Pulm Lecture 1 ARDS and Rest of Bacterial Stuff

convalescent phase of pertussis

convalescent phase of pertussis

After 2-4 weeks

• Coughing episodes become less frequent and less severe

• Can last 1-3 months

Severe dyspnea of rapid onset + hypoxemia + diffuse pulmonary infiltrates =

respiratory failure

Common causes of ARDS

Pneumonia and sepsis (~40-60%)

• Aspiration of gastric contents, trauma, multiple transfusions, drug overdose

• Trauma like pulmonary contusion, multiple bone fractures, chest wall trauma/flail chest

Increased risks of ARDS

• Multiple comorbidities

• Older age

• Chronic alcohol abuse

• Metabolic acidosis

• Pancreatitis

• Severity of critical illness

three phases of ARDS

exudative, proliferative, and fibrotic

Elaborate on the exudative phase of ARDS

first 7 days of illness after exposure and onset of respiratory symptoms

exudative phase symptoms

Dyspnea, tachypnea, increased work of breathing->respiratory fatigue->respiratory failure

- Severe hypoxemia +/- hypercapnia

CXR findings of exudative phase

opacities consistent with pulmonary edema involving ≥ 75% of lung fields

Elaborate on proliferative phase of ARDS

-day 7 to day 21

-Most patients extubated during this phase

Elaborate on fibrotic phase

• Some patients require long-term MV support and/or supplemental oxygen

• Extensive alveolar-duct and interstitial fibrosis

• Intimal fibroproliferation in the pulmonary microcirculation -> progressive vascular occlusion and pulmonary hypertension

Treatment of ARDS

1) Recognition and treatment of underlying medical and surgical disorders

(2) Minimization of unnecessary procedures and their complications

(3) Standardized "bundled care" approaches for ICU patients

(4) Prompt recognition of nosocomial infections (5) Provision of adequate nutrition

Mechanical ventilation can aggravate lung injury...What are the two principal mechanisms

“Volutrauma” from repeated alveolar overdistention from excess tidal volume

“Atelectrauma” from recurrent alveolar collapse

Manage vent settings carefully

When managing patients with mechanical ventilation what position do we put them in and what are some risks

Prone Positioning

• Improves arterial oxygenation and reduces mortality

• Risks-> accidental endotracheal extubation, loss of central venous catheters, orthopedic injury

how and why do we do fluid management

Aggressive attempts to reduce left atrial filling pressures with fluid restriction and diuretics

• Limited hypotension and hypoperfusion of critical organs like Kidneys

Prognosis of ARDS

Mortality 34.9% - 46.1%

• Most patients regain nearly normal lung function

• Exercise limitation and decreased physical quality of life commonyears later despite normal PFT's

Respiratory Distress Syndrome in the Newborn was formerly also known as what

hyaline membrane disease

what is primary cause of Respiratory Distress Syndrome in the Newborn

deficiency of pulmonary surfactant in an immature lung

Patho process of Respiratory Distress Syndrome in the Newborn

Surfactant deficiency--> alveolar collapse--> low lung compliance and volume--> ventilation and perfusion mismatch--> hypoxemia

what babies are increased risk of this

decreased gestational age (premature babies)

diagnosis of Respiratory Distress Syndrome in the Newborn

Clinical findings of a preterm infant with progressive respiratory failure shortly afterbirth + characteristic chest imaging

• CXR->low lung volume + diffuse reticulogranular ground glass appearance with air bronchograms

signs of respiratory distress in newborn

Tachypnea, nasal flaring, expiratory grunting, cyanosis, and intercostal, subcostal, and subxiphoid retractions

• Decreased breath sounds, pallor, and diminished perfusion

clinical course of Respiratory Distress Syndrome in the Newborn

Progresses over the first 48 to 72 hours with increased respiratory distress

• Begins to resolve after 72 hours

• Resolution of symptoms by one week of age

Management of Respiratory Distress Syndrome in the Newborn

-Antenatal corticosteroid therapy in high-risk pregnant individuals

-Initial respiratory support (noninvasive)

-Surfactant

- Supportive care

what does the supportive care of Respiratory Distress Syndrome in the Newborn

• Maintenance of thermal neutral environment

• Optimal fluid balance with avoidance of fluid overload

• Maintenance of adequate perfusion

• Caffeine therapy for neonates with clinically significant apnea and in all extremely preterm infants (GA <28 weeks)

• Early nutrition

Indications for mechanical ventilation

Decrease the work of breathing and reverse life-threatening hypoxemia and respiratory acidosis

May be used as an adjunct to other forms of therapy

types of mechanical ventilation

Noninvasive ventilation (NIV)

invasive ventilation (MV) (or conventional mechanical)

What does noninvasive ventilation consist of

-Tight-fitting face mask or nasal mask

-Bilevel positive airway pressure ventilation

downsides of noninvasive ventilation

-patient intolerance

-Limited success in patients with acute hypoxemic respiratory failure

when is noninvasive ventilation used

COPD exacerbations and respiratory acidosis

When is conventional MV implemented

once a cuffed tube is inserted into the trachea

T or F 25-30% of MV patients will require prolonged MV (>21 days)

False

5-13%

Elaborate on tracheostomy

• More comfortable

• Requires less sedation

• More secure airway

• May also reduce weaning time

When is tracheostomy indicated

indicated if a patient needs MV for > 10-14 days

complications of tacheostomy

Bleeding, cardiopulmonary arrest, hypoxia, structural damage, pneumothorax, pneumomediastinum, wound infection

Bacterial Infectious Disorders

not a question just like to separate my quizlets

What is pneumonia

Infection of the pulmonary parenchyma

4 types of pneumonia

Community-acquired (CAP)

hospital-acquired (HAP)

ventilator-associated (VAP)

Healthcare-associated (HCAP)

what is HCAP pneumonia?

cases of CAP caused by multi drug resistant (MDR) pathogens

most common bacteria with community acquire pneumonia

Strep Pneu

typical bacteria

S. pneumonia, H. influenza, S. aureus and gram-negativebacilli such as klebsiella pneumonia and pseudomonas aeruginosa

for the 50 thousandth time what are the atypical bacterias

mycoplasma pneumonia, chlamydia pneumonia, Legionella

respiratory viruses (influenza, parainfluenza, respiratorysyncytial virus)

what are atypicals associated with and what should it be treated with

-Resistant to all beta-lactam agents

-Must be treated with a macrolide, fluoroquinolone or a tetracycline

Aspiration leads to what type of bacteria and what is it seen with

Anaerobes

Alcohol or drug overdose, seizure disorder

Often complicated by abscess formation

___ pneumonia is a well-known complication of influenza infection

S. aureus

risk factors for CAP

alcoholism, asthma, immunosuppression, institutionalization, age >70

Clinical Manifestations of CAP

Fever, chills/sweats, cough, SOB, pleuritic chest pain, GI symptoms, fatigue, headache, myalgias

• Accessory muscle use, ↑/↓tactile fremitus, crackles, pleural friction rub

CXR for CAP

Results may suggest an etiologic involvement

Ex. upper lobe cavitary lesion TB

T or F Establishing a microbial etiology may or may not be necessary

true

Urinary antigen test is for what bacteria

Legionella and pneumococcal

Polymerase chain reaction is for what bacteria and what type of patients

-Legionella, mycoplasma pneumonia, chlamydia pneumonia, mycobacteria

-ICU admitted patients

CAP inpatients vs outpatient asessment tool

Pneumonia Severity Index (PSI)

• CURB-65 criteria• 0 = outpatient

• 1-2 = likely admission

• 3+ = likely ICU admission

initial therapy of CAP is ___

empiric

CURB-65 criteria

Confusion

Uremia (BUN > 19)

RR > 30

BP (SBP < 90 or DBP < 60)

Age > 65y.o.

Inpatient treatment for CAP

Inpatient treatment is typically IV

• Switch to oral treatment when patient can ingest the drugs, ishemodynamically stable, and is showing clinical improvement

• 5-day course is usually sufficient for otherwise uncomplicated CAP

Longer course of inpatient treatment is associated with what

Bacteremia, metastatic infection, or infection with a virulent pathogen (ex. P.aeruginosa or CA-MRSA)

CAP adjuvant treatment

Adequate hydration, oxygen therapy for hypoxemia, vasopressors, and assisted ventilation when necessary

• Steroids? Prednisone, Methylprednisolone

if failure to improve after 3 days of treatment suspect what

Noninfectious etiology, drug resistance, unsuspected pathogen

complications of CAP

Respiratory failure, shock and multiorgan failure, coagulopathy, exacerbation of comorbid illnesses, metastatic infection, lung abscess, and complicated pleural effusion

follow up for CAP

F/u CXR in 4-6 weeks

Pneumococcal vaccine

ventilator associated pneumonia is a common complication of

MV

Potential etiologic agents of VAP include

both MDR and non-MDR bacterial pathogens

Often institution-specific

VAP clinical manifestations

-Fever, leukocytosis, increase in respiratory secretions, pulmonaryconsolidation on physical examination, radiographic infiltrate

-Tachypnea, tachycardia, worsening oxygenation

what shoudl u do if you suspect VAP

Obtain diagnostic specimens and then begin treatment

t or f Most patients without risk factors for MDR infection can be treated with asingle agent

true

Lower incidence of atypical pathogens in VAP... what is the exception

Legionella

typical course length of VAP

7/8 days

with VAP treatment failure is not uncommon... what are some reasons for this

Inappropriate initial therapy, drug resistance, pneumonia due to a new superinfection, the presence of extra pulmonary infection, drug toxicity

complications of VAP

Prolongation of mechanical ventilation, pulmonary hemorrhage, bronchiectasis and parenchymal scarring leading to recurrent pneumonia, death

f/u of VAP

findings on CXR often worsen initially during treatment

• Clinical criteria is more helpful

prevention of VAP

• Avoid intubation or minimize its duration

• Minimizing microaspiration around the endotracheal tube cuff

• Minimize transportation of the patient outside the ICU for diagnostic tests or procedures

how to Minimize microaspiration around the endotracheal tube cuff

-elevate the head of the bed (at least 30° above horizontal but preferably 45°)

-Specially modified endotracheal tubes

HAP in ___ patients is similar to VAP

non-intubated

In HAP there is a higher frequency of ____ pathogens

non-MDR

Allows monotherapy in a larger proportion of cases of HAP than of VAP

____ may be more common in HAP than VAP

anaerobes

Greater risk of macroaspiration

T or F in HAP there is Lower mortality rates and risk of antibiotic failure

true

Pneumonia accounts of __% of nosocomial infections

~24

Associated with more deaths than infections at any other body site

Mitigation strategies of pneumonia

• Frequent testing of readiness for extubation

• Remediation of risk factors in patient care

• E.g., minimizing aspiration-prone supine positioning

• Aseptic care of respirator equipment

• Noninvasive mechanical ventilation whenever feasible

What is a lung abscess?

Necrosis and cavitation of the lung following microbial infection

there can be single or multiple lung abscesses... usually marked by a single dominant one of what measurement

>2 cm in diameter

primary abscess is most common...how does this come about

• Aspiration• Often caused principally by anaerobic bacteria

• Occur in the absence of an underlying pulmonary or systemic condition

secondary abscess arise in what setting

underlying condition or a systemic process

Acute vs chronic lung abscess duration

Acute (<4-6 weeks in duration) or chronic (~40% of cases)

lung abscess is formed by colonization of what

Colonization of the gingival crevices by anaerobic bacteria or microaerophilicstreptococci

• Especially in patients with gingivitis and periodontal disease

primary abscess disease process

Anaerobic bacteria in the gingival crevices aspirated--> pneumonitis--> parenchymal necrosis and cavitation

secondary abscess can also arise from what

septic emboli

• Tricuspid valve endocarditis (often involving Staphylococcus aureus)

• Lemierre’s syndrome (classically involving Fusobacterium necrophorum

most common bacteria in lung abscess

Pseudomonas aeruginosa and other gram-negative rods most common

t or f obtaining culture of abscess is optional but you could do it

false

Obtaining culture is important

Lung Abscess Clinical Manifestations

Fevers, cough, sputum production, and chest pain

• Chronic and indolent presentations common with anaerobic lung abscesses

• Abscesses due to non-anaerobic organisms may present with a more fulminant course ( high quick fever, s.aureus)

Physical Exam Findings of lung abscess

Fevers, poor dentition/gingival disease, cavernous breath sounds

initial diagnostics for lung abscess

CXR initially but CT is better

primary abscess diagnostics

empirical therapy initiated, invasive diagnostics infrequently utilized

secondary abscess or empiric abx fail

sputum and blood cultures, serologic studies for opportunistic pathogens

• Bronchoscopy with bronchoalveolar lavage or protected brush specimen collection and/or CT-guided percutaneous needle aspiration

primary lung abcess treatment

1) Clindamycin OR•

(2) an IV β-lactam/β-lactamase combination, followed by amoxicillin-clavulanate

• Tx until abscess is cleared

• 3-4 weeks, up to 14 weeks

secondary abscess treatment

Tx directed at identified pathogen

t or f Abscess > 6-8cm is more likely to respond to antibiotic therapy without additional interventions

FALSE

Less likely to respond

complications of lung abscess

Persistent cystic changes (pneumatoceles) or bronchiectasis, recurrence of abscesses despite appropriate therapy, empyema, life-threatening hemoptysis, massive aspiration of lung abscess contents

prevention of lung abscess

Airway protection, oral hygiene, and minimized sedation with elevation of the head of the bed for patients at risk for aspiration

pneumococcal infections have to do with what bacteria

streptococcus pneumoniae

how do we prevent these pneumococcal infections

Routine childhood administration of pneumococcal polysaccharide-protein conjugate vaccine (PCV)

Not all pneumococcal serotypes are equally likely to cause disease

Pneumococcal Infections are transmitted by what

respiratory droplets