Pneumonia (PNA)

Balance between the organisms residing in the lower respiratory tract and the local and systemic defense mechanisms (both innate and acquired) become disturbed

Bacterial, viral, or fungal organisms that reach the alveoli, cause an immune response giving rise to inflammation of the lungs

Multi-Organ System Failure

Macrophages engulf pathogens triggering cytokine molecules and recruitment of neutrophils to site of infection

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Inflammation of lung parenchyma

Lining capillaries become "leaky", which leads to exudative congestion

Consolidation of lung(s)

Infection from the lungs enters the blood stream

Bacteremia

bacterial infection present in the body(streptococcus pneumoniae)

secretion of coagulase protein that activates host hemostatic factor prothrombin

bacterial display of surface proteins that bind polymerized fibrin called agglutinins

culmination of abscess lesions

recruitment and destruction of immune cells via secreted factors associated with the pathogen controlled process

transformation of abscess lesions into purulent exudate w/ which bacteria (streptococcus pneumoniae) disseminate to produce new infectious lesions or infect new hosts

can often progress to

Sepsis

body has a localized infection, normal response: process that localizes and controls phagocytic cells to fight the bacterial invasion while also repairing injured tissue with pro-inflammatory and anti-inflammatory mediators

Impaired systemic defense mechanisms (e.g. autoimmune)

sepsis occurs when release of pro-inflammatory mediators becomes generalized instead of staying within local boundaries

The development of potentially reversible physiologic derangement involving two or more organ systems not involved in the disorder that resulted in ICU admission, and arising in the wake of potentially life-threatening physiologic insult.

Inability to produce productive cough to clear secretions

Altered organ function that causes the body to fail to maintain homeostasis

Other than the organ systems failing, this process can also affect the hematologic system, immune system, and the endocrine system.

patients at higher risk

chronic medical conditions (diabetes, lung disease, cancer, kidney disease)

signs and symptoms

clammy/sweaty skin

Development of atelectasis

blood then spreads the pro-inflammatory mediators (cytokines and tumor necrosis factor) throughout the interstitial space throughout the body producing a generalized response

Contributes to development/worsening of PNA

This process is often caused by uncontrolled infection in the body, which then leads to multiple organ system dysfunction.

Compromised mucociliary clearance due to smoking hx predisposes risk for PNA

fever, shivering, or feeling very cold

Several descriptive scales use the same six organ systems to characterize MOSF - respiratory, cardiovascular, renal, hepatic, neurologic, and hematologic systems.

extreme pain/discomfort

SOB

high heart rate

Predisposes individuals to infection by intracellular organisms such as bacteria, viruses and fungi

Bronchial breath sounds due to alteration of low pass filtering function of alveoli from consolidation

Histologic features of the organ systems that fail are less understood, but often include edema, inflammation, tissue ischemia/necrosis, fibrosis and repair.

confusion/disorientation

d/t increase in cytokines in bloodstream

d/t proinflammatory mediators being carried throughout the bloodstream to produce a more generalized response instead of local, pain becomes more widespread

Gastrointestinal/Hepatic

Neurologic

Heart/Cardiovascular System

Hematologic

Kidney

Immunologic

Lung

Endocrine/Metabolic

Presence of patchy white opacities on radiography

d/t breakdown of the blood brain barrier allowing inflammatory mediators through to interact with the brain causing a change in metabolism and cell signaling, allows other neurotoxic factors through

d/t a systemic response by the body to attack the infection, increased cardiac output and oxygen required by tissues is increased. eventually RR increases to compensate for metabolic acidosis

d/t increased parasympathetic activity which affects ability to thermoregulate

weakened immune systems

children <1 yo

Due to impaired gas exchange

Could be from atelectasis, intravascular thrombosis, trauma to the lungs, or altered regional flow that contributes to issues with ventilation/perfusion

This leads to increased capillary permeabillity, that causes alveolar flooding and then increased diffusion distance for O2

Systemic signs and symptoms such as fever with chills, malaise, myalgias

Results in decreased gas exchange and the need for increased respiratory effort

if not treated quickly enough the cellular injury and release of pro-inflammatory and anti-inflammatory mediators spreads throughout the bloodstream to reach other organs and leads to organ dysfunction and potentially death

Due to the trauma to the lung tissue, the process of tissue repair starts and that is when there is an increase in inflammatory cells rushed to the injured areas, and this could result in fibrosis and therefore, decreased lung function.

Due to impairment of normal selective excretory function

adults 65+ yo

Starts are oliguria (production of abnormally small amounts of urine), then rising creatinine levels, then drastic fluid/electrolyte changes, eventually leading to a need for dialysis

d/t increased workload of the heart as it tries to pump blood throughout body to help defeat the infection

Generalized reduction in peripheral vascular tone

Due to interacting effects of reduced regional blood flow, impaired motility, and alterations in the normal microbial flora.

Leads to an increase in capillary permeability producing diffuse capillary leak, and contributing to further dysfunction in other organ systems

Multiple causes such as the iatrogenic effects of sedatives and analgesics, metabolic alterations, subclinical cerebral edema and reduced cerebral perfusion pressure, and, perhaps, micro-abscesses in the brain

Alterations in regional blood flow to specific organ beds

Microvascular plugging/stasis, resulting from occlusion of the microvasculature, which results in arteriovenous shunting

Due to multiple abnormalities of specific and non-specific immune function

Myocardial depression, affecting the R side of the heart in particular

Leukocytosis (an increase in the number of white cells in the blood, especially during an infection), and thrombocytopenia (low blood platelet count that help to repair and form plugs in blood vessel injuries) are common in MOSF

Most clinically relevant is nosocomial ICU-acquired infection, caused by relatively avirulent organisms.

Hyperglycemia and relative insulin resistance are both common in MOSF. Failure of a gland to stimulate another gland to release hormones.

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