Anaesthesia, 1992, Volume 47, pages 855-856 CASE REPORT
Laryngospasm during transtracheal high frequency jet ventilation
P. SCHUMACHER, G. STOTZ, M. SCHNEIDER
AND
A. URWYLER
Summary A 74-year-old woman developed severe cardiovascular depression during percutaneous transtracheal high frequency j e t ventilation for laser surgery of the epiglottis. This was found to be caused by acute airway obstruction secondary to severe laryngospasm. We recommend profound neuromuscular blockade during percutaneous transtracheal jet ventilation, in order to prevent this complication. Key words Anaesthetic techniques; intravenous. Ventilation; high frequency, jet, percutaneous transtracheal ventilation. Complications; laryngospasm, barotrauma, cardiovascular depression.
Patients undergoing percutaneous transtracheal high frequency jet ventilation (HFJV) have an increased risk of barotrauma and circulatory depression when upper airway obstruction occurs. Tumours of the trachea or larynx, surgical debris or blood may predispose to this, but more commonly obstruction is caused by anatomical factors; in the anaesthetised o r sedated patient the tongue [I], the soft palate or the epiglottis [2] may approximate to the posterior pharyngeal wall. We report an unusual case in which severe laryngospasm, occurring during laser surgery for an epiglottic tumour, resulted in airway obstruction during expiration and acute circulatory failure.
Case history A 60 kg, 74-year-old woman was scheduled for laser surgery to a tumour of the epiglottis. Symptoms consisted of 'thick' speech and occasional dyspnoea, especially in the morning. She was otherwise well and had no history of cardiac or pulmonary problems. Routine biochemical and haematological investigations showed no abnormality. Pre-operative sedation was achieved with clorazepate 25 mg orally given 60 min before the induction of anaesthesia. Monitoring consisted of electrocardiograph (ECG), pulse oximetry, capnography and radial arterial pressure recording. Neuromuscular blockade was assessed with a nerve stimulator using the train-of-four (TOF) technique. After pre-oxygenation, anaesthesia was induced with propofol 80 mg and fentanyl 75 pg intravenously. After it was ascertained that inflation of the lungs was possible via
a mask, atracurium 2 5 m g was administered and anaesthesia was maintained with a propofol infusion a t a rate of 500 mg.h-' with fentanyl given as necessary. Four minutes later, a 13-G intratracheal catheter (VBM, Medizintechnik GmbH, Sulz am Neckar, West Germany) [3] was inserted percutaneously through the cricothyroid membrane under direct vision, using a fibreoptic bronchoscope that had been introduced orally and was positioned just below the vocal cords. Percutaneous transtracheal HFJV was initiated using a jet ventilator (Model VS 600, Instrumental Development Corporation, Switzerland) with a driving pressure of 274 kPa at a frequency of 150 per min and an inspiratory :expiratory ratio of 1 :2. Oxygen 100% was delivered and a size 4 oropharyngeal airway was inserted to assist expiration. When laser surgery was started 10 min later, the epiglottis appeared to be grotesquely swollen and the surgeon was unable to visualize the laryngeal inlet through the laryngoscope. Laser surgery proceeded without difficulty for 20 min, at which stage the pulse oximeter suddenly failed to register and the systolic blood pressure decreased rapidly to 20-30 mmHg with a heart rate of 30 beatmin-'. Simultaneously, the movement of the chest wall produced by the HFJV stopped. Ephedrine, given in three separate doses of IOmg, did not improve the blood pressure. Just before this catastrophic event, atracurium 5 mg had been administered because TOF monitoring showed that three out of four twitches were present. O n the assumption that airway obstruction had occurred, the anaesthetist urged the surgeon to re-establish its patency. The surgeon thought
G . Stotz, MD, Resident Anaesthesiologist, P. Schumacher, MD, M. Schneider, MD, A. Urwyler, M D , Staff Anaesthesiologists, Department of Anaesthesia, University of Basel/Kantonsspital, 403 1 Basel, Switzerland. Accepted 23 February 1992.
0003-2409/92/010855 f 0 2 $08.00/0
@ 1992 The Association of Anaesthetists of G t Britain and Ireland
855
856
P . Schumacher et al.
that there was no anatomical reason for complete airway obstruction, but while attempting tracheal intubation, managed to visualize the posterior part of the vocal cords, which were noted to be firmly closed. Suxamethonium 100 mg was injected and 30 s later a sound was heard of a large quantity of gas escaping from the airway, the blood pressure rapidly returned to normal and the pulse oximeter again registered 100% oxygen saturation. Surgery was completed without further complication and postoperatively the patient showed no evidence of barotrauma.
Discussion Percutaneous transtracheal high frequency jet ventilation is an accepted method for artificial ventilation of the lungs during certain ENT procedures, particularly laser surgery of the larynx. Alternative techniques, using a tracheal tube, carry the risk of setting fire to the tube and subsequent damage to the patient’s airway. In addition, optimal surgical conditions often cannot be guaranteed. In our institution, the method of percutaneous transtracheal HFJV through a 13-G catheter is well established and, with the additional precaution of placing the cannula under direct vision using a fibreoptic bronchoscope, no complications such as bleeding, submucosal air insufflation or posterior tracheal wall lesions have occurred. It is possible to maintain satisfactory ventilation by means of transtracheal HFJV even when small-gauge catheters are used because of the high driving pressure [4,51. However, passive exhalation requires more time and is dependent on patency of the airway. Occlusion of the expiratory pathway rapidly leads to hypoventilation, manifested by hypercarbia and hypoxaemia, and may interfere with cardiac output by increasing the intrathoracic pressure, with the risk of producing serious barotrauma to the lungs. Upper airway obstruction is usually associated with anatomical, functional or pathological supraglottic lesions [3] such as epiglottitis, tumours, oedema and trauma. During ENT surgery, obstruction secondary to blood and tumour debris has also been reported [6]. In our experience, in patients with a normal anatomy, the tongue is usually the cause of obstruction, because of displacement towards the posterior pharyngeal wall. Because of this we always place a nasal or oral airway
(Guedel or Wendel tube) until the surgeon is ready to introduce the operating laryngoscope. The airway occlusion seen in this patient was caused by laryngospasm rather than by the grossly swollen epiglottis. Insufficient depth of anaesthesia, visceral pain and mechanical stimulation by blood or secretions may have led to the development of a gas-tight closure of the larynx. The diagnosis was difficult, because laryngospasm is very uncommon under these circumstances, since the glottis is usually visible and may even be spread by the operating laryngoscope.. In addition, neuromuscular blockade was thought to be adequate. It is interesting that laryngospasm under these conditions can so rapidly lead to cardiovascular failure. The laryngospasm which occurs in a spontaneously breathing patient or during mask ventilation may be relieved by positive pressure ventilation, head lift and jaw tilt. In contrast, during transtracheal HFJV, increasing the subglottic pressure is of no benefit and carries the risk of rapid cardiovascular impairment and barotrauma to the lungs. During transtracheal jet ventilation it is essential that the expiratory pathway is unobstructed. In addition, adequate neuromuscular blockade should be provided to avoid the danger of laryngospasm. If attention is paid to these details, the risks of this technique is minimised.
References BARRAT GE, COULTHARD SW. Upper airway obstruction: diagnosis and management options. In: BROWN BR, ed. Anaeslhesia and ENT surgery. Philadelphia: F.A. Davis Company, 1987: 73-96. NANDIPR, CHARLESWORTH CH, TAYLOR SJ, NUNNJF, DORE CJ. Effect of general anaesthesia on the pharynx. British Journal of Anaesthesia I99 1; 66: 157-62. [3] RAVUSSIN P, FREEMAN J. A new transtracheal catheter for ventilation and resuscitation. Canadian Anaes/he/is/s’ Sociely Journal 1985; 32: 6 0 4 . [4] SANDERS RD. Two ventilating attachments for bronchoscopes. Delaware Medical Journal 1967; 3 9 170-5. [5] KLAIN M, SMITH RD. High frequency percutaneous transtracheal jet ventilation. Critical Care Medicine 1977; 5: 280-7. [6] CRAFTTM. CHAMBERS PH, WARDME, GOATVA. Two cases of barotrauma associated with transtracheal jet ventilation. British Journal of Anaesthesia 1990; 64:524-7.
Laryngospasm during transtracheal high frequency jet ventilation
P. SCHUMACHER, G. STOTZ, M. SCHNEIDER
AND
A. URWYLER
Summary A 74-year-old woman developed severe cardiovascular depression during percutaneous transtracheal high frequency j e t ventilation for laser surgery of the epiglottis. This was found to be caused by acute airway obstruction secondary to severe laryngospasm. We recommend profound neuromuscular blockade during percutaneous transtracheal jet ventilation, in order to prevent this complication. Key words Anaesthetic techniques; intravenous. Ventilation; high frequency, jet, percutaneous transtracheal ventilation. Complications; laryngospasm, barotrauma, cardiovascular depression.
Patients undergoing percutaneous transtracheal high frequency jet ventilation (HFJV) have an increased risk of barotrauma and circulatory depression when upper airway obstruction occurs. Tumours of the trachea or larynx, surgical debris or blood may predispose to this, but more commonly obstruction is caused by anatomical factors; in the anaesthetised o r sedated patient the tongue [I], the soft palate or the epiglottis [2] may approximate to the posterior pharyngeal wall. We report an unusual case in which severe laryngospasm, occurring during laser surgery for an epiglottic tumour, resulted in airway obstruction during expiration and acute circulatory failure.
Case history A 60 kg, 74-year-old woman was scheduled for laser surgery to a tumour of the epiglottis. Symptoms consisted of 'thick' speech and occasional dyspnoea, especially in the morning. She was otherwise well and had no history of cardiac or pulmonary problems. Routine biochemical and haematological investigations showed no abnormality. Pre-operative sedation was achieved with clorazepate 25 mg orally given 60 min before the induction of anaesthesia. Monitoring consisted of electrocardiograph (ECG), pulse oximetry, capnography and radial arterial pressure recording. Neuromuscular blockade was assessed with a nerve stimulator using the train-of-four (TOF) technique. After pre-oxygenation, anaesthesia was induced with propofol 80 mg and fentanyl 75 pg intravenously. After it was ascertained that inflation of the lungs was possible via
a mask, atracurium 2 5 m g was administered and anaesthesia was maintained with a propofol infusion a t a rate of 500 mg.h-' with fentanyl given as necessary. Four minutes later, a 13-G intratracheal catheter (VBM, Medizintechnik GmbH, Sulz am Neckar, West Germany) [3] was inserted percutaneously through the cricothyroid membrane under direct vision, using a fibreoptic bronchoscope that had been introduced orally and was positioned just below the vocal cords. Percutaneous transtracheal HFJV was initiated using a jet ventilator (Model VS 600, Instrumental Development Corporation, Switzerland) with a driving pressure of 274 kPa at a frequency of 150 per min and an inspiratory :expiratory ratio of 1 :2. Oxygen 100% was delivered and a size 4 oropharyngeal airway was inserted to assist expiration. When laser surgery was started 10 min later, the epiglottis appeared to be grotesquely swollen and the surgeon was unable to visualize the laryngeal inlet through the laryngoscope. Laser surgery proceeded without difficulty for 20 min, at which stage the pulse oximeter suddenly failed to register and the systolic blood pressure decreased rapidly to 20-30 mmHg with a heart rate of 30 beatmin-'. Simultaneously, the movement of the chest wall produced by the HFJV stopped. Ephedrine, given in three separate doses of IOmg, did not improve the blood pressure. Just before this catastrophic event, atracurium 5 mg had been administered because TOF monitoring showed that three out of four twitches were present. O n the assumption that airway obstruction had occurred, the anaesthetist urged the surgeon to re-establish its patency. The surgeon thought
G . Stotz, MD, Resident Anaesthesiologist, P. Schumacher, MD, M. Schneider, MD, A. Urwyler, M D , Staff Anaesthesiologists, Department of Anaesthesia, University of Basel/Kantonsspital, 403 1 Basel, Switzerland. Accepted 23 February 1992.
0003-2409/92/010855 f 0 2 $08.00/0
@ 1992 The Association of Anaesthetists of G t Britain and Ireland
855
856
P . Schumacher et al.
that there was no anatomical reason for complete airway obstruction, but while attempting tracheal intubation, managed to visualize the posterior part of the vocal cords, which were noted to be firmly closed. Suxamethonium 100 mg was injected and 30 s later a sound was heard of a large quantity of gas escaping from the airway, the blood pressure rapidly returned to normal and the pulse oximeter again registered 100% oxygen saturation. Surgery was completed without further complication and postoperatively the patient showed no evidence of barotrauma.
Discussion Percutaneous transtracheal high frequency jet ventilation is an accepted method for artificial ventilation of the lungs during certain ENT procedures, particularly laser surgery of the larynx. Alternative techniques, using a tracheal tube, carry the risk of setting fire to the tube and subsequent damage to the patient’s airway. In addition, optimal surgical conditions often cannot be guaranteed. In our institution, the method of percutaneous transtracheal HFJV through a 13-G catheter is well established and, with the additional precaution of placing the cannula under direct vision using a fibreoptic bronchoscope, no complications such as bleeding, submucosal air insufflation or posterior tracheal wall lesions have occurred. It is possible to maintain satisfactory ventilation by means of transtracheal HFJV even when small-gauge catheters are used because of the high driving pressure [4,51. However, passive exhalation requires more time and is dependent on patency of the airway. Occlusion of the expiratory pathway rapidly leads to hypoventilation, manifested by hypercarbia and hypoxaemia, and may interfere with cardiac output by increasing the intrathoracic pressure, with the risk of producing serious barotrauma to the lungs. Upper airway obstruction is usually associated with anatomical, functional or pathological supraglottic lesions [3] such as epiglottitis, tumours, oedema and trauma. During ENT surgery, obstruction secondary to blood and tumour debris has also been reported [6]. In our experience, in patients with a normal anatomy, the tongue is usually the cause of obstruction, because of displacement towards the posterior pharyngeal wall. Because of this we always place a nasal or oral airway
(Guedel or Wendel tube) until the surgeon is ready to introduce the operating laryngoscope. The airway occlusion seen in this patient was caused by laryngospasm rather than by the grossly swollen epiglottis. Insufficient depth of anaesthesia, visceral pain and mechanical stimulation by blood or secretions may have led to the development of a gas-tight closure of the larynx. The diagnosis was difficult, because laryngospasm is very uncommon under these circumstances, since the glottis is usually visible and may even be spread by the operating laryngoscope.. In addition, neuromuscular blockade was thought to be adequate. It is interesting that laryngospasm under these conditions can so rapidly lead to cardiovascular failure. The laryngospasm which occurs in a spontaneously breathing patient or during mask ventilation may be relieved by positive pressure ventilation, head lift and jaw tilt. In contrast, during transtracheal HFJV, increasing the subglottic pressure is of no benefit and carries the risk of rapid cardiovascular impairment and barotrauma to the lungs. During transtracheal jet ventilation it is essential that the expiratory pathway is unobstructed. In addition, adequate neuromuscular blockade should be provided to avoid the danger of laryngospasm. If attention is paid to these details, the risks of this technique is minimised.
References BARRAT GE, COULTHARD SW. Upper airway obstruction: diagnosis and management options. In: BROWN BR, ed. Anaeslhesia and ENT surgery. Philadelphia: F.A. Davis Company, 1987: 73-96. NANDIPR, CHARLESWORTH CH, TAYLOR SJ, NUNNJF, DORE CJ. Effect of general anaesthesia on the pharynx. British Journal of Anaesthesia I99 1; 66: 157-62. [3] RAVUSSIN P, FREEMAN J. A new transtracheal catheter for ventilation and resuscitation. Canadian Anaes/he/is/s’ Sociely Journal 1985; 32: 6 0 4 . [4] SANDERS RD. Two ventilating attachments for bronchoscopes. Delaware Medical Journal 1967; 3 9 170-5. [5] KLAIN M, SMITH RD. High frequency percutaneous transtracheal jet ventilation. Critical Care Medicine 1977; 5: 280-7. [6] CRAFTTM. CHAMBERS PH, WARDME, GOATVA. Two cases of barotrauma associated with transtracheal jet ventilation. British Journal of Anaesthesia 1990; 64:524-7.
