Time used for ventilation in two-rescuer CPR with a bag-valve-mask device during out-of-hospital cardiac arrest.

INTRODUCTION: Professional rescuers only deliver chest compressions 39% of the available time before intubation during out-of-hospital cardiac arrest. In manikin-studies lay rescuers need approximately 15s to deliver two ventilations. It is not known how much time professional rescuers use for two ventilations and we hypothesised that the time used for two ventilations with a bag-valve-mask device before tracheal intubation is longer than recommended and that the extended time contributes to the high no flow time. METHODS: Quality of CPR was available for analysis in 628 cases of out-of-hospital cardiac arrest in the ambulance service in Oslo, Akershus, London, and Stockholm from 2002 to 2005. The 2000 Guidelines were used as the reference. Ventilations were registered from changes in transthoracic impedance as measured through the standard defibrillation pads. We included episodes only with CPR with a 15:2 pattern for at least 1 min and identified all pauses between chest compressions before intubation. RESULTS: In the remaining 172 episodes we identified 3097 chest compression pauses. In 1587 (51%) of the pauses we identified two ventilations and a mean pause length for each episode was calculated. The median of these means was 5.5s (IQR; 4.5, 7). These pauses comprised a median 9% (IQR; 4%, 15%) of the time before intubation in these episodes. In 892 (29%) of the pauses we identified a different number of ventilations, or other interventions in addition to ventilation. In the remaining 618 pauses (20%) no ventilations were registered. CONCLUSIONS: Professional rescuers delivered two bag-valve-mask ventilations within the 5-6s as indicated in the 2000 Guidelines, slightly longer than the 3-4s recommended in the 2005 Guidelines. However, only half the pauses were used for two ventilations, and the total time for two ventilations accounted for only 27% of the time without chest compressions. Excessive time for ventilation cannot explain the high no-flow time during CPR by professional rescuers before intubation.

Chest compressions by ambulance personnel on chests with variable stiffness: abilities and attitudes.

INTRODUCTION: Quality of cardiopulmonary resuscitation (CPR) performed by professionals is reported to be substandard even with automated corrective feedback. We hypothesised that lack of quality is not due to physical capabilities. MATERIALS AND METHODS: Eighty ambulance personnel from the same services where the quality of clinical CPR was investigated, performed two-rescuer CPR with similar corrective feedback for 5min on each of four manikins with different chest stiffness. The personnel also scored their agreement with statements on clinical CPR performance. RESULTS: All study subjects performed CPR well within Guidelines recommendations on all four manikins with mean compression depth 44+/-3mm, compression rate 101+/-3min(-1), and 7+/-2 ventilations per minute. Three quarters stated that during CPR on patients their personal sense of correct depth and force determined their performance. Fifty-five percent believed that too deep chest compressions could cause serious injury to the patient, and 39% that compressing to Guidelines recommended depth may often result in severe patient injury. A quarter felt that the potential benefits of compressing to the Guidelines depth could not justify the injuries it would cause. Breaking ribs made 54% feel very uncomfortable. CONCLUSIONS: Ambulance personnel were physically capable of consistently compressing to the Guidelines depth even on the stiffest chest. These laboratory results cannot be directly compared to the clinical out-of-hospital ALS situation, but strongly indicate that the inadequate chest compressions found in our clinical study were not due to lack of physical capability. We speculate that this may at least partly be explained by their fear of causing patient injury and trust in their own opinion of what is the correct compression depth and force in preference to the feedback.

Quality of lay person CPR performance with compression: ventilation ratios 15:2, 30:2 or continuous chest compressions without ventilations on manikins.

The new CPR guidelines emphasise chest compression depth and have increased the compression:ventilation ratio to cause less time intervals without chest compressions. How this change may influence the quality of chest compressions is not documented. Sixty-eight volunteers among travellers at Oslo international airport and a senior citizen centre performed 5 min of CPR on a manikin with compression:ventilation ratios 15:2, 30:2 or continuous chest compressions. Median age was 37.5 years (range 15-87), 59% were men, and 71% reported CPR training median 8 years (3-15) previously. Three of 22, 4 of 23 and 3 of 23 subjects in the 15:2, 30:2 and continuous compressions groups respectively stopped before 5 min had passed. Mean compression depth was 41 +/- 11, 45 +/- 8 and 30 +/- 8 mm, respectively. Depth was reduced as a function of time in the continuous compression group. Number of compressions per minute was 40 +/- 9, 43 +/- 14 and 73 +/- 24 and percent no flow time 49 +/- 13%, 38 +/- 20% and 1 +/- 2%, respectively. In conclusion, continuous chest compressions without ventilations gave significantly more chest compressions per minute, but with decreased compression quality. No flow time for 30:2 was significantly less than for 15:2.

Incidence of Newborn Stabilization and Resuscitation Measures and Guideline Compliance during the First Minutes of Life in Norway.

BACKGROUND: Most newborns manage the transition from intra- to extrauterine life without interventions, yet neonatal morbidity caused by failure of transition remains an important health problem. OBJECTIVE: To determine the incidence of neonatal stabilization and resuscitation measures and guideline compliance during the first minutes after birth. METHODS: This is a prospective, observational study of all births in three Norwegian hospitals. All interventions performed, including suctioning, use of pulse oximetry, continuous positive airway pressure (CPAP), positive pressure ventilation (PPV), supplemental oxygen, intubation, and administration of drugs, were registered at every on-call team shift during the study period. RESULTS: A total of 1,507 live-born infants were included, of whom 264 (18%) were brought to the resuscitation crib. Oropharyngeal suctioning was performed in 77 (5%), deep blind suctioning was carried out in 10 (1%) and 84 (6%) were monitored using pulse oximetry. PPV was provided in 58 cases (4%) - 8 (21%) of <34 weeks and 50 (3%) of ≥34 weeks of gestation. Sustained inflation is not routinely used in these departments. CPAP (without PPV) was provided in 17 cases (1%) - 4 (0.3%) were intubated and ventilated through the endotracheal tube. Supplemental oxygen was given to 39 infants (3%) - 9 without pulse oximetry monitoring. The median (interquartile range) birth weight and gestational age of the newborns requiring PPV and/or CPAP were 3,220 g (2,643-3,858) and 39 weeks (37-41), respectively. CONCLUSION: In this study, the need for resuscitation and/or stabilization measures was commonly considered, and 4% of all newborns received PPV. Despite strong guideline emphasis on the use of pulse oximetry to guide oxygen administration, many infants received oxygen treatment without pulse oximetry monitoring.

A combination of metabolic strategies plus cardiopulmonary bypass improves short-term resuscitation from prolonged lethal cardiac arrest.

BACKGROUND: The metabolic or late phase of cardiac arrest is highly lethal. Emergency cardiopulmonary bypass (ECPB) can resuscitate many patients even after prolonged cardiac arrest and provides immediate vascular access for correction of metabolic derangement during the reperfusion process. We developed a rodent model of ECPB resuscitation which showed the superiority of ECPB over conventional CPR, especially when combined with hypothermia. For this study we examined a metabolic strategy against ischemia-reperfusion injury (MS-IR) that included: leukoreduction, low Ca(2+), Mg(2+), buffered pH, red blood cells and a colloid. We tested whether ECPB plus MS-IR and/or hypothermia improves short-term hemodynamic outcomes compared to a standard ECPB reperfusate. METHODS: Using a 2×2 factorial design we tested ECPB with (a) MS-IR versus a standard crystalloid solution; and (b) hypothermia versus normothermia in our rat model. The four reperfusion strategies included: (1) MS-IR plus hypothermia, (2) MS-IR with normothermia, (3) standard plasma-lyte (STD) reperfusate plus hypothermia, or (4) STD plus normothermia. Animals underwent 12 min of untreated asphyxial arrest and were resuscitated with ECPB and one of the four strategies for 30 min. Thereafter, ECPB was discontinued and ventilatory support was provided for 3 hours, while hemodynamic, perfusion and other metrics were serially measured. RESULTS: All rats achieved ROSC with ECPB. Significant differences between the groups emerged after 3 hrs: the best outcomes were in animals with MS-IR plus hypothermia (lactate: 1.1 ± 0.1 mmol/L; MAP: 83 ± 4 mm Hg, seizures: 0/10), while the worst outcomes were with STD and normothermia (lactate: 8.9 ± 1.4 mmol/L, MAP: 36 ± 4 mm Hg, seizures: 7/10, p < 0.001). The outcomes of the other two groups (MS-IR only; hypothermia only) were intermediate. MS-IR and hypothermia improved outcome in an additive fashion. CONCLUSIONS: While most human ECPB is applied with a normothermic crystalloid priming solution, we observed that in rodents the addition of MS-IR plus hypothermia resulted in considerable short-term benefit after prolonged arrest. Future long-term and translational survival studies are warranted to optimize ECPB resuscitation methods.

A randomized trial of the capability of elderly lay persons to perform chest compression only CPR versus standard 30:2 CPR.

AIM OF THE STUDY: Early cardiopulmonary resuscitation (CPR) improves survival after cardiac arrest, but there is a discrepancy between the age group normally attending CPR-classes and the age group most likely to witness a cardiac arrest. We wanted to study if elderly lay persons could perform 10min of CPR on a realistic manikin with continuous chest compressions (CCC) and conventional CPR (30:2). METHODS: Volunteers were tested 5-7 months after CPR-classes. They were randomized to CCC or 30:2, and to receive feedback (FB) or not. Quality of CPR, age adjusted maximum heart rate (HRmax), and subjective exhaustion ratings were measured and evaluated in a blinded fashion. Temporal development and group differences were evaluated with ANOVA procedures. RESULTS: All 64 volunteers were able to perform CPR for 10min and rated their efforts as mild to moderate in concordance with a mean HRmax of 78%. Quality of CPR was similar in all groups, except for chest compression rate that was slightly higher and had less variability in the FB group. Overall chest compression depth was 41+/-4.5mm. Analysis of temporal development of chest compression depth revealed a small initial decline before leveling off. As expected, CCC group had less pauses and higher total number of chests compressions. CONCLUSION: Lay people in the age group 50-76 were able to perform CPR with acceptable quality for 10min and we found only very slight temporal quality deterioration. This makes training programs for the elderly meaningful to improve survival after cardiac arrest.

The effect of transport on quality of cardiopulmonary resuscitation in out-of-hospital cardiac arrest.

INTRODUCTION: Most manikin and clinical studies have found decreased quality of CPR during transport to hospital. We wanted to study quality of CPR before and during transport for out-of-hospital cardiac arrest patients and also whether quality of CPR before initiation of transport was different from the quality in patients only receiving CPR on scene. MATERIALS AND METHODS: Quality of CPR was prospectively registered with a modified defibrillator for consecutive cases of out-of-hospital cardiac arrest in three ambulance services during 2002-2005. Ventilations were registered via changes in transthoracic impedance and chest compressions were measured with an extra chest compression pad placed on the patients' sternum. Paired t-tests were used to analyse quality of CPR before vs. during transport with ongoing CPR. Unpaired t-tests were used to compare CPR quality prior to transport to CPR quality in patients with CPR terminated on site. RESULTS: Quality of CPR did not deteriorate during transport, but as previously reported overall quality of CPR was substandard. Quality of CPR performed on site was significantly better when transport was not initiated with ongoing CPR compared to episodes with initiation of transport during CPR: fraction of time without chest compressions was 0.45 and 0.53 (p<0.001), compression depth 37 mm and 34 mm (p=0.04), and number of chest compressions per minute 61 and 56 (p=0.01), respectively. CONCLUSION: CPR quality was sub-standard both before and during transport. Early decision to transport might have negatively affected CPR quality from the early stages of resuscitation.