Hipotermija za neuroprotekciju odraslih nakon kardiopulmonalne reanimacije
Abstract
Background
Good neurological outcome after cardiac arrest is difficult to achieve. Interventions during the resuscitation phase and treatment within the first hours after the event are critical. Experimental evidence suggests that therapeutic hypothermia is beneficial, and several clinical studies on this topic have been published. This review was originally published in 2009; updated versions were published in 2012 and 2016.
Objectives
We aimed to perform a systematic review and meta‐analysis to assess the influence of therapeutic hypothermia after cardiac arrest on neurological outcome, survival and adverse events.
Search methods
We searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 10); MEDLINE (1971 to May 2015); EMBASE (1987 to May 2015); the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1988 to May 2015); and BIOSIS (1989 to May 2015). We contacted experts in the field to ask for information on ongoing, unpublished or published trials on this topic.The original search was performed in January 2007.
Selection criteria
We included all randomized controlled trials (RCTs) conducted to assess the effectiveness of therapeutic hypothermia in participants after cardiac arrest, without language restrictions. We restricted studies to adult populations cooled by any cooling method, applied within six hours of cardiac arrest.
Data collection and analysis
We entered validity measures, interventions, outcomes and additional baseline variables into a database. Meta‐analysis was performed only for a subset of comparable studies with negligible heterogeneity. We assessed the quality of the evidence by using standard methodological procedures as expected by Cochrane and incorporated the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach.
Main results
We found six RCTs (1412 participants overall) conducted to evaluate the effects of therapeutic hypothermia ‐ five on neurological outcome and survival, one on only neurological outcome. The quality of the included studies was generally moderate, and risk of bias was low in three out of six studies. When we compared conventional cooling methods versus no cooling (four trials; 437 participants), we found that participants in the conventional cooling group were more likely to reach a favourable neurological outcome (risk ratio (RR) 1.94, 95% confidence interval (CI) 1.18 to 3.21). The quality of the evidence was moderate.
Across all studies that used conventional cooling methods rather than no cooling (three studies; 383 participants), we found a 30% survival benefit (RR 1.32, 95% CI 1.10 to 1.65). The quality of the evidence was moderate.
Across all studies, the incidence of pneumonia (RR 1.15, 95% CI 1.02 to 1.30; two trials; 1205 participants) and hypokalaemia (RR 1.38, 95% CI 1.03 to 1.84; two trials; 975 participants) was slightly increased among participants receiving therapeutic hypothermia, and we observed no significant differences in reported adverse events between hypothermia and control groups. Overall the quality of the evidence was moderate (pneumonia) to low (hypokalaemia).
Authors' conclusions
Evidence of moderate quality suggests that conventional cooling methods provided to induce mild therapeutic hypothermia improve neurological outcome after cardiac arrest, specifically with better outcomes than occur with no temperature management. We obtained available evidence from studies in which the target temperature was 34°C or lower. This is consistent with current best medical practice as recommended by international resuscitation guidelines for hypothermia/targeted temperature management among survivors of cardiac arrest. We found insufficient evidence to show the effects of therapeutic hypothermia on participants with in‐hospital cardiac arrest, asystole or non‐cardiac causes of arrest.
PICO
Plain language summary
Hlađenje tijela nakon oživljavanja zbog srčanog zastoja: može li pomoći?
Istraživačko pitanje
U ovom Cochrane sustavnom pregledu ispitano je da li ljudima koji se oživljavaju zbog srčanog zastoja može pomoći ako im se tijelo ohladi na temperaturu od 34°C ili nižu.
Dosadašnje spoznaje
Ispitanici i analizirani rezultati
Oko 30‐50% svih osoba koje pate od koronarne srčane bolesti dožive smrt zbog iznenadnog zastoja srca u neko doba tijekom bolesti. Iznenadna srčana smrt znači da srce prestaje raditi i da se zaustavlja cirkulacija krvi u tijelu. Ako se te osobe ne pokušaju oživjeti, moždane stanice vrlo brzo postanu nepovratno oštećene i osoba umire. Nakon oživljavanja prvih je par sati terapije ključno kako bi se izbjeglo ili ograničilo oštećenje mozga. Jedan oblik terapije koji bi možda mogao spriječiti oštećenje stanica sastoji se od pothlađivanja tijela kroz nekoliko sati, nakon uspješnog oživljavanja, na temperaturu od 34°C ili nižu.
Postupak
U ovom Cochrane sustavnom pregledu analizirani su klinički pokusi u kojma su uspoređeni rezultati osoba čija su tijela ohlađena na 32°C do 34°C nakon oživljavanja s osobama čije tijelo nije hlađeno nakon uspješnog oživljavanja.
Datum pretraživanja literature
Dokazi se odnose na studije objavljene do svibnja 2015.
Značajke istraživanja
U ovu analizu uključeno je 6 studija (s ukupno 1412 ispitanika), od kojih su četiri (437 osoba) ispitale učinke hlađenja tijela standardnim metodama nakon uspješnog oživljavanja zbog prestanka rada srca. Jedna studija koristila je hemofiltraciju (hlađenje tijela izvana ‐ postupak sličan dijalizi) kao metodu hlađenja, i jedna studija u kojoj je hlađenje tijela na 33°C uspoređeno sa hlađenjem tijela na 36°C zasebno su analizirane u ovom sustavnom pregledu.
Izvori financiranja studija
Studiju koja je ispitala vanjsko hlađenje financirala je tvrtka koja proizvodi uređaje za dijalizu. Od ostalih pet studija uključenih u glavnu analizu, dvije su primile financiranje od vladinih izvora ili neprofitnih udruga, a tri studije nisu navele izvore financiranja.
Ključni rezultati
Kad se usporede osobe čije je tijelo ohlađeno na 32°C do 34°C s onima čije tijelo nije uopće hlađeno, utvrđeno je da bi 63% onih čije je tijelo hlađeno doživjelo nikakvo ili mininalno oštećenje mozga, u uporedbi s 33% onih čije tijelo nije hlađeno. Hlađenje tijela imalo je važan učinak na jednostavno preživljenje, sa ili bez oštećenja mozga: 57% osoba bi preživjelo ako je njihovo tijelo bilo ohlađeno u usporedbi s 42% onih čije tijelo uopće nije hlađeno. Nisu zabilježene ozbiljne nuspojave, ali hlađenje tijela bilo je povezano s povećanim rizikom od razvoja upale pluća (49% naspram 42% onih koji nisu hlađeni) i povećanim rizikom od niske koncentracije kalija u krvi (18% naspram 13%).
Kvaliteta dokaza
Dio studija imao je određene metodološke nedostatke, uključujući malen broj ispitanika i neprimjerene metode balansiranja broja ispitanika između intervencijske i kontrolne skupine. Međutim, kad se uzmu u obzir razlike među istraživanjima, jasno je da te manjkavosti nisu imale značajniji učinak na glavne rezultate.
