Early detection of post-operative pulmonary complications such as pneumonia using physiotherapy-led lung ultrasound: A case study
Lung ultrasound (LUS) has been shown to have higher diagnostic accuracy (95% sensitivity and 95% specificity) in the detection of pneumonia in patients with respiratory symptoms when compared to chest radiograph (CXR) (49% sensitivity and 92% specificity). Physiotherapists trained in LUS could use this diagnostic technique to monitor patients for pneumonia especially when they begin to show signs of post-operative pulmonary complications (PPC).
Case presentation: A 51 year old male underwent an elective quadruple coronary bypass graph. His history included a permanent pacemaker, diabetes, asthma, cardiomyopathy and he was a current smoker right up to the day before the surgery.
Day 1 post-operatively: His fraction of inspired oxygen (FiO2) requirements increased initially to 0.60 and then to 0.80 via nasal high flow (NHF) with a slightly elevated white cell count (WCC) of 13.3 × 109/L. His CXR showed changes consistent with volume loss so he was treated with intermittent positive pressure breathing (IPPB) and mobility with an aim to improve lung expansion.
Day 2: His FiO2 increased further to 0.90 via NHF and continuous positive airway pressure (CPAP) however no new blood results were available at this time. The CXR was repeated and reviewed by the consultant anaesthetist who deemed it unremarkable with no indication to change the patient's current management plan. The treating physiotherapist (SH) performed a LUS scan shortly after the CXR, due to the higher sensitivity and specificity of LUS with regards to pneumonia, and identified diffuse left sided B-lines and an irregular pleura consistent with a unilateral lower respiratory tract infection (LRTI). This information was fed back to the patient's surgeon who immediately prescribed antibiotics.
Day 3: Repeated use of IPPB and mobility with physiotherapy continued while the patient maintained increased levels of respiratory support via NHF and CPAP. The WCC was 18.8 × 109/L.
Day 4: Oxygen requirements dropped to FiO2 0.70. A repeat CXR showed extensive left sided consolidation consistent with a LRTI that was later confirmed as pneumonia. On subsequent days the patient continued to make progress and was discharged to the ward day 7.
In this case initial chest radiographs were not sensitive enough to assist clinicians in diagnosing a PPC such as pneumonia. Increasing respiratory support was attributed to global lung volume loss. The addition of physiotherapy-led LUS indicated a differential diagnosis by highlighting a unilateral pathological process consistent with pneumonia. The additional information offered by LUS advocated a change in patient management with antibiotics commencing earlier than initially indicated by CXR alone.
Physiotherapists are well placed to monitor patients for post-operative pulmonary complications such as pneumonia. With its higher levels of diagnostic accuracy LUS can further supplement physiotherapy assessment skills by enhancing their ability to differentially diagnose post-operative pulmonary complications sooner.
This work was presented at Physiotherapy UK 2019 and at the ACPRC conference in April as a non-indexed poster.