Relation between Glasgow Coma Scale and aspiration pneumonia

Abstract

Decreased level of consciousness is associated with increased risk of gastric aspiration. 1 Huxley EJ Viroslav J Gray WR Pierce AK Pharyngeal aspiration in normal adults and patients with depressed consciousness. Am J Med. 1978; 64: 564-568 Summary Full Text PDF PubMed Scopus (550) Google Scholar The risk of aspiration is, however, unquantified with regard to the degree of impaired consciousness. Accordingly, emergency airway management by endotracheal intubation is practised in accordance with perceived risk of aspiration pneumonia in comatose patients. A few studies have addressed the relation between gag reflex, cough reflex, and the Glasgow Coma Scale (GCS) in patients with pharmacological causes for cerebral depression. 2 Moulton C Pennycook AG Relation between Glasgow coma score and cough reflex. Lancet. 1994; 343: 1261-1262 Summary PubMed Scopus (84) Google Scholar , 3 Moulton C Pennycook AG Makower R Relation between Glasgow coma scale and the gag reflex. BMJ. 1991; 303: 1240-1241 Crossref PubMed Scopus (45) Google Scholar Both of these reflexes provide protective mechanisms against aspiration of gastric contents. These authors demonstrated that the correlation between the GCS and the presence of protective reflexes is poor. The cough reflex was still present (normal or attenuated) in seven of 12 patients at the lowest level of GCS (GCS 3). In contrast, the gag reflex may be impaired even at high GCS values. 2 Moulton C Pennycook AG Relation between Glasgow coma score and cough reflex. Lancet. 1994; 343: 1261-1262 Summary PubMed Scopus (84) Google Scholar , 3 Moulton C Pennycook AG Makower R Relation between Glasgow coma scale and the gag reflex. BMJ. 1991; 303: 1240-1241 Crossref PubMed Scopus (45) Google Scholar A GCS of 8 or less is widely accepted to indicate protection of the airway by intubation. 4 Gentleman D Dearden M Midgley S Maclean D Guidelines for resuscitation and transfer of patients with serious head injury. BMJ. 1993; 307: 547-552 Crossref PubMed Scopus (84) Google Scholar We undertook a prospective study designed to assess the relation between degree of impaired consciousness, as defined by GCS at the time of patient discovery by prehospital care personnel, and frequency of suspected aspiration pneumonia on admission to the intensive care unit. Aspiration pneumonia was defined by analysis of the chest radiographs taken within the first 24 h.