儿科生命体征与脱水计算

🧠 为什么重要

儿童年龄越小，生命体征越快：婴儿每分钟约100至160次心跳和30至60次呼吸，幼儿90至140次和24至40次，学龄前儿童80至120次和22至34次，学龄儿童75至120次和18至30次，青少年则接近成人范围。儿童的代偿能力很好，因此TACHYCARDIA（心动过速）是出现问题的早期信号，HYPOTENSION（低血压）则是晚期不祥的信号。通过体重减轻（WEIGHT LOSS）评估脱水（DEHYDRATION）：轻度3%至5%，中度6%至9%，重度10%或以上，并结合囟门和眼窝凹陷、黏膜干燥、无泪、皮肤弹性下降、毛细血管再充盈超过2秒、嗜睡，以及尿量低于1 mL/kg/hr或婴儿每天湿尿布少于6片。轻度至中度脱水用口服补液盐（ORAL REHYDRATION SOLUTION）治疗，少量多次给予（约50至100 mL/kg，在4小时内）；要避免白开水、果汁、汽水和运动饮料，它们的糖和电解质配比不对。重度脱水或无法保留液体时，需要等渗IV推注20 mL/kg。补液完成后，鼓励尽早恢复正常饮食。婴儿比成人脱水更快，因为他们体内水分比例更高、肾脏未发育成熟且代谢率更高。

Pediatric vital signs run faster when younger: infants about 100 to 160 beats and 30 to 60 breaths per minute, toddlers 90 to 140 and 24 to 40, preschoolers 80 to 120 and 22 to 34, school-age 75 to 120 and 18 to 30, adolescents approaching adult ranges. Children compensate well, so TACHYCARDIA is an early sign of trouble and HYPOTENSION is a late, ominous one. Assess DEHYDRATION by WEIGHT LOSS: mild 3 to 5%, moderate 6 to 9%, severe 10% or more, plus sunken fontanel and eyes, dry mucous membranes, absent tears, decreased skin turgor, capillary refill over 2 seconds, lethargy, and urine output below 1 mL/kg/hr or fewer than 6 wet diapers a day in an infant. Mild to moderate dehydration is treated with ORAL REHYDRATION SOLUTION in small frequent amounts (about 50 to 100 mL/kg over 4 hours); avoid plain water, juice, soda and sports drinks, which are the wrong mix of sugar and electrolytes. Severe dehydration or inability to keep fluids down requires an isotonic IV bolus of 20 mL/kg. Early refeeding with a normal diet is encouraged once rehydrated. Infants dehydrate faster than adults because of a higher body water percentage, immature kidneys and a higher metabolic rate.

🏥 真实场景

🍼 一位母亲给她呕吐的8个月大婴儿喝苹果汁和水，因为“他需要补液”。婴儿的情况恶化了。护士教她每隔几分钟用茶匙喂一小口口服补液盐，婴儿能保留住，并数湿尿布的数量。到了晚上，囟门变平，宝宝也有眼泪了。用对液体、用对量，就是全部的干预措施。

🍼 A mother gives her vomiting 8-month-old apple juice and water because 'he needs fluids'. The infant worsens. The nurse teaches oral rehydration solution by teaspoon every few minutes, which stays down, and counts wet diapers. By evening the fontanel is flat and the baby is making tears. The right fluid in the right amounts is the whole intervention.

📌 要点总结

• 儿童心动过速出现得早；低血压出现得晚Tachycardia is early; hypotension is late in children
• 体重减轻：3–5%为轻度，6–9%为中度，10%+为重度Weight loss: 3–5% mild, 6–9% moderate, 10%+ severe
• ORS少量多次小口喂；重度给予20 mL/kg等渗液体推注ORS in small frequent sips; severe gets a 20 mL/kg isotonic bolus

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