Pilot study: transport ventilator feasible in OHCA CPR, blood gases similar to bag ventilation
The prehospital study enrolled 29 bag-ventilated and 12 ventilator patients and was not powered to detect differences in survival or other clinical outcomes.
Key takeaways
- A pilot study published October 27, 2026 in BMC Emergency Medicine compared a transport mechanical ventilator with bag-valve ventilation during CPR for adults in out-of-hospital cardiac arrest.
- The analysis included 29 patients ventilated by bag and 12 ventilated by a HAMILTON-T1 transport ventilator in volume-controlled mode.
- The authors found no statistically significant differences in PCO₂, pH or pO₂, and reported sustained ROSC and 28-day survival as similar between groups.
- The authors stated the study was not powered to detect differences in clinical outcomes and called the findings hypothesis-generating.
- For crews: the study ventilator settings were tidal volume 6-8 mL/kg, rate 10 breaths/min, PEEP 0 cmH₂O, I:E 1:5, FiO₂ 1.0, with flow trigger off.
A pilot study published October 27, 2026 in BMC Emergency Medicine reports that a transport mechanical ventilator could be used during CPR for adults in out-of-hospital cardiac arrest, and that blood gas measurements were comparable to those seen with bag-valve ventilation [1].
The study was run by the Ramathibodi Emergency Medical Operation team, with enrollment between September 2024 and October 2025, according to the abstract indexed on PubMed [1]. The authors are listed as Tienpratarn W, Kusolthammarat P, Yuksen C and Phongsawad S [1].
The authors described the work as exploratory. They wrote that the investigation was "not powered to detect differences in clinical outcomes," and that the findings are "hypothesis-generating" [1].
What the records show
The design was prospective and time-sequenced, the abstract says. Patients aged 18 or older were treated with bag-valve ventilation during the first 6 months of the study period, and with mechanical ventilation after that [1]. Patients were not randomized, per the description of the design in the abstract [1].
Mechanical ventilation was delivered with a HAMILTON-T1 transport ventilator set to volume-controlled mode [1]. The abstract lists these settings [1]:
- Tidal volume: 6-8 mL/kg
- Respiratory rate: 10 breaths/min
- PEEP: 0 cmH₂O
- I:E ratio: 1:5
- FiO₂: 1.0
- Flow trigger: off
To judge ventilation, the team drew arterial or venous PCO₂ samples at least 3 minutes after intubation, or at return of spontaneous circulation (ROSC) [1].
The analysis covered 29 patients in the bag-valve group and 12 in the mechanical ventilation group [1]. Mean age was 67 ± 15 years with bag ventilation and 66 ± 20 years with the ventilator. Men made up 55.2% of the bag-valve group and 66.7% of the ventilator group [1].
| Measure | Bag-valve ventilation | Mechanical ventilation |
|---|---|---|
| Patients analysed | 29 | 12 |
| Mean age (years) | 67 ± 15 | 66 ± 20 |
| Male | 55.2% | 66.7% |
The authors reported no statistically significant difference between the groups in PCO₂, pH or pO₂ [1]. They described sustained ROSC and 28-day survival as similar across groups [1]. The abstract does not give the outcome figures themselves.
On feasibility, the authors concluded that ventilator use worked operationally in the field "despite several implementation challenges" [1]. The protocol was registered with the Thai Clinical Trials Registry as TCTR20241008007 on 08 October 2024 [1].
Why it matters for EMS
The authors note that evidence on mechanical ventilation during CPR in out-of-hospital cardiac arrest is limited, especially in prehospital care [1]. Many crews carry transport ventilators, and this study offers early physiologic data from a specific ventilator model and a specific set of settings used during active resuscitation, compared against bag ventilation [1].
The settings reported, including a rate of 10 breaths/min, zero PEEP, an I:E ratio of 1:5 and the flow trigger turned off, describe how the device was configured in this program [1]. Practice in any given system follows local protocols and medical direction.
What the records do not tell us
- Outcome numbers. The abstract calls ROSC and 28-day survival similar but does not report the rates or confidence intervals.
- Implementation problems. The abstract mentions "several implementation challenges" but does not describe them.
- Blood gas values. Mean PCO₂, pH and pO₂ values for each group are not given in the abstract, and arterial and venous samples were both accepted.
- Bias from design. Because groups were assigned by time period rather than at random, other changes over the study period could affect results. The abstract does not say how this was addressed.
- Generalizability. The study came from a single named EMS team. The abstract does not include US data, other ventilator models or pediatric patients.
- Safety events. The abstract does not report complications such as barotrauma or device failures.
- Full text. The publisher page linked by the DOI did not load for this report, so details beyond the abstract could not be checked.
What to watch
The authors wrote that the results may inform the design of future adequately powered studies [1]. The abstract does not name a follow-up trial or a timeline.
Questions readers ask
Is mechanical ventilation during CPR as effective as bag-valve ventilation?
In this pilot study, the authors found no statistically significant differences in PCO₂, pH or pO₂ and described sustained ROSC and 28-day survival as similar. The study was not powered to detect differences in clinical outcomes, and the authors called the findings hypothesis-generating.
What ventilator settings were used during CPR in the HAMILTON-T1 pilot study?
The ventilator ran in volume-controlled mode with tidal volume 6-8 mL/kg, respiratory rate 10 breaths/min, PEEP 0 cmH₂O, I:E ratio 1:5, FiO₂ 1.0 and the flow trigger off.
How many patients were in the transport ventilator CPR study?
The analysis included 29 patients who received bag-valve ventilation and 12 who received mechanical ventilation, all adults aged 18 or older in out-of-hospital cardiac arrest.
Who conducted the prehospital mechanical ventilation CPR study?
Patients were managed by the Ramathibodi Emergency Medical Operation team between September 2024 and October 2025, and the protocol was registered with the Thai Clinical Trials Registry as TCTR20241008007.
Sources
- Tienpratarn W, et al. Transport mechanical ventilation during cardiopulmonary resuscitation in out-of-hospital cardiac arrest: an exploratory prehospital pilot study. BMC Emergency Medicine (PubMed) (2026-10-27). pubmed.ncbi.nlm.nih.gov/42934518/
This is news, not medical advice. EMS clinicians: follow your local protocols and medical direction.
