Action sequence for layperson cardiopulmonary resuscitation.

Although some minor modifications were forged, the general consensus was to maintain most of the current guidelines for phone first/phone fast, no-assisted-ventilation CPR, the A-B-C (vs C-A-B) sequence of CPR, and the recovery position. The decisions to leave these guidelines as they are were based on a lack of evidence to justify the proposed changes, coupled with a reluctance to make revisions that would require major changes in worldwide educational practices without such evidence.Nonetheless, some major changes were made. The time-honored procedure ol pulse check by lay rescuers was eliminated altogether and replaced with an assessment for other signs of circulation. Likewise, it was recommended that even the professional rescuer now check for these other signs of circulation. Although professional rescuers may simultaneously check for a pulse, they should do so only for a short period of time (within 10 seconds). There was also enthusiasm for deleting the ventilation aspect of EMS dispatcher-assisted CPR instructions that are provided to rescuers at the scene who are inexperienced in CPR. lt was made clear, though, that the data are applicable only to adult patients who are receiving CPR and that the data are appropriate most for EMS systems with rapid response times.

Intra-aortic administration of epinephrine above aortic occlusion does not alter outcome of experimental cardiopulmonary resuscitation.

Intra-aortic balloon occlusion during experimental cardiopulmonary resuscitation (CPR) improves coronary perfusion pressure and resuscitability and provides unique access to the central circulation. It has been hypothesized that administration of epinephrine into the aortic arch in combination with aortic occlusion would further improve haemodynamics during CPR, resuscitability and 24 h survival. In 16 anaesthetised dogs intravascular catheters were placed for hemodynamic and blood gas monitoring. An aortic balloon catheter was placed by femoral artery insertion with its tip just distal to the left subclavian artery. Ventricular fibrillation for 7.5 min without CPR, 2.5 min of Basic Life Support with chest compressions and ventilation with 100% oxygen were followed by 30 min of Advanced Cardiac Life Support (ACLS) with systemic canine drug dosages. The intra-aortic balloon was inflated when ACLS started and gradually deflated shortly after restoration of spontaneous circulation (ROSC). Epinephrine, in 100 microg/kg boluses every 5 min until the heart was restarted or 30 min had elapsed was administered through the intra-aortic catheter in the experimental group (n = 8) and via a central venous catheter in the control group (n = 8). Coronary perfusion pressure increased during the ACLS period in both groups (P < 0.05) with no difference between the groups and there was no difference in the frequency of ROSC (experimental group 5/8, control group 4/8). Furthermore with respect to 24 h survival, there was no difference between the experimental group (2/8) and the control group (3/8). Severe macroscopic haemorrhagic necrosis of the myocardium in the dogs with ROSC was found in 4/5 in the experimental group compared to 1/4 in the control group. In conclusion, intra-aortic administration of 100 microg/kg epinephrine doses combined with aortic occlusion during experimental CPR did not alter outcome.

A comparison of techniques for placement of double-lumen endobronchial tubes.

STUDY OBJECTIVE: To compare two methods of double-lumen endobronchial tube placement for thoracic surgery and to identify factors that provide a rational basis for placement method selection. DESIGN: Prospective, randomized study. SETTING: Teaching hospital. PATIENTS: 58 ASA physical status II, III, and IV patients scheduled for surgical procedures requiring elective left-sided endobronchial intubation. INTERVENTIONS: Patients were assigned randomly to either a group in which the initial placement method was the traditional approach of placing the endobronchial tube through the larynx and then advanced blindly into the left mainstem bronchus, or to a second group in which the left mainstem bronchus was intubated under direct vision using the fiberoptic bronchoscope. MEASUREMENTS AND MAIN RESULTS: Of the 32 patients who underwent the traditional approach, primary success occurred in 27 patients and eventual success in 30. In 27 patients undergoing the directed approach, primary success occurred in 21 patients and eventual success in 25. Two patients in each group required the alternative method. The blind approach took 88 (+/- 91) seconds and the directed approach took 181 (+/- 193) seconds (p = 0.029). Timing data were analyzed using analysis of variance with respect to method and secretions and then t-tests as appropriate. Categorical data were analyzed using the Kruskal-Wallis and Fisher's exact tests as appropriate. All values are reported as means +/- SD. CONCLUSION: Both the blind and directed approaches resulted in successful left mainstem placement of the endobronchial tube in the majority of patients but either method may fail when used alone. More time was required using the directed approach. Operator experience with both methods will increase the likelihood of success. The choice of the initial approach may be influenced by patient factors as well as available equipment and personnel.

High-dose recombinant human erythropoietin stimulates reticulocyte production in patients with multiple organ dysfunction syndrome.

OBJECTIVE: To investigate erythropoietin (EPO) production and the erythropoietic potency of recombinant human EPO in the multiple organ dysfunction syndrome. DESIGN: Randomized, prospective, controlled clinical trial. MATERIALS AND METHODS: Patients received either 600 IU/kg intravenous EPO three times weekly (n = 9) or saline (control, n = 10). MEASUREMENTS: EPO levels, circulating soluble receptors for tumor necrosis factor and interleukin-2, levels of interleukin-6 and intercellular adhesion molecule, and early peripheral blood cell progenitors. RESULTS: EPO production in the control group remained low. Pharmacologic EPO blood levels were associated with increased reticulocyte counts compared with both controls (p < 0.04) and baseline (p < 0.006). Increased levels of soluble receptors for tumor necrosis factor in the treatment group compared with the controls did not prevent this effect. Interleukin 6 inhibited reticulocyte production. CONCLUSION: Despite increased cytokine levels, pharmacologic EPO blood levels were associated with increased reticulocyte counts in patients with multiple organ dysfunction syndrome.

Effects of intra-aortic balloon occlusion on hemodynamics during, and survival after cardiopulmonary resuscitation in dogs.

OBJECTIVE: To evaluate the effect of balloon occlusion of the proximal descending aorta during cardiopulmonary resuscitation (CPR) on hemodynamics, restoration of spontaneous circulation, and 24-hr survival. DESIGN: Prospective, randomized, controlled trial. SETTING: Experimental laboratory in a university hospital. SUBJECTS: Eighteen anesthetized dogs. INTERVENTIONS; Catheters were placed for hemodynamic and blood gas monitoring. An aortic balloon catheter was placed with its tip just distal to the left subclavian artery. After 10 mins of ventricular fibrillation without CPR, 3 mins of Basic Life Support (chest compressions and ventilation with 100% oxygen) was followed by up to 30 mins of Advanced Cardiac Life Support with canine drug dosages. In the treatment group (n = 8), the intra-aortic balloon was inflated when Advanced Cardiac Life Support started and not deflated until shortly after restoration of spontaneous circulation. The control animals (n = 10) were treated with an identical resuscitation but without intra-aortic balloon occlusion. MEASUREMENTS AND MAIN RESULTS: In the treatment group, coronary perfusion pressure was greater during Advanced Cardiac Life Support (p = .026). Restoration of spontaneous circulation was more frequent (7/8 dogs) as compared with the control group (3/10 dogs) (p = .025). There was a trend toward greater 24-hr survival in the treatment group (5/8 dogs) than in the control group (3/10 dogs). CONCLUSIONS: Balloon occlusion of the proximal descending aorta during experimental CPR improves restoration of spontaneous circulation. Further laboratory and human studies are needed to determine the clinical efficacy of this technique.

CPR training without an instructor: development and evaluation of a video self-instructional system for effective performance of cardiopulmonary resuscitation.

Traditional classroom-based instruction of cardiopulmonary resuscitation (CPR) has failed to achieve desired rates of bystander CPR. Video self-instruction (VSI) is a more accessible alternative to traditional classroom instruction (TRAD), and it achieves better CPR skill performance. VSI employs a 34-min training tape and an inexpensive manikin. VSI combines simplified and reordered content focusing on the delivery of one-rescuer CPR with the 'practice-as-you-watch' approach of an exercise video. Performance of CPR skills immediately following VSI was compared to performance immediately following TRAD using an instrumented manikin, a valid and reliable skill checklist, and an overall competency rating. Compared with TRAD subjects, VSI subjects performed more compressions correctly (P < 0.001), more ventilations correctly (P < 0.001), and more assessment and sequence skills correctly (P < 0.001). TRAD subjects delivered twice as many compressions that were too shallow, and underinflated the lungs twice as often. VSI subjects were rated 'competent' or better 80.0% of the time, compared with TRAD subjects, who achieved this rating only 45.1% of the time (P < 0.001). TRAD subjects were rated to be 'not competent' in performing CPR nearly 10 times more often than VSI subjects (P < 0.001). Subjects 40 years of age and older performed better after VSI than after TRAD. Superior skill performance among subjects exposed to VSI persisted 60 days following training. VSI has the potential to reach individuals unlikely to participate in TRAD classes because of its greater convenience, lower cost, and training in about 0.50 h compared with 3-4 h for TRAD classes.

Nonpharmacologic treatment of postoperative nausea.

UNLABELLED: Nausea is the most common postoperative complication of anesthesia. Appropriately applied acupressure offers a safe and cost-effective nursing approach to the prevention of this problem. This study tested the effect of acupressure on the incidence of postoperative nausea in same-day surgery patients. METHODS: Ninety outpatient surgery patients were randomly assigned to one of three groups. The treatment group (n = 30) received bilateral elastic bands designed to exert pressure on the appropriate location on the distal aspect of the wrist during the perioperative period. The placebo group (n = 30) had elastic bands incapable of acupressure placed on their wrists. The control group (n = 30) received routine nursing and medical interventions for nausea and vomiting. Antiemetics were prescribed by the anesthesiologist and administered to patients in all three groups if nausea persisted and/or emesis occurred. The incidences of nausea or vomiting were tabulated separately for operating room, PACU phase I, and PACU phase II, and compared using Fisher's Exact Test. RESULTS: The incidence of nausea and vomiting did not differ overall in the OR or PACU phase I. However, in PACU phase II the incidence was 10% in the treatment group, 20% in the placebo group, and 50% in the control group (overall, P = .0001). Treatment wrist bands reduced the incidence of nausea and vomiting as compared with the control group (P = .0001), as did the placebo wrist bands (P = .0033). The numerical trend suggests that the incidence is reduced by half. The incidence of nausea can be significantly reduced by the use of placebo and suggests that further reduction can be obtained by using acupressure.

A comparison of prolonged manual and mechanical external chest compression after cardiac arrest in dogs.

The effects of manual and a new mechanical chest compression device (Heartsaver 2000) during prolonged CPR with respect to haemodynamics and outcome were tested in a prospective, randomized, controlled experimental trial during ventricular fibrillation in 12 dogs of 9-13 kg body weight after 1 min of cardiac arrest. During the first 10 min of CPR the dogs were resuscitated according to the Basic Life Support (BLS) algorithm, followed by 20 min of Advanced Life Support (ALS) algorithm. After 30 min of CPR both manual and mechanical CPR groups were resuscitated following a standardized ALS protocol. During CPR, coronary perfusion pressure and end tidal CO2 were greater with mechanical CPR. All animals were successfully resuscitated and neurological deficit scores were not different. The CPR trauma score was less in the mechanical group. Mechanical external chest compression provided better haemodynamics than the manual technique, though outcome did not differ. Both optimally performed manual and mechanical techniques produce flow sufficient to maintain organ viability for 30 min of CPR after a 1 min arrest interval.

Influence of prostaglandin E1 on tissue ischemia during surgical repair of the abdominal aorta.

OBJECTIVE: To evaluate tissue protection by PGE1 during leg ischemia in patients undergoing aortic surgery. DESIGN: Randomized, controlled prospective clinical trial. SETTING: Single university hospital. PARTICIPANTS: 19 consecutive patients undergoing abdominal aortic aneurysm repair. INTERVENTIONS: Patients received infusions of 30 ng/kg/min of PGE1 or saline. MEASUREMENTS AND MAIN RESULTS: Hemodynamic variables, lactate, creatine phosphokinase, and thromboxane B2 (TXB2) were measured. In the control group, the decrease in cardiac index (CI) after aortic cross-clamping (AXC) persisted until unclamping together with a decrease in femoral venous O2 content (CfvO2). In the PGE1 group, CI returned to baseline with a trend toward greater CfvO2 levels. During reperfusion in the PGE1 group, O2 consumption and lactate levels exceeded preclamp values. Pulmonary hypertension occurred equally in both groups but did not correlate with TXB2, which was not altered by surgery or by PGE1 infusion. CONCLUSIONS: Intraoperative PGE1 treatment offers no benefit and may exacerbate tissue ischemia during AXC by redistributing microcirculatory flow or limiting cellular oxygen utilization in a manner that overwhelms any possible protective effect.

Epinephrine and sodium bicarbonate during CPR following asphyxial cardiac arrest in rats.

Although high-dose epinephrine during CPR improves coronary perfusion pressure (CoPP) and rate of return of spontaneous circulation (ROSC) in some models, its impact on long term outcome (> or = 72 h) has not been evaluated. Previous studies of sodium bicarbonate (NaHCO3) therapy during CPR indicate that beneficial effects may be dependent on epinephrine (EPI) dose. We hypothesized that EPI and NaHCO3 given during CPR have a significant impact on long term outcome. One hundred male Sprague-Dawley rats were prospectively studied in a block randomized placebo controlled trial. Rats were anesthetized, paralyzed, mechanically ventilated, instrumented, and each underwent 10 min of asphyxia, resulting in 6.8 +/- 0.4 min of circulatory arrest. Resuscitation was performed by mechanical ventilation and manual external chest compressions. EPI 0.0 (placebo), 0.01, 0.1, or 1.0 mg/kg IV was given at the onset of CPR, followed by NaHCO3 0.0 (placebo) or 1.0 mEq/kg IV. Successfully resuscitated rats were monitored and ventilated for 1 h without hemodynamic support. Neurologic deficit scores (NDS), cerebral histopathologic damage scores (CHDS) and myocardial histopathologic damage scores (MHDS) were determined in rats that survived 72 h. EPI improved CoPP and ROSC in a dose-dependent manner up to 0.1 mg/kg. Rats receiving EPI 0.1 and 1.0 mg/kg during CPR exhibited prolonged post-ROSC hypertension and metabolic acidemia, increased A-a O2 gradient, and an increased incidence of post-ROSC ventricular tachycardia or fibrillation. Overall survival was lower with EPI 0.1 and 1.0 mg/kg compared to 0.01 mg/kg. Although NDS was significantly less with EPI 0.1 mg/kg compared to placebo, there was no difference in CHDS between groups. In contrast, MDS was significantly higher with EPI 0.1 mg/kg compared to placebo or EPI 0.01 mg/kg. There was an overall trend toward improved survival at 72 h in rats that received NaHCO3 which was most evident in the EPI 0.1 mg/kg group. We conclude that (1) EPI during CPR has a biphasic dose/response curve in terms of survival, when post-resuscitation effects are left untreated and (2) NaHCO3 doses greater than 1.0 mEq/kg may be necessary to treat the side-effects of high-dose EPI. Further work is needed to determine if treating the immediate post-resuscitation effects of high-dose EPI can prevent detrimental effects on long-term outcome.

Sodium bicarbonate may improve outcome in dogs with brief or prolonged cardiac arrest.

OBJECTIVE: Despite the absence of outcome evaluation, the use of sodium bicarbonate in cardiac arrest has declined based on advanced cardiac life-support guidelines. The effects of bicarbonate therapy on outcome in a canine model of ventricular fibrillation cardiac arrest of brief (5-min) and prolonged (15-min) duration were examined. DESIGN: Prospective, randomized, controlled trial. SETTING: Experimental animal laboratory in a university medical center. SUBJECTS: Thirty-two adult dogs, weighing 10 to 17 kg. INTERVENTIONS: The animals were prepared with ketamine, nitrous oxide/oxygen, halothane, and pancuronium. Ventricular fibrillation was then electrically induced and maintained in arrest for 5 mins (n = 12) or 15 mins (n = 20). Canine advanced cardiac life-support protocols were instituted, including defibrillation, cardiopulmonary resuscitation (CPR), and the administration of epinephrine (0.1 mg/kg), atropine, and lidocaine. The bicarbonate group received 1 mmol/kg of sodium bicarbonate initially, and base deficit was corrected to -5 mmol/L with additional bicarbonate, whereas acidemia was untreated in the control group. Cardiopulmonary values were recorded at intervals between 5 mins and 24 hrs, and the neurologic deficit score was determined at 24 hrs after CPR. MEASUREMENTS AND MAIN RESULTS: The treatment group received an additional 2 to 3 mmol/kg of bicarbonate in the early postresuscitation phase. Compared with controls, the bicarbonate group demonstrated equivalent (with brief arrest) or improved (with prolonged arrest) return of spontaneous circulation and survival to 24 hrs, with lessened neurologic deficit. The acidosis of arrest was decreased in the prolonged arrest group without hypercarbia. Improved coronary and systemic perfusion pressures were noted in the bicarbonate group with prolonged arrest, and the epinephrine requirement for return of spontaneous circulation was decreased. CONCLUSIONS: The empirical administration of bicarbonate improves the survival rate and neurologic outcome in a canine model of cardiac arrest.

Quality of bystander cardiopulmonary resuscitation influences outcome after prehospital cardiac arrest.

To evaluate the influence of quality of bystander cardiopulmonary resuscitation (CPR) on outcome in prehospital cardiac arrest we consecutively included patients with prehospital cardiac arrest treated by paramedics in a community run ambulance system in Oslo, Norway from 1985 to 1989. Good CPR was defined as palpable carotid or femoral pulse and intermittent chest expansion with inflation attempts. Outcome measure was hospital discharge rate. One hundred and forty-nine of 334 patients (45%) received bystander CPR. The discharge rate after good BCPR (23%) was higher than after no good BCPR (1%, P < 0.0005) or after no BCPR (6%, P < 0.0005). There was no difference between no good and no BCPR (P = 0.1114). There were no differences in paramedic response interval between the groups, but the mean interval from start of unconsciousness to initiation of CPR (arrest-CPR interval) was significantly shorter in the group receiving good bystander CPR (2.5 min, 95% confidence interval (CI): 1.7-3.3 min) than no good CPR (6.6 min, CI: 5.2-8.0 min) or no bystander CPR (7.8 min, CI: 7.2-8.4 min). Bystanders started CPR more frequently in public than in the patient's home (58 vs. 34%, P < 0.0005). Good bystander CPR was associated with a shorter arrest-CPR interval and improved hospital discharge rate as compared to no good BCPR or no BCPR.