Blood transfusions, fluid therapy, SIRS. Ch 2-4 Flashcards

Question

Key considerations in sepsis scoring for neonates

Answer 1

Scoring of 0-4 for 14 parameters **HISTORY** - 1. placentitis? Y=3/N=0 2. Gestation length - \<300=3, 300-310=2, 311-330=1 \>330=0 **PE**: 3. Petechiae/scleral injection 4. Fever - 5. Hypotonia, coma, seizure - Marked=2, mild=1 6. Anterior uv, d+, ARDS, joint effusions - Y=3, N=0 **LAB**: 7. Neuts - \<2=3, 2-4 or \>12=2, 8-12=1 8. Band neuts/µL - \>200=3, 50-200=2 9. Toxic neuts - Marked=4, mod=3, mild=2, none=0 10. Fib - \>600=2, 4-600 =1, \<400=0 11. Glucose - \<50=2, 50-80=1, \>80=0 12. IgG - \<200=4, 2-400 =3, 4-800=3, \>800=0 13. PaO2 - \<40=3, 40-50=2, 50-70=1, \>70=0 14. Metabolic acidosis - Y=1, N=0 **TOTAL SCORE ≥11 IS PREDICTIVE OF SEPSIS** (or use cutoff of 12 if PaO2 and metabolic acidosis are included)

Answer 2

Altered organ function in acutely ill patient such that homeostasis cannot be maintained

Answer 3

No equine consensus. Various human scoring systems, none really validated in EQ other than 1 in surgical colics only (JVIM 2016) - **score \>8 on d1 and \>6 on d2 assoc w nonsurvival** Looks at lab parameters from 8 organ/systems

Answer 4

Graded 0-4 (0=normal) 1 - Normal walk, stilted trot but no obv head not 2 - Stilted walk, obv lameness at trot but can easily lift limbs 3 - Lameness obvious at walk, reluctant to lift limb(s) 4 - Marked lameness, difficulty weight bearing and reluctant to move

Answer 5

* Via pattern recognition receptors (PRRs) which detect pathogen associated molecular patterns (PAMPs); evolutionary conserved molecules unique to microbes, usually essential for their survival/virulence * 3 main types of mammalian PRRs incl 1) secreted PRRs, incl defensins; (2) cell membrane PRRs involved in phagocytosis; and (3) cell membrane PRRs involved in signal transduction * PAMPs incl bacterial cell wall extracts (LPS), peptidoglycan, prokaryotic DNA

Answer 6

3 main domains 1. Lipid A 2. Core polysaccharide 3. O antigen _Variation in no/length of FAs on glucosamine disaccharide backbone of lipid A confers degree of toxicity_

Answer 7

Large pool of GRAM NEGATIVE gut bacteria - LPS is major component of their outer membrane. Endotoxin must gain access to circulation to exert toxic effect

Answer 8

* Lipopolysaccharide binding protein (LBP) (acute phase protein) binds LPS & extracts it from aggregated micelles in the blood - transport to various sites which determines host response in large part - [LBP] can ↑\>100fold in 24hr * Can be transported to the cell surface of host inflammatory cells to evoke inflamm response or can be transferred to other neutralising lipoproteins, such as high-density lipoprotein, for eventual removal from the blood * Once at the cell surface, LPS is transferred to **CD14**, expressed by monocytes/macrophages - membrane and soluble CD14 -can bind/neutralise LPS * Conversely CD14 can also potentiate toxic effects of endotoxins, by transferring it to membrane CD14 or to cells that do not express it. * CD14 does not structurally cross the cell membrane; has to associate w 2ary protein, toll-like receptor (TLR), that contains a transmembrane portion capable of comms w intracellular domain. * TLR-4 is mandatory for responsiveness to endotoxin * Once the CD14-TLR4-endotoxin complex is compiled at the cell surface, TLR-4 req help of a 160–amino acid molecule, MD2, to transmit a signal to the cytosol → intracellular signalling pathways incl NF𝞳B ⇒ stimulates inflamm response * Most of the deleterious effects of endotoxin rx from overzealous endogenous synthesis of pro-inflammatory mediators and initiation of SIRS - AA metabolites most widely studied

Answer 9

2 therapeutic options * **Polymixin B** - a cationic antibiotic that has bacteriocidal properties & binds/neutralises endotoxin through direct interaction with lipid A (highly conserved so PB theoretically has broader endotoxin-binding capabilities than anticore-endotoxin antibodies) * Can be stored at room temp. Does have inherent nephrotoxic and neurotoxic side effects when used IV at bactericidal doses, but for neutralisation, sub-bactericidal doses are efficacious without toxicity; recommended dose is 1000-6000IU/kg q 8-12hrs, care w azotaemic patients nonetheless. Effect is dose dependent, use higher end of dose range if ↑endotoxin anticipated * **2) Anti-endotoxin antibodies** - anticore antibodies have conflictin rx. Endoserum = hyperimmune serum from horses vacc w Salmonella typhimurium, Re mutant. Disadv of requiring refrigeration. Dilutied w sterile isotonic saline or LRS (1:10 to 1:20) and administered IV over 1-2 hr to reduce risk hypersensitivity reactions. * Hyperimmune anticore plasma to Escherichia coli J5 (Equiplas) can be used in foals for concurrent tx of endotoxemia, septicemia, & FPT, given at 20-40 ml/kg, or in adults. * Plasma products are expensive, req freezer storage, ∴ need thawed * Others incl **flunixin** - 0.25 mg/kg IV q 8 hr is commonplace; benefit of this low-dose incl reduced risk of potential toxic side effects (not cited elsewhere)

Answer 10

8% adults, upto 14% in fit horses 15% in neonates

Blood transfusions, fluid therapy, SIRS. Ch 2-4 Flashcards

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