title: Racemic ketamine in adult head injury patients: use in endotracheal suctioning.
abstract: BACKGROUND
  Endotracheal suctioning (ETS) is essential for patient care in an ICU but may represent a cause of cerebral secondary injury. Ketamine has been historically contraindicated for its use in head injury patients, since an increase of intracranial pressure (ICP) was reported; nevertheless, its use was recently suggested in neurosurgical patients. In this prospective observational study we investigated the effect of ETS on ICP, cerebral perfusion pressure (CPP), jugular oxygen saturation (SjO2) and cerebral blood flow velocity (mVMCA) before and after the administration of ketamine.
  
  
  METHODS
  In the control phase, ETS was performed on patients sedated with propofol and remifentanil in continuous infusion. If a cough was present, patients were assigned to the intervention phase, and 100 γ/kg/min of racemic ketamine for 10 minutes was added before ETS.
  
  
  RESULTS
  In the control group ETS stimulated the cough reflex, with a median cough score of 2 (interquartile range (IQR) 1 to 2). Furthermore, it caused an increase in mean arterial pressure (MAP) (from 89.0 ± 11.6 to 96.4 ± 13.1 mmHg; P <0.001), ICP (from 11.0 ± 6.7 to 18.5 ± 8.9 mmHg; P <0.001), SjO2 (from 82.3 ± 7.5 to 89.1 ± 5.4; P = 0.01) and mVMCA (from 76.8 ± 20.4 to 90.2 ± 30.2 cm/sec; P = 0.04). CPP did not vary with ETS. In the intervention group, no significant variation of MAP, CPP, mVMCA, and SjO2 were observed in any step; after ETS, ICP increased if compared with baseline (15.1 ± 9.4 vs. 11.0 ± 6.4 mmHg; P <0.05). Cough score was significantly reduced in comparison with controls (P <0.0001).
  
  
  CONCLUSIONS
  Ketamine did not induce any significant variation in cerebral and systemic parameters. After ETS, it maintained cerebral hemodynamics without changes in CPP, mVMCA and SjO2, and prevented cough reflex. Nevertheless, ketamine was not completely effective when used to control ICP increase after administration of 100 γ/kg/min for 10 minutes.
authors.forename: Anselmo
authors.initials: A
authors.lastname: Caricato
authors.forename: Alessandra
authors.initials: A
authors.lastname: Tersali
authors.forename: Sara
authors.initials: S
authors.lastname: Pitoni
authors.forename: Chiara
authors.initials: C
authors.lastname: De Waure
authors.forename: Claudio
authors.initials: C
authors.lastname: Sandroni
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Bocci
authors.forename: Maria Giuseppina
authors.initials: MG
authors.lastname: Annetta
authors.forename: Mariano Alberto
authors.initials: MA
authors.lastname: Pennisi
authors.forename: Massimo
authors.initials: M
authors.lastname: Antonelli
mesh_terms: D000328:Adult; D000778:Anesthetics, Dissociative / Q000009:adverse effects / Q000627:therapeutic use; D006259:Craniocerebral Trauma / Q000150:complications / Q000628:therapy*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000627:therapeutic use; D007260:Infusion Pumps; D007427:Intracranial Pressure / Q000187:drug effects*; D007558:Italy; D007649:Ketamine / Q000009:adverse effects / Q000627:therapeutic use*; D010880:Piperidines / Q000008:administration & dosage / Q000627:therapeutic use; D015742:Propofol / Q000008:administration & dosage / Q000627:therapeutic use; D000077208:Remifentanil; D013396:Suction / Q000009:adverse effects / Q000379:methods*; D014132:Trachea / Q000187:drug effects*
chemical_list: D000778:Anesthetics, Dissociative; D006993:Hypnotics and Sedatives; D010880:Piperidines; D007649:Ketamine; D000077208:Remifentanil; D015742:Propofol