Airway obstruction with cricoid pressure

Cricoid pressure may cause airway obstruction. We investigated whether this is related to the force applied and to the technique of application. We recorded expired tidal volumes and inflation pressures during ventilation via a facemask and oral airway in 52 female patients who were anaesthetised and about to undergo elective surgery. An inspired tidal volume of 900 ml was delivered using a ventilator. Ventilation was assessed under five different conditions: no cricoid pressure, backwards cricoid pressure applied with a force of 30 N, cricoid pressure applied in an upward and backward direction with a force of 30 N, backwards cricoid pressure with a force of 44 N and through a tracheal tube. An expired tidal volume of < 200 ml was taken to indicate airway obstruction. Airway obstruction did not occur without cricoid pressure, but did occur in one patient (2%) with cricoid pressure at 30 N, in 29 patients (56%) with 30 N applied in an upward and backward direction and in 18 (35%) patients with cricoid pressure at 44 N. Cricoid pressure applied with a force of 44 N can cause airway obstruction but if cricoid pressure is applied with a force of 30 N, airway obstruction occurs less frequently (p = 0.0001) unless the force is applied in an upward and backward direction.

[1]  M. Morgan.  ‘Would they be proud of us?’ , 2000, Anaesthesia.

[2]  T. Clayton,et al.  Gastric pressure during emergency caesarean section under general anaesthesia. , 1999, British journal of anaesthesia.

[3]  R. J. Morais,et al.  Percutaneous tracheostomy , 1999, Anaesthesia.

[4]  T. Meek,et al.  Cricoid pressure: can protective force be sustained? , 1998, British journal of anaesthesia.

[5]  T. M. Bourne,et al.  A survey of how British obstetric anaesthetists test regional anaesthesia before Caesarean section , 1997, Anaesthesia.

[6]  David Machin,et al.  Sample Size Tables for Clinical Studies , 1997 .

[7]  N. Herman,et al.  Cricoid Pressure: Teaching the Recommended Level , 1996, Anesthesia and analgesia.

[8]  C. McBeth,et al.  Cricoid pressure applied after placement of the laryngeal mask prevents gastric insufflation but inhibits ventilation. , 1996, British journal of anaesthesia.

[9]  G. Lyons,et al.  Failed intubation revisited: 17-yr experience in a teaching maternity unit. , 1996, British journal of anaesthesia.

[10]  K. Allman.  The effect of cricoid pressure application on airway patency. , 1995, Journal of clinical anesthesia.

[11]  T. Cook,et al.  A survey of airway management during induction of general anaesthesia in obstetrics: are the recommendations in the confidential enquiries into maternal deaths being implemented? , 1994, International journal of obstetric anesthesia.

[12]  B. Gupta,et al.  An improved technique for antecubital central line placement. , 1994, Anesthesia and analgesia.

[13]  B. J. Pryle,et al.  Regurgitation and Esophageal Rupture with Cricoid Pressure: A Cadaver Study , 1993 .

[14]  Stephen P. Gatt,et al.  A clinical sign to predict difficult tracheal intubation; a prospective study , 1985 .

[15]  R S Cormack,et al.  Difficult tracheal intubation in obstetrics , 1983, Anaesthesia.

[16]  T. Howells,et al.  The determination of an effective cricoid pressure , 1983, Anaesthesia.

[17]  R. Simons,et al.  The application of cricoid pressure , 1983 .

[18]  D. Moir,et al.  Observations on intragastric pressure , 1967, Anaesthesia.

[19]  B. Sellick.  Cricoid pressure to control regurgitation of stomach contents during induction of anaesthesia. , 1961, Lancet.

[20]  J. Brimacombe,et al.  Mechanical airway obstruction after cricoid pressure with the laryngeal mask airway. , 1994, Anesthesia and analgesia.

[21]  D. la Cour.  Prevention of rise in intragastric pressure due to suxamethonium fasciculations by prior dose of d-tubocurarine. , 1970, Acta Anaesthesiologica Scandinavica.