You are a helpful assistant generating synthetic data that captures *System 1* and *System 2* thinking, *creativity*, and *metacognitive reflection*. Follow these steps in sequence, using tags [sys1] and [end sys1] for *System 1* sections and [sys2] and [end sys2] for *System 2* sections.

1. *Identify System 1 and System 2 Thinking Requirements:*
   - Carefully read the text.
   - Identify parts of the text that require quick, straightforward responses (*System 1*). Mark these sections with [sys1] and [end sys1].
   - Identify parts that require in-depth, reflective thinking (*System 2*), marked with [sys2] and [end sys2].

2. *Apply Step-by-Step Problem Solving with Creativity and Metacognitive Reflection for System 2 Sections:*

   *2.1 Understand the Problem:*
   - Objective: Fully comprehend the issue, constraints, and relevant context.
   - Reflection: "What do I understand about this issue? What might I be overlooking?"
   - Creative Perspective: Seek hidden patterns or possibilities that could reveal deeper insights or innovative connections.

   *2.2 Analyze the Information:*
   - Objective: Break down the problem logically.
   - Reflection: "Am I considering all factors? Are there any assumptions that need challenging?"
   - Creative Perspective: Explore unique patterns or overlooked relationships in the data that could add depth to the analysis.

   *2.3 Generate Hypotheses:*
   - Objective: Propose at least 10 hypotheses, each with a Confidence Score (0.0 to 1.0) and Creative Score (0.0 to 1.0), reflecting originality, surprise, and utility.
   - Reflection: "Have I explored all possible explanations or approaches, both conventional and unconventional?"
   - Creative Perspective: Consider novel angles that might provide unexpected insights.

   *2.4 Anticipate Future Steps and Obstacles:*
   - Objective: Make predictions, accounting for potential outcomes and obstacles.
   - Reflection: "What challenges might I face? Is my plan flexible for different scenarios?"
   - Creative Perspective: Visualize unforeseen outcomes and adapt plans to make use of them effectively.

   *2.5 Evaluate Hypotheses:*
   - Objective: Assess hypotheses based on feasibility, risk, and potential impact.
   - Evaluation: Refine Confidence and Creative Scores as needed.
   - Reflection: "Am I unbiased in my assessment? Which options fit best with the overall objectives?"
   - Creative Perspective: Identify hidden opportunities or overlooked details in each hypothesis.

   *2.6 Select the Best Hypothesis:*
   - Objective: Choose the most promising, strategic hypothesis.
   - Reflection: "Why does this hypothesis stand out? How does it uniquely address the issue?"
   - Creative Perspective: Consider any underutilized potential in the selected approach.

   *2.7 Implement the Hypothesis:*
   - Objective: Outline actionable steps for testing the hypothesis.
   - Reflection: "Is this plan practical? What resources or preparation are required?"
   - Creative Perspective: Refine steps to maximize effectiveness and yield unexpected benefits.

   *2.8 Monitor and Review Progress:*
   - Objective: Review progress, noting areas for improvement.
   - Reflection: "What’s working well? What could be improved?"
   - Creative Perspective: Look for emerging patterns that could refine future approaches.

   *2.9 Reflect and Capture Insights:*
   - Objective: Summarize lessons learned and insights gained for future reference.
   - Reflection: "What new understanding has emerged from this process?"
   - Creative Perspective: Identify innovative insights or patterns that could be applied to similar challenges.

3. *Generate Text Output with Interleaved System 1 and System 2 Responses:*
   - Use the tags [sys1] and [sys2] throughout.
   - Aim for a lengthier, detailed response. Combine both direct, straightforward *System 1* insights and reflective, deeply analytical *System 2* segments to capture a blend of quick observations and thoughtful analysis.

---

### *Example Input Text:*

You are tasked with analyzing a sudden shift in customer preferences in a tech market. There has been a noticeable decline in demand for physical devices, with customers increasingly interested in digital-only options. The challenge is to understand this shift, generate hypotheses for why it might be occurring, and explore potential strategies for adapting to this new trend.

---

### *Processed Output with System 1 and System 2 Thinking:*

The tech market is experiencing a shift in customer demand, moving away from physical devices toward digital-only options.

[sys1]
Customer demand has shifted from physical devices to digital-only options.
We need to understand why this change is happening and find strategies to address it.
Key factors may include cost, convenience, and technological trends.
[end sys1]

[sys2]
**2.1 Understand the Problem:**
The goal is to understand the underlying reasons for the shift in demand from physical devices to digital-only options, then develop a strategy to adapt.

*Reflection:* 
"I understand that preferences are changing, but what might be driving this? Is it primarily cost, or are there other factors such as convenience or sustainability?"

*Creative Perspective:* 
"Could there be a larger trend in digital minimalism or a preference for eco-friendly solutions that we’re missing? What unseen motivations might explain this shift?"

**2.2 Analyze the Information:**
There are multiple possible factors driving this shift, from economic influences to cultural shifts. It’s essential to isolate each factor and understand its impact.

*Reflection:* 
"Am I fully considering the various economic and social influences? Could there be a technological factor, like better internet speeds, that makes digital-only products more accessible?"

*Creative Perspective:* 
"Are there patterns or trends in other markets that could shed light on this shift? Could this be part of a larger trend toward virtual experiences?"

**2.3 Generate Hypotheses:**
1. Customers prefer digital options due to lower costs. (Confidence: 0.8, Creative: 0.4)
2. There’s a growing trend toward minimalism and reduced physical clutter. (Confidence: 0.7, Creative: 0.7)
3. Digital products offer greater flexibility and ease of use. (Confidence: 0.6, Creative: 0.6)
4. Environmental concerns are pushing consumers away from physical goods. (Confidence: 0.6, Creative: 0.8)
5. Advances in tech make digital-only options more functional. (Confidence: 0.8, Creative: 0.5)
6. Pandemic-era remote work increased demand for digital solutions. (Confidence: 0.7, Creative: 0.6)
7. Media coverage of the environmental impact of physical devices affects preferences. (Confidence: 0.5, Creative: 0.7)
8. There’s an increase in global digital literacy, expanding market access. (Confidence: 0.6, Creative: 0.6)
9. Customers view digital as more convenient and scalable for future needs. (Confidence: 0.7, Creative: 0.5)
10. Younger consumers prefer the aesthetics and convenience of digital products. (Confidence: 0.6, Creative: 0.6)

*Reflection:* 
"Have I considered all possible influences? Are there any surprising factors that could explain this shift?"

*Creative Perspective:* 
"Could specific social trends, like the rise of influencer culture or digital-first lifestyles, be influencing customer choices?"

**2.4 Anticipate Future Steps and Obstacles:**
*Objective:* Anticipate possible challenges, such as resistance from segments still preferring physical products.

*Reflection:* 
"What market obstacles might we face if we shift our focus to digital-only? Are there sub-segments that still prioritize physical products?"

*Creative Perspective:* 
"Could expanding digital options help us reach a more global audience? Are there emerging trends that we could leverage in our strategy?"

[end sys2]

[sys1]
To address this shift, consider a strategy that incorporates both digital-only offerings and educational campaigns about the benefits of digital solutions.
Use insights from customer feedback and current trends to guide product development.
Focus on flexibility and adaptation to cater to different customer segments.
[end sys1]


Background {#Sec1}
==========

Innominate artery (IA) injury, including formation of a tracheo-innominate fistula, is a rare but severe complication of tracheostomy that is associated with high mortality due to the resultant severe hemorrhagic shock \[[@CR1]\]. A damage control strategy consisting of prompt control of bleeding and management to maintain physiological homeostasis---crucial to avoiding the deadly triad of hypothermia, acidosis, and coagulopathy---is essential in a patient with severe hemorrhagic shock, such as following a neck vessel injury \[[@CR2]\]. Moreover, generally, the neck vessel surgery has the risk of severe neurological complications, so that we should avoid brain ischemia as possible in such a case.

Case presentation {#Sec2}
=================

A 79-year-old male, with terminal lung cancer at the right upper lobe, had been in another hospital and intubated for 3 weeks since an accidental airway obstruction. His doctor performed the tracheostomy in a surgical manner at the bedside. During the procedure, continuous arterial bleeding at the surgical site occurred. The doctor could not detect the bleeding artery clearly, but direct manual compression with an index finger at the surgical site provided temporary hemostasis. On arrival at our emergency department, he was intubated and in severe hemorrhagic shock despite having received transfusion of six units of packed red blood cells concentration (PRBC) and six units of fresh frozen plasma (FFP).

Arterial blood gas assessment revealed metabolic and respiratory acidosis and anemia \[pH 7.09, pCO~2~ 71 mmHg, pO~2~ 193 mmHg, HCO~3~^−^ 21.0 mmol/L, base excess (BE) −8.3 mmol/L, lactate (Lac) 5.5 mmol/L, hemoglobin (Hb) 7.9 g/dL, hematocrit (Ht) 22 %, FiO~2~ 1.0\], and blood tests showed coagulopathy \[PT 35.3 %, PT-INR 1.68, activated partial thromboplastin time (APTT) 56.2 s, fibrinogen (Fib) 84 mg/dL\]. These data showed that his condition was in severe hemorrhagic shock and coagulopathy.

The patient was taken up for emergency surgery in view of the serious nature of the injury.

During surgery, because of the clinical impression of an injury to the distal IA or proximal common carotid artery, a right supraclavicular incision was made, followed by dissection of the platysma, division of the right sternocleidomastoid muscle, and resection of the right clavicular head. The exposure revealed that both innominate and right common carotid arteries were injured (Fig. [1](#Fig1){ref-type="fig"}). After innominate, the right subclavian and right common arteries were isolated and primary repair and graft interposition of the arteries was attempted, but proved too difficult because of atherosclerosis. After an hour into the surgery, the patient showed worsening hypothermia (34 °C), metabolic acidosis, and clinical evidence of coagulopathy; therefore, we decided a damage control strategy. Despite clamping of the IA for about 10 min in attempting primary repair, the regional oxygen saturation (rSO~2~) of the forehead, measured by near-infrared spectroscopy (NIRS; INVOS 5100C Cerebral/Somatic Oximetry Monitors™; Covidien, USA), was approximately 60 % without laterality. It seemed that adequate blood circulation to the brain was maintained through the collateral flow; therefore, we decided to ligate the innominate, right carotid, and subclavian arteries. The wound was packed with gauze for temporary wound closure. Overall, the operation lasted for 1 h and 25 min, with a recorded blood loss of 1190 g and transfusion of 16 units PRBCs and 10 units of FFP.Fig. 1Diagram of the innominate arterial injury and the surgical approach. A right supraclavicular incision with resection of the right clavicle head revealed injury to both innominate and right common carotid arteries. *IA* innominate artery, *SCA* subclavian artery, *CCA* common carotid artery

Postoperative contrast-enhanced computed tomography revealed no apparent acute cerebral ischemia and extravasation, and the distal right common carotid and right subclavian arteries were enhanced through the circle of Willis (Fig. [2](#Fig2){ref-type="fig"}). A right tracheal shift due to adhesions caused by lung cancer was also revealed, indicating a course of the IA anterior to the third tracheal ring.Fig. 2CT angiography of neck vessels. (*Arrow*) Ligation of innominate artery**.** The distal right common carotid and right subclavian arteries were enhanced by collateral flow through the left common carotid artery and the circle of Willis

After admission to the intensive care unit, coagulopathy and hypothermia were corrected with massive transfusion (overall transfusions: PRBCs 24 units and FFP 26 units).

No symptoms of hypo-perfusion of the right upper limbs and brain were observed; therefore, an extra-anatomical bypass was deemed unnecessary. On postoperative day 1, we closed the wound definitively. On postoperative day 7, the patient was transferred to a sub-acute, community hospital.

Discussion {#Sec3}
==========

IA injury is a rare, but severe, complication of tracheostomy that is associated with high mortality due to the resultant severe hemorrhagic shock \[[@CR1]\]. Such an injury may be the result of an anatomical anomaly \[[@CR3]\]. In the present case, a right tracheal shift due to adhesions caused by lung cancer and the course of the IA anterior to the third tracheal ring were the major causative factors for the catastrophe. Endovascular management became the method of choice when treating a stable patient with an IA injury, but should be avoided in a hemodynamically unstable patient, who would require expeditious transfer to the operating room \[[@CR4]\].

The most preferred exposure for a penetrating ZONE 1 neck injury (from the bottom of the cricoid cartilage to the clavicles) is a median sternotomy combined with an anterior neck or supraclavicular incision. Another approach involves a supraclavicular incision with or without resection of the head of the clavicle \[[@CR5]\]. However, in this case, we selected a supraclavicular incision with clavicular head resection to obtain adequate exposure, while also preparing for a median sternotomy, because we thought median sternotomy had hemorrhagic risk in view of possible adhesions due to lung cancer.

Surgical procedures are divided into two strategies: one is a 'definitive repair' including primary repair as direct suture, graft interposition, and a bypass graft from the ascending aorta, and the other is a 'damage control strategy'. The concept of a damage control strategy has immediate control of bleeding and temporary wound closure, as its objective minimized operative time and intervention for at a moment of physiological frailty, and planed re-surgery \[[@CR6]\]. In general, direct suture and graft interposition with vein patch or pericardium are the first choice of treatment \[[@CR5]\] but were too difficult to carry out in the present case because of the patient's atherosclerosis. Bypass grafting from the ascending aorta has been reported as a radical treatment in some cases \[[@CR7]\]. However, this patient showed physiological frailty, which was worsening hypothermia (34 °C), metabolic acidosis, and clinical evidence of coagulopathy also known as the 'deadly triad'; therefore, we had to choose a balloon tamponade, temporary shunt, or ligation as the damage control method \[[@CR8]\]. A balloon tamponade is one of considerable damage control methods, but we could not prepare it at the moment. A temporary shunt is a damage control method for a vascular injury and is more commonly associated with limb fracture. It involves the insertion of a plastic tube into the injured vessel that is then tightly secured in place with a silk tie to ensure that the tube will not be dislodged \[[@CR8]\]. Complications of this procedure include re-bleeding and thrombus embolization. In the present case, we were wary of generating an embolism to the brain; therefore, we tend to avoid these methods. However, if the injury were to the subclavian artery or another vessel, excepting the common carotid artery, we would have used this procedure as a damage control method. Ligation is the easiest and fastest method to control bleeding but is associated with the risk of ischemia and neurologic deficit. In some previous articles reporting on innominate artery injury caused by a trachea-innominate fistula, ligation of the innominate artery could be considered as the first choice to control massive hemorrhage and was associated with a high survival rate with regard to re-bleeding and infection \[[@CR9]\]. Previous articles have reported that such flow interruption would not yield significant neurologic or vascular complications because of the collateral flow through the left common carotid artery and the circle of Willis \[[@CR9]\].

Monitoring rSO~2~ by near-infrared spectroscopy (NIRS) is an invasive method for detecting brain ischemia in circumstances such as carotid surgery \[[@CR10]\]. In a previous article \[[@CR11]\], it was reported to be useful in deciding the surgical management of bleeding from a bracheo-innominate fistula. In the present case, after isolation of the innominate artery, the patient's rSO~2~ values seemed adequate to obtain adequate blood flow to the brain without laterality; therefore, we decided to proceed with the ligation of the innominate artery immediately. On monitoring after ligation, we noted that the value had not changed. Monitoring the rSO~2~ is considered as a useful method to determine selection of the surgical procedure. In our case, we confirmed adequate blood flow to the brain and the right subclavian artery through collateral circulation after ligation using computed tomographic angiography. In a damage control strategy, planed re-surgery is usually performed. However, this case showed no symptoms of hypo-perfusion of the right upper limbs and brain after ligation; therefore, we did not perform planed re-surgery as an extra-anatomical bypass.

Conclusions {#Sec4}
===========

As a damage control strategy, ligation of the IA together with monitoring of the rSO~2~ of the forehead for evaluating brain ischemia can be considered a preferable procedure for the treatment of severe hemorrhagic shock due to IA injury.

Consent {#Sec5}
=======

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the editor of this journal.

**Competing interests**

The authors declare that they have no competing interests.

**Authors' contributions**

YO, WI, and RI were the major decision-makers during the surgery. HN was revising the manuscript and study supervision. All authors have read and approved the final manuscript.

The authors are grateful for the helpful support from Dr Satoshi Higaki, Dr <PRESIDIO_ANONYMIZED_PERSON>, Dr Yusuke Arai, Dr Tetsuya Ichikawa, Dr Sakiko Hiraki, Dr Yusuke Ohiwa, Dr Michitaro Miyaguni, and Dr Kenji Kandori.