How can I present data on intraoperative and post-operative electrolyte levels and post-operative intracranial pressures in pediatric patients who underwent craniotomy surgery with albumin as a colloid in a research paper?

Presenting Data on Albumin Use in Pediatric Craniotomy: A Structured Approach

Your dataset should be organized into three primary analytical sections: baseline characteristics with electrolyte profiles, intraoperative fluid management and electrolyte changes, and postoperative outcomes including ICP measurements and electrolyte derangements, with particular emphasis on hypernatremia and hyperchloremia given the known risks in neurosurgical patients. 1, 2

Baseline Patient Characteristics Table

Present your cohort demographics and preoperative data in a comprehensive Table 1:

• Patient demographics: Age distribution, sex, weight/BMI, and ASA classification 3
• Surgical indications: Tumor type/location, vascular lesions, or other pathology requiring craniotomy 3
• Preoperative laboratory values: Baseline sodium, chloride, and albumin levels (noting that preoperative hypoalbuminemia is associated with increased mortality and should be highlighted) 3
• Comorbidities: Particularly those affecting fluid/electrolyte management 3

Intraoperative Management and Electrolyte Changes

Create a detailed section analyzing fluid administration and electrolyte shifts:

• Total albumin volume administered: Specify whether 5% or 25% albumin was used, as this impacts sodium load (both contain approximately 145-154 mmol/L sodium) 4, 5
• Crystalloid co-administration: Document concurrent use of normal saline versus buffered crystalloids, as this significantly impacts chloride load 4
• Intraoperative electrolyte trends: Present sodium and chloride changes from baseline to end of surgery using line graphs or box plots showing median values with interquartile ranges 6
• Temporal analysis: Consider presenting electrolyte changes at specific surgical timepoints (e.g., incision, tumor resection, closure) 6

A critical caveat: Current guidelines recommend against routine albumin use in neurosurgery, and specifically recommend 0.9% saline over buffered solutions in traumatic brain injury due to concerns about tonicity and ICP management 4. Your discussion must address why albumin was chosen despite these recommendations.

Postoperative Outcomes Analysis

Structure your outcomes data to address both electrolyte derangements and neurological complications:

Electrolyte Complications

• Hypernatremia stratification: Categorize patients by severity (mild 146-149 mmol/L, moderate 150-159 mmol/L, severe ≥160 mmol/L) as this correlates with mortality in craniotomy patients 1
• Hyperchloremia incidence: Document chloride levels >110 mmol/L, as large chloride loads from albumin and saline are associated with adverse outcomes 4
• Time to peak abnormality: Present when maximum sodium/chloride elevations occurred postoperatively 1

ICP and Neurological Outcomes

• ICP measurements: Present mean ICP values, peak ICP, and percentage of patients with ICP >20 mmHg (the threshold for intervention in pediatric patients) 4
• Correlation analysis: Use multivariable regression to assess whether postoperative hypernatremia or hyperchloremia independently predicts elevated ICP, controlling for surgical factors, albumin volume, and baseline characteristics 1, 2
• Temporal relationship: Critically important—analyze whether ICP elevations temporally correlate with electrolyte derangements, as albumin use in TBI is associated with increased ICP during the first week postoperatively 2

Statistical Presentation Recommendations

Use pattern mixture modeling if you have missing data or patients who discontinued ICP monitoring, as this addresses informative dropouts that are common in neurosurgical populations 2. This is particularly relevant since approximately 30-40% of intracranial lesions may expand in the first 12-36 hours, potentially affecting monitoring duration 7, 8.

Present adjusted analyses controlling for:

• Age-specific factors (pediatric ICP thresholds vary: 40 mmHg for 0-5 years, 50 mmHg for 5-11 years, 50-60 mmHg for >11 years) 4
• Tumor histology and location 3
• Total fluid volume administered 2
• Concurrent medications affecting ICP (sedation, osmotic therapy) 4

Critical Methodological Considerations

Your discussion must acknowledge that albumin use in neurosurgical patients is controversial and potentially harmful 4, 2. The SAFE study demonstrated increased mortality in TBI patients receiving albumin, with evidence suggesting this occurs through increased ICP during the first postoperative week 2. While your population underwent elective craniotomy rather than trauma, the mechanism of ICP elevation may be similar.

Address these specific points:

• Why albumin was used: Current guidelines recommend against routine albumin use in neurosurgery and critical illness 4
• Sodium load implications: Both 5% and 25% albumin contain high sodium concentrations that may contribute to hypernatremia 4, 5
• Alternative fluid strategies: Guidelines recommend buffered crystalloids for most surgical patients, with 0.9% saline specifically for brain-injured patients 4

Visual Data Presentation

• Figure 1: Flowchart showing patient selection and data completeness for each variable 6
• Figure 2: Box plots comparing intraoperative versus postoperative sodium and chloride levels 6
• Figure 3: Scatter plot with regression line showing correlation between peak sodium levels and maximum ICP 1, 2
• Figure 4: Kaplan-Meier curves if analyzing time to electrolyte normalization or ICP control 2

Never present data without clearly stating the clinical implications—if you found elevated ICP correlating with hypernatremia, explicitly state the mortality risk (e.g., severe hypernatremia carries OR 67.00 for 30-day mortality in craniotomy patients) 1.

Your Results section should objectively present findings without interpretation, but ensure every table and figure directly addresses whether albumin use was associated with electrolyte derangements and whether these correlated with elevated ICP 6. The Discussion must then reconcile your findings with current evidence suggesting albumin may be harmful in neurosurgical populations 4, 2.