1/10 Just sharing an interesting #respiratory case.

A 78yrs lady with #COPD, #cardiacfailure & elevated BMI was treated for cardiac failure, hypercapnoeic acidotic respiratory failure with #NIV(BiPAP) & diuretics.

2/10 Pt improved & weaned off NIV by day 4, and maintained on 1L/min O2 to achieve saturation of 88-92%. On day 5, deteriorated with worsening SOB and hypoxaemia but non drowsy.

The latest CXR now is shown here:

3/10 O/E: O2 saturation 90% on 28% VM. There was no contralateral tracheal deviation or hyper-resonant percussion over the chest, but there was decreased breathing sounds/air entry in the left upper zone anteriorly.
Arterial ABG (28%) pH 7.35, pCO2 8.1, pO2 7.6, BE 5.1, HCO3 31

4/10 Pt was at risk of further deterioration with decompensated type 2 respiratory failure and may need further NIV. Our concern was whether she had developed a pneumothorax even with a ‘normal’ looking chest x ray.

5/10 A CT thorax was performed which confirmed our suspicion. A left sided pneumothorax was identified. See CT images below:

6/10 An intercostal #chestdrain was inserted (frontal & in 2nd ICS) given the apical & anterior nature of the #pneumothorax. We believed this was required given the risk she may need further NIV support. See image below:

7/10 Patient improved in her #oxygenation levels & luckily did not require further #ventilatory support. She responded to conservative medical management.

8/10 Learning points:

A CXR only captures an image in 2D. The radiographic findings of a pneumothorax may be subtle or atypical. A #pneumothorax may not be visible if you still have an expanded lung present in the field of where the CXR imaging was taken. See image below:

9/10 Some of the benefit of #NIV?
Increase FiO2
Reduction in inspiratory muscle work & avoidance of respiratory muscle fatigue
Augments tidal volume
Reduce CO2 production
Improves compliance by reversing micro-atelectasis
Enhanced cardiovascular function (reduce afterload)

10/10 It was unclear if NIV was the cause but could have contributed. NIV initiated in the presence of #pneumothorax will lead to #tensionpneumothorax & increases the risk of mortality.
Prompt recognition & treatment of pneumothorax is important to minimise mortality.

Note: In hindsight, when we looked at her #CXR at deterioration again, maybe you could make out the slight increase in translucency on the left upper region to suggest a #pneumothorax. #RespisBest #RespEd