Anesthetic management of Morgagni hernia repair in an elderly woman.

Adult onset congenital diaphragmatic hernia (CDH) is uncommon but not rare. Morgagni hernia is a rare variant of CDH. The defect tends to be small and patients may remain asymptomatic and diagnosed incidentally. When these patients become symptomatic, they usually present with gastrointestinal and cardiorespiratory symptoms or sometimes as an emergency due to obstruction or strangulation of herniated viscera. Chest radiograph, computed tomography scan, and magnetic resonance imaging are the imaging modalities used for diagnosis of CDH. Cardiopulmonary compromise due to mass effect of hernial contents on lungs, heart and great vessels, and obstruction or strangulation of herniated viscera poses the special challenge before anesthesiologists. Our patient was diagnosed to have Morgagni hernia, at the age of 72 years and underwent laparotomy for the same. This case highlights the key feature of the successful anesthetic management of adult onset CDH.

INTRODUCTION

Late-onset congenital diaphragmatic hernia (CDH) accounts for only 5–30% of all CDH, and of those cases chances of Morgagni hernia are only 1.5–6%. This emphasizes the rarity of Morgagni hernia in adult patients.[123] Herniation of abdominal viscera in the thoracic cavity through foramen of Morgagni may produce severe cardiopulmonary or gastrointestinal complications. Our patient became symptomatic for the 1st time at the age of 72 years, which is quite rare. She had a history of acid peptic disease and presented with worsening of cardiorespiratory symptoms. Diagnosis of Morgagni hernia was made on the basis of clinical and radiological findings. In this case report, we present the successful anesthetic management of a late onset Morgagni hernia repair in the 72-year-old female patient.

CASE REPORT

A 72-year-old female patient; weighing 42 kg was presented with complaints of worsening of dyspnea and frequent chest infection for last 6 months. One and a half year back patient sought medical advice for recurrent abdominal pain, nausea and vomiting. She was diagnosed as hiatus hernia with moderate esophagitis at that time. Since then she had on and off epigastric discomfort and occasional nausea and vomiting. Medical history included hypertension and hypothyroidism and patient was on amlodipine and levothyroxine for the same. Patient had no past history of surgery or trauma. Patient was examined and on auscultation there were decreased breath sounds on the lower part of right side of the chest. Chest X-ray was advised, and it showed gas-filled bowel loops in right hemithorax with blunting of right costophrenic angle [Figure 1]. For further evaluation, computed tomography (CT) scan of the thorax was done, and it showed large diaphragmatic hernia from the retrosternal part with herniation of multiple bowel loops [Figures 2 and 3]. Diagnosis of late onset symptomatic right-sided CDH (Morgagni hernia) was made, and the patient was scheduled for laparotomy.

Figure 1

Antero posterior chest X-ray showing gas-filled bowel loops on right hemithorax

Figure 2

An axial computed tomography image shows gas-filled bowel loops in right hemithorax

Figure 3

Lateral thoraco-abdominal computed tomography showing bowel loops in right hemithorax compressing right lung

During preanesthetic check-up, patient was tachypneic but maintaining oxygen saturation (SpO2) 98% on air. Airway Mallampati grade III and systemic examination was normal except decreased breath sounds over the lower part of right hemithorax. Laboratory investigations, electrocardiogram (ECG), and echocardiography were normal. Combined balanced general and epidural anesthesia was planned.

At arrival in operation theater, patient's pulse rate was 90 beat/min, her blood pressure was 110/74 mmHg and SpO2 on room air was 97–98%. Large gauge intravenous access was secured. The patient received aspiration prophylaxis and premedicated with intravenous glycopyrrolate 0.2 mg and midazolam 1 mg. Nasogastric tube was inserted, and stomach was deflated. After preoxygenation, rapid sequence induction with cricoid pressure was performed using fentanyl 80 µg, thiopentone sodium 250 mg and succinylcholine 75 mg. Trachea was intubated with left-sided 32-Fr double lumen bronchial tube. Anesthesia was maintained with atracurium, isoflurane, 50% O2 in the air and controlled mode ventilation. Lung isolation technique was used in the initial phase of surgery and once diaphragmatic defect was repaired both the lungs were ventilated. During one lung ventilation SpO2 decreased to 94–96% and that time 100% O2 and positive end expiratory pressure (PEEP) was used. Thoracic epidural catheter (T10-T11) was placed after the induction of anesthesia.

Intraoperative monitoring was instituted with ECG, SpO2, EtCO2, temperature, urine output, invasive blood pressure, and central venous pressure (CVP) with double lumen catheter in right internal jugular vein and CVP was measured to be 18 cmH2O. Right subcoastal laparotomy was done and a defect was found in retroxiphoid part of diaphragm (6 cm × 4 cm) through which transvers colon, small intestine, and omentum were herniating in the right hemithorax [Figure 4]. Right hemithorax was decompressed by returning the viscera into the abdominal cavity, and the defect was closed with primary suturing. As the thorax was decompressed, CVP came down to 10 cmH2O.

Figure 4

Defect in diaphragm (Morgagni hernia)

At the completion of surgery, residual neuromuscular effect was antagonized with standard doses of glycopyrrolate and neostigmine and the trachea was extubated, then the patient was shifted to postanesthesia care unit. Patient tolerated the procedure well and remained hemodynamically stable. Epidural morphine was given for pain relief. Postoperative chest X-ray was done, and it was normal.

DISCUSSION

The incidence of CDH is 1:2000–1:5000 with equal gender preferences. The defect arises during early embryological development (around 10 weeks) due to incomplete closure of the diaphragm or early migration of the mid gut from umbilical coelom in to the abdominal cavity before the diaphragm is fully developed. Three common sites of herniation are: (A) Posterolaterally through foramen of Bochdalek (78–90%) (B) esophageal hiatus (14–24%) (C) retrosternally through foramen of Morgagni (1.5–6%).[12] Beyond infancy, CDH is an unusual finding. CDH study group conducted a 10-year study across 30 centers revealed that of total 3098 cases only 79 (2.6%) presented with late onset.[3] This emphasizes the rarity of our case as our patient was 72-year-old at the time of presentation.

Late onset CDH are more difficult to diagnose as sign and symptoms become chronic, vague, and inconsistent. Symptoms can be either cardiorespiratory or gastrointestinal, with the latter becoming more common as the age of onset of symptom increases.[24] Suspicion of CDH should be aroused when patient presents with both cardiorespiratory and gastrointestinal symptoms and on examination when there is decreased breath sounds in either hemithorax. To confirm the diagnosis, chest radiographs are the most commonly performed and initial imaging modality to evaluate the diaphragm. Sometimes, CDH may be misdiagnosed as pleural effusion or hydro-pneumothorax on chest X-ray. When chest radiographs are indeterminate, spiral CT and magnetic imaging must be considered for evaluating diaphragm.[5]

In cases of adult-type disorder, the acute herniation of viscera through congenital diaphragmatic defect is considered to be induced by an elevation of intraperitoneal pressure, once in the thoracic cavity the viscera usually remain there due to abdomino-thoracic pressure gradient.[67] Although there was no history of trauma, but our patient had a history of the acid peptic disease, reflux esophagitis nausea, and vomiting. These could be the initial symptoms of herniation of abdominal viscera, but that were missed and the patient was treated as an acid peptic disease, later on she developed severe cardiorespiratory insufficiency. Herniated viscera in the thorax may produce mass effect and can lead to cardiovascular impairment by compression of heart and mediastinal shift which can kink vena cavae, pulmonary veins, impair venous return to heart and cause cardiac output to decrease.[8]

There is paucity of case reports about anesthetic management of late onset Morgagni hernia in anesthesia literature; we could find only two case reports of Morgagni hernia in elderly patient of more than 70 years that were too in surgical literature. Anesthetic management of a patient Morgagni hernia remains challenging for anesthesiologists, although principles remain same as for the late onset traumatic diaphragmatic hernia. Patient with CDH should be considered as full stomach because of possible gastrointestinal obstruction, and, therefore, these patients required aspiration prophylaxis. Nasogastric tube should be inserted and aspirated before induction. Large gauge intravenous access is necessary to manage any hemodynamic instability. Invasive blood pressure and CVP monitoring should be the standard practice considering combined mass effect of herniated viscera, and inflated lung may lead to cardiorespiratory impairment.

Whenever possible or when the difficult airway is anticipated, awake fiberoptic intubation is the gold standard otherwise rapid sequence induction with cricoid pressure must be considered. We intended awake fiberoptic intubation in our patient, but we could not negotiate the available bronchoscope through 32-Fr double lumen tube (DLT) and opted for rapid sequence induction with cricoid pressure. Surgical approach either laparotomy or thoracotomy collapsed lung should not be inflated to avoid the combined mass effect of herniated viscera and inflated lung, in this way, DLT is helpful. Anesthetic agents which are cardiac depressant should not be used; in our case we used low dose thiopentone and fentanyl.

Any event which increases intraabdominal pressure especially during induction, intubation, and extubation is detrimental. Positive pressure ventilation with potential gastric insufflation and expansion of compressed lung may decrease venous return and cardiac output. For the same reason Loehning et al.[9] recommend low tidal volume and low airway pressure strategy. Nitrous oxide may also worsen mass effect should, therefore, be avoided.

Early diagnosis and management of symptomatic CDH is advisable otherwise patients having CDH may present as acute bowel obstruction or cardiorespiratory distress and taken for emergency surgery. Some authors have described the safe use of single lumen endotracheal tube instead DLT during emergency situations, provided lung protective strategy should be used, although this should not be the standard practice.[58]

Laparoscopic repair of CDH hernia has also been described and is considered to be safe and effective procedure, but it provide different challenges for anesthesiologists as there are more chances of pneumothorax and very high airway pressures during procedure. Basic principles of anesthetic management remain the same, and to avoid pneumothorax, intraabdominal pressure should be kept low, and one must avoid nitrous oxide. If there is a decrease in SpO2 during the procedure, ask for lowering the intraabdominal pressure or stop surgery and ventilate the lung with 100% oxygen and PEEP.[10] Postprocedure chest radiograph should be advised to look for pneumothorax.

CONCLUSION

Anesthetic management of CDH repair in adult patients is challenging for anesthesiologists and requires special care. Aspiration prophylaxis, awake fiberoptic intubation or rapid sequence induction, lung isolation technique, meticulous monitoring, adequate plane of anesthesia and avoidance of nitrous oxide is the key of successful anesthetic management.