Comprehensive Hospital Pharmacy Practice and Clinical PK Notes

Clinical Workflow, EPIC Logistics, and Pharmacokinetic Consultations

• EPIC PK Consult List Management: Pharmacists use a specialized list (PK consult list) to track patients on Floor 7 and 8 requiring pharmacokinetic monitoring.

• Adjusting Times in EPIC:

  • Pharmacy cannot adjust the timing of a vancomycin dose if a drug level entry has been inserted into the Medication Administration Record (MAR).

  • To fix this, the pharmacist must find the action (e.g., "Drug level due") on the MAR, edit the entry, and cancel it.

  • Once the level entry is removed, the pharmacist can use the "adjust times" function for the medication.

• Phone Forwarding Logistics:

  • The satellite pharmacy is not staffed after $09:00\,PM$\until $08:00\,AM$.

  • During off-hours, phone lines are forwarded to the 4th Floor satellite.

  • In the morning, the satellite pharmacist "unfolds" or forwards the lines back to the local station so calls ring directly to them.

• ID Consult Documentation: Infectious Disease (ID) consults often appear in the "Inpatient Consult" section before they appear in official notes because the team is still working on the assessment; the official note is only visible upon completion/acknowledgment.

Vancomycin Pharmacokinetics and Clinical Case Analysis

• Patient Case: David Henderson:

  • Diagnosis: Rheumatoid Arthritis (RA) causing bone degeneration in the left proximal femur, concerning for metastatic disease and impending fracture.

  • Surgical Intervention: Placement of an antibiotic cement mixture into the femur head. The cement includes:

    • $3\,g$ of tobramycin.

    • $3\,g$ of vancomycin.

    • $3\,g$ of amphotericin B.

  • Drug Elution: This surgical cement acts as a "drug-eluting" delivery system, slowly releasing antibiotics directly into the bone/hip site.

• Dosing Requirements:

  • Target Trough: $\text{15 to 20}\,\mu g/ml$ for bone/joint infections.

  • Renal Function Data: Serum creatinine ($SCr$) is $0.8\,mg/dL$. The patient has high GFR and stable renal function.

  • Dosing Discrepancy: The patient was ordered $1000\,mg$ Q24h. The pharmacist noted this is likely inappropriate (under-dosed) for a suspected GFR of $\text{80 to 90}\,ml/min$ and BMI/weight assessment, suggesting Q12h or a loading dose of $1750\,mg$ instead.

  • Requirement for Height/Weight: EPIC cannot calculate an accurate creatinine clearance ($CrCl$) without a recorded height and weight. Pharmacists must prompt nursing to enter these values to finalize dosing.

• Historical Data: When determining a new vancomycin dose, pharmacists should check the recent past (within a year) to see previous doses, levels, and corresponding renal function. If historical data is missing or from another hospital, "population numbers" (averages based on demographics) are used instead.

Aminoglycoside Dosing and Monitoring (Tobramycin)

• Body Weight Selection Rule for Dosing:

  • If \text{Actual Body Weight (ABW) < Ideal Body Weight (IBW)}, use $\text{ABW}$.

  • If \text{ABW > IBW}, use $\text{Adjusted Body Weight}$.

  • Specific Example: Patient $\text{IBW} = 73\,kg$, $\text{ABW} = 58.5\,kg$. In this case, use ABW ($58.5\,kg$) for dosing.

• EPIC Monitoring (TDM): Pharmacists use the code ".TDM" to pull up renal function assessment templates.

• Clinical Assessment of Renal Stability:

  • Serum Creatinine Trend: Monitoring the change (e.g., from $1.06$ to $1.08\,mg/dL$). Minor fluctuations are expected, but a jump to $1.5\,mg/dL$ would necessitate holding the drug and getting a level.

  • Urine Output ($UOP$) Calculation:

    • Total daily output: $2425\,ml$.

    • Weight: $58.5\,kg$.

    • $\frac{2425}{58.5 \times 24} = 1.7\,ml/kg/hr$.

    • A value of $1.7\,ml/kg/hr$ signifies very good renal function and stability.

• Short Courses: If a patient is only on tobramycin for a short duration (e.g., 3 days for a Pseudomonas UTI), serum levels may not be ordered; the focus remains on daily renal function monitoring.

Enoxaparin (Lovenox) Prophylaxis and Communication Strategy

• Dosing Adjustments:

  • Standard prophylaxis is $40\,mg$ daily.

  • If CrCl < 30\,ml/min, the dose is reduced to $30\,mg$ daily.

• Monitoring Anti-Xa Levels:

  • Levels should be drawn 4 hours after the 3rd or 4th dose.

  • Case Example: If the first dose was June 10 at $18:00$, the second on June 11 at $18:00$, the third is June 12 at $18:00$. The level draw is set for June 12 at $22:00$.

• Service Communication Hierarchy:

  • Teaching Services (e.g., Medicine Red/Blue/Orange/Green teams): Led by an attending but run by a main resident, interns, and students. Pharmacists contact the intern first to facilitate learning.

  • Hospitalist Services: Attending physicians with no teaching service. Pharmacists contact the attending directly.

Patient-Controlled Analgesia (PCA) Dose Calculations

• Definitions:

  • Demand Dose: The dose delivered when the patient pushes the button.

  • Lockout Interval: The minimum time required between demand doses (e.g., Q10 minutes).

  • Basal Rate: A continuous infusion of the drug (e.g., $40\,\mu g/hr$).

• Hourly Max Calculation:

  • $Intervals\,per\,hour = \frac{60}{Lockout}$.

  • $Hourly\,Max = (Demand\,Dose \times Intervals\,per\,hour) + Basal\,Rate$.

  • Fentanyl Example: $40\,\mu g$ Q10min with $40\,\mu g/hr$ basal.

    • $40 \times 6 = 240\,\mu g$.

    • $240 + 40 = 280\,\mu g/hr$.

• Fentanyl Concentrations:

  • Standard: $10\,\mu g/ml$ ($300\,\mu g$ total in a $30\,ml$ syringe).

  • High Concentration: $50\,\mu g/ml$ ($2000\,\mu g$ total in a $40\,ml$ syringe).

• Step-up Criteria: To switch to high concentration to reduce syringe change frequency (e.g., from 24 changes/day to 3-4), the patient's requirement must exceed $150\,\mu g/hr$.

Pharmacy Operations and Safety Systems

• JCAHO (Joint Commission) Lists: Pharmacists must run "Duplicate Lists" to comply with accrediting agency standards for hospital safety. This ensures patients aren't on multiple medications for the same indication unnecessarily.

• ADT Events: Admission, Discharge, and Transfer. These track every movement of a patient, such as transferring from the Emergency Room (Ocala Neighborhood Hospital) to the North Tower or to the Operating Room (OR).

• Omnicell and Medication Distribution:

  • Stocked Items: Commonly used medications (e.g., famotidine, folic acid) available to any patient in a specific unit.

  • Patient Specific Bins (PSB): For meds not commonly stocked. The satellite pharmacy fills the first 1-2 doses $(\text{red "stat" label})$, and the main pharmacy carousel fills subsequent 72-hour supplies $(\text{white labels})$.

• Chemotherapy Safety:

  • Initial Review: Includes dose audits to ensure prior doses were given and accounted for.

  • Double Check Protocol: The first pharmacist checks the drug and puts notes in EPIC; the second pharmacist performs a "separate, independent check" to avoid bias and minimize risk.

  • Third Check: A final verification is performed in the IV center by a third pharmacist (e.g., Kurt) before the bag reaches the patient.

Questions & Discussion

• Question: What does "unfolding the lines" mean?

  • Response: It refers to the process of forwarding phone lines back to the local satellite pharmacy from the central pharmacy where they were held overnight. This allows nurses to reach the floor pharmacist directly during the day.

• Question: What are ADT events?

  • Response: Admission Discharge Transfer events. They track the movement of a patient throughout the system, including bed-to-bed transfers and floor changes.

• Question: Why did the pharmacist change the Fentanyl concentration?

  • Response: The patient required $280\,\mu g/hr$, and the standard syringe only contained $300\,\mu g$. This meant the nurse had to change the syringe every hour. The high-concentration syringe ($2000\,\mu g$) lasts over 6 hours, significantly reducing nursing labor and the risk of the infusion running dry.