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)     

Rethinking bystander CPR for out-of-hospital cardiac arrest

Citation

SOS-KANTO study group: Cardiopulmonary resuscitation by bystanders with chest compression only (SOS-KANTO): an observational study. Lancet 2007, 369:920–926 [1].

Background

Mouth-to-mouth ventilation is a barrier to bystanders doing cardiopulmonary resuscitation (CPR), but few clinical studies have investigated the efficacy of bystander resuscitation by chest compressions without mouth-to-mouth ventilation (cardiac-only resuscitation).

Methods

Objective

To compare the effect of bystander-provided cardiac-only resuscitation to conventional CPR in adults who had out-of-hospital cardiac arrest.

Design

Prospective multicenter observational study.

Setting

58 emergency hospitals and emergency medical service units in the Kanto region of Japan.

Subjects

Patients with witnessed out-of-hospital cardiac arrest who were subsequently transported by paramedics to participating emergency hospitals. Exclusion criteria were age <18 years, further cardiac arrest after the arrival of paramedics, documented terminal illness, presence of a do-not-resuscitate order, and bystander resuscitation without documented chest compressions.

Intervention

None. On arrival at the scene, paramedics assessed the technique of bystander resuscitation, recording it as conventional CPR (chest compressions with mouth-to-mouth ventilation), cardiac-only resuscitation (chest compressions alone), or no bystander CPR. Patients were followed and revaluated 30 days after the arrest to determine neurologic status.

Outcome

The primary endpoint was favorable neurological outcome 30 days after cardiac arrest using the Glasgow-Pittsburgh cerebral-performance scale, with favorable neurological outcome defined as a category 1 (good performance) or 2 (moderate disability) on a 5-point scale.

Results

4068 adult patients who had out-of-hospital cardiac arrest witnessed by bystanders were included; 439 (11%) received cardiac-only resuscitation from bystanders, 712 (18%) conventional CPR, and 2917 (72%) received no bystander CPR. Any resuscitation attempt was associated with a higher proportion having favorable neurological outcomes than no resuscitation (5.0%vs 2.2%, p < 0.0001). Cardiac-only resuscitation resulted in a higher proportion of patients with favorable neurological outcomes than conventional CPR in patients with apnea (6.2%vs 3.1%; p = 0.0195), with shockable rhythm (19.4%vs 11.2%, p = 0.041), and with resuscitation that started within 4 min of arrest (10.1%vs 5.1%, p = 0.0221). However, there was no evidence for any benefit from the addition of mouth-to-mouth ventilation in any subgroup. The adjusted odds ratio for a favorable neurological outcome after cardiac-only resuscitation was 2.2 (95% CI 1.2–4.2) in patients who received any resuscitation from bystanders.

Conclusion

Cardiac-only resuscitation by bystanders is the preferable approach to resuscitation for adult patients with witnessed out-of-hospital cardiac arrest, especially those with apnea, shockable rhythm, or short periods of untreated arrest.     

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.     

Arterial blood gases with 700 ml tidal volumes during out-of-hospital CPR

The optimal tidal and minute ventilation during cardiopulmonary resuscitation (CPR) is not known. In the present study seven adult, non-traumatic, out-of-hospital cardiac arrest patients were intubated and mechanically ventilated at 12 min(-1) with 100% oxygen and a tidal volume of 700 ml (10 +/- 2 ml kg(-1)). Arterial blood gas samples were analysed after 6-8 min of unsuccessful resuscitation and mechanical ventilation. Mean PaCO2 was 5.2 +/- 1.3 kPa and mean PaO2 30.7 +/- 17.2 kPa. The patient with the highest (14 ml kg(-1)) and lowest (8 ml kg(-1)) tidal volumes per kg had the lowest and highest PaCO2 values of 2.6 and 6.8 kPa, respectively. Linear regression analysis confirmed a significant correlation between arterial pCO2 and tidal volume in ml/kg, r2 = 0.87. We conclude that aiming for an estimated ventilation of 10 ml kg(-1) tidal volume at frequency of 12 min(-1) might be expected to achieve normocapnia during ALS.     

Prevention of oral bacterial flora transmission by using mouth-to-mask ventilation during CPR

The Emergency Cardiac Care Committee of the American Heart Association has recently recommended utilizing protective barrier precautions during CPR (1,2). We assessed 17 mask and faceshield resuscitation devices for adequacy of barrier protection. Eight of the devices were faceshields (CPR Microshield, Hygenic, MedCare Mask, Resusci, Samaritan, Sealeasy, Portex); 8 were mask devices (Laerdal, Dyna Med, MTM Emergency Lung Ventilator, MTM Emergency Resuscitator, Res-Q-Flo, Rightway Mouth-to-Mask Resuscitation, Trufit), and one of the devices did not meet the criteria for either faceshield or mask (Lifesaver). All masks were disinfected, applied to the investigator's face as directed by the manufacturers' instructions, and then cultured for oral aerobic bacterial flora on the rescuer side. No mask devices cultured positive for oral aerobic bacterial flora, while 6 of 8 faceshield devices cultured positive for oral aerobic bacterial flora (P less than 0.007). The CPR Microshield and the Portex faceshield were the only devices that did not develop a positive culture. We conclude that all ventilation devices with a one-way valve, except the Sealeasy device, provide adequate barrier type protection from oral aerobic bacterial flora when simulating mouth-to-barrier type protection when performing mouth-to-mouth ventilation.     

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.     

Simulated mouth-to-mouth ventilation and chest compressions (bystander cardiopulmonary resuscitation) improves outcome in a swine model of prehospital pediatric asphyxial cardiac arrest.

OBJECTIVE: To compare the efficacy of four methods of simulated single-rescuer bystander cardiopulmonary resuscitation (CPR) in a clinically relevant swine model of prehospital pediatric asphyxial cardiac arrest. DESIGN: Prospective, randomized study. SUBJECTS: Thirty-nine anesthetized domestic piglets. INTERVENTIONS: Asphyxial cardiac arrest was produced by clamping the endotracheal tubes of the piglets. For 8 mins of simulated bystander CPR, animals were randomly assigned to the following groups: group 1, chest compressions and simulated mouth-to-mouth ventilation (FI(O2) = 0.17, FI(CO2) = 0.04) (CC+V); group 2, chest compressions only (CC); group 3, simulated mouth-to-mouth ventilation only (V); and group 4, no CPR (control group). Standard advanced life support was then provided, simulating paramedic arrival. Animals that were successfully resuscitated received 1 hr of intensive care support and were observed for 24 hrs. MEASUREMENTS AND MAIN RESULTS: Electrocardiogram, aortic blood pressure, right atrial blood pressure, and end-tidal CO2 were monitored continuously until the intensive care period ended. Arterial and mixed venous blood gases were measured at baseline, 1 min after cardiac arrest, and 7 mins after cardiac arrest. Minute ventilation was determined during each minute of bystander CPR. Survival and neurologic outcome were determined. Twenty-four-hour survival was attained in eight of 10 group 1 (CC+V) piglets vs. three of 14 group 2 (CC) piglets (p < or = .01), one of seven group 3 (V) piglets (p < or = .05), and two of eight group 4 (control) piglets (p < or = .05). Twenty-four-hour neurologically normal survival occurred in seven of 10 group 1 (CC+V) piglets vs. one of 14 group 2 (CC) piglets (p < or = .01), one of seven group 3 (V) piglets (p < or = .05), and none of eight group 4 (control) piglets (p < or = .01). Arterial oxygenation and pH were markedly better during CPR in group 1 than in group 2. Within 5 mins of bystander CPR, six of 10 group 1 (CC+V) piglets attained sustained return of spontaneous circulation vs. only two of 14 group 2 (CC) piglets and none of the piglets in the other two groups (p < or = .05 for all groups). CONCLUSIONS: In this pediatric asphyxial model of prehospital single-rescuer bystander CPR, chest compressions plus simulated mouth-to-mouth ventilation improved systemic oxygenation, coronary perfusion pressures, early return of spontaneous circulation, and 24-hr survival compared with the other three approaches.     

Effectiveness of mouth-to-mouth ventilation after video self-instruction training in laypersons

Background

Mouth-to-mouth ventilation is a skill taught in cardiopulmonary resuscitation (CPR) training for laypersons. However, its effectiveness is questioned. Our aim was to determine the effectiveness of mouth-to-mouth ventilation training using a self-instruction CPR training video for laypersons.

Methods

Video-self-instruction CPR training was conducted with CPR Anytime (American Heart Association [AHA] & Laerdal Corporation) for laypersons who had not received CPR training during the recent 5 years. Immediately before, immediately after, and 8 weeks after the CPR training, an AHA basic life support instructor carried out a skill performance test using a standardized checklist. Also, 8 weeks after the training, a skill test concerning chest compression and mouth-to-mouth ventilation was conducted using a trained reporter.

Results

Cardiopulmonary resuscitation training of 84 laypersons was conducted. The mean performance score (from 0 to 2) for mouth-to-mouth ventilation was 0.24 right before the training, 1.58 right after the training, and 0.95 eight weeks after the training. The mean performance scores for chest compression were 0.13, 1.79, and 1.40, right before, right after, and 8 weeks after the CPR training, respectively. The rates of successful mouth-to-mouth ventilation and compression were 11.9%, and 39.1%, respectively.

Conclusions

The effectiveness and short-term retention rate of mouth-to-mouth ventilation after video self-instruction CPR training in laypersons was significantly lower than for chest compressions.     

Optimum cardiopulmonary resuscitation for basic and advanced life support: a simulation study

Optimum cardiopulmonary resuscitation (CPR) for both basic and advanced cardiac life support depends on a compromise between the number of chest compressions delivered and the amount of ventilation provided. This study used theoretical models of blood flow and both arterial and venous blood gas values to investigate the influence of different compression to ventilation ratios on CPR efficiency, as well as the effects of different inspired oxygen concentrations. With mouth-to-mouth ventilation, greater numbers of compressions between each ventilation provided progressively greater blood flow. However, a greater the number of compressions, reduced the arterial oxygen levels and carbon dioxide clearance. There was an optimum ratio, in terms of both oxygen delivery and carbon dioxide clearance, of around 20:1 compressions to ventilation. Optimum oxygen delivery was 0.19 L/min at 20:1, which was better than the oxygen delivery for standard CPR based on a ratio of 15:2 (0.13 L/min). When patients were ventilated with supplemental oxygen (either 50 or 85%) the lungs rapidly became saturated with oxygen, and oxygen delivery depended more on blood flow. Higher numbers of compressions provided greater oxygen delivery, but at the cost of increasing hypercarbia, which is thought to affect resuscitation success rates adversely. The simulation results suggested ratios around 20:1 would be the best compromise between blood flow, oxygen delivery (0.25 L/min) and avoidance of hypercarbia. The best results were provided by continuous chest compressions and simultaneous, asynchronous ventilation in an intubated patient. Arterial and venous oxygen and carbon dioxide levels were well maintained, with very good oxygen delivery (0.32 L/min). Intubation with continuous chest compressions and asynchronous ventilation can therefore significantly improve the quality of CPR as a whole, and not just ventilation.     

Community attitudes towards performing cardiopulmonary resuscitation in Western Australia.

OBJECTIVE: to determine the attitudes of the Western Australian community towards performing cardiopulmonary resuscitation, and the factors affecting these attitudes. METHODS: telephone survey of a randomly selected sample of people from suburban Perth and rural Western Australia; practical assessment of a sub-sample of volunteers from those surveyed, to correlate survey answers with practical skills. RESULTS: of 803 people surveyed, the majority (90.7%) definitely would give mouth-to-mouth ventilation to a friend or relative, but less than half (47.2%) would to a stranger. The reluctance was mostly (56%) because of health and safety concerns, particularly related to HIV infection. Higher percentages of people would definitely provide cardiac massage for a friend or relative (91.4%) or stranger (78.1%). People were more likely to give mouth-to-mouth and cardiac massage if they had been trained in cardiopulmonary resuscitation (CPR), trained several times, trained recently, and used their CPR skills in real life. There were no significant differences between city and country people in whether they would provide CPR, but older people were less willing to provide mouth-to-mouth or cardiac massage. On practical assessment of 100 volunteers, there were significant errors and omissions in airway assessment, mouth-to-mouth resuscitation and cardiac massage. Volunteers with better practical scores were more prepared to provide CPR. DISCUSSION: our results indicate a significant reluctance of the Western Australia public to perform mouth-to-mouth, except to a friend or relative. Earlier CPR training, practice and use seemed to diminish this reluctance. Practical CPR skills were not well executed. Those with better skills were less reluctant to use them. We recommend increasing CPR training in the community, greater frequency of refresher courses and public education on the risks of CPR to improve rates of bystander CPR.     

Percutaneous transtracheal emergency ventilation during respiratory arrest: comparison of the oxygen flow modulator with a hand-triggered emergency jet injector in an animal model

The oxygen flow modulator is a device for percutaneous transtracheal emergency ventilation. Simulating a respiratory arrest situation, we studied the effects of this device in comparison with a hand-triggered emergency jet injector during pulmonary resuscitation. Nine pigs were anesthetized and mechanically ventilated. After surgical exposure, an emergency transtracheal airway catheter was inserted into the trachea. Ventilation was stopped until SpO2 was below 70%. Each animal was subsequently randomly ventilated via the transtracheal airway catheter with either the hand-triggered emergency jet injector or the oxygen flow modulator. After 10 minutes, respiratory and hemodynamic parameters were recorded. Ventilation was stopped again until SpO2 reached 70%, and the animal was ventilated with the second device. With both devices, pulmonary resuscitation was successful. Whereas PaO2 differed not significantly between the two devices, PaCO2 was lower during percutaneous transtracheal ventilation with the hand-triggered emergency jet injector.     

Analysis of a 2-year-old resuscitation service

The results of attempted resuscitation of 561 patients with cardiac or respiratory arrest are reported. A one-way speech, multiple-call system, and two mobile resuscitation trolleys were used. Most of the patients were between 50 and 80 years of age. Threequarters of the patients presented with cardiac arrest which manifested as asystole almost twice as often as ventricular fibrillation. The commonest causes of arrest were acute myocardial infarction, unknown causes, cardiac failure, recent surgery, and respiratory arrest. Autopsies were obtained in one-third of patients who died. Most calls were between 10.00 hours and 22.00 hours and came from the medical wards. The initial method of assisted ventilation was by endotracheal tube and Ambu-bag in almost one-half of the patients, face mask and Ambu-bag in one-quarter and mouth-to-mouth or mouthto-nose in only one-tenth. A spontaneous electrocardiogram and/or pulse was restored in approximately one-third of patients, spontaneous breathing in 22%, and consciousness in 9%, and 18% returned to their pre-arrest status. Successful resuscitation was achieved in 25% but only 8% survived to leave hospital. Patients with respiratory arrest fared more than twice as well as those with cardiac arrest.The factors relating to successful resuscitation are discussed.     

Patients with cardiac arrest are ventilated two times faster than guidelines recommend: An observational prehospital study using tracheal pressure measurement

Aim

To measure ventilation rate using tracheal airway pressures in prehospitally intubated patients with and without cardiac arrest.

Methods

Prospective observational study. In 98 patients (57 with and 41 without cardiac arrest) an air-filled catheter was inserted into the endotracheal tube and connected to a custom-made portable device allowing tracheal airway pressure recording and subsequent calculation of ventilation rate.

Results

In manually ventilated patients with cardiac arrest 39/43 (90%) had median ventilation rates higher than 10/min (overall median 20, min 4, max 74). During mechanical ventilation, 35/38 (92%) had ventilation rates higher than 10/min. The ventilation rate in patients with cardiac arrest was higher than in patients without cardiac arrest, both for manual and mechanical ventilation. Subanalysis comparing episodes with and without compression in cardiac arrest patients showed no clinically significant difference in ventilation rate after compressions were terminated.

Conclusion

Cardiac arrest patients were ventilated two times faster than recommended by the guidelines. Tracheal airway pressure measurement is feasible during resuscitation and may be developed further to provide real-time feedback on airway pressure and ventilation rate during resuscitation.     

The attitudes of Japanese high school students toward cardiopulmonary resuscitation

BACKGROUND AND OBJECTIVES: It is essential to have a clear understanding of the present condition of cardiopulmonary resuscitation (CPR) training courses and the associated problems. The present study was performed to identify the current conditions of CPR training in Japanese high schools and the attitudes of students toward CPR. METHODS AND RESULTS: We distributed a questionnaire study to the students of 12 cooperating high schools regarding their willingness to perform CPR in 5 hypothetical scenarios of cardiopulmonary arrest: a stranger, a trauma patient, a child, an elderly person, and a relative. Between February and March 2006, a total of 3316 questionnaires were completed. Across all scenarios, only 27% of respondents from general high schools reported willingness to perform chest compression (CC) plus mouth-to-mouth ventilation (MMV), and 31% reported willingness to perform CC alone. Fifty-nine percent of students had previous CPR training, and only 35% were willing to perform CC plus MMV. Most of the respondents who reported that they would decline to perform full CPR, stated that poor knowledge and/or fear of incomplete performance of CPR were deciding factors. CONCLUSIONS: Japanese high school students are reluctant to perform CC plus MMV, despite having received training. The present educational system in Japan has limitations in encouraging high school students to perform CC plus MMV.     

Attitudes to basic life support among medical students following the 2003 SARS outbreak in Hong Kong

BACKGROUND: In 2003 severe acute respiratory syndrome (SARS) affected 1,755 people in Hong Kong, including 386 health care professionals, some of whom were infected during resuscitation attempts of affected patients. This study seeks to explore whether this epidemic has altered the willingness of Hong Kong medical students to perform basic life support and mouth-to-mouth ventilation during an out-of-hospital cardiac arrest. METHODS: A questionnaire was used to survey Year 4 medical students at the end of their undergraduate anaesthesia attachment, during which basic life support (BLS) skills were taught. The survey was conducted during July and August 2003, approximately two months after Hong Kong was removed from the World Health Organisation SARS Infected Areas list, and was designed to examine student confidence in BLS skills, their perceptions of the risks associated with performing BLS and their willingness to perform BLS in varying situations. RESULTS: The response rate was over 60% (35 from a possible 54). Students were positive regarding the adequacy of their BLS training. They were concerned about disease transmission during resuscitation but were less positive regarding whether the risks had increased due to SARS. In all situations they were significantly more likely to perform mouth-to-mouth ventilation for a family member compared with a stranger (p < 0.001) and to withhold mouth-to-mouth ventilation if either vomit or blood were present in the victim's mouth. CONCLUSIONS: Hong Kong medical students feel able to perform BLS if required. They are concerned about the risk of disease transmission, including SARS, during resuscitation, but would be more likely to withhold mouth-to-mouth resuscitation in the presence of vomit or blood than due to a fear of contracting SARS.     

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).     

Attitudes of 100 patients with chronic obstructive pulmonary disease to artificial ventilation and cardiopulmonary resuscitation

One hundred clinically stable outpatients with chronic obstructive pulmonary disease were surveyed at home by respiratory nurse specialists (RNS) about their views towards cardiopulmonary resuscitation (CPR) and in hospital ventilation. Written information about COPD, CPR and ventilation was provided and consent obtained. The breathing problem-based quality-of-life questionnaire (BP-QoL) was completed. The following information was recorded: age, sex, spirometry, hospital admissions, and antidepressant and oxygen usage in the previous year. Patients were then asked to imagine a scenario in which they were admitted to hospital and their chest condition deteriorated in spite of standard treatment. 'Having reached that stage would you wish to have noninvasive ventilation (NIV), invasive ventilation (IV) or CPR?' Three months later patients were asked to complete a postal patient satisfaction questionnaire. Results: Of 100 patients 41 were male and the mean age was 74.1 years. Fifty four patients had a FEV1 <40% and 37 had a FEV1 between 40 and 59% predicted. Twenty-four patients were on long-term oxygen therapy, eight had taken antidepressants and 56 had been admitted to hospital in the previous year. Forty-eight patients wanted all additional treatments to be attempted if needed and 12 wanted none. Nineteen patients said 'no' for CPR and 10 said 'no' for CPR and IV. There was no significant statistical difference between the groups answering 'yes' or 'no'. Seventy-six per cent of patient satisfaction questionnaires were returned. All patients were satisfied with the way they had been approached and the information received, and 98% of them thought that this issue should be discussed with all patients. Conclusion: Attitudes towards resuscitation can be discussed with COPD patients by RNS without causing distress. Attitudes to resuscitation could not be predicted from parameters of respiratory disease severity or age.     

机械通气对院内心肺复苏成功率的影响

目的:观察机械通气对院内心肺复苏成功率的影响。方法:回顾性分析机械通气复苏院内心跳呼吸骤停68例的临床资料。结果:5min内获机械通气复苏者的心肺复苏成功率明显高于5min以上者,P<0.05。结论:及时机械通气可提高院内心肺复苏成功率。     

Evaluation of mouth-to-mask ventilation devices.

A number of mouth-to-mask ventilation devices have become commercially available in the past several years. In this study, we compared the volumes delivered by eight of these devices to the volumes delivered by mouth-to-mouth ventilation. METHOD: Fourteen respiratory care practitioners participated in the study. Ventilation was delivered to an adult resuscitation manikin. Each subject ventilated the manikin using mouth-to-mouth technique and each of the following mouth-to-mask devices: Boehringer EVA, Hospitak, Hudson, Intertech Safe Response, Laerdal Pocket Mask, Life Design Systems (LDS), Respironics SealEasy, and Vital Signs. Evaluation periods of 1 minute were used, minute ventilation and respiratory rate were measured, and tidal volume was calculated. RESULTS: There was a significant difference between the volumes delivered by the masks (p less than 0.001). The volumes delivered by each mask were less than mouth-to-mouth volumes (p less than 0.05 in each case). The mean +/- SD mouth-to-mouth volume was 1.04 +/- 0.32 L. The mean +/- SD volumes for each of the devices was 0.54 +/- 0.34 L for the EVA, 0.77 +/- 0.21 L for the Hospitak, 0.51 +/- 0.26 L for the Hudson, 0.81 +/- 0.35 L for the Safe Response, 0.65 +/- 0.25 L for the Pocket Mask, 0.82 +/- 0.27 L for the LDS, 0.79 +/- 0.32 L for the SealEasy, and 0.76 +/- 0.21 L for the Vital Signs. CONCLUSIONS: We found considerable variability between the volumes delivered with commercially available mouth-to-mask ventilation devices. Although the volumes delivered during mouth-to-mask technique were less than those delivered with mouth-to-mouth technique, the volumes delivered by some of the mouth-to-mask devices were large enough to allow them to be substituted for mouth-to-mouth technique.