01Approach to the Critical Patient/attcp59

Immediate priorities

›Recognition in the critically ill

›Unexplained sepsis or septic shock without identified source

›Acalculous cholecystitis as occult source in ICU patient

›Rising vasopressor requirement without alternative cause

›New organ dysfunction in prolonged ICU stay

›Rising WBC and inflammatory markers

›Feeding intolerance and abdominal distension

›Subtle presentation in sedated or intubated patient

›Classic biliary symptoms frequently absent

›High index of suspicion based on clinical trajectory

›Airway and breathing threats

›Sepsis-associated respiratory compromise

›SpO2 < 90% on room air

›Rising work of breathing

›If airway protection inadequate, rapid sequence intubation preparation

›Depressed mental status from sepsis

›Aspiration risk during deterioration

›Circulation and shock threats

›Septic shock physiology

›SBP < 90 mmHg

›MAP < 65 mmHg

›Hypoperfusion markers

›Lactate >= 2 mmol/l

›Oliguria and altered mentation

›If septic shock, broad-spectrum antibiotics within 1 hour

›Surviving Sepsis Campaign Class I recommendation

›Blood cultures before antibiotics when feasible

02History/hx64

Presentation pattern

›Classic triad

›Right upper quadrant pain

›Onset, severity, and progression

›Radiation to right shoulder or scapula

›Fever

›Chills and rigors

›Antipyretic use masking

›Nausea and vomiting

›Anorexia

›Feeding intolerance in ICU patient

›Atypical and occult presentation

›Sedated or intubated ICU patient

›Unexplained sepsis as only manifestation

›New organ dysfunction without classic biliary symptoms

›Altered mental status as sole sign

›Delirium in older adult

›Subtle decline in critically ill

Clinical context

›ICU and critical illness context

›Duration of critical illness

›Prolonged mechanical ventilation

›Vasopressor requirement

›Recent surgery or trauma

›Major operative stress

›Burns

›Nutritional context

›Prolonged fasting

03Physical Exam/exam48

Vital signs and general

›Stability snapshot

›Temperature

›Fever as systemic inflammatory marker

›Hypothermia as severe sepsis marker

›Heart rate and blood pressure

›Tachycardia in sepsis

›SBP < 90 mmHg as shock marker

›Mental status

›Altered mentation as sepsis sign

›May be only sign in ICU patient

›General appearance

›Toxic appearance

›Diaphoresis

›Rigors

›Jaundice

›Present in minority

›Suggests concomitant obstruction or severe inflammation

Abdominal exam

›Right upper quadrant findings

›Tenderness

›With or without guarding

›Localized to gallbladder fossa

›Murphy sign

›Inspiratory arrest with right upper quadrant palpation

›Often unreliable in sedated or intubated patient

›Palpable mass

›Distended gallbladder

04Differential Diagnosis/ddx42

Biliary and hepatic mimics

›Acute calculous cholecystitis

›Most common mimic

›Distinguished by gallstones on imaging

›Lower gangrene rate than acalculous disease

›Shared presentation

›Right upper quadrant pain and fever

›Positive Murphy sign

›Ascending cholangitis

›Charcot triad

›Fever, jaundice, right upper quadrant pain

›ICD-10 K83.0

›Imaging clue

›Common bile duct dilation

›Biliary obstruction

›Hepatic abscess

›Fever and right upper quadrant pain

›Rim-enhancing collection on CT

›ICD-10 K75.0

Non-biliary mimics

›Acute pancreatitis

›Epigastric pain radiating to back

›Elevated lipase

›ICD-10 K85.9

›Peptic ulcer disease or perforation

›Epigastric pain

›Free air on imaging

›ICD-10 K27.9

05Laboratory Tests/lt42

Infection and inflammation

›Complete blood count

›Leukocytosis with left shift

›Nonspecific but expected

›WBC > 18,000 supports Tokyo Grade II

›Neutrophil-to-lymphocyte ratio

›Elevated NLR correlates with severity

›Lower lymphocyte counts in Grade III

›Inflammatory markers

›C-reactive protein

›Trend over time

›Limited specificity

›Procalcitonin

›Bacterial infection support

›Severity trending

Hepatobiliary and metabolic

›Liver function tests

›Transaminases

›Mild elevation from cytolysis

›Marked elevation suggests alternative pathology

›Bilirubin

›Mild elevation possible

›Cholestatic pattern less common than calculous disease

›Pancreatic and perfusion

›Lipase

›Rule out pancreatitis

›Normal in uncomplicated acalculous cholecystitis

›Lactate

06Diagnostic Tests/dt85

Scoring Systems

›Tokyo Guidelines TG18 severity grading

›Grade I mild

›No organ dysfunction

›Mild inflammatory changes

›Grade II moderate

›WBC > 18,000

›Palpable right upper quadrant mass

›Symptom duration > 72 hours

›Marked local inflammation

›Grade III severe

›Cardiovascular dysfunction requiring vasopressors

›Neurologic, respiratory, renal, hepatic, or hematologic dysfunction

›Surgical risk stratification

›Charlson Comorbidity Index

›CCI >= 4 identifies poor surgical candidates

›Guides cholecystostomy decision

›ASA Physical Status

›ASA >= 3 suggests high perioperative risk

›Favors percutaneous drainage

›Limitations

›Grading guides but does not replace clinical judgment

›Serial reassessment required

›Trajectory supersedes single score

MRI

›MRI and MRCP role

›Problem-solving indications

›Suspected concomitant choledocholithiasis

07Disposition/dispo33

Level of care

›Admission for all confirmed or suspected cases

›Not an outpatient diagnosis

›Risk of gangrene and perforation

›Mandatory surgical consultation

›Surgical floor

›Hemodynamically stable patients

›Awaiting cholecystectomy

›ICU admission indications

›Sepsis or hemodynamic instability

›Vasopressor requirement

›Rising lactate despite resuscitation

›Tokyo Grade III organ dysfunction

›Respiratory or renal failure

›Multiorgan involvement

Consults and follow up

›Specialty consultation

›Surgery

›Operative decision in all cases

›Timing of cholecystectomy

›Interventional radiology

›Percutaneous cholecystostomy when non-operative

›Gastroenterology

›EUS-guided gallbladder drainage option

›Discharge and follow up criteria

›Post-cholecystectomy discharge

›Tolerating diet

›Pain controlled and afebrile

08Treatment/t69

Initial stabilization

›Resuscitation and supportive care

›IV fluid resuscitation

›Balanced crystalloid for hypoperfusion

›Electrolyte correction

›NPO status

›During acute illness

›Pending surgical decision

›Analgesia

›Acetaminophen as first-line

›Minimize opioids given bile stasis risk

›Nutritional strategy

›Avoid total parenteral nutrition where possible

›Recognized risk factor for acalculous cholecystitis

›Transition to enteral feeding when feasible

›Adequate hydration

›Support splanchnic perfusion

›Prevent further ischemia

Empiric antibiotics

›Risk-stratified empiric coverage

›Not critically ill

›Amoxicillin-clavulanate when local Enterobacteriaceae resistance < 20%

›1.2 g IV every 8 hours

›Critically ill

›Piperacillin-tazobactam 4.5 g IV every 6 to 8 hours

›Extended infusion per local protocol

›Beta-lactam allergy

›Ciprofloxacin 400 mg IV every 12 hours plus metronidazole 500 mg IV every 8 hours

09Special Populations/sp39

Pregnancy

›Pregnancy considerations

›Imaging approach

›Ultrasound as first-line without radiation

›MRI without gadolinium when cross-sectional needed

›Antibiotic selection

›Beta-lactams generally preferred

›Avoid fluoroquinolones and tetracyclines

›Surgical timing

›Cholecystectomy safest in second trimester

›Percutaneous drainage as temporizing option

›Maternal and fetal monitoring

›Maintain maternal SpO2 >= 95%

›Fetal monitoring at viable gestation

Geriatric

›Older adult features

›Atypical presentation

›Afebrile infection common

›Delirium as primary symptom

›Higher comorbidity burden

›Increased surgical risk

›Favors cholecystostomy in frail patients

›Medication adjustments

›Renal dosing of antibiotics

›Avoid nephrotoxic combinations

›Mortality consideration

›Myocardial infarction or heart failure as independent risk factor for in-hospital death

›Cardiac evaluation and ECG

10Background/b50

Epidemiology

›Frequency and burden

›Proportion of acute cholecystitis

›Accounts for 5 to 10% of all acute cholecystitis

›Predominantly affects critically ill patients

›Mortality

›Historically up to 30% in critically ill cohorts

›Approximately 2.5% in-hospital mortality in contemporary series

›Complication rates

›Gangrenous cholecystitis

›31.2% in acalculous vs 5.6% in calculous disease

›High perforation risk if diagnosis delayed

›Age distribution

›92.8% of patients over 50 years in one series

›Increasing with comorbidity burden

Pathophysiology

›Central mechanisms

›Gallbladder ischemia

›Hypoperfusion and low-flow states

›Vasopressor-induced splanchnic ischemia

›Bile stasis

›Prolonged fasting and TPN

›Absent enteral stimulation of gallbladder emptying

›Inflammatory cascade

›Nonobstructive injury

›Ischemia-reperfusion injury

›Eicosanoid-mediated inflammation

›Progression

11Patient Discharge Instructions/pdi20

copy discharge instructions

›Home care after gallbladder treatment

›Take all antibiotics exactly as prescribed until finished

›Rest and stay well hydrated

›Follow any low-fat diet advice if your gallbladder was preserved

›Keep surgical or drain sites clean and dry

›Warning signs to return to the ER

›Fever or shaking chills

›Worsening abdominal pain

›Yellowing of skin or eyes

›Persistent nausea or vomiting

›Inability to keep fluids down

›Redness, swelling, or drainage from a wound or tube site

›Follow up

›Surgical follow up in 2 to 4 weeks after cholecystectomy

›Drain or tube management appointments if a cholecystostomy was placed

›Repeat imaging in 4 to 6 weeks if treated without surgery

›Recovery expectations

›Gradual improvement expected after treatment

›Report any return of pain or fever promptly

›Attend all scheduled follow-up visits

12References/r12

Guidelines and key sources

›Guideline sources

›Tokyo Guidelines TG18 for acute cholecystitis grading and management

›World Society of Emergency Surgery acute cholecystitis recommendations

›Surviving Sepsis Campaign for septic shock management

›Key reviews and studies

›Gallaher and Charles, Acute Cholecystitis: A Review, JAMA 2022

›Huffman and Schenker, Acute Acalculous Cholecystitis: A Review, Clin Gastroenterol Hepatol 2010

›Barie and Eachempati, Acute Acalculous Cholecystitis, Curr Gastroenterol Rep 2003

›Sadaka, Tseng, Itani, Percutaneous Cholecystostomy Drainage, JAMA Surgery 2025

›Coding standards

›ICD-10 K81.0 acute cholecystitis

›SNOMED CT acalculous cholecystitis disorder concept

Evidence & Review

Evidence & Review