Marko Sainio

Deeper chest compression – More complications for cardiac arrest patients?

AIM OF THE STUDY Sternal and rib fractures are frequent complications caused by chest compressions during cardiopulmonary resuscitation (CPR). This study aimed to investigate the potential association of CPR-related thoracic and abdominal injuries and compression depth measured with an accelerometer. METHODS We analysed the autopsy records, CT scans or chest radiographs of 170 adult patients, suffering in-hospital cardiac arrest at the Tampere University Hospital during the period 2009-2011 to investigate possible association of chest compressions and iatrogenic injuries. The quality of manual compressions during CPR was recorded on a Philips, HeartStart MRx Q-CPR™-defibrillator. RESULTS Patients were 110 males and 60 females. Injuries were found in 36% of male and 23% of female patients. Among male patients CPR-related injuries were associated with deeper mean - and peak compression depths (p<0.05). No such association was observed in women. The frequency of injuries in mean compression depth categories <5, 5-6 and >6 cm, was 28%, 27% and 49% (p=0.06). Of all patients 27% sustained rib fractures, 11% sternal fracture and eight patients had haematomas/ruptures in the myocardium. In addition, we observed one laceration of the stomach without bleeding, one ruptured spleen, one mediastinal haemorrhage and two pneumothoraxes. CONCLUSION The number of iatrogenic injuries in male patients was associated with chest compressions during cardiopulmonary resuscitation increased as the measured compression depth exceeded 6 cm. While there is an increased risk of complications with deeper compressions it is important to realize that the injuries were by and large not fatal.

Quality controlled manual chest compressions and cerebral oxygenation during in-hospital cardiac arrest

AIM The quality of cardiopulmonary resuscitation (CPR) is associated with the rate of return of spontaneous circulation (ROSC) during human cardiac arrest. Current advances in defibrillator technology enable measurement of CPR quality during resuscitation, but it is not known whether this is directly reflected in cerebral oxygenation. In this descriptive study we aimed to evaluate whether the quality of feedback-monitored CPR during in-hospital cardiac arrest is reflected in near infrared frontal cerebral spectroscopy (NIRS). METHODS Nine patients suffering an in-hospital cardiac arrest in a university hospital were included. All patients underwent quality-controlled CPR performed by a dedicated medical emergency team using a Philips HeartStart MRx defibrillator (Philips, Eindhoven, Netherlands) with a CPR quality (Q-CPR, Laerdal Medical, Stavanger, Norway) analysis feature. Simultaneously, bilateral frontal cerebral oximetry was measured using INVOS 5100c (Somanetics, Troy, MI, USA) NIRS. RESULTS During quality controlled resuscitation, regional cerebral oxygenation (rSO(2)) as measured with NIRS was low but it improved during CPR (p=0.043) and 8 min after ROSC (p=0.022). After the onset of NIRS recording, there were four episodes exceeding 30s, during which the quality of CPR was substandard. When CPR technique was corrected and maintained for 2 min, a minor non-significant increase in rSO(2) was observed in two cases. CONCLUSIONS High quality CPR was not significantly reflected in cerebral oxygenation as quantified using NIRS. Even after ROSC and subsequent significant increase in cerebral oxygenation, rSO(2) readings were below previously suggested threshold of cerebral ischaemia. Improving CPR technique after an episode of low quality CPR did not significantly increase rSO(2).

The quality of manual chest compressions during transport--effect of the mattress assessed by dual accelerometers.

The quality of cardiopulmonary resuscitation (CPR) has an impact on survival. The quality may be impaired if the patient needs to be transported to the hospital with ongoing CPR. The aim of this study was to analyse whether the quality of CPR can be improved during transportation by using real‐time audiovisual feedback. In addition, we sought to evaluate the real compression depths taking into account the mattress and stretcher effect.

Effect of mattress and bed frame deflection on real chest compression depth measured with two CPR sensors

AIM Implementation of chest compression (CC) feedback devices with a single force and deflection sensor (FDS) may improve the quality of CPR. However, CC depth may be overestimated if the patient is on a compliant surface. We have measured the true CC depth during in-hospital CPR using two FDSs on different bed and mattress types. METHODS This prospective observational study was conducted at Tampere University Hospital between August 2011 and September 2012. During in-hospital CPR one FDS was placed between the rescuers hand and the patients chest, with the second attached to the backboard between the patients back and the mattress. The real CC depth was calculated as the difference between the total depth from upper FDS to lower FDS. RESULTS Ten cardiac arrests on three different bed and mattress types yielded 10,868 CCs for data analyses. The mean (SD) mattress/bed frame effect was 12.8 (4) mm on a standard hospital bed with a gel mattress, 12.4 (4) mm on an emergency room stretcher with a thin gel mattress and 14.1 (3) mm on an ICU bed with an emptied air mattress. The proportion of CCs with an adequate depth (≥50 mm) decreased on all mattress types after compensating for the mattress/bed frame effect from 94 to 64%, 98 to 76% and 91 to 17%, in standard hospital bed, emergency room stretcher and ICU bed, respectively (p<0.001). CONCLUSION The use of FDS without real-time correction for deflection may result in CC depth not reaching the recommended depth of 50 mm.

Blood pressure during resuscitation in man—The effect of pause during rhythm analysis revisited

AIMS This study reports invasive arterial pressures before and after the rhythm analysing pauses during CPR and evaluates the possible association of the quality of CPR and the length of the pause with blood pressure around the pause. MATERIALS AND METHODS Five patients who experienced out-of hospital or in-hospital cardiac arrest were included in the study. Using a monitor/defibrillator with sensing capabilities, the parameters of CPR quality including chest compression depth, rate, force and the duration of interruption were recorded and compared to blood pressure. RESULTS Altogether 42 pauses were observed in five patients with a duration of 9±5 s (mean±SD). The values for systolic (SAP), mean (MAP) and diastolic arterial pressures (DAP) were 107±30, 44±12 and 14±12 mmHg before the pause and 119±34, 49±13 and 14±14 mmHg after the pause, respectively. There was a statistically significant increase in both SAP (12.1±28.2 mmHg; p=0.021) and MAP (4.2±8.7 mmHg (p=0.008) and the duration of the pause was identified as an independent factor for that in a linear mixed model. The pause duration up to ten seconds maintained the pressure achieved if the compression depth was immediately according to the guidelines (p=0.046). CONCLUSIONS Contrary to the previous animal studies, this preliminary study in humans demonstrates that blood pressures achieved before the rhythm analysis pause do not necessarily decrease after the pause but may even increase if the duration of the pause is under ten seconds and the quality of CPR is good both before and after the pause.

Simultaneous beat-to-beat assessment of arterial blood pressure and quality of cardiopulmonary resuscitation in out-of-hospital and in-hospital settings

OBJECTIVE The current recommendation for depth and rate of chest compression (CC) during cardiopulmonary resuscitation (CPR) is based on limited hemodynamic data recorded during human CPR. We have evaluated the possible association between CC depth and rate and continuously measured arterial blood pressure during adult CPR. METHODS This prospective study included data from 104 patients resuscitated inside or outside hospital. Adequate data on continuously measured invasive arterial blood pressure (BP) and the quality of CPR from a defibrillator capable recording CPR quality parameters was successful in 39 patients. We used logistic regression and mixed effects modeling to identify CC depths and rates associated with systolic blood pressure (SBP) ≥ 85 mm Hg and diastolic blood pressure (DBP) ≥ 30 mm Hg. RESULTS We analyzed 41,575 compression-BP pairs. The values for blood pressure varied greatly between the patients. SBP varied from 25 to 225 mm Hg and DBP from 2 to 59 mm Hg. CC rate 100-120/min and CC depth ≥ 60 mm (without mattress deflection correction) was associated with DBP ≥ 30 mm Hg in both femoral (OR 1.14; 95% CI 1.03, 1.26; p<0.05) and radial (OR 4.70; 95% CI 3.92, 5.63; p<0.001) recordings. For any given subject there was a weak upward trend in blood pressure as CC depth increased. CONCLUSION Deeper CC does not equal higher BP in every patient. The heterogeneity of patients creates a challenge to find the optimal way to resuscitate patients individually. CLINICAL TRIAL REGISTRATION Clinicaltrials.gov NCT00951704.

Good quality of life before cardiac arrest predicts good quality of life after resuscitation

The survival rate of cardiac arrest patients is increasing. Our aim was to compare the quality of life before and after cardiac arrest and analyse the factors associated with outcome.