Presented by:Dr.MATETY.JATTADHAR,DNB 1st year internal medicine resident.

Moderator : Dr.Ashutosh ojha sir,MD

HEAT STROKE- REVIEW ARTICLE

1.Definition2.Classification3.Pathogenesis and pathophysiology4.Differential diagnosis5.Clinical picture6.Treament7.Novel treatment approaches in future

1.DEFINITION: A form of hyperthermia a/w systemic

inflammatory response, leading to syndrome of multiorgan dysfunction in which ENCEPHALOPATHY predominates.. cns dysfunction, multiorgan failure hyperthermia >40.5degreesC.

CLASSIFICATION:

A) classic- elderly,prepubertal children(due to exposure to environmental heat and poor heat- dissipation mechanisms)

B)Exertional-strenous physical activity(atheletes,soldiers,fire fighters, agricultural workers,overmotivation from coaches). It is associated with physical exercise and results when excessive prodution of metabolic heat overwhelms physiological heat-loss mechanisms.

▪ Children are prone because of high surface area/mass ratio, under developed thermo regulatory system, small blood volume, low sweating rate.

PATHOGENESIS & PATHOPHYSIOLOGY

Tranisition from compensable thermoregulatory phase to noncompensable phase.Cardiac output insufficient to copeup(cv collapse)Core body temp increases.Direct cytotoxic response.Gastrointestinal permeability increases.S.I.R.Scns dysfunction,Liver dysfunction, ARF,DIC,Muscle break down, Cardiac dysfunction

DIFFERENTIAL DIAGNOSIS

Once ruled out by clinical history, other conditions to be consideredmeningitis,encephalitis,epilepsy,drug intoxication(cocaine,amphetamine),severe dehydration,Any metabolic syndrome(neuroleptic malignant,serotonin,thyroid storm,phechromocytoma miltisystem crisis.)

CLINICAL PICTURE

It has 3 phases-Hyperthermic-Neurologic Acute phase.Hematologic enzymatic phase peaking 24-48hrs after the onset.Late Renal- hepatic phase.

CNS Dysfunction-behavioural changes, Delirium,Dizziness,Agitation,Seizures,Slurred speech.Brain edema.Brain injury concentrated in cerebellum

TREATMENT:

Treated symptomatically and conservatively.Rapid and effective cooling( temp <38 degreesC).Cold water immersion.Application of ice packs, cold packs,wet gauage sheets, fanning.

Maintain core temp <38degC, by infusing cold fluids 4degC, 1000ml/30min through central catheter.Maintain urine output >50ml/kg/hr.DIC-FFP,Cryo precipitate,platelets.

❖ Antipyretics-aspirin ,PCM are ineffective in heat stroke since(fever and hyperthermia)raise the core body temperature through different physiological pathway…

❖ NOVEL TREATMENT APPROACHES IN FUTURE:--

✔ Allopurinol to decrease portal LPS levels by protecting integrity of tight cell to cell junctions..

✔ Recombinant activated protein –C.(To decrease inflammation and DIC).

✔ Chinese rhubarb,a plant species to decrease inflammation and facilitate recovery from, HEAT- associated acute liver and kidney injury..

MY VIEWS ABOUT THE ARTICLE

It is a NEJM article downloaded on june 19,2019.This article is collected from HELLER INSTITUTE OF MEDICAL RESEARCH ,SHEBA MEDICAL CENTER,ISRAEL.This article is very much relevant and applicable in tropical countries like INDIA,Where HEAT STROKE is more common..New things I have learnt through this article is,maintaining core temperature <38deg C,by infusing cold fluids(4degC,1000ML/30Min) through central catheter or use of extracorporeal blood cooling for resistant hyperthermia..Antipyretics are toxic and should be avoided.Dantrolene has not been proved to be effective..