pneumomediastinium; G and H: Abdominal enhanced CT-scan on day 9 showed gas accumulation in the right abdominal wall, free gas in the abdominal cavity is less than in the previous CT exam.

FINAL DIAGNOSIS

Community-acquired pneumonia.

TREATMENT

She was treated with Amoxicillin-clavulanate 1.2 g every eight hours for one week. Sputum cultures were obtained prior to antibiotic treatment and were not found to be positive. And as the patient did not have a high fever on admission, no blood culture was obtained. On the 8^th day of her admission, a bronchoscopy was arranged for bronchial-alveolar lavage to detect the possible pathogens in the lower respiratory tract. Local anesthesia was initially administered with lidocaine 2% aerosol inhalation for 30 min. Midazolam 3 mg was injected intravenously 1 min before the operation, and oxygen was supplied via a 12 F nasopharyngeal cannula (NPC), approximately 5-6 cm from the tip of the catheter to the nostril, with the oxygen flow rate of 5-10 L/min. Preoperative vital signs were BP 125/86 mmHg, pulse 90 bpm, RR 16 bpm, SpO₂ 88% (with NPC 5 L/min). After four minutes of bronchoscopy, the patient suddenly vomited 20 mL of water, followed by severe abdominal pain. Vital signs were BP 195/91 mmHg, pulse 135 bpm, RR 25 bpm, SpO₂ 89%. She was immediately given nimodipine, and the flow of oxygen was increased to 15 L/min, with consideration of treatment in the intensive care unit, including ventilator management. Physical examination revealed obvious abdominal distension, as well as hardness and tenderness of the whole abdomen. Pneumoperitonium was considered and the bronchoscopy was stopped immediately, followed by emergency decompression by inserting a gastric tube for gastrointestinal (GI) decompression. Ultrasound of the abdomen indicated a tension pneumoperitonium with no significant effusion, while thoracic and abdominal CT scans indicate massive gas accumulation in the abdominal cavity with no pneumothorax or pneumomediastinum (Figure 1C-F). An abdominal decompression with a drainage tube into the abdominal cavity was therefore performed. The drainage tube was a single lumen catheter (8 Fr) inserted percutaneously with a needle and guidewire, and was kept in place for 2 d. And the patient was sent back to the general ward with relief of symptoms. Six hours after which, the patient presented with approximately 20 mL of coffee-colored vomit with no signs of peritonitis. A multidisciplinary expert consultation discussed her situation and a laparotomy was suggested, but finally refused by her family. A contrast abdominal CT scan was done the following day (Day 9), which showed much less gas in the abdominal cavity than on the previous day's CT (Figure 1G and H).

OUTCOME AND FOLLOW-UP

The subsequent clinical course was uneventful. Her bronchoalveolar lavage fluid sample was negative for metagenomic next generation sequencing (mNGS), ruling out corona virus disease 2019, tuberculosis, or nontuberculous mycobacterial infection. With mycoplasma pneumonia detected by mNGS, moxifloxacin was given to her. And the patient was eventually discharged 5 d after bronchoscopy and recovered well.

DISCUSSION

Pneumoperitonium was a rare complication during bronchoscopy. We searched Pubmed data base and found only eight cases were reported during the last 20 years. As shown in Table 1, eight previously published cases and the current case with pneumoperitonium during bronchoscopy were reviewed. A total of nine cases were reported, including eight adults and one child. 22% (2/9) of the patients had pneumoperitonium during rigid bronchoscopy, while 78% had it at fiberoptic bronchoscopy. Four patients (44%) underwent transbronchial lung biopsy (TBLB) or transbronchial needle aspiration (TBNA). NPC was the most common oxygen supply method in six patients (66%), while the remaining one and two patients used a bag mask and mechanical ventilation (MV), respectively. In addition, sudden onset of abdominal pain or distension was the most common clinical presentation, as shown in three and five patients, respectively. However, a cardiorespiratory arrest was present in one case. Only 4 (44%) patients had isolated pneumoperitonium, and pneumothorax/pneumomediastinum were complicated with pneumoperitonium in the other 5 cases. Most of the reported cases were tension pneumoperitonium. Hypotension and respiratory failure were also present in five cases. Six patients were intubated after pneumoperitonium, while only one patient died after pneumoperitonium and the other eight recovered well. Four patients had laparotomy/laparoscopy, and gastric ruptures were found in only 3 cases.

Table 1 Case series reported pneumoperitoneum associated with bronchoscopy.

Ref.	Age	Sex	BSP type	Biopsy procedure	O2 supply	Symptoms during BSP	PT or PM	Isolated PP	Tension PP	Respiratory or hemodynamic failure	Intubaion and MV	Viscus rupture	Laparotomy or Conservative treatment	Outcome
Nikolaev et al[1], 2003	82	F	Fiberoptic	TBLB	NPC	Sudden stuporotic bradycardic	PT + PM	No	Yes	No	Intubation air-bag	No	Laparoscopy	Discharged 3 d later
Abraham et al[2], 2011	76	F	Fiberoptic	TBNA	NPC	Abdominal pain	PM	No	Yes	No	No	No	Conservative observation in ICU	Discharged 2 d later
Dastidar[5], 2013	14 mo	M	Rigid	Foreign body removal	MV	Distended abdomen	PT + PM	No	No	No	Aborted	No	Conservative observation in ICU	Discharged 1 d later
Bednarz et al[8], 2015	42	F	Rigid	No	Bag mask	Respiratory arrest distended abdomen	No	Yes	Yes	RF and shock	Intubation	Gastric rupture	Emergent laparotomy	Recovered
El-kersh and Karnib[3], 2017	61	F	Fiberoptic	No	NPC	Abdominal pain tachycardia tachypnea	No	Yes	Yes	RF	Intubation	Gastric rupture	Emergent laparotomy	Recovered
Muriana et al[6], 2018	80	M	Fiberoptic	EBUS TBNA	NPC	Distended abdomen severe bradycardia arterial hypotension	No	Yes	Yes	RF and shock	Intubation	No	Needle decompression	Discharged 13 d later
Po et al[4], 2021	80	M	Fiberoptic	BALF	MV	Distended abdomen persistent hypotension	PM	No	Yes	Shock	Intubation	NA	Refused laparotomy by family	Died
Pereira et al[9], 2021	61	F	Fiberoptic	No	NPC	Sudden abdominal distension; cardiorespiratory arrest	PT + PM	No	Yes	RF and shock	Bag-mask ventilation & intubation	Gastric laceration	Needle decompression exploratory laparotomy	Discharged 4 d later
This case	51	F	Fiberoptic	No	NPC	Abdominal pain	No	Yes	Yes	No	No	No	Needle decompression	Discharged 5 d later
In summary	42-82 yr	F 6 M 3	Fiberoptic 7 Rigid 2	TBLB 1 TBNA 2 Foreign body 1	NPC 6 MV 2 bag mask 1	Abdominal pain 3 Distended abdomen 5 hypotension 2 cardiorespiratory arrest 1	PT + PM 3 PM 2 No 4	No 5 Yes 4	Yes 9 No 1	RF + shock 3 RF 1 Shock 1 No 4	Intubation 6 No 2	Gastric rupture 3 No 6	Conservative observation 2 Laparotomy 4 Needle decompression3	Discharged 8 Died 1

BSP: Bronchoscopy; IV: Intravenous; TBLB: Transbronchial lung biopsy; PT: Pneumothorax; PM: Pneumomediastinum; PP: Pneumoperitonium; MV: Mechanical ventilation; EBUS: Endobronchial ultrasound guidance; TBNA: Tranbronchila needle aspiration; NA: Not available; NPC: Nasopharyngeal cannula; RF: Respiratory failure.

The mechanism of pneumoperitonium during bronchoscopy is manifested by high-pressure air in the ruptured airway, alveoli, or hollow viscus[5,8,9]. In some cases, such as rigid bronchoscopy[5,8], TBLB[1], TBNA[2,6], or foreign body removal[5], pneumoperitonium occurs as an intro-airway procedural complication. Damage to the airway or the alveoli may occur due to these procedures, leading to pneumoperitonium[10]. Also, pneumothorax and pneumomediastinum could be found more frequently in these types of pneumoperitonium[11-15]. Additionally, the “Macklin” effect is one of the mechanisms related to pneumothorax or pneumomediastinum complicated with pneumoperitonium[16].

Isolated pneumoperitonium without complicated pneumothorax or pneumomediastinum is more likely to be associated with an air source from the lesion of GI tract[3,8]. However, one previously reported case showed that isolated pneumoperitonium could also be seen after TBNA[6]. Therefore, when isolated pneumoperitonium was present during bronchoscopy without an intro-airway procedure, it should be considered that there is a high possibility that the pneumoperitonium is of GI source. It was described[17] that some patients undergoing bronchoscopy under sedation and oxygen delivery by NPC experienced the development of pneumoperitoneum secondary to gastric rupture due to multiple factors, such as the reduced muscle tone in the pharynx induced by anesthesia, and thus air entering the stomach with one-way valve mechanism, resulting in NPC dislocation in the esophagus. With these risk factors, the large amounts of air supplied by the oxygen supply tube may enter the GI tract, inducing high air pressure in the hollow viscus and eventually leading to perforation at its most vulnerable site of the gastriointestinal wall. And it was speculated that when the perforation occurs in the ventral side of the GI tract, and most patients have very little content left in the GI tract after the bronchoscopy preparation, air could be the only substance that leaks into the peritoneum, with no other GI content entering into the peritoneum and causing peritonitis.

Tension pneumoperitonium was reported in the majority of the cases we reviewed, and in more than half of these cases there was acute circulatory or respiratory failure[3,4,6,8] or cardiopulmonary arrest[9], which may lead to a fatal outcome[18]. The initial step in treatment should be prompt resuscitation and life support. Tension barotrauma should be confirmed by radiological examination as soon as possible after the patient's vital signs have stabilized. At the same time, a needle or tube decompression should be considered for a better venous return and respiratory compliance, which could further improve the cardiopulmonary status. If a tension pneumoperitonium is caused by gastric or intestinal microperforation, showing only pneumoperitoneum during bronchoscopy without signs of peritonitis, non-surgical pneumoperitonium should be considered, and it could be cured by a needle or tube decompression[6].

Only four out of the nine patients with pneumoperitonium eventually underwent laparotomy or laparoscopy in our review. Three of the patients who underwent laparotomy that were confirmed gastric rupture but got repaired and recovered well, while the other patient died when his family refused the laparotomy. In addition to this, four patients who were radiologically found negative to have visceral rupture were closely monitored and eventually diagnosed with NSP and recovered with conservative therapy. Therefore, it should always be borne in mind that NSP is a form of pneumoperitonium complicated with bronchoscopy, for which surgical procedure could be avoided with a good outcome[6,7,19].

High flow oxygen supply or high positive pressure ventilation maybe a significant cause of pneumoperitonium during bronchoscopy[20]. Besides, mechanical ventilation, bag-mask ventilation, and high flow NPC have also been reported as causes of pneumoperitonium in other clinical circumstances, such as sedation or surgical procedures[14,20]. NPC was considered the most probable cause of isolated pneumoperitonium during bronchoscopy without biopsy in three cases, based on our review of previous cases, including the case we report here. Therefore, clinicians should be aware of the risk of pneumoperitonium when a high flow NPC oxygen supply is used during bronchoscopy and should monitor this complication closely during the procedure. And furthermore, not only should cardiopulmonary monitoring and resuscitation kits be prepared, but decompression kits should be prepared at the bedside during bronchoscopy for high-risk patients undergoing, for example, high flow NPC, positive ventilation, deep sedation, and invasive procedures. And when using NPC oxygenation, confirm the position of the catheter.

A protocol for the management of pneumoperitonium during bronchoscopy is proposed in Figure 2, based on the features of the case series reviewed and our case reported.

Figure 2 Protocol for the management of pneumoperitonium during bronchoscopy. BSP: Bronchoscopy; MV: Mechanical ventilation; CT: Computed tomography.

CONCLUSION

In summary, due to the serious clinical consequences, attention should be paid to the possibility of tension pneumoperitonium during bronchoscopy while the unstable cardiopulmonary status should be treated immediately. And meanwhile, varied treatments could be adopted according to whether pneumoperitonium is complicated with pneumothorax or pneumomediastinum, and whether there are signs of persistent peritonitis. When NSP is considered, conservative therapy maybe a reasonable option with good recovery. Furthermore, patients at high risk should be closely monitored.