Tests for gastro-oesophageal reflux disease (GERD) and pulmonary aspiration
| Test | Application | Limitation |
| Upper gastrointestinal endoscopy# | May demonstrate reflux oesophagitis; biopsies may be performed | ∼50% sensitivity for diagnosis of GERD [97] |
| 24-hr multi-channel oesophageal pH monitoring | 77–100% sensitivity, 85–100% specificity for GERD [98]; distinguishes distal and proximal reflux events | ∼33% false-negative rate for GERD without oesophagitis [98]; does not detect non-acid reflux |
| 24-hr combined impedance and pH monitoring | ≥90% sensitivity for GERD [99]; evaluates both acid and non-acid reflux | Less availability, time consuming, increased cost |
| Nuclear gastro-oesophageal scintigraphic study with delayed thoracic imaging | Positive result proves both gastric reflux and aspiration | Reduced sensitivity due to intermittency of aspiration episodes; local expertise may be lacking |
| Modified barium swallow | May demonstrate swallowing disorder | Only suggests aspiration, must correlate clinically; does not assess GER |
| Upper airway visualisation¶ | Findings of posterior laryngitis and contact granulomas strongly suggest GERD | Other findings reportedly associated with GERD are nonspecific [100] |
| BAL for lipid-laden macrophages | Most studies in paediatric population; 57–100% sensitivity, 57–89% specificity to diagnose chronic aspiration [101–107] | Requires local expertise; may not correlate with other clinical measures of GERD [108] |
| Lung biopsy | Finding of foreign material proves aspiration-related disease; alternative diagnosis may be found | Bronchoscopic biopsy may miss diagnosis; surgical biopsy may be associated with significant morbidity |
BAL: bronchoalveolar lavage. #: oesophagogastroduodenoscopy; ¶: laryngoscopy/bronchoscopy.