Table 4 Review of eligible studies

1

Comparing CPR ambulance transport: Manual versus Mechanical methods [18]

144 simulated runs conducted on a manikin.

Prospective observational study comparing between both types of CPR in different environment settings such as vehicle type, road conditions, vehicle speed.

Compression adequacy (defined as 1.5 to 2 inches in depth, 60 compressions per min +/- 10% and correct hand position).

Thumper provided pre-defined correct compressions for 97% of the runs (n = 70) while manual compressions were performed correctly 37% of the runs (n = 27).

The device is able to deliver higher number of effective and consistent compression at correct position as compared to manual CPR.

97% rate for the device remains valid for different environment settings while 37% rate for manual CPR varied in different settings.

Thumper was used.

2

Quality of mechanical, manual standard and active compression-decompression CPR on the arrest site and during transport in a manikin model [19]

36 runs conducted on a manikin which runs are split between 3 groups.

Randomized, cross-over, out-of-hospital study comparing between three type of CPR at cardiac arrests sites and during transportation.

Compression depth, frequency, compression – decompression ratio based on European Resuscitation Council Guidelines (ERC).

Compression depth, frequency and compression ratio in mechanical CPR device were within recommended guidelines during ambulance transports as compared to other 2 groups.

Mechanical CPR adhered more closely to ERC guidelines. Working conditions for standard CPR in ambulance transport is undesirable.

3

Quality of cardiopulmonary resuscitation before and during transport in out-of hospital cardiac arrest [22]

Adult patients over 18 years of age suffering from non-traumatic OHCA for all causes and received CPR before and during transportation.

Retrospective, observational study.

Chest compression and ventilation rates, hands-off ratio (time without compressions divided by total CPR time).

Hands-off ratio were lower for mechanical CPR both before (p =0.016) and during transport (p =0.002).

For manual CPR, Time without chest compressions during transport and compression rate was lower due to difficult conditions. As such, the device is more appropriate. No conclusion is drawn about patient outcomes due to small sample size.

LUCAS was used.

Compression rates for mechanical CPR were closer to recommended guidelines (100/min) while manual CPR was higher (96/min vs. 119/min).

Manual CPR during transport: 66

Mechanical CPR during transport: 9

No difference in CPC scores between two groups.

4

Video-recording and time motion analysis of manual versus mechanical cardiopulmonary resuscitation during ambulance transport [25]

Adult patients over 18 years of age with OHCA for all rhythms.

Prospective and randomized study where video- recording and time- motion studies was conducted.

Chest compression rate, instantaneous compression rates, unnecessary no chest compression interval, based on guidelines in ILCOR.

No-chest compression interval (Mechanical: 33.4% vs. Manual: 31.63%, p =0.160).

Due to small sample size, short ambulance transport (average 4 minutes) and difficulty in setting/removal of device, it is hard to identify potential benefits of mechanical CPR.

Manual: 12

Mechanical: 8

Average chest compression rate excluding no chest compression interval (mechanical: 52.3/min vs. manual: 113.3/min, p <0.050).

Thumper was used.

Lower ventilation rate excluding no chest compression interval (mechanical 11.7/min vs. manual 16.1/min, p < 0.050). Higher variability in chest compression rates for manual CPR.

5

The impact of a New CPR Assist Device on rate of return of spontaneous Circulation in Out of hospital Cardiac Arrest [23]

Adult patients with OHCA. No exclusions listed.

Retrospective case–control study with matched control subjects.

ROSC upon arrival at Emergency Department (Asytole/ Agonal, PEA and VT/VF).

ROSC for case matched subjects in all rhythms (mechanical: 39% versus manual: 29%, p = 0.003), Asytole/agonal (mechanical: 37% vs. manual: 22%, p = 0.008), PEA (mechanical: 38% vs. manual: 23%, p =0.079) and VF/VT (no difference).

Mechanical CPR may improve ROSC and benefit patients with non-shockable rhythms.

Manual: 138

Mechanical: 124

All mechanical CPR subject groups received manual CPR prior to deployment of the device.

AutoPulse was used.

6

Use of an Automated, Load-distributing Band Chest Compression Device for Out-of-Hospital Cardiac Arrest Resuscitation [12]

Adult patients over 18 years of age with non- traumatic OHCA.

Phased, non-randomized observational study of clinical outcomes of patients treated before and after transition from manual CPR to using mechanical CPR device, AutoPulse.

ROSC, survival to hospital admission and hospital discharge, and neurological outcome at discharge.

ROSC (mechanical: 34.5% vs. manual: 20.2%), Survival to hospital admission (mechanical: 20.9% vs. manual: 11.1%), Survival to hospital discharge (mechanical: 9.7% vs. manual: 2.7%). No difference in CPC (p = 0.360) and OPC (p = 0.400) Better mechanical CPR performance if ambulance response time is less than 8 minutes.

Mechanical CPR is better.

Manual: 499

Mechanical: 210

7

Manual Chest Compression vs. Use of Automated chest compression device during resuscitation following out of hospital cardiac arrest: a randomized trial [13]

Adult patients over 18 years of age, non-traumatic OHCA and resuscitation attempted by EMS.

Multi-centre randomized trial.

Survival with spontaneous circulation 4 hours after emergency call is made, Survival to hospital discharge, CPC at hospital discharge.

No difference in survival to 4 hours (mechanical: 29.5% vs. manual: 28.5%, p =0.740), survival to discharge (mechanical: 5.8% vs. manual: 9.9%, p =0.060). Difference in CPC score at hospital discharge (mechanical: 3.1% vs. manual: 7.5%, p = 0.006).

Study was terminated when it was found that mechanical CPR was associated with worse neurological outcomes and a trend towards worse survival than manual CPR.

AutoPulse was used.

Manual: 517

Mechanical: 554

8

Clinical consequences of the introduction of chest compression in the EMS system for treatment of out-of-hospital cardiac arrest – a pilot study [24]

Adult patients over 18 years of age, witnessed, non-traumatic OHCA.

Non-randomized, controlled trial. LUCAS was used.

ROSC at any time during treatment, Survival at hospital admission, survival to hospital discharge with neurological recovery.

No significant difference in ROSC, survival to hospital admission or hospital discharge.

No sufficient evidence to support that Mechanical CPR would improve outcome. This was due to long delay between arrival of ALS vehicle and use of Mechanical CPR (6 minutes).

Manual: 169

No difference in CPC scores between 2 groups (majority 1 and 2).

Mechanical: 159

9

Mechanical active compression-decompression cardiopulmonary resuscitation (ACD-CPR) versus manual CPR according to pressure of end tidal carbon dioxide (P_ETCO₂) during CPR in out-of-hospital cardiac arrest (OHCA) [20]

Adult patients over 18 years of age, non-traumatic OHCA.

Prospective, cluster level, pseudo-randomized trial.

ETCO₂ was measured after tracheal intubation for 15 minutes or until detection of ROSC. Readings were categorized to initial, minimum, average and maximum.

ETCO₂ was significantly higher in mechanical CPR as compared to manual CPR according to initial (3.38 vs. 2.71, p = 0.010), average (3.26 vs.2.69, p = 0.040) and minimum (2.24 vs. 1.69, p = 0.010). No significant differences according to maximum value between 2 groups (4.88 vs.4.48, p = 0.230).

No differences in survival outcomes and there was a long time interval between cardiac arrest to start of CPR and to ROSC for both groups.

Mechanical CPR performed compressions with higher cardiac output than manual chest compressions.

LUCAS was used.

Manual: 62

Mechanical: 64

10

Effectiveness of mechanical versus manual chest compressions in out- of-hospital cardiac arrest resuscitation: a pilot study [21]

Adult patients over 16 years of age with non-traumatic OHCA.

Prospective, odd/even day randomization study.

ETCO₂ measurements at 5 minutes after intubation and CPR began, and a second measure at initiation of transport to hospital.

Statistical significant between both groups. 80% in manual group has decreasing ETCO₂ while 20% has increasing ETCO₂.

Mechanical CPR produced better cardiac output, overall, ;when compared to manual CPR.

Odd days were using mechanical CPR and even days using manual CPR.

Manual: 10

Mechanical:10

All patients (3 excluded) in mechanical CPR do not have decreasing ETCO₂. No difference in patient outcomes.

Thumper was used.