By Billy Hammond (Copyright AELS)

As I was cutting grass this morning and sweating profusely, I remembered what I’d learned in physiology – that heat exhaustion is caused by excessive sweating. This causes a drop in blood volume and a drop in arterial blood pressure that leads to syncope (fainting).

After I got home, I pulled up Robert and Hedges “Clinical Procedures in Emergency Medicine” on my kindle to review the details of heat exhaustion (not to be confused with heat stroke, which is a far more severe condition.)

I was a bit surprised to learn that current thinking attributes the “postural hypotension [read that as a drop in blood pressure when you stand up] developing after exercise” to “exercise-induced changes in blood pressure regulation.” The changes are said to be related to the “recalibration of the aterial baroreflex to lower pressures after exercise, impaired sympathetic vascular regulation, and H1 and H2 receptor– mediated vasodilatation.”*

Basically, it is a condition with a wide range of symptoms that include malaise, flu-like symptoms, orthostasis (decrease in BP after standing), dehydration, nausea, headache, and collapse. The individual’s thermoregulatory system is intact. The mental status is normal and the body temperature is normal or slightly elevated.

The good news is that rehydration, rest and supportive care in a cool place are adequate treatment.

According to Roberts and Hedges’, some authors recommend lying the patient in either a supine (flat, back down – face-up) position with the feet elevated or with the individual’s head between the knees to decrease skin blood flow and increase venous flow to the heart.

Recovery is usually within a few minutes to hours. It’s necessary to watch the individual since there is always the possibility of progression to the more dangerous Heat Stroke.

*Roberts, James R.; Hedges, Jerris R.. Roberts and Hedges’ Clinical Procedures in Emergency Medicine E-Book (Roberts, Clinical Procedures in Emergency Medicine) (Kindle Locations 64369-64371). Elsevier Health Sciences. Kindle Edition.

熱ばて(暑さへばり、熱性疲労 )

昨日、汗びっしゃりで草刈りをしながら生理学のコースの熱ばてについての説明を思い出した。「熱ばては過剰発汗の原因で発生する。それによる血液量減少と動脈圧低下で失神する。」と学んだ。

家に戻ってからキンドルで『Robert and Hedges Clinical Procedures in Emergency Medicine』を出して熱ばての詳細を調べた。注意:『熱ばて』と『熱射病』には関連性があるが、それぞれは別のもの。

驚いたのは、『熱ばて』の運動後の起立性低血圧症は 現在、『運動原因の血圧調整変化』が原因とされている。その変化は「運動後の動脈の圧反射の再キャリブレーション・交感神経の血管調節低下・H1H2受容体仲介の血管拡張」に関連されているそうだ。*

基本的に症状は幅広い。倦怠感、インフルエンザに似た症状、起立性低血圧、脱水、悪心、頭痛及び失神が含まれている。温度調節システムは正常である。精神状態も正常。体温は正常または少し高め。

良いニューズは涼しい場所で水分補給・安静・対症療法で治る。

他にRoberts and Hedges’には何人かの著者は皮膚の血流を減少させ、心臓の動脈血流を増加させるために足を上げて背臥位または頭を膝の間に置く座位を勧めると分かった。

回復期間は数分~数時間。但し、回復までより危険な熱射病に進まないように観察が必要。

*Roberts, James R.; Hedges, Jerris R.. Roberts and Hedges’ Clinical Procedures in Emergency Medicine E-Book (Roberts, Clinical Procedures in Emergency Medicine) (Kindle Locations 64369-64371). Elsevier Health Sciences. Kindle Edition.

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English books by Billy Hammond published by AELS

(AELS出版英語書籍リスト)

 

I. Majoh Gakuin and Hikari Juku – Japanese Witch Schools Trilogy

1. Majoh Gakuin & Hikari Juku – Japanese Witch Schools

2. Lost Witch (The second book)

3. Fate & Magic (The final book in the trilogy)

II. Brindle – Scryer Extraordinaire Trilogy

1. Brindle – Scryer Extraordinaire

2. Brindle – Scryer Extraordinaire – Returns

3. Brindle – Scryer Extraordinaire – Challenges (The final book in the trilogy)

III. Fantasy fiction set in Japan

1. 21st Century Ninja

2. Regressed

3. Japanese Woman

IV. Fantasy fiction set outside of Japan

1. Dimension Jumpers

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