Background We previously demonstrated that abdominal gas insufflation (AGI) reduces intra-abdominal bleeding. To date, this is the only method that holds promise for reducing mortality from internal bleeding in a pre-hospital setting. We aimed to assess the optimal AGI pressure and the effectiveness of a portable miniaturized insufflator in abdominal bleeding control. Materials and methods We randomized 15 Yorkshire swine to receive AGI of 20, 25 or 30 mm Hg after sustaining a standardized severe splenic injury, to determine the ideal pressure for optimal bleeding control. We randomized six (40%) to insufflation with a custom-designed, battery-operated, 7-oz portable CO2 tank, whereas we used a standard laparoscopic insufflator for the remainder. Intravenous fluid boluses were administered as needed to maintain a mean arterial pressure of >60 mm Hg. At 30 min, the animals were re-laparotomized and their hemoperitoneum was quantified. Results Target peritoneal pressures were achieved and maintained successfully with both insufflation methods. There was a trend toward greater blood loss and fluid requirements in the 30-mmHg group (P = 0.71 and 0.97, respectively). Increasing the AGI led to less predictable blood loss and fluid resuscitation requirements, as well as worsening of tissue perfusion markers (pH and lactate), likely because of iatrogenic abdominal compartment syndrome. Conclusions All target peritoneal pressures were easily and reliably achieved with the portable CO2 insufflator. Abdominal gas insufflation produced optimal bleeding control at 20 mm Hg. This technology could be used in a pre-hospital setting to control otherwise lethal hemorrhage at pressures typically used for standard laparoscopic surgery and proven to be safe.