Casper Karen, Murphy George, Weinstein Carl, Brinsfield Kathryn
Boston University School of Medicine, Boston, Massachusetts, USA.
Prehosp Emerg Care. 2003 Jul-Sep;7(3):299-302. doi: 10.1080/10903120390936455.
Bystander cardiopulmonary resuscitation (CPR) improves survival. The authors attempted to determine whether the rates at which CPR is performed differ when a cardiac arrest is witnessed by someone known or unknown to the victim.
Retrospective observational cohort study of all witnessed nontraumatic cardiac arrests (Utstein) from Boston from 1994 to 1998. Cardiac arrests were excluded if the original record was unavailable or if medical or public safety personnel witnessed the cardiac arrest. The relationship between the provider of CPR and the victim was determined by the emergency medical technicians at the scene and later categorized as known or unknown. Survival (survival to hospital discharge) was determined through telephone follow-up with the arrest victim's caregivers.
Known bystanders performed CPR 15.5% (42 of 271) of the time (95% confidence interval (95% CI], 11.2%, 19.8%). Unknown bystanders performed CPR 45.8% (66 of 144) (95% CI, 37.6%, 54.1%) of the time. The odds ratio of receiving CPR if an unknown bystander witnessed a cardiac arrest was 4.61 (95% CI, 2.89, 7.34). Arrests witnessed by unknown bystanders had a 24.3% (35 of 144) (95% CI, 17.2%, 31.4%) survival rate. Those witnessed by known bystanders had a 17.7% (95% CI, 13.1%, 22.3%) survival rate (p = 0.110). In a logistic regression model including both bystander status and location of arrest, unknown bystander status remained statistically significantly associated with having CPR performed regardless of location (OR = 3.56, p = 0.01; 95% CI, 1.64, 7.72). Location was not statistically significant in the presence of bystander status (OR = 1.17, p = 0.686).
Victims of cardiac arrest are more likely to receive CPR when the event is witnessed by bystanders unknown to the victim than if the arrest is witnessed by friends or family.
旁观者实施心肺复苏术（CPR）可提高存活率。作者试图确定当心脏骤停由受害者认识或不认识的人目睹时，实施CPR的比率是否存在差异。
对1994年至1998年波士顿所有非创伤性目击心脏骤停（Utstein模式）进行回顾性观察队列研究。如果原始记录不可用，或者医疗或公共安全人员目睹了心脏骤停，则将其排除。CPR实施者与受害者之间的关系由现场急救医疗技术人员确定，随后分为认识或不认识。通过与心脏骤停受害者的护理人员进行电话随访来确定存活率（存活至出院）。
认识的旁观者实施CPR的时间占15.5%（271例中的42例）（95%置信区间[95%CI]，11.2%，19.8%）。不认识的旁观者实施CPR的时间占45.8%（144例中的66例）（95%CI，37.6%，54.1%）。如果不认识的旁观者目睹心脏骤停，接受CPR的比值比为4.61（95%CI，2.89，7.34）。不认识的旁观者目睹的心脏骤停存活率为24.3%（144例中的35例）（95%CI，17.2%，31.4%）。认识的旁观者目睹的心脏骤停存活率为17.7%（95%CI，13.1%，22.3%）（p = 0.110）。在一个包括旁观者身份和心脏骤停地点的逻辑回归模型中，无论地点如何，不认识的旁观者身份与实施CPR在统计学上仍显著相关（比值比 = 3.56，p = 0.01；95%CI，1.64，7.72）。在存在旁观者身份的情况下，地点在统计学上不显著（比值比 = 1.17，p = 0.686）。
与心脏骤停由朋友或家人目睹相比，当心脏骤停由受害者不认识的旁观者目睹时，受害者更有可能接受CPR。
