HEMATOLOGY Hot Topics and Morphology BCSLS Telehealth Broadcast June 16, 2005 Kin Cheng

CASE # 1 –76 year old female –Previously well –Acute back pain and vomiting after mowing the lawn

Physical (10:00 PM): –Afebrile P-108; BP 139/69 –Alert and oriented but “deathly ill looking” –Soft, non-tender abdomen with bowel sounds

MCHC >365 Hematocrit: RBC x MCV MCH = Hgb / RBC MCHC = Hgb / Hct 3 x RBC = Hgb 3 x Hgb = Hct

MCHC >365 Handling Cold agglutinin : Warm sample Lipemic, icteric, hemolysed: Saline replacement Protein: Warm specimen, rerun Spherocytes

SPUN SAMPLE

Spun Hct: 0.11

Pre & Post Saline Replacement Pre- replace Post replace WBC9.2 R7.4 R RBC Hgb10131 Platelets324100

Pre- saline Post- saline Hct MCV MCHC453359

Manual Differential Neuts: 5.0 Lymphs: 2.7 Eos: 0.1 NRBC: 5 / 100 WBC

Agar Plate

Histogram

Intubated at 01:30 Hypotensive post-intubation ICU bed found at referral centre (04:00) Arrested in transit (04:30 )

Autopsy: green discoloration of skin with skin slippage and advanced organ autolysis No identifiable source of sepsis

Clostridial Gas Gangrene 6/150 species capable of causing gas gangrene Toxin and gas producing bacteria Lethal Necrotize soft tissues Clostridial myonecrosis: Common surgical infection if poor surgical technique

Clostridial gas gangrene Anerobic, gram pos bacilli (Hematology stain is NOT gram stain) Spore forming bacteria Found in soil, contaminated raw meat and poultry, normal skin, colon flora

Clostridial infection 80% caused by C. perfringens 20%: –C. novyi – C. septicum –C. bifermentans –C. histolyticum –C. fallax

Clostridium perfringens (welchii) Produce 12 types of toxins (lecithinase) Extraordinary spectrum of clinical manifestations from transient bacteremia to gas gangrene or sepsis with hemolysis Rate of myonecrosis: 2 cm/hr Fatal within 12 hours.

C. perfringens Introduction of bacteria into tissues Bacterial proliferation in low (<30%) oxygen environment Incubation period: 1 – 12 hrs Release exotoxin

C. perfringens >17 Exotoxins: –Lecihinase –Collagenase –Hyaluronidase –Fibrinolysin’hemolysin

C. perfringens Alpha toxin: lecithinase –Destroys red cell membranes, muscle cells, platelets and WBC –Induces platelet aggregation and clot formatioin Kappa toxin: destroys connective tissues Theta toxin: Destroys WBC and disarms inflammatory responses.

Clostridium spp Clinical IllnessOrganism Gas gangreneC. perfringens (80%) Food poisoningC. perfringens Antibiotic diarrheaC. difficile TetanusC. tetani BotulismC. botulinum

C. perfringens Massive intravascular hemolysis Hb-emia, Hb-uria, hyperkalemia Renal failure, coagulopathy Often fully conscious with normal BP Shock and death % mortality Survival measured in hours

C. perfringens Elderly and immunocompromized Cancer patients with mucosal disruption –Chemotherapy & radiotherapy –Tumor infiltration –Malnutrition Hepatobilliary disease, liver abscess, colonic perforation, trauma or surgery Septic abortion / ruptured ectopic pregnancy

Case # 1 Despite absence of effective RBC mass patients transiently maintain normal BP and mentation presumably due to free Hb –Maintenance of intravascular oncotic pressure –Maintenance of adequate tissue oxygenation

Questions??