Pulmonology Module

Overview

The Pulmonology module tracks specialist consultations for sleep apnea patients requiring expert evaluation. Pulmonologists (also called pneumologists) provide advanced assessment for complex cases, comorbid respiratory conditions, and treatment-resistant sleep apnea. Model: Neumologia
Location: apps/exams/models.py:153-180

While basic sleep apnea can be managed in primary care with appropriate protocols, pulmonology referrals are essential for:

Complex ventilatory needs (BiPAP ST, high pressures)
Comorbid lung disease (COPD, asthma, interstitial lung disease)
Central sleep apnea components
Obesity hypoventilation syndrome
Treatment failure despite good adherence

Data Fields

fecha_consulta

DateField

required

Consultation Date - Date when the pulmonology consultation occurred

Format: Date field (YYYY-MM-DD)
Form Label: “Fecha de Consulta”
Form Widget: Date picker input

medico_tratante

CharField

required

Attending Physician - Name of the pulmonologist who conducted the consultation

Max Length: 100 characters
Format: Text field
Form Label: “Médico Tratante”
Example: “Dr. María González López”

especialidad

CharField

required

Specialty/Subspecialty - Specific area of pulmonology expertise

Max Length: 200 characters
Format: Text field
Form Label: “Especialidad”
Examples:
- “Neumología General”
- “Medicina del Sueño”
- “Neumología Intervencionista”
- “Trastornos Respiratorios del Sueño”
- “Cuidados Críticos Respiratorios”

The especialidad field captures both the general specialty (Pulmonology/Neumología) and any subspecialty focus (Sleep Medicine, Interventional Pulmonology, etc.). This helps track which expert evaluated the patient.

Relationships

ingreso

ForeignKey

Links to the patient’s active admission recordRelated Name: neumologias
On Delete: CASCADE

registrado_por

ForeignKey

User who registered this consultation record in the systemRelated Name: neumologias_registradas
On Delete: SET_NULL
Note: This is the system user logging the consultation, not necessarily the pulmonologist

created_at

DateTimeField

Timestamp when this consultation record was entered into the systemAuto-generated: Automatically set on record creation
Note: May differ from fecha_consulta if consultation documented retroactively

Registration Workflow

View: register_neumologia (apps/exams/views.py:188-213)

def register_neumologia(request, patient_id):
    patient = get_object_or_404(Patient, id=patient_id)
    
    # Find patient's active admission
    ingreso_actual = patient.ingresos.filter(estado='ACTIVO').first()
    
    if request.method == 'POST':
        form = NeumologiaForm(request.POST)
        if form.is_valid():
            neumologia = form.save(commit=False)
            
            # Link to active admission
            neumologia.ingreso = ingreso_actual
            neumologia.registrado_por = request.user
            
            neumologia.save()
            
            messages.success(
                request,
                f'Consulta de Neumología registrada para {patient.nombre} exitosamente'
            )
            return redirect('patient_clinical', patient_id=patient.id)
    else:
        form = NeumologiaForm()
    
    return render(request, 'exams/register_neumologia.html', {
        'patient': patient,
        'form': form
    })

Key Workflow Considerations

Active Admission Linkage:

Consultations tied to current treatment cycle via ingreso_actual
Allows tracking specialist involvement throughout treatment phases
Data isolation between different admission cycles

Dual User Tracking:

medico_tratante field: Name of the consulting pulmonologist
registrado_por relationship: System user who documented the consultation
This separation allows administrative staff to log consultations while preserving physician attribution

Simple Data Model:

Intentionally lightweight (only 3 clinical fields)
Focus on tracking consultation occurrence, not detailed clinical findings
Clinical details likely documented in external systems or paper charts
Acts as consultation registry and care coordination tool

Common Referral Indications

Complex Ventilatory Needs

Obesity Hypoventilation Syndrome (OHS)

Definition: BMI ≥30 + daytime hypercapnia (PaCO₂ > 45 mmHg) without other causeSleep Apnea Connection:

90% of OHS patients also have OSA
Simple CPAP often insufficient
Requires BiPAP ST with backup rate
Higher pressures needed than typical OSA

Pulmonology Role:

Confirm OHS diagnosis with arterial blood gas (ABG)
Titrate BiPAP ST settings (IPAP, EPAP, respiratory rate)
Monitor EtCO₂ trends (see Monitoring module)
Coordinate with bariatric surgery team
Consider supplemental oxygen

Red Flags:

BMI ≥ 35 + unexplained fatigue or pedal edema
Normal sleep study but severe daytime symptoms
High AHI but symptoms worse than expected

Treatment-Emergent Central Sleep Apnea

Definition: Central apneas emerge or worsen during CPAP therapyMechanisms:

Unmasking of underlying central apnea
CPAP-induced hyperventilation lowering CO₂ below apnea threshold
Heart failure-related (Cheyne-Stokes respiration)

Pulmonology Role:

Differentiate from mask leak (false central apneas)
Trial adaptive servo-ventilation (ASV)
Adjust BiPAP settings to stabilize breathing
Evaluate for underlying cardiac or neurologic disease
Consider acetazolamide or supplemental CO₂

Indication: Persistent high residual AHI (>10) despite good CPAP adherence and no mask leak

High-Pressure Requirements

Definition: Optimal pressure >15 cmH₂O for CPAP or >25 cmH₂O for IPAPConsiderations:

High pressures cause discomfort and poor adherence
Increased aerophagia (air swallowing)
May indicate anatomic abnormality needing surgery
Risk of mask leak at high pressures

Pulmonology Role:

Verify high pressure is truly needed (re-titration study)
Optimize mask fit for high-pressure tolerance
Consider advanced modes (ASV, volume-assured pressure support)
Coordinate with ENT for surgical evaluation
Trial positional therapy or oral appliances as adjuncts

Comorbid Respiratory Conditions

COPD-OSA Overlap Syndrome

Definition: Coexistence of COPD and OSA (affects 10-15% of each population)Clinical Impact:

More severe hypoxemia during sleep
Increased risk of pulmonary hypertension
Higher cardiovascular mortality
Frequent COPD exacerbations

Pulmonology Role:

Optimize COPD treatment (bronchodilators, inhaled steroids)
Determine if supplemental oxygen needed in addition to PAP
Set appropriate oxygen flow rate with PAP device
Monitor for CO₂ retention (BiPAP ST may be needed)
Pulmonary rehabilitation referral

Key Point: CPD patients with unexplained symptoms (despite normal spirometry) should be screened for OSA

Asthma and Sleep Apnea

Relationship:

OSA worsens asthma control (inflammation, vagal tone)
Poorly controlled asthma fragments sleep
CPAP improves asthma symptoms in 40-50% of patients

Pulmonology Role:

Optimize asthma control before PAP therapy
Address nocturnal asthma symptoms
Monitor for CPAP intolerance in severe asthma (rare)
Track asthma medication needs (should decrease with CPAP)

Clinical Pearl: Refractory asthma (especially nocturnal symptoms) should prompt OSA screening

Interstitial Lung Disease (ILD)

OSA Prevalence: 60-88% of ILD patients have OSA (much higher than general population)Mechanisms:

Shared risk factors (older age, obesity)
ILD medications (corticosteroids) worsen OSA
Hypoxemia amplified by sleep-disordered breathing

Pulmonology Role:

Baseline oxygen saturation assessment
Titrate supplemental oxygen with PAP therapy
Monitor disease progression
Coordinate with transplant team if applicable
Adjust immunosuppression considering OSA impact

Caution: Some ILD patients poorly tolerate positive pressure; close monitoring during initiation

Diagnostic Uncertainty

Normal Polysomnography but Symptomatic

Scenario: Patient has classic OSA symptoms (snoring, witnessed apneas, daytime sleepiness) but normal or borderline sleep studyPossible Explanations:

Positional OSA (only supine, patient slept on side during study)
REM-related OSA (minimal REM sleep during study)
Upper airway resistance syndrome (UARS)
Other sleep disorders (narcolepsy, restless legs)

Pulmonology Role:

Review raw polysomnography data (not just report)
Order repeat study with specific instructions
Consider home sleep apnea test in natural sleep environment
Trial empiric CPAP therapy
Referral to sleep medicine specialist

Paradoxical Symptom Worsening with Treatment

Scenario: Patient compliant with CPAP, good AHI correction, but feels worsePossible Causes:

Mask leak causing sleep fragmentation
Pressure too high (frequent arousals)
Central apnea emergence
Coincidental development of another sleep disorder
Psychological factors (nocebo effect)

Pulmonology Role:

Download device data (detailed analysis)
Order follow-up titration or PAP study
Consider alternative therapy (oral appliance, surgery)
Coordinate with psychology if adjustment disorder

Clinical Workflow

When to Refer

Urgent Referral

Within 1-2 weeks for suspected OHS (BMI 35+ with symptoms), severe OSA with heart failure, high CO₂ on monitoring (EtCO₂ above 45), or severe hypoxemia (O₂ sat below 85% on study).

Routine Referral

Within 1-2 months for treatment failure (high residual AHI), complex comorbidities (COPD, ILD, asthma), high pressure requirements, or diagnostic uncertainty.

Consultation Documentation

Best Practices:

Pre-Consultation:
- Provide complete sleep study reports (basal + titration)
- Include monitoring data (adherence, residual AHI)
- Document previous treatments tried
- List all respiratory medications
Consultation Day:
- Record fecha_consulta accurately
- Capture full name of specialist (medico_tratante)
- Note primary specialty and any subspecialty (especialidad)
Post-Consultation:
- Obtain written consultation note for patient chart
- Update treatment plan based on recommendations
- Schedule follow-up if indicated
- Track outcomes of specialist recommendations

While this module captures basic consultation metadata, maintain detailed clinical notes separately (in paper chart or EMR system). The consultation record here serves as:

Proof of specialist involvement for insurance/compliance
Care coordination tracking
Quality metric (specialist utilization rate)

Data Retrieval

View: patient_clinical (apps/exams/views.py:31,35)

# Get all pulmonology consultations for active admission
sesiones_neumologia = Neumologia.objects.filter(
    ingreso=ingreso_actual
).order_by('-id')

Pulmonology consultations are filtered by the patient’s active admission and ordered by ID (most recent first). This chronological tracking helps visualize the patient’s care trajectory and specialist involvement intensity.

Quality Metrics

Consultation Utilization Tracking

System-Level Metrics:

# Example analytics queries (not in source, but useful)

# Referral rate for complex cases
high_ahi_patients = PolisomnografiaBasal.objects.filter(iah__gte=30).count()
high_ahi_with_neuma = Neumologia.objects.filter(
    ingreso__polisomnografias_basales__iah__gte=30
).distinct().count()
referral_rate = high_ahi_with_neuma / high_ahi_patients * 100

# Time to consultation
from django.db.models import F
time_to_consult = Neumologia.objects.annotate(
    days_from_basal=F('fecha_consulta') - F('ingreso__polisomnografias_basales__fecha_basal')
).aggregate(Avg('days_from_basal'))

Quality Indicators:

Appropriate referral rate: 15-30% of moderate-severe OSA patients
Time to consultation: Under 30 days for urgent, under 60 days for routine
Repeat consultation rate: Under 10% (suggests effective initial consultation)

Polysomnography

Sleep study results inform referral decisions

Monitoring

Treatment failure data triggers specialist referral

Medical Equipment

Specialist prescribes advanced device settings

Clinical Resources

Common Pulmonology Recommendations

After pulmonology consultation, typical recommendations include:

Device changes: CPAP → BiPAP, BiPAP → BiPAP ST, addition of ASV
Pressure adjustments: Increase IPAP/EPAP, add pressure support
Oxygen supplementation: Add O₂ bleed-in to PAP device
Additional testing: Daytime ABG, pulmonary function tests, 6-minute walk test
Medication adjustments: Optimize COPD/asthma treatment
Surgical referral: ENT for UPPP, septoplasty, or other airway surgery
Alternative therapy: Trial of oral appliance, positional device
Specialized sleep center: Referral to academic center for complex cases

Communicating with Pulmonologists

Effective Referral Letter Should Include:

Demographics: Age, BMI, neck circumference
Sleep Study Results: AHI, ODI, lowest O₂ sat, sleep efficiency
Current Treatment: Device type, pressures, adherence data, residual AHI
Comorbidities: Especially cardiovascular and respiratory conditions
Specific Question: What are you asking the consultant to address?

Example: “45yo M, BMI 38, severe OSA (AHI 52). On CPAP 14 cmH₂O with 85% adherence but residual AHI 18. Download shows persistent central apneas. Please evaluate for treatment-emergent central sleep apnea and advise on need for ASV.”

Documentation Index

​Overview

​Data Fields

​Relationships

​Registration Workflow

​Common Referral Indications

​Complex Ventilatory Needs

​Comorbid Respiratory Conditions

​Diagnostic Uncertainty

​Clinical Workflow

​When to Refer

Urgent Referral

Routine Referral

​Consultation Documentation

​Data Retrieval

​Quality Metrics

​Consultation Utilization Tracking

​Related Modules

Polysomnography

Monitoring

Medical Equipment

​Clinical Resources

Overview

Data Fields

Relationships

Registration Workflow

Common Referral Indications

Complex Ventilatory Needs

Comorbid Respiratory Conditions

Diagnostic Uncertainty

Clinical Workflow

When to Refer

Consultation Documentation

Data Retrieval

Quality Metrics

Consultation Utilization Tracking

Related Modules

Clinical Resources