ARTICLE FILE
TITLE:
Devil in disguise – A rare presentation of traumatic diaphragmatic hernia.
Abstract:
A 53 year old female sustained blunt injury chest and abdomen with other associated injuries was operated for right humerus fracture. Two days later she developed respiratory distress, following which chest x-ray and CT chest surprisingly showed signs of diaphragmatic hernia, which was not evident in initial imaging modalities. She was taken for surgical repair of traumatic diaphragmatic hernia.Surgery and postoperative period were uneventful. Timely recognition and intervention led to her uneventful recovery.
KEYWORDS:
Blunt trauma
Diaphragmatic hernia
Delayed presentation
Introduction:
Diaphragmatic injury represents <1% of all traumatic injuries (1,2). Diaphragmatic injury is an uncommon but significant diagnosis in trauma patients. Blunt injuries are more likely to be occult; however, a pattern of associated injuries to the aorta, lung, spleen and bladder should prompt further workup for traumatic diaphragmatic injury (3). Suspicion of a diaphragmatic injury should begin with the identification of mechanism of injury, meticulous physical examination and assessment of associated injuries. Most common cause of traumatic diaphragmatic injury is penetrating injury (67%) followed by blunt trauma (33%)(3). Left sided diaphragmatic injury is two to three times more common with blunt trauma (4-6).
CASE REPORT:
A 53year old female, victim of road traffic accident, came with right sided proximal humerus fracture, right sided second, third and sixth rib fractures with mild pleural collection probably hemothorax. No other obvious external injury, neurological status normal, no spine tenderness, no evidence of abdominal injury which was confirmed by a normal abdominal sonography, she had anaemia with haemoglobin of 8.2g/dl, probably a loss from humerus fracture and haemothorax. She was on 2L/min of oxygen via nasal prongs. She was planned for humerus fixation next day after optimising haemoglobin with one unit of packed red blood cells. Humerus fixation was carried out under ultrasound guided right sided brachial plexus block at interscalene level, the very next day. The local anaesthetic drug used were 10ml of 2%lignocaine with adrenaline and 10ml of 0.5% bupivacaine with 25micrograms of fentanyl. Postoperatively, she was transferred to intensive care unit (ICU) for overnight observation. As her oxygen requirement increased from 2L/min to 5L/min via nasal cannula, hemidiaphragmatic palsy and atelectasis secondary to interscalene block was suspected and she was kept on overnight non invasive ventilation. A repeat chest X-ray showed minimally elevated hemidiaphragm on opposite side (left side) and there was a dilemma in differentiating atelectasis and interlobar effusion. On first postoperative day, she clinically improved, weaned off oxygen and non invasive ventilation. Her bowel habits were normal and she was mobilised. As she was asymptomatic, she was shifted to ward on that day.
She was absolutely fine till third postoperative day, after which she developed respiratory distress. She was shifted back to ICU, chest X-ray repeated (Figure 1), which showed bowel shadows in chest. Pulmonogist opinion was sought, who strongly suspected diaphragmatic hernia and advised high resolution computed tomography of chest which finally confirmed it with following findings. Defect in anterior portion of left hemidiaphragm; distal portion of stomach, distal transverse colon, splenic flexure and proximal portion of descending colon seen herniating through the defect into left hemithorax. Evidence of gastric volvulus present, bilateral pleural effusion (left > right); atelectasis involving basal segments of right lower lobe, lingual segments of left upper lobe and left lower lobe and ill defined areas of heterogenous enhancement noted in segment seven of the liver – likely liver laceration with adjacent perihepatic fluid / hematoma.
Immediate surgical intervention was planned as signs of gastric volvulus was present. After explaining risks and benefits of surgical repair and obtaining a high risk consent, she was taken up for surgery under thoracic epidural and general anaesthesia, after placing central venous line and arterial line for better blood pressure monitoring. She was monitored with electrocardiogram, non invasive blood pressure, invasive blood pressure, pulse oximetry, end tidal carbon dioxide and Urine output. Intraoperatively, 8x7cms defect in muscular part of left hemidiaphragm was made out (Figure 2). Abdominal contents that herniated into chest were stomach, transverse colon and splenic flexure, which were healthy and viable. So, herniated contents were reduced and diaphragm was repaired primarily and wound was closed with pericardial, left intercostal and abdominal drains .
We decided to ventilate the patient electively in ICU to avoid atelectasis, which is a most frequent complication(7). Epidural analgesia and intravenous fentanyl were used for post operative pain relief. Postoperative period was uneventful and she was extubated on second postoperative day. Pericardial, abdominal, intercostal drains were removed on third, fourth and fifth postoperative day respectively. She developed pneumonia and atrial fibrillation, which were treated appropriately. She was shifted to ward on sixth postoperative day and discharged on tenth postoperative day.
DISCUSSION:
Traumatic diaphragmatic hernia is usually identified in chest xray. Sometimes the injury may be subtle where imaging may be non diagnostic. In such cases, a high index of suspicion needs to be maintained as a delay in diagnosis may lead to life threatening complications like herniation and strangulation of abdominal organs. In cases with delayed presentation, the patient may not have symptoms or signs initially. Over time, the diaphragmatic defect tends to enlarge and herniation of abdominal organs becomes more likely, especially on left side. Small right sided diaphragmatic defects are mostly stable as liver provides a tamponading effect.
During normal quiet breathing, the intraperitoneal pressure ranges from +2 to +10cm H2O and the intrapleural pressure ranges from -5 to -10cm H2O with the normal pleuroperitoneal gradient ranging from +7 to +20cm H2O. During maximal inspiration, the pleuroperitoneal gradient may increase upto +100cm H2O. In blunt injury abdomen, when this pleuroperitoneal gradient exceeds +150 to +200cm H2O, the muscular part or tendinous tissue of diaphragm can rupture or avulse from its attachment.
Diaphragmatic injury severity scale:
American association for surgery of trauma – Organ injury scale:
Grade 1 – diaphramatic contusion
Grade 2 – diaphragmatic laceration <2cm
Grade 3 – diaphragmatic laceration 2-10cm
Grade 4 – laceration > 10cm with tissue loss <25cm2
Grade 5 – laceration > 10cm with tissue loss >25cm2
The overall mortality associated with diaphragmatic injury is 25%, primarily not only due to the presence of life-threatening chest or abdominal injury, but can also result from complications of the injury itself which may include gastrointestinal herniation, pulmonary sequelae due to altered respiratory mechanics, diaphragm paralysis, and pleural fistula. Among these, gastrointestinal herniation contributes to mortality the most, due to bowel ischemia and infarction.
In our case, it’s a delayed presentation of traumatic diaphragmatic hernia without any complicating bowel disease for which timely intervention was done and patient recovered well. The reasons for delayed presentation may be
initially the small diaphragmatic defect might have enlarged with time, no clue to suspect blunt injury abdomen of such a severity, the interscalene block for humerus fixation might have caused right diaphragm palsy, when patient tries to compensate with more negative intrapleural pressure causing bowel contents to get into chest, still the reason for uneventful intraoperative period might be the upright (beach chair) position kept for humerus fixation, the reason for the respiratory distress occured postoperatively could be due to supine position, which makes the bowel slide into chest, with non invasive ventilation, the positive pressure in lungs (chest), pushes the bowel back into abdomen and the patient symptomatically improved & again in ward the distress might be due to increase in size of defect associated with supine position, the bowel would have slided more. Ultimately, we were able to diagnose it and surgically correct it successfully at right time without any complications.
Conclusion:
To avoid delayed diagnosis of traumatic diaphragmatic hernia, one should understand the nature of injury, should have high index of suspicion for it and get it imaged at the earliest when the patient shows signs of respiratory distress. Once diagnosed, plan the surgical management accordingly, so as to avoid complications.