# Fine-Tuning a Personalized OpenBioLLM Using Offline Reinforcement Learning
## 3 Methods
### Template Based on Chain of Thought
Heart rate of 110 beats/minute and respiratory rate of 28 times/minute are both higher than normal, which may indicate that the patient has cardiopulmonary function problems. Systolic blood pressure of 95 mmHg and mean arterial pressure of 75 mmHg are low, which may indicate hypotension. Shock index 1.5 is within the normal range, but close to the critical value and needs to be monitored. SpO2 88% is lower than normal, indicating that the patient may have insufficient oxygenation. 3. Laboratory values:

Potassium, sodium, chloride, blood glucose, blood urea nitrogen, magnesium, carbon dioxide, hemoglobin, white blood cell count, platelets, PT, PTT, INR, pH, base excess and bicarbonate values are mostly within the normal range or close to normal, but creatinine 2.0 mg/dL and INR 1.5 indicate possible renal impairment and coagulation abnormalities. 4. Ventilator treatment plan:

PEEP 10 cmH2O: Considering that the patient's PaCO2 is 50 mmHg, indicating obvious alveolar collapse, I think a slightly higher PEEP helps to keep the alveoli open and reduce atelectasis, which is suitable for patients with insufficient oxygenation. Tidal volume 500 mL: For a patient weighing 75 kg, 500 mL of tidal volume may be slightly large, but considering the SpO2 88%, I think a larger tidal volume may be needed to improve oxygenation. FiO2 0.6: 60% oxygen concentration is a relatively high value, and I think the patient needs additional oxygen to maintain normal oxygen saturation. I think the patient's treatment plan needs to be adjusted based on the patient's response and continuous monitoring. Considering the patient's hypooxygenation and possible risk of organ failure, I chose such a ventilator setting to improve oxygenation and support organ function. Treatment plan:

* PEEP: 10 cmH2O

* Tidal volume: 500 mL

* FiO2: 0.6

In the process of state generation and treatment recommendations, cot_2 is used as a chain of thought prompt template. The input it receives is the patient's demographic information, medical history, and physiological indicators. Compared with cot_1, it lacks **treatment decision** items. The purpose of designing this template is to allow the OpenBioLLM to analyze and give treatment recommendations based on the patient's condition. A structured output format is designed at the end of cot_2 to facilitate the acquisition of the treatment decision given by the OpenBioLLM for comparison with the treatment decision of the CQL algorithm. The content of the cot_2 template is as follows. * There is a patient in the ICU, and their physiological indicators are as follows:

Demographics:

Age: 65 years old

Sex: male

Weight: 75 kg

Readmission to ICU: yes Elixhauser score: 12 points

Vital signs:

SOFA (Sequential Organ Failure Assessment): 6 points

SIRS (Systemic Inflammatory Response Syndrome): yes

GCS (Glasgow Coma Scale): 14

Heart rate: 110 beats/min

SysBP (Systolic Blood Pressure): 95 mmHg

DiaBP (Diastolic Blood Pressure): 60 mmHg

MeanBP (Mean Blood pressure): 75 mmHg

Shock index: 1.5

Respiratory rate: 28 times/min

Temperature: 37.8 \({}^{\circ}\)C

SpO2 (peripheral capillary oxygen saturation): 88%

Laboratory values:

Potassium: 4.0 mmol/L

Sodium: 135 mmol/L

Chloride: 98 mmol/L

Glucose : 120 mg/dL

BUN (blood urea nitrogen): 45 mg/dL

Creatinine: 2.0 mg/dL

Magnesium: 1.8 mg/dL

CO2 (carbon dioxide): 32 mmol/L

Hemoglobin: 10 g/dL

WBC (white blood cell count): 15,000/mm

Platelets: 150,000/mm\({}^{3}\)

PTT (Partial Thromoplastin Time): 40 s

PT (Prothrombin Time): 15 s

INR (International Normalized Ratio): 1.5

pH : 7.45

PaCO2 (Partial Pressure of Carbon Dioxide in Arterial Blood): 50 mmHg

Base Excess: 4 mEq/L

Bicarbonate: 28 mmol/L

Please analyze the patient's condition and give a treatment plan and reason. The treatment plan should be a definite value. Please attach a treatment plan template in the following format at the end:

PEEP:?cmH2O

Tidal volume:?mL

FiO2:?