To prevent cardiac arrest of the patient in hemorrhagic shock, keeping cardiac output with fluid resuscitation is essential. The patient, however, manifested cardiac arrest despite various effort of fluid resuscitation. In this case, the culprit of bleeding was right pulmonary artery. Substantial amount of rapidly infused fluid administration via venous catheter might be lost as bleeding from injured pulmonary artery. Blood flow from right to left heart might be severely limited and, as a result, cardiac output of left heart might be severely decreased, resulting in cardiac arrest. This suggests immediate hemostasis of culprit injury is primary needed to make fluid resuscitation effective in the case of pulmonary artery injury. When the patient became shock, we once stabilized his circulation with rapid fluid administration and then decided starting hemostasis. More prompt start of hemostasis might prevent his cardiac arrest, but it is unknown whether we could prevent cardiac arrest in anyway.
Few reports are available for CPR performed on patients in the lateral position. To our knowledge, there are three case reports with successful neurological outcome after intraoperative CPR in the lateral position. CPR time described in those reports is less than 6 min. We performed 25 min of CPR in the lateral position, and this is the first report of CPR for an extended period of time in the lateral position with successful neurological outcome. Abraham et al.  describe the two thumb encircling technique in a 6 year old and achieve systolic blood pressures in the 50–60 mmHg. Bengali et al.  describe one resuscitator standing next to the patient and applying compressions by placing one hand on either side of the patient. They were able to achieve systolic blood pressures near 70 mmHg and EtCO2 above 20 mmHg. Takei et al.  describe two person lateral compressions and had systolic blood pressure of 70–80 mmHg. In our case, two rescuers performed chest compression, one rescuer pushing patient’s sternum and the other rescuer simultaneously pushing his mid-thoracic spine from his back at 100 times per minute as deeply as possible. We could perform this two-person lateral CPR and hemostasis procedure at the same time. Successful recovery without any neurological complication suggests effective CPR was performed in the lateral position.
As a factor of high-quality chest compression, 2010 American Heart Association (AHA) Guideline  recommends providing chest compressions of adequate rate and adequate depth, allowing complete chest recoil after each compression, and minimizing interruptions in compressions. Most of CPR are performed with the patient in the spine position, but in some surgical situation, making patient in the supine position is challenging. For example, most of thoracic surgeries are performed in the lateral position and immediate transposition from lateral to supine is difficult because of firmly fixing body-supporting devices, a lot of inserted catheters, and inability of gathering sufficient staff to make transposition. In addition, repositioning the patient may make it impossible for surgeon to access to the surgical site and address the cause of cardiovascular collapse. So in the case of intraoperative cardiac arrest in the special position, immediate initiation of CPR without repositioning is sometimes required to prevent the delay of resuscitation and minimize interruptions of compression.
To perform high-quality CPR, adequate monitoring and feedback is important, especially when CPR is delivered under unusual circumstance. Recent consensus  emphasizes the importance of monitoring a patient’s response to resuscitation. The consensus statement recommends keeping arterial diastolic pressure above 25 mmHg to maintain sufficient coronary perfusion pressure when an arterial catheter is available. The consensus statement also recommends keeping EtCO2 above 20 mmHg. While EtCO2 monitoring has some limitations, it is a good surrogate marker of pulmonary blood flow and cardiac output. In our case, an arterial catheter was inserted and the patient was intubated, so arterial pressure monitoring and capnography were available. We performed chest compression for 25 min in the lateral position, and the value of systolic arterial pressure was kept about 35–50 mmHg, diastolic pressure about 25–35 mmHg during CPR. This is well above the value of recommendation. In our case, however, the value of end-tidal CO2 was significantly lower (around 5–20 mmHg) during CPR. Decrease of pulmonary blood flow due to the massive hemorrhage and disturbed expansion of lung due to surgical manipulation disturbed pulmonary respiration and it was challenging to keep EtCO2 above 20 mmHg during CPR. In spite of low value of EtCO2 at the initiation of CPR, EtCO2 showed increasing trend during CPR along with the hemostasis procedure and rapid transfusion. This implies that EtCO2 can be the index of restoration of pulmonary blood flow and cardiac output.
In spite of low EtCO2 value during CPR, patient showed successful neurological and cardiac outcome. Firstly, the prevention of postoperative hyperthermia may be one of the factors that influenced this good outcome. Hyperthermia after cardiopulmonary resuscitation is reported to be a potential factor for an unfavorable functional neurologic recovery . In our case, the patient was kept in normothermia and didn’t develop hyperthermia after resuscitation, which might help decrease brain damage and lead to successful neurological outcome. In addition, we cooled the patient’s head with the ice pack so as to decrease the oxygen consumption of the brain as soon as he manifested shock. We stopped sevoflurane administration during CPR, but remaining sevoflurane might suppress the oxygen demand of the brain and lead to cerebral protection. Whether these factors, however, had cerebral protective effects on the patient is still unknown.
How long CPR should be continued, or when to stop CPR may largely depend on the situation. We performed 25 min of CRP and got a successful cardiac and neurological outcome. This implies that even though prolonged CPR should be performed, we shouldn’t easily give up continuing CPR if the cause of CPA is accessible and effective CPR is performed.