Infectious Disease Lecture

Severe Sepsis

A critical condition characterized by sepsis accompanied by evidence of end organ dysfunction.

Septic Shock

A severe form of sepsis where persistent hypotension does not improve with fluid resuscitation.

SIRS

Systemic Inflammatory Response Syndrome, indicating an overall inflammatory response in the body.

Positive SIRS Criteria

Requires two or more of the following: fever >100.4°F, hypothermia

SOFA

Sequential Organ Failure Assessment, a scoring system to evaluate organ involvement or failure.

qSOFA

A bedside screening tool for sepsis, assessing three criteria: respiratory rate ≥22 bpm, altered mental status, systolic BP ≤100 mmHg.

Band Neutrophils

Immature neutrophils in the blood, indicating an inflammatory or infectious process.

Sepsis 3

Defines sepsis as infection leading to organ dysfunction that predicts mortality.

Empiric Antibiotics

Antibiotics given before culture results, typically Vancomycin and Ceftriaxone for sepsis.

Vasopressors

Medications used to treat septic shock by increasing blood pressure.

Mean Arterial Pressure (MAP)

The average blood pressure in a person's arteries during one cardiac cycle; goal in sepsis treatment is >65 mmHg.

Serum Lactate

A marker of tissue hypoperfusion; elevated levels indicate potential severe infection.

Infection vs. Sepsis

Infection becomes sepsis when there's a dysregulated host response to pathogens.

Common Causes of Sepsis

Pneumonia, urinary tract infections, and bloodstream infections.

Priority in Sepsis Treatment

Immediate initiation of antibiotics and fluid resuscitation within the first hour.

Cerebrospinal Fluid (CSF)

Fluid surrounding the brain and spinal cord, analyzed in cases of meningitis and encephalitis.

Intracranial Pressure

Pressure within the skull, elevated in conditions such as meningitis.

Altered Mental Status

A change in awareness or cognitive function, often seen in encephalitis cases.

Lumbar Puncture

A medical procedure to collect cerebrospinal fluid for testing.

Acyclovir

An antiviral medication used to treat infections caused by certain types of viruses, such as herpes simplex virus.

CSF Findings in Bacterial Meningitis

Elevated white blood cells, elevated protein, and decreased glucose.

CSF Findings in Viral Meningitis

Elevated white blood cells, normal to elevated protein, and normal glucose.

Meningitis

Inflammation of the protective membranes covering the brain and spinal cord.

Encephalitis

Inflammation of the brain, often caused by viral infections.

Common Viruses Causing Encephalitis

Herpes simplex virus (HSV) and West Nile virus.

SIRS Criteria Examples

Fever, elevated heart rate, rapid breathing, white blood cell count abnormalities.

Pseudomonas Coverage

Use of specific antibiotics for infections caused by Pseudomonas aeruginosa.

Septic Workup

Comprehensive evaluation for sepsis, including laboratory tests and imaging.

Empiric Therapy for Meningitis

Combination of Vancomycin and a third-generation cephalosporin.

Listeria Monocytogenes

A common cause of meningitis in young infants and the elderly.

Vaccines for Meningitis

Vaccines available for protection against Neisseria meningitidis.

Clinical Diagnosis of Sepsis

Based on SIRS criteria, SOFA scoring, and clinical judgment.

Neurocognitive Effects

Cognitive dysfunction resulting from encephalitis or severe infections.

Bacterial Meningitis Common Causes

Streptococcus pneumoniae and Neisseria meningitidis.

Viral Meningitis Common Causes

Enteroviruses and herpes simplex virus.

Sepsis Mortality Risk

Delay in treatment and antibiotics contributes significantly to mortality rates.

Fever of Unknown Origin (FUO)

A fever that remains undiagnosed despite extensive workup.

Elevated CSF Protein

Suggestive of inflammation, infection, or intracranial pathology.

CSF Glucose Levels

A critical marker in differentiating bacterial from viral meningitis.

Serologic Testing

Blood tests to identify specific infections or antibodies.

Empiric Antibiotic Adjustments

Making changes in antibiotic treatment based on culture results.

Meningococcal Vaccination Schedule

Routine immunization schedule for preventing Neisseria meningitidis infection.

Cerebral Herniation Risk

Increased risk during lumbar puncture if intracranial pressure is elevated.

Management of Sepsis

Involves aggressive fluid resuscitation, antibiotic therapy, and monitoring.

Complications of Meningitis

May include hearing loss, learning disabilities, or neurological dysfunction.

Signs of Meningeal Irritation

Includes neck stiffness and positive Brudzinski's sign.

Contextual Factors in Sepsis

Age, underlying conditions, and previous infections can impact severity.

Host Factors in Infection

Immunocompetence, chronic disease, and age affecting infection outcome.

Acute Confusion in Infection

Considered a critical symptom in assessing patients with potential encephalitis.

Pathogen Virulence

The degree of pathogenicity and ability of an organism to cause disease.

Acute Inflammatory Response

The body's immediate response to infection or injury.

Neutrophil Shift

An increase in immature neutrophils, indicating an inflammatory response.

Mean Arterial Pressure Goal

Maintained at >65 mmHg during septic shock treatment.

Chronic Conditions Affecting Sepsis

Diabetes, renal disease, or malignancies may worsen infection outcomes.

Diagnosis of Encephalitis

Often requires imaging and laboratory testing to identify causal viruses.