Cricothyrotomy in the emergency department revisited

Percutaneous transcricoid jet ventilation compared with surgical cricothyroidotomy in a sheep airway salvage model

BACKGROUND

We developed a large animal model of the "cannot intubate/cannot ventilate" (CNI/V) scenario to compare percutaneous transcricoid manual jet ventilation (MJV) with surgical cricothyroidotomy (SC).

METHODS

Twelve sheep weighing 40-80 kg were assigned to MJV or SC groups. After sedation, intubation, and line placement, CNI/V was simulated by removing the tracheal tube and inducing paralysis with vecuronium. When SaO2 reached 80% (t=0), MJV catheter insertion or SC was initiated. Upon successful airway placement, ventilation began using 100% oxygen at 20 breaths/min. MJV was administered at 50 psi. HR, BP, SaO2, pH, PCO2, and PO2 were recorded at t=0, 30, 60, 90, 120, 150, 180, 300, 600, and 1200 s. Data were reported as mean+/-S.E.M. over the whole observation period. Baseline values were compared using Student's t-tests. Repeated-values ANOVA was used for post-procedure group comparisons. Statistical tests were two-tailed and alpha was set at 0.05.

RESULTS

Body weights were not significantly (P=0.08) different between MJV (65+/-6 kg) and SC (52+/-3 kg) groups. Baseline respiratory and hemodynamic variables were also not significantly different. Median procedure time for MJV (20 s) and SC (24 s) was not significantly (P=0.69) different. Post-procedure values were not significantly different for SaO2 (P=0.65), pH (P=0.70), PCO2 (P=0.47), PO2 (P=0.84), MAP (P=0.09), or HR (P=0.16) over the entire 20 min resuscitation period.

CONCLUSION

Using a realistic model of CNI/V we found no difference in respiratory or hemodynamic variables between MJV and SC. Adequate ventilation and perfusion was maintained solely by MJV for up to 20 min.

Difficult Airway Society guidelines for management of the unanticipated difficult intubation

Problems with tracheal intubation are infrequent but are the most common cause of anaesthetic death or brain damage. The clinical situation is not always managed well. The Difficult Airway Society (DAS) has developed guidelines for management of the unanticipated difficult tracheal intubation in the non-obstetric adult patient without upper airway obstruction. These guidelines have been developed by consensus and are based on evidence and experience. We have produced flow-charts for three scenarios: routine induction; rapid sequence induction; and failed intubation, increasing hypoxaemia and difficult ventilation in the paralysed, anaesthetised patient. The flow-charts are simple, clear and definitive. They can be fully implemented only when the necessary equipment and training are available. The guidelines received overwhelming support from the membership of the DAS.

DISCLAIMER

It is not intended that these guidelines should constitute a minimum standard of practice, nor are they to be regarded as a substitute for good clinical judgement.

Effect of surgical cricothyrotomy on the unstable cervical spine in a cadaver model of intubation

Cricothyrotomy is indicated for patients who require an immediate airway and in whom orotracheal or nasotracheal intubation is unsuccessful or contraindicated. Cricothyrotomy is considered safe with cervical spine (c-spine) injury; however, the amount of c-spine movement that occurs during the procedure has not been determined. In this experimental study, an established cadaver model of c-spine injury was used to quantify movement during cricothyrotomy. A complete C5--6 transection was performed by using an osteotome on 13 fresh-frozen cadavers. Standard open cricothyrotomy was performed on each cadaver, with c-spine images recorded in real time on fluoroscopy, then transferred to video and Kodachrome still images. Outcome measures included movement across the C5--6 site with regard to angulation expressed in degrees of rotation and linear measures of axial distraction and anterior-posterior (AP) displacement expressed as a proportion of C5 body width. Data were analyzed by using descriptive statistics to determine mean change from baseline in each of three planes of movement. Significance was assumed if 95% confidence intervals did not include zero. A significant amount of movement was observed with regard to AP displacement (6.3% of C5 width) and axial distraction (-4.5% of C5 width, indicating narrowing of the intervertebral space). These correspond to 1--2 mm AP displacement and less than 1 mm axial compression. No significant angular displacement was observed. In conclusion, cricothyrotomy results in a small but significant amount of movement across an unstable c-spine injury in a cadaver model. This degree of movement is less than the threshold for clinical significance.

Tension pneumothorax and contralateral presumed pneumothorax from endobronchial intubation via cricothyroidotomy

Cricothyroidotomy can be a life-saving procedure for the "can't intubate, can't ventilate" patient who has upper-airway obstruction. The procedure is usually fast and easy to do; however, complications have been reported. We report two cases in which cricothyroidotomy with an endotracheal tube led to unrecognized endobronchial intubation, ipsilateral tension pneumothorax, contralateral presumed pneumothorax, and unnecessary emergency surgery. Additionally, these led to the triad of hypotension, hypoxemia, and, probably, elevated intracranial pressure, which can worsen cerebral injury. We discuss methods to avoid these complications.

Safety and efficacy of the Rapid Four-Step Technique for cricothyrotomy using a Bair Claw

The Rapid Four-Step Technique (RFST) has been demonstrated to be faster than standard open crico thyrotomy technique, but may have a higher incidence of cricoid injury with tracheal hook traction applied caudad. The "Bair Claw" is a novel device that may help eliminate these complications. This randomized, experimental trial used a fresh-frozen cadaver model of cricothyrotomy to compare speed and safety between RFST using a Bair Claw and standard open technique. Outcome measures included time to definitive airway, size of largest endotracheal (ET) tube able to be passed, and incidence of complications. We observed that RFST using a Bair Claw was significantly faster than standard open technique. There was no significant difference with regard to size of ET tube able to be passed with RFST using a Bair Claw versus standard open technique, and there was no damage to trachea or larynx observed with either technique. We concluded that RFST using a Bair Claw is faster and appears to be equally safe when compared to standard open technique in a fresh-frozen cadaver model of cricothyrotomy. The two techniques were equal with regard to maximal ET tube size.

Use of the intubating laryngeal mask airway by medical and nonmedical personnel

The intubating laryngeal mask airway (ILMA) is a newly available device designed to allow for blind endotracheal intubation and treatment of patients with difficult airways. We studied the intubation success rates and speed with initial use of this device on an intubation manikin to determine whether this device might be easily used by trained and untrained personnel. Rapid and successful intubation with a device requiring limited or no training could have widespread implications for both health care providers and laypersons. The study consisted of 2 parts. In part 1, health care providers with intubation experience, health care providers without prior intubation experience, and nonmedical personnel were instructed to enter a room and intubate a manikin using the ILMA. A single page set of schematic directions was provided within the ILMA setup. The main outcomes were the intubation success rate and the time required for successful ventilation and intubation. In part 2, participants were retested after a standardized <60 second device demonstration. The 111 participants in the study included 44 emergency physicians (40%), 21 anesthesiologists (19%), and 46 other medical or nonmedical personnel (41%). On first attempted use of the device, and with no prior training, 59% of all participants successfully intubated the manikin. Attending and resident physicians had an 83% initial success rate. The median time to ventilation was 47 seconds, and the median time from ventilation until intubation was 29 seconds. Following the <60 second demonstration, 108 of 111 (97%) participants achieved success, with the median time to ventilation 18 seconds, and the median time from ventilation until intubation 17 seconds. All attending and resident physicians succeeded in intubation following the demonstration. Success rates on first attempt correlated with level of training, prior intubation experience, and prior LMA use (all P < .001). After a <60 second demonstration, medical and nonmedical personnel with and without prior intubation training can successfully use the ILMA to rapidly establish an airway in a manikin model. The ILMA should be further studied to determine if it may permit endotracheal intubation by first responders, paramedical personnel, and other medical staff with limited or no laryngoscopy skills.

Comparison of wire-guided cricothyrotomy versus standard surgical cricothyrotomy technique

We compared a wire-guided cricothyrotomy technique vs. standard surgical cricothyrotomy in terms of accuracy in placement, complications, performance time, incision length, and user preference. We conducted a randomized, crossover controlled trial in which Emergency Medicine (EM) attendings and residents performed cricothyrotomies by both standard and wire-guided techniques (using a commercially available kit) on human cadavers after a 15-min training session. Procedure time, incision length, and physician preference were recorded. Cadavers were inspected for accuracy of placement and complications. Airway placement was accurate in 13 of 15 cases for the standard technique (86.7%), and 14 of 15 cases for the wire-guided technique (93.3%). When comparing wire-guided vs. standard techniques, there were no differences in complication rates or performance times. The wire-guided technique resulted in a significantly smaller mean incision length than the standard technique (0.53 vs. 2.53 cm, respectively, p<0.0001). Overall, 14 of 15 physicians stated that they preferred the wire-guided to the standard technique. Our data suggest that this wire-guided cricothyrotomy technique is as accurate and timely to use as the standard technique and is preferred by our physician operators. In addition, the technique results in a smaller incision on human cadaver models.

Outcomes of emergency surgical airway procedures in a hospital-wide setting

OBJECTIVE

To review the circumstances, complications, and outcomes of emergency surgical airway procedures and to compare the relative merits of cricothyroidotomy and tracheotomy for airway control in a hospital-wide patient population.

STUDY DESIGN

Retrospective review.

METHODS

Patient data were obtained from the inpatient charts and electronic patient records of 35 patients who required an emergency surgical airway over a 6-year period at an urban medical center.

RESULTS

Emergency cricothyroidotomy and tracheotomy were successfully performed in 34 of 35 patients (97%). Orotracheal intubation was successfully achieved in one patient with a failed cricothyroidotomy. The overall complication rates for emergency cricothyroidotomy and tracheotomy were similar (20% and 21%, respectively). Inpatients requiring an emergency surgical airway had a higher complication rate (32% vs. 0%) but better overall survival (91% vs. 46%) than patients treated in the emergency department. No long-term complications were observed from emergency cricothyroidotomies that were not converted to tracheotomies.

CONCLUSION

The establishment of an emergency surgical airway by either tracheotomy or cricothyroidotomy is effective with low overall morbidity. The need to convert every emergency cricothyroidotomy to a tracheotomy should be reevaluated.

Use of the Trousseau dilator in cricothyrotomy

When performing cricothyrotomy, once the initial incision has been created, the scalpel handle may be inserted into the incision and rotated, or a Trousseau dilator may be used to widen the opening. During endotracheal (ET) tube passage, the Trousseau dilator may be left in place or a tracheal hook may be inserted for tracheal stabilization. This experimental crossover trial of cricothyrotomy in a cadaver model compared: 1) scalpel handle rotation to the use of a Trousseau dilator in widening the initial incision, and 2) the use of a tracheal hook to a Trousseau dilator during ET tube passage. Part 1: Cricothyrotomy incisions were made in 30 formalin-fixed cadavers using a #11 scalpel blade. The opening was initially widened using a Trousseau dilator or a scalpel handle rotated through 360 degrees. Progressively larger ET tubes were passed using a tracheal hook for stabilization at the thyroid cartilage, and the size of the largest ET tube passed without significant resistance was recorded. Each opening was then widened using the other technique and ET tubes again passed as above. The dimensions of the opening after initial dilatation and after final ET tube passage were also recorded. Part 2: A tracheal hook inserted cephalad at the thyroid cartilage or a Trousseau dilator was used to stabilize the trachea during passage of progressively larger ET tubes, and the size of the largest ET tube passed without significant resistance was recorded. The insertion techniques were then reversed and ET tubes again passed as above. The trachea was inspected for damage and the balloon cuff checked for rupture after each attempt. Descriptive statistics were applied using a paired t-test and a chi-square analysis. We found no significant difference between the two techniques with regard to initial opening dimensions, final opening dimensions, or maximal ET tube size. There was no damage to local tissue and no balloon cuff ruptures. We found that the average size of the largest ET tube passed was significantly greater with the use of a tracheal hook (internal diameter mean 7.0 mm, median 7.0 mm) than with a Trousseau dilator (internal diameter mean 5.7 mm, median 5.5 mm). There was no damage to local tissue and no cuff ruptures. We conclude that the scalpel handle rotation technique is equal to the use of the Trousseau dilator with regard to opening size and maximal ET tube size but that use of a tracheal hook rather than a Trousseau dilator allows for passage of a larger ET tube in a cadaver model of cricothyrotomy.

Complications of emergency intubation with and without paralysis

Expert and definitive airway management is fundamental to the practice of emergency medicine. In critically ill patients, rapid sedation and paralysis, also known as rapid-sequence intubation, is used to facilitate endotracheal intubation in order to minimize aspiration, airway trauma, and other complications of airway management. An alternative method of emergent endotracheal intubation, intubation minus paralysis, is performed without the use of neuromuscular blocking agents. The present study compared complications of these two techniques in the emergency setting. Sixty-seven intubations minus paralysis were prospectively compared with 166 rapid-sequence intubations. Complications were greater in number and severity in the nonparalyzed group and included aspiration (15%), airway trauma (28%), and death (3%). None of these difficulties were observed in the rapid-sequence group (P < .0001). These results show that rapid-sequence intubation when compared with intubation minus paralysis significantly reduces complications of emergency airway management and should be made available to emergency physicians trained in its use.

Cricothyrotomy technique: standard versus the Rapid Four-Step Technique

Standard cricothyrotomy technique uses a tracheal hook cephalad to the opening to stabilize the trachea during endotracheal (ET) tube passage. A newly described Rapid Four-Step Technique (RFST) uses the tracheal hook caudal to the opening to stabilize the trachea during ET tube passage. This experimental crossover trial compared standard cephalad tracheal hook traction to caudad traction as recommended by RFST in a cadaver model of cricothyrotomy. Outcome measures included the incidence of complications and the size of ET tube able to be passed with each technique. The anterior necks of 30 formalin-fixed cadavers were dissected to completely reveal the cricothyroid membranes and surrounding structures. Two emergency medicine residents performed all cricothyrotomies. Each cadaver was randomly assigned to undergo either standard open technique followed by RFST, or RFST followed by standard open technique. Standard open technique was performed using a #11 scalpel blade, a Trousseau dilator for widening the opening, and a tracheal hook held cephalad through the thyroid cartilage. RFST was performed using a #11 scalpel blade and a tracheal hook held caudad through the cricoid cartilage. Cuffed ET tubes without stylettes were passed in progressively larger sizes until significant resistance was met as determined independently by two physicians. The size of the largest ET tube passed for each technique was recorded. After each attempt the trachea was inspected for evidence of structural damage and the balloon cuff was checked to assess for cuff rupture. There were no complications with standard technique; five cadavers (16.7%) had complications with RFST including one (3.3 %) with balloon cuff rupture and four (13.3 %) with cricoid cartilage fractures. Tracheal damage prevented standard technique performance on three of the cadavers. There was no significant difference between maximal ET tube sizes for standard technique (median size 7.0, mean 6.95 mm internal diameter) versus RFST (median size 7.0, mean 6.82 mm internal diameter). We conclude that RFST may be associated with a higher incidence of complications than standard technique as demonstrated by our cadaver model of cricothyrotomy. We were unable to demonstrate a difference between the two techniques with regards to size of ET tube able to be passed.

Comparison of 2 cricothyrotomy techniques: standard method versus rapid 4-step technique

STUDY OBJECTIVE

To compare the success rate, complication rate and time required for the rapid 4-step technique versus the standard technique for cricothyrotomy.

METHODS

We conducted a prospective, randomized crossover study. Twenty-seven emergency medicine interns, 1 junior medicine resident, and 4 senior medical students, without prior cricothyrotomy experience, were randomly divided into 2 groups. Group 1 was initially instructed in and then performed the standard technique; group 2 was initially instructed in and then performed the rapid 4-step technique. Each group was then instructed in and performed the alternate method. Cricothyrotomies were performed on preserved human cadavers.

RESULTS

A surgical airway was established in 28 of 32 attempts with the use of the rapid 4-step technique (88%); the average time elapsed before tube placement was 43 seconds. Thirty of 32 attempts involving the standard technique (94%) were successful; the average time to tube placement was 134 seconds (95% confidence interval for a difference of 91 seconds, 63 to 119; P < .001). Complications were identified in 12 attempts involving the standard technique (38%; 1 considered major) and in 12 involving the rapid four-step technique (38%; 3 considered major). The incidence of major complications was 6% higher for the rapid 4-step technique (95% confidence interval, -9% to 21%).

CONCLUSION

In a group of inexperienced subjects working on a preserved human cadaver model, the rapid 4-step technique for cricothyrotomy was performed in about one third the time required for performance of the standard technique. This finding was both clinically and statistically significant. Although the 2 techniques had similar success and complication rates, we noted a trend toward more severe complications in the rapid 4-step technique.

Prehospital airway management in the acutely injured patient: the role of surgical cricothyrotomy revisited

BACKGROUND

Ensuring an unobstructed airway and adequate oxygenation are first priorities in the resuscitation of the trauma patient. In situations of difficult endotracheal intubation, rapid sequence protocols frequently include the use of paralytic agents and cricothyrotomy for airway management. Recent literature findings suggest that the prehospital use of cricothyrotomy is too frequent. The purpose of this study was (a) to evaluate the efficacy of a rapid sequence intubation protocol without the use of paralytic agents, and (b) to determine the need for cricothyrotomy by using this protocol in the field.

METHODS

We prospectively analyzed 383 acutely injured patients who were in need of airway control. Success rates, indications, and complications of endotracheal intubation and cricothyrotomy were analyzed.

RESULTS

Successful orotracheal intubation on the scene with the use of this protocol was performed in 373 of 383 patients (97%). Two patients (0.5%) arrived at the trauma center with unrecognized esophageal intubation. Eight patients underwent cricothyrotomy in the field, six without previous attempts at intubation.

CONCLUSION

Experienced emergency medical services personnel can effectively perform endotracheal intubation with narcotic analgesics without the use of paralytic agents in the field. With proper training for field airway management, cricothyrotomy in the field can be reduced to a few indications with high success rates.

Airway management in the emergency department: a one-year study of 610 tracheal intubations

STUDY OBJECTIVE

To describe the methods, success rates, and immediate complications of tracheal intubations performed in the emergency department of an urban teaching hospital.

METHODS

This was an observational, consecutive series undertaken in an urban university hospital with an emergency medicine residency training program and an annual ED census of 60,000 patients. The study population included all patients for whom intubation was attempted in the ED during a 1-year period (July 1, 1995 through June 30, 1996). At the time of each intubation, the intubator filled out an intubation data collection form. If an intubation was performed in the ED but no form was filled out, the data were obtained from the medical record.

RESULTS

A total of 610 patients required airway control in the ED; 569 (93%) were intubated by emergency medicine residents or attending physicians. Rapid-sequence intubation (RSI) was used in 515 (84%). A total of 603 patients (98.9%) were successfully intubated; 7 patients could not be intubated and underwent cricothyrotomy. In 33 patients, inadvertent placement into the esophagus occurred; all such situations were rapidly recognized and corrected. Eight (24%) of the 33 esophageal intubations resulted in a reported immediate complication. Overall, 49 patients (8.0%; 95% confidence interval [CI], 6% to 11%) experienced a total of 57 immediate complications (9.3%; 95% CI, 7% to 12%). Three patients sustained a cardiac arrest after intubation; two of these patients had agonal rhythms before intubation, and one probably had a succinylcholine-induced hyperkalemic cardiac arrest.

CONCLUSION

At this institution, the majority of ED intubations were performed by emergency physicians and RSI was the most common method used. Emergency physicians intubated critically ill and injured ED patients with a very high success rate and a low rate of serious complications.

Declining rate of cricothyrotomy in trauma patients with an emergency medicine residency: implications for skills training

OBJECTIVE

To report the change in cricothyrotomy rate with emergency medicine (EM) residency development and to address the implications for training in this skill.

METHODS

A retrospective chart review was used to determine the cricothyrotomy rate at a 1,000-bed urban Level-1 trauma center with EM, surgery, and anesthesiology residencies. All adult trauma patient visits to the ED between July 1, 1985, and June 30, 1995, were reviewed. The cricothyrotomy rate was defined as the total number of cricothyrotomies per trauma admissions during a study phase.

RESULTS

The study period was divided into 3 phases. Phase 1 (academic years 1985-1989): prior to the inception of the EM residency; phase 2 (academic years 1990-1992): initiation and establishment of the residency; and phase 3 (academic years 1993-1994): full implementation of the EM residency. The cricothyrotoiny rate during phase 1 was 1.8% (95% CI: 1.6 to 2.0), vs 1.1% (95% CI: 0.0 to 2.8) and 0.2% (95% CI: 0.0 to 0.2) during phases 2 and 3, respectively.

CONCLUSIONS

The cricothyrotomy rate decreased with the full implementation of the EM residency. Whether this trend was an effect of the presence of an EM faculty and residency training program, a parallel approach to airway management nationwide, or another unidentified factor will require further investigation. Nonetheless, given the increasing rarity of this procedure, it is likely that many EM, surgical, and anesthesiology residents will not acquire clinical experience with this technique during training.

Efficacy of prehospital surgical cricothyrotomy in trauma patients

OBJECTIVE

The use of surgical cricothyrotomy (SC) in the prehospital setting is controversial, and the need to teach this procedure to paramedics and intermediate emergency medical technicians remains unclear. The purpose of this study is to define the efficacy, complication rate, and overall survival after SC performed in the prehospital setting.

METHODS

In our region, emergency medical technicians receive training in this technique using an animal model with bi-annual updates required. We retrospectively reviewed data in our regional trauma register (15,686 injured patients) for the years 1991-1995.

RESULTS

Prehospital emergency airway intubation was required in 376 patients, 56 of whom received SC. The primary indications for SC were facial fractures and deformities (32%) and blood in the airway (30%). In 79% of the patients requiring SC, attempted orotracheal intubation prior to SC was unsuccessful, with a mean of 1.9 attempts per patient. SC was judged to provide an adequate airway in the field in 89% of attempts. Complications at the scene included six failed attempts, one case of excessive bleeding, and one adverse patient reaction (agitation). When patients arrived at the trauma center, the SC was judged to be acceptable in 64%, whereas 16% were functioning with some question of adequacy and required airway manipulation (most commonly a mainstem bronchial intubation). Overall survival to hospital discharge was 27%; however, survival to emergency department discharge (an indicator of emergency airway adequacy) was 62%. Using TRISS methodology, there were five unexpected survivors and six unexpected deaths. Only three patients were discharged with a "good neurologic recovery."

CONCLUSION

(1) Prehospital SC can be performed effectively with few complications after training on animal models (2) Good neurologic outcome is rare after the use of this procedure. (3) Although it is effective, clear indications must be developed and followed for the prehospital use of SC.

High tracheostomy and other errors--revisited

Timely cricothyrotomy may be life-saving, but it is not without its complications. Together with tracheostomy performed too high, there are high incidences of stenosis and voice changes afterwards-often neglected because the patient has so many other problems. Jackson warned of these problems over 70 years ago-his message is still relevant.

Epiglottitis in adults

Acute epiglottitis has become a disease of adults, probably as a result of immunization of children against Haemophilus influenzae. This article is a review of the literature on epiglottitis, including signs and symptoms, investigation, differential diagnosis, and treatment in the emergency department. The microbiology is discussed and the importance of prophylaxis in exposed persons is stressed.

Surgical cricothyroidotomy in trauma patients: analysis of its use by paramedics in the field

OBJECTIVE

To analyze the indications for and the success rate, complications, and neurologic outcomes of surgical cricothyroidotomy when performed in the field by ambulance paramedics.

METHODS

The ambulance and hospital records of all trauma patients on whom a surgical cricothyroidotomy was attempted in the field by ambulance paramedics over a 5-year period were reviewed. A telephone survey of survivors was used to assess long-term complications and neurologic outcome.

RESULTS

Surgical cricothyroidotomy was attempted on 50 patients, or 9.8% of those requiring definitive airway control. The most common indications were clenched teeth, blood or vomit obscuring visualization of the upper airway, severe maxillofacial injuries, and inaccessibility because the patient was trapped. Airway establishment was successful in 47 patients (94%). Major complications occurred in 2 patients (4%), where inadvertent dislodgement of the tube developed, requiring replacement. No patient developed significant subglottic stenosis. Nineteen patients (38%) survived and no patient died because of an inadequate airway. Evaluation of neurologic outcome revealed 12 patients (63%) with no significant deficits, 3 (16%) with moderate disability, 2 (10%) with severe disability, and only 2 in a persistent vegetative state.

CONCLUSIONS

Surgical cricothyroidotomy can be performed on the critically injured patient in the field by ambulance paramedics with a high success rate and a low complication rate. The use of surgical cricothyroidotomy should be included in airway protocols for well-trained, ambulance Advanced Life Support paramedics.

Subglottic airway hemorrhage associated with idiopathic thrombocytopenic purpura

A case of subglottic airway hemorrhage in a 6-year-old child with acute idiopathic thrombocytopenic purpura is presented. No previous cases have been reported in which idiopathic thrombocytopenic purpura was associated with this life-threatening complication. In this case, stridor responded to racemic epinephrine and oxygen. Emergency physicians and pediatricians should be aware of this rare complication.

Prehospital surgical airway management: 1 year's experience from the Helicopter Emergency Medical Service

Advanced Trauma Life Support requires surgical airway techniques to be used in patients when oral or nasal intubation is impossible or contraindicated. Few reports have examined the results of surgical cricothyroidotomy in prehospital trauma management. During a 12-month period, 600 patients were seen and treated by the Helicopter Emergency Medical Service medical team. Advanced airway techniques were performed at the scene in 143 cases (24 per cent). Of these cases, orotracheal intubation was performed in 132 (92.3 per cent) and surgical cricothyroidotomy in 11 (7.7 per cent). The indications for cricothyroidotomy were: (1) failed intubation in patients with facial injuries, (2) intubation impossible due to patient position during entrapment, and (3) severe burns. Four patients, who were already in cardiopulmonary arrest, succumbed in the field despite cricothyroidotomy. Three patient later died in hospital and four (37 per cent) survived. Three of the survivors made a good recovery, including one who was in cardiorespiratory arrest at the scene, and one remains severely disabled. Surgical cricothyroidotomy is a life-saving procedure in prehospital trauma management that must be performed without delay or hesitation if conventional airway manoeuvres are impossible or fail.

Emergency cricothyrotomy

The indications for the ruling for the Gulf Forces that emergency cricothyrotomy is to be performed where the airway is thought to be compromised are reviewed. The advantages of this procedure are outlined and some of the likely consequences regarding the incidence of complications and their management predicted.

Can nurses perform surgical cricothyrotomy with acceptable success and complication rates?

STUDY OBJECTIVE

This study was undertaken to determine whether flight nurses can perform surgical cricothyrotomies with acceptable success and complication rates.

METHODS

This case series examined the survival, success, and complication rates of surgical cricothyrotomy. A specially trained flight nurse retrospectively reviewed all prehospital, emergency department, inpatient, autopsy, and outpatient follow-up records.

RESULTS

Fifty-five consecutive patients in whom surgical cricothyrotomy was attempted by a flight nurse during a two-and-one-half-year period were studied. Patients ranged in age from 9 to 76 years. The airway was not cannulated successfully by a flight nurse in two patients. In two patients, the tube was not in the cricothyroid space (one in the upper tracheal rings, and the other in the larynx). In three patients, packing was insufficient to stop bleeding from around the operative site; and in three the tube became occluded by blood in the emergency department. Finally, two patients developed subglottic stenosis.

CONCLUSION

Surgical cricothyrotomy in the field can be performed reliably by specially trained nurses. Because only the most critically ill or injured patients with unmanageable airways are subjected to this procedure, a significant complication rate can be anticipated.

Manual translaryngeal jet ventilation and the risk of aspiration in a canine model

STUDY OBJECTIVES

Manual translaryngeal jet ventilation (TLJV) is a safe and effective method of maintaining normal ventilation in apneic subjects. Little data exist on the amount of airway protection afforded with this technique of airway management. We sought to evaluate the risk of aspiration during manual TLJV.

SETTING

Data were collected in a laboratory animal model.

DESIGN

A prospective, nonrandomized, controlled trial was performed.

PARTICIPANTS

Seventeen adult apneic mongrel dogs were enrolled.

INTERVENTIONS

Intratracheal Gastrograffin was instilled and radiographic changes assessed during ventilation using a 0 to 3 scale (none to severe). Thirty-six trials were performed, with equal numbers at both 30 degrees and 45 degrees head elevation. The three groups studied were animals without airway protection (control), animals with a cuffed endotracheal tube (tube), and animals with a percutaneous TLJV cannula and a 50-psi oxygen source ventilated at a rate of 20 breaths per minute (jet).

MEASUREMENTS AND MAIN RESULTS

Significantly less radiographic evidence of aspiration was noted in the jet and tube groups at 30 degrees and 45 degrees compared with control animals (P = .002 each). At 45 degrees head elevation a trend toward increased aspiration scores in the jet group compared with the tube group (P = .065) was observed.

CONCLUSION

In our model, manual TLJV at 20 breaths per minute and an I:E ratio of 1:2 provided protection from aspiration comparable to that observed with a cuffed endotracheal tube at 30 degrees head elevation. At 45 degrees elevation, this protection was diminished.