Mouth-to-mouth ventilation of cardiac arrested humans using a barrier mask

INTRODUCTION: Concern for possible disease transmission during mouth-to-mouth resuscitation has decreased the incidence of bystander cardiopulmonary resuscitation (CPR). Barrier masks have become available that may be effective in CPR as well as protective against cross-contamination. HYPOTHESIS: A silicone rubber barrier mask incorporating a one-way-valved airway (Kiss of Life [KOL]) designed to prevent contamination of the rescuer, permits satisfactory mouth-to-mouth ventilation of victims of cardiopulmonary arrest. METHODS: Ten adult patients who did not survive non-traumatic cardiac arrest were ventilated with exhaled room air using a KOL barrier mask while external cardiac massage continued. Arterial blood gases were obtained every two minutes for a maximum of 10 minutes. The operator was blinded to the results of these blood tests. RESULTS: Eight men and two women with ages from 55 to 99 years were studied. Four patients were edentulous and two of these had marked mandibular atrophy. The two patients with mandibular atrophy were poorly ventilated with the barrier mask. One other patient was not ventilated successfully. This patient had undergone multiple attempts at endotracheal intubation and had transtracheal needle ventilation performed prior to use of the barrier mask. One patient had elevated PaCO2 despite being well-ventilated clinically. Six patients were ventilated well clinically and had satisfactory PaCO2 and PaO2 values. CONCLUSION: The barrier mask studied appears to be an effective aid to ventilation in CPR. Patients without facial support, as in edentulous patients with mandibular atrophy, are not ventilated well with this device.     

Alternative ventilation strategies in cardiopulmonary resuscitation

The introduction of the 2000 Guidelines for Cardiopulmonary Resuscitation emphasizes a new, evidence-based approach to the science of ventilation during cardiopulmonary resuscitation (CPR). New laboratory and clinical science underemphasizes the role of ventilation immediately after a dysrhythmic cardiac arrest (arrest primarily resulting from a cardiovascular event, such as ventricular defibrillation or asystole). However, the classic airway patency, breathing, and circulation (ABC) CPR sequence remains a fundamental factor for the immediate survival and neurologic outcome of patients after asphyxial cardiac arrest (cardiac arrest primarily resulting from respiratory arrest). The hidden danger of ventilation of the unprotected airway during cardiac arrest either by mouth-to-mouth or by mask can be minimized by applying ventilation techniques that decrease stomach gas insufflation. This goal can be achieved by decreasing peak inspiratory flow rate, increasing inspiratory time, and decreasing tidal volume to approximately 5 to 7 mL/kg, if oxygen is available. Laboratory and clinical evidence recently supported the important role of alternative airway devices to mask ventilation and endotracheal intubation in the chain of survival. In particular, the laryngeal mask airway and esophageal Combitube proved to be effective alternatives in providing oxygenation and ventilation to the patient in cardiac arrest in the prehospital arena in North America. Prompt recognition of supraglottic obstruction of the airway is fundamental for the management of patients in cardiac arrest when ventilation and oxygenation cannot be provided by conventional methods. "Minimally invasive" cricothyroidotomy devices are now available for the professional health care provider who is not proficient or comfortable with performing an emergency surgical tracheotomy or cricothyroidotomy. Finally, a recent device that affects the relative influence of positive pressure ventilation on the hemodynamics during cardiac arrest has been introduced, the inspiratory impedance threshold valve, with the goal of maximizing coronary and cerebral perfusion while performing CPR. Although the role of this alternative ventilatory methodology in CPR is rapidly being established, we cannot overemphasize the need for proper training to minimize complications and maximize the efficacy of these new devices.     

Airway management during cardiopulmonary resuscitation--a comparative study of bag-valve-mask, laryngeal mask airway and Combitube in a bench model

Gastric inflation and subsequent regurgitation are a potential risk of ventilation during cardiopulmonary resuscitation (CPR). In respect of recent investigations, principal respiratory components such as respiratory system compliance, resistance and lower esophageal sphincter pressure were adapted according to CPR situations. The purpose of our study was to assess lung ventilation and gastric inflation when performing ventilation with bag-valve-mask, laryngeal mask airway, and combitube in a bench model simulating an unintubated cardiac arrest patient. Twenty-one student nurses, without any experience in basic life support measures, ventilated the bench model with all three devices. Mean ( +/- S.D.) gastric inflation with the laryngeal mask airway (seven cases) was significantly lower than with the bag-valve-mask (0.6 +/- 0.8 vs 3.0 +/- 2.11 min(-1), P < 0.01). There was no gastric inflation when ventilation was performed with the combitube. Only seven of 21 volunteers exceeded 1-min lung volumes of > 5 1 when using the bag-valve-mask, whereas mean (+/-S.D.) 1-min lung volumes with both laryngeal mask airway and combitube were significantly higher (laryngeal mask airway 15.0+/-6.61, combitube 16.6 +/- 6.81 vs bag-valve-mask 4.8 +/- 2.71, P < 0.01). The time for insertion was significantly faster with both bag-valve-mask and laryngeal mask airway compared with the combitube (median: bag valve mask 22 s, laryngeal mask airway 37 s vs combitube 70 s, P < 0.01). This may tip the scales towards using the laryngeal mask airway during basic life support airway management. In conclusion, our data suggests that both laryngeal mask airway and combitube may be appropriate alternatives for airway management in the first few minutes of CPR.     

Willingness to perform mouth-to-mouth ventilation by health care providers: A survey

BackgroundDuring cardiopulmonary resuscitation (CPR), mouth-to-mouth ventilation (MTM) is only effective if rescuers are willing to perform it.MethodsTo assess the degree of willingness or reluctance in performing MTM, a survey including 17 hypothetical scenarios was created. In each scenario health hazards for the rescuer needed to be balanced against the patient's need for MTM. Respondents were recruited from health care workers attending courses at a medical simulation center. Respondents reported their willingness or reluctance to perform MTM for each scenario using a 4 point scale.ResultsThe questionnaire had responses by 560 health care workers. Reluctance to perform MTM varied with the scenario. Some health care workers refused to ventilate patients who could benefit from MTM. In all scenarios even when resuscitation was both futile and potentially hazardous, some health care workers were willing to perform MTM. Age and level of experience tend to reduce the propensity to engage in MTM. Parental propensity to ventilate one's own child was stronger than any other motivator.ConclusionsHIV infection is not the only condition for which rescuers hesitate to perform MTM. Bag-valve-mask devices for mechanical ventilation should be available in all locations where health care workers may be called upon to resuscitate apneic patients making the decision to perform MTM moot.     

Quantification, distribution, and possible source of bacterial biofilm in mouse automated watering systems.

The use of automated watering systems for providing drinking water to rodents has become commonplace in the research setting. Little is known regarding bacterial biofilm growth within the water piping attached to the racks (manifolds). The purposes of this project were to determine whether the mouse oral flora contributed to the aerobic bacterial component of the rack biofilm, quantify bacterial growth in rack manifolds over 6 mo, assess our rack sanitation practices, and quantify bacterial biofilm development within sections of the manifold. By using standard methods of bacterial identification, the aerobic oral flora of 8 strains and stocks of mice were determined on their arrival at our animal facility. Ten rack manifolds were sampled before, during, and after sanitation and monthly for 6 mo. Manifolds were evaluated for aerobic bacterial growth by culture on R2A and trypticase soy agar, in addition to bacterial ATP quantification by bioluminescence. In addition, 6 racks were sampled at 32 accessible sites for evaluation of biofilm distribution within the watering manifold. The identified aerobic bacteria in the oral flora were inconsistent with the bacteria from the manifold, suggesting that the mice do not contribute to the biofilm bacteria. Bacterial growth in manifolds increased while they were in service, with exponential growth of the biofilm from months 3 to 6 and a significant decrease after sanitization. Bacterial biofilm distribution was not significantly different across location quartiles of the rack manifold, but bacterial levels differed between the shelf pipe and connecting elbow pipes.     

Transtracheal O2 insufflation (TOI) as an alternative method of ventilation during cardiopulmonary resuscitation

We examined the efficiency of continuous transtracheal O₂ insufflation (TOI) as a method of ventilation during cardiopulmonary resuscitation (CPR) in a canine model. The tip of the insufflation catheter was placed 1 cm above the carina. The effects of TOI at flow rates of 0.2, 0.5, and 1.01/kg per min during and after CPR were examined in dogs with induced ventricular fibrillation. During CPR, adequate oxygenation and ventilation were maintained with TOI at flow rates of 0.5 and 1.0 1/kg per min, but not at 0.21/kg per min. After CPR, TOI was adequate to maintain oxygenation, but not ventilation. TOI alone did not prevent post-CPR hypercarbia in successfully resuscitated animals. Still, this study suggests that TOI might be useful as a temporary measure for emergency ventilation during CPR, especially in situations such as upper airway abnormalities, when mask ventilation or endotracheal intubation is not feasible.     

Advances in airway management

Emergency ventilation is an essential component of basic life support. Respiratory emergencies occur far more frequently than cardiac arrest and, if not treated promptly and effectively, may lead to cardiac arrest. Many respiratory emergencies require assisted ventilation to prevent the occurrence of hypoxemia, hypercarbia, and cardiac decompensation. Emergency assisted ventilation is often difficult to perform and is associated with several adverse complications, such as gastric inflation, regurgitation, and pulmonary aspiration. The American Heart Association sponsored conferences in 1999 and 2000 to review and revise guidelines for cardiopulmonary resuscitation. This article reviews the science behind guideline changes related to pulmonary resuscitation and discusses recent advances in emergency airway management, focusing on noninvasive techniques for ventilation (mouth-to-mouth ventilation, bag-mask ventilation) and alternative airway devices (laryngeal mask airway, the Combitube).     

Transtracheal O2 insufflation (TOI) as an alternative method of ventilation during cardiopulmonary resuscitation

We examined the efficiency of continuous transtracheal O₂ insufflation (TOI) as a method of ventilation during cardiopulmonary resuscitation (CPR) in a canine model. The tip of the insufflation catheter was placed 1 cm above the carina. The effects of TOI at flow rates of 0.2, 0.5, and 1.01/kg per min during and after CPR were examined in dogs with induced ventricular fibrillation. During CPR, adequate oxygenation and ventilation were maintained with TOI at flow rates of 0.5 and 1.0 1/kg per min, but not at 0.21/kg per min. After CPR, TOI was adequate to maintain oxygenation, but not ventilation. TOI alone did not prevent post-CPR hypercarbia in successfully resuscitated animals. Still, this study suggests that TOI might be useful as a temporary measure for emergency ventilation during CPR, especially in situations such as upper airway abnormalities, when mask ventilation or endotracheal intubation is not feasible.     

Intubating laryngeal mask airway, laryngeal tube, 1100 ml self-inflating bag-alternatives for basic life support?

Insufficient oxygenation, ventilation and gastric inflation with subsequent regurgitation of stomach contents is a major hazard of bag-valve-face mask ventilation during the basic life support phase of cardiopulmonary resuscitation (CPR). The European Resuscitation Council has recommended smaller tidal volumes of approximately 500 ml as an effort to reduce gastric inflation; furthermore, the intubating laryngeal mask airway and the laryngeal tube have been recently developed in order to provide rapid ventilation and to secure the airway. The purpose of our study was to examine whether usage of a newly developed medium-size self-inflating bag (maximum volume, 1100 ml) in association with the intubating laryngeal mask airway, and laryngeal tube may provide adequate lung ventilation, while reducing the risk of gastric inflation in a bench model simulating the initial phase of CPR. Twenty house officers volunteered for our study. When using the laryngeal tube, and the intubating laryngeal mask airway, respectively, the medium-size (maximum volume, 1100 ml) versus adult (maximum volume, 1500 ml) self-inflating bag resulted in significantly (P<0.05) lower mean+/-S.E.M. lung tidal volumes (605+/-22 vs. 832+/-4 ml, and 666+/-27 vs. 887+/-37 ml, respectively), but comparable peak airway pressures. No gastric inflation occurred when using both devices with either ventilation bag. In conclusion, both the intubating laryngeal mask airway and laryngeal tube in combination with both an 1100 and 1500 ml maximum volume self inflating bag proved to be valid alternatives for emergency airway management in a bench model of a simulated unintubated cardiac arrest victim.     

Assessment of the use of the laryngeal tube for cardiopulmonary resuscitation in a manikin.

During 60 3-min CPR sequences, the face mask, laryngeal tube and tracheal tube were compared using an Ambu Megacode Trainer. Ten 3-min sequences each were performed for both a combination of the face mask and laryngeal tube with a bag-valve device (compression-ventilation ratio 5:1). With continuous chest compressions, ten 3-min CPR sequences each were performed for a combination of the laryngeal tube and tracheal tube with a bag-valve device and ten 3-min CPR sequences each for a combination of the laryngeal tube and tracheal tube with an automatic transport ventilator. Signs of gastric inflation occurred only with the face mask. Ventilation with the laryngeal tube was significantly better than with the face mask and comparable to the tracheal tube during ventilation with the bag-valve device and with the automatic transport ventilator. Chest compressions caused a significant decrease in tidal volumes during ventilation with the automatic transport ventilator. The findings of this study support the idea of the laryngeal tube as a new adjunct for emergency airway management, but will have to be verified during clinical practice.     

Smaller tidal volumes during cardiopulmonary resuscitation: comparison of adult and paediatric self-inflatable bags with three different ventilatory devices

Gastric inflation and subsequent regurgitation of stomach contents is a major hazard of bag-valve-face mask ventilation during the basic life support phase of cardiopulmonary resuscitation (CPR). Recent investigations suggested that use of a paediatric self-inflating bag may reduce stomach inflation while ensuring sufficient lung ventilation. The purpose of our study was to examine whether use of a paediatric self-inflating bag in association with laryngeal mask airway, combitube, and bag-valve-face mask may provide adequate lung ventilation, while reducing the risk of gastric inflation in a bench model simulating the initial phase of CPR. Sixteen intensive care unit registered nurses volunteered for our study. Use of a paediatric versus adult self-inflating bag resulted in a significantly (P < 0.01) lower mean (+/- S.D.) tidal lung volume with both the laryngeal mask airway and combitube (laryngeal mask airway 349 +/- 149 ml versus 725 +/- 266 ml, combitube 389 +/- 113 ml versus 1061 +/- 451 ml). Lung tidal volumes were below the European Resuscitation Council recommendation with both self-inflatable bags in the bag-valve-face mask group (paediatric versus adult self-inflatable bag 256 +/- 77 ml versus 334 +/- 125 ml). Esophageal tidal volumes were significantly (P < 0.05) lower using the paediatric self-inflatable bag in the bag-valve-face mask group; almost no gastric inflation occurred with the laryngeal mask airway, and none with the combitube. In conclusion, use of the paediatric self-inflating bag may reduce gastric inflation, but measured lung tidal volumes are below the European Resuscitation Council recommendation when used with either, the laryngeal mask airway, combitube, or bag-valve-face mask.     

Securing the prehospital airway: a comparison of laryngeal mask insertion and endotracheal intubation by UK paramedics

Methods: Patients undergoing general anaesthesia were studied. Paramedics trained in laryngeal mask use and endotracheal intubation participated in the study. A Portex disposable laryngeal mask was inserted and removed, followed by a Portex endotracheal tube. Time taken from beginning of the procedure to ventilation of the patient was recorded.

Results: Laryngeal mask insertion and endotracheal intubation was attempted on 52 patients. Median age was 63.5 years (range 39–83). Laryngeal mask insertion was successful in 88.5% (46 of 52) patients; endotracheal intubation was successful in 71.2% (37 of 52) patients (after no more than two attempts), p = 0.049. Intubation success was related to laryngoscopic view (87.5% grade 1, 56.3% grade 2, 0.0% grade 3. p<0.0001). When laryngeal mask/endotracheal tube insertion were both successful (n = 35 of 52), there was no significant difference in median time to secure the airway (laryngeal mask 47.0 seconds (range 24–126) compared with endotracheal tube 52.0 seconds (range 27–148) p = 0.22). Laryngeal mask insertion was successful in 80.0% (12 of 15) patients in whom endotracheal intubation had failed.

Conclusions: Even under optimal conditions, 30% of attempts at intubation by paramedics were unsuccessful. A disposable laryngeal mask has a higher success rate in securing the airway and overall, secures the airway more reliably than endotracheal intubation.

     

Bacterial growth in secretions and on suctioning equipment of orally intubated patients: a pilot study.

BACKGROUND: Contamination of equipment, colonization of the oropharynx, and microaspiration of secretions are causative factors for ventilator-associated pneumonia. Suctioning and airway management practices may influence the development of ventilator-associated pneumonia. OBJECTIVES: To identify pathogens associated with ventilator-associated pneumonia in oral and endotracheal aspirates and to evaluate bacterial growth on oral and endotracheal suctioning equipment. METHODS: Specimens were collected from 20 subjects who were orally intubated for at least 24 hours and required mechanical ventilation. At baseline, oral and sputum specimens were obtained for culturing, and suctioning equipment was changed. Specimens from the mouth, sputum, and equipment for culturing were obtained at 24 hours (n=18) and 48 hours (n=10). RESULTS: After 24 hours, all subjects had potential pathogens in the mouth, and 67% had sputum cultures positive for pathogens. Suctioning devices were colonized with many of the same pathogens that were present in the mouth. Nearly all (94%) of tonsil suction devices were colonized within 24 hours. Most potential pathogens were gram-positive bacteria. Gram-negative bacteria and antibiotic-resistant organisms were also present in several samples. CANCLUSIONS: The presence of pathogens in oral and sputum specimens in most patients supports the notion that microaspiration of secretions occurs. Colonization is a risk factor for ventilator-associated pneumonia. The equipment used for oral and endotracheal suctioning becomes colonized with potential pathogens within 24 hours. It is not known if reusable oral suction equipment contributes to colonization; however, because many bacteria are exogenous to patients' normal flora, equipment may be a source of cross-contamination.     

Comparison of ventilation and cardiac compressions using the Impact Model 730 automatic transport ventilator compared to a conventional bag valve with a facemask in a model of adult cardiopulmonary arrest

PURPOSE: To determine the performance of two person CPR on an instrumented manikin by registered nurses using conventional bag valve mask (BVM) ventilation or the Impact Model 730 automatic transport ventilator (Impact 730, Impact Instrumentation, Inc., West Caldwell, NJ) in CPR mode using a face mask. DESIGN: Randomized crossover quasi-experimental. SETTING: Laboratory simulation. SUBJECTS: Twenty-eight registered nurses trained in performing adult cardiopulmonary resuscitation (CPR). INTERVENTIONS: Basic Life Support was provided by subjects using a conventional bag valve mask (BVM) ventilation or mask ventilation with an automatic transport ventilator, the Impact 730, which incorporates a metronome to facilitate chest compression timing. Subjects alternated performing 4min of CPR using the BVM or Impact 730 to deliver breaths with a mask while the other subject performed compressions. MEASUREMENTS AND MAIN RESULTS: Flow, volume and pressure were measured using a pneumotachograph and pressure transducer, and ease of use was measured using a 10cm visual analogue scale. There was no statistical or clinical difference between the actual and recommended tidal lung volume (mean+/-S.D.) delivered by the Impact 730 (-120.4+/-91.5ml) versus the BVM (-119.8+/-187.3+/-ml). Ventilation with the BVM resulted in more (137.7+/-143.9ml) air per breath passing through the simulated lower esophageal sphincter compared to the Impact 730 (14.0+/-16.8ml, p<0.05). The reduced mask leak per breath with the Impact 730 (176.1+/-98.3ml) compared to the BVM (367.6+/-337.7ml, p<0.05) is likely to have resulted from the subject being able to manage the mask with two rather than one hand and is reflected in the higher ease of use score on a 10cm visual analogue scale with the Impact 730 (8.06+/-1.35cm) versus the BVM (6.46+/-2.46cm, p<0.05). Subjects tended to deliver slightly more compressions and breaths when using the BVM. CONCLUSION: Compared to the BVM, the Impact 730 is as effective, easier to use and limits the amount of gas entering the stomach when used during adult CPR in a simulated setting.     

Does compression-only cardiopulmonary resuscitation generate adequate passive ventilation during cardiac arrest?

INTRODUCTION: The need for rescue breaths in bystander CPR has been questioned after several studies have shown that omitting ventilation does not worsen outcome. Chest compression may produce passive tidal volumes large enough to provide adequate ventilation in animal studies, but no recent clinical studies have examined this phenomenon. We measured passive ventilation during optimal chest compression to determine whether compression-only CPR provides adequate gas exchange during cardiac arrest. METHODS: Adult cardiac arrest patients were treated according to European Resuscitation Council guidelines. Chest compressions were performed using a mechanical chest compression device (LUCAS) with active decompression disabled to mimic manual compression. Respiratory variables were measured during periods of compression-only CPR. RESULTS: Emergency Department data were collected during compression-only CPR from 17 patients (11 male) aged 47-82 years who had suffered an out-of-hospital cardiac arrest. Median tidal volume per compression was 41.5 ml (range 33.0-62.1 ml), being considerably less than measured deadspace in all patients. Maximum end-tidal CO2 was 0.93 kPa (range 0.0-4.6 kPa). Minute volume CO2 was 19.5 ml (range 15.9-33.8; normal range 150-180 ml). CONCLUSIONS: At an advanced stage of cardiac arrest, passive ventilation during compression-only CPR is limited in its ability to maintain adequate gas exchange, with gas transport mechanisms associated with high frequency ventilation perhaps generating a very limited gas exchange. The effectiveness of passive ventilation during the early stages of CPR, when chest and lung compliance is greater, remains to be investigated.     

肝脓肿的细菌培养分析

８４例肝脓肿患者脓液需氧和厌氧细菌培养，结果有４９例培养阳性，总阳性率５８．３％，其中单一需氧菌和单一厌氧菌阳性者，分别占阳性标本的３４．７％和２０．４％，两者混合阳性占４４．９％。共检出细菌８２株（需氧菌４４株，厌氧菌３８株），其中以大肠埃希菌（３４．１％）和消化链球菌（４７．４％）多见。表明，厌氧菌感染在细菌性肝脓肿中占有重要地位。     

Ventilation performance using a self-inflating anesthesia bag: effect of operator characteristics

Adequate ventilation is required for successful cardiopulmonary resuscitation (CPR). Operator characteristics that influence ventilation performance are not well defined. This study compared ventilation performance and operator characteristics in 74 medical personnel using a self-inflating anesthesia bag. Ventilation device, operator hand size, ventilation technique, average tidal volume, cumulative minute ventilation, and ventilation pressures were recorded during 3 minutes of ventilation. Ventilation volumes and airway pressures were not correlated with hand size or device type. Techniques that used one hand to squeeze the bag resulted in significantly lower average tidal volume than two-handed techniques, with no significant difference in peak or average airway pressure. There was no difference between emergency department and prehospital personnel in average tidal volume delivered. However, prehospital personnel ventilated at significantly higher airway pressures. Emergency department nurses delivered the greatest average tidal volume (923 cc), while emergency department physicians delivered the least (775 cc). Paramedics recorded the highest airway pressures (average, 53 cm H2O; peak, 72 cm H2O), while respiratory therapists recorded the lowest pressures (average, 34 cm H2O; peak, 54 cm H2O). Ventilation during CPR is a complex, learned skill. Large variation exists among different operators. However, appropriate tidal volumes can be delivered using safe airway pressures. Ongoing assessment and retraining of individuals performing ventilation during CPR are essential.     

Transthoracic biphasic waveform defibrillation at very high and very low energies: a comparison with monophasic waveforms in an animal model of ventricular fibrillation

The laryngeal mask airway (LMA) and Combitube have been recommended for use during cardiopulmonary resuscitation (CPR). An overview of current practice was sought by conducting a postal survey of 265 Resuscitation Training Departments, at different hospitals, throughout the UK. One hundred fifty-three (58%) completed questionnaires were returned. Only 38 (25%) hospitals which replied were currently using the LMA in resuscitation while seven (5%) were using the Combitube. The reasons for not using these airway adjuvants included concerns about airway protection, difficulties in training, cost, and the concept that when anaesthetists were available on cardiac arrest teams these devices were unnecessary.     

The critical airway, rescue ventilation, and the combitube: Part 1

Emergency and unexpected difficult airway management can rapidly deteriorate into a critical airway event such as "cannot ventilate, cannot intubate" (CVCI). A critical airway event (i.e., inadequate mask ventilation, failed intubation, and CVCI) can be resolved by rescue ventilation, thus avoiding potential neurological disability or death. Recommended options include use of the larygeal mask airway, the esophageal-tracheal Combitube (ETC; Tyco-Healthcare-Nellcor, Pleasanton, Calif), transtracheal jet ventilation, or a surgical airway. This article reviews proper use of the ETC in combination with the self-inflating bulb (SIB) and/or portable carbon dioxide detector to resolve critical airway situations. The combined use of these 3 devices provides on ideal integrated system for airway control and ventilation. In addition, critical airway events and rescue ventilation options; ETC design, technical aspects, training, insertion, and ventilation; determining ETC location (i.e., esophagus vs trachea); and monitoring ETC lung ventilation are reviewed. The SIB primarily assesses ETC location within the esophagus or the trachea; the carbon dioxide detector also permits monitoring lung ventilation. Use of the ETC in prehospital, emergency medicine, and anesthesia settings, including ETC advantages, contraindications, and reported complications will be reviewed in Part 2. How to safely exchange the ETC for a definitive airway also will be reviewed.     

A human immunodeficiency virus-resistant airway for cardiopulmonary resuscitation.

Due to fear of transmitted disease, mouth-to-mouth cardiopulmonary resuscitation (CPR) is now rare, even though early CPR is associated with a fivefold to 30-fold increase in survival. The authors have devised a one-piece silicone mask (Kiss of Life [KOL], Brunswick Biomedical Technologies, Inc, Warehom, MA) with a one-way valve and circular recess to form a no-contact lip seal, enabling mouth-to-mouth CPR to be given. The ventilatory volume during mannequin CPR using the KOL mask was 0.75 +/- 0.235 L. This volume was significantly (P less than .05) greater than that generated by alternate widely used airways (range, 0.195 +/- 0.147 to 0.617 +/- 0.208 L). To assess mask performance in vivo, the authors measured exhaled volumes in 10 apneic anesthetized patients under three conditions: with the KOL mask, a standard anesthetic mask and bag, and an anesthetic mask with an endotracheal tube. The results were: anesthetic mask and tube, 1.5 L (range, 1.2 to 1.7 L); KOL mask, 1.1 L (range, 1.0 to 1.3 L); anesthetic mask alone, 0.7 L (range, 0.5 to 0.8 L). To test permeability, we exposed two KOL masks to a high titer of human immunodeficiency virus (HIV)-1 soup (10(6) culture infection doses/mL) for 10 and eight masks for 60 minutes, respectively, and cultured swabs of the interior of the valve for 1 month. There was no growth in any culture. These data suggest that the KOL mask has excellent ventilating characteristics, is practical (pocket-portable, disposable), experimentally impermeable to HIV-1, and inexpensive.(ABSTRACT TRUNCATED AT 250 WORDS)