Introduction of Parenteral Nutrition
By 陳昭文, 外傷科
What is Parenteral nutrition (PN)？
非經腸道營養也commonly, via venous access
PPN: peripheral parenteral nutrition, 低濃度(＜1000mosm/1,約 12％dextrose)
TPN: total, or central parenteral nutrition, higher tolerated conc.
Indication of TPN:
當病患無法藉由腸道攝食足夠之營養, 則應考慮非經腸道營養之給予。The
common possible causes are described as below; 亦可參考本院 TPN 處方籤背面之
appendix…
1.G-I disease: IBD, short-bowel syndrome, instertinal fistula, pancreatitis…
2.preoperative preparation: for malnutrition patients
3.postoperative complication: ileus, fistula, or prologation of sarvation
4.others:severe burn or trauma, anorexia nervosa, some liver or renal disease…
**一般術前評估 TPN 施用與否,可依循幾個準則：
-第一印象, PE(muscular atrophy, flabby skin…), 較主觀而不科學！
-body weight loss＞15％
-Lab finding: serum Alb＜3g/dl, transferrin＜200mg/dl, total lymphocyte＜1200/ul
How is the TPN ordered？
Thinking process: Total calorie and fluid -＞ protein -＞carbohydrate
-＞ C-N ratio(＊1) is used for rechecking the rationality！
Daily requirement
Energy requirement:
Harris-Benedict equation for BEE(basal energy expenditure)
Mal:66+(13.7×W)+(5×H)-(6.8×A)
Female:655+(9.6×W)+(1.7×H)-(4.7×A)
TEE: BEE × stress factor (or activity factor)
簡易心法 1:mild stress : 1.0-1.2
moderate stress : 1.2-1.5
severe stress : 1.5-2.5
簡易心法 2: BEE 約略等於 25kcal/kg/day
Macronutrient daily requirement:
Protein:0.8-2.5g/kg/day, 4kcal/gm
Fat:1-2g/kg/day, 9kcal/gm, (intralipid 10％:1.1kcal/ml, 20％:2kcal/ml)
Carbohydrate:2-5g/kg/day, 3.4kcal/gm(？？？mohydrate vs ahydrous glucose)
Micronutrient daily requirement:
Electrolyte
Na:60-200mEq/day*(60-80mEq/day)
K:50-150mEq/day*(30-60mEq/day)
Ca:8-32mEq/day*(4.6-9.2mEq/day)
e- supply vary from place to place！！
Mg:8-24mEq*(8.1-20mEq/day)
Phosphate: 15-30mM/day*(12-24mEq/day)
Vitamin:5ml/day (from Lyo-povigen), VitK10-25mg/week(TPN 習慣給 1-2ml/d)
trace element: 2ml/day(不一定有必要, 但通常會給予)
Acetate: 50-120mEq/day (product bicarbonate to correct acidosis)
Additive:
RI: TPN 中, initial dose:5-1u/l(*2)
Heparin:有些醫院會加入 TPN，防止 thrombosis (1000u/liter)
Explaination of the special term:
T15:standard solution, 以 Aminosyn;不用大腦,懶人專用！(1ml=1.02kcal)
TH: 以 aminopoly-H 泡製, rich in branched-chain amino acid
TR: 以 amiyu 泡製, rich in essential amino acid,
R/Q: respiratory quotient, CO2 Prduction/02 consumption
3-in-1 admixture: 早期為 Y-set, 現為三合一大袋一包.
Calorie-nitrogen ratio: 正確地說,應為 non-protein calorie 與 nitrogen 之比值,
Nitrogen balance: 氮素平衡, NB = (intake protein/6.25) – (UUN+4), “4”表 UUN
以外之氮素損失,各家定義數值不同.
PN osmolality: 【10xprotein(g) + 6xCHO(g) + 0.3xml(20％ intrallpid)】/ total
fluid(L),單位為 mosm/l, 對 PPN 較有意義.
Protein sparing: carbohydrate intake 可減少蛋白質異化, minimal requirement 約
為 100gm, that is, 每天給予 1000ml 之 10％ G/W 可 ”短期保護蛋白質”！！
Example:
假設 30y/o 病人 160cm, 60kg, stress factor 1.4 (暫不考慮 activity factor)
our thinking process:
1.find the total calories and fluid requirement
則其 BEE=66+(13.7x60)+(5x160)-(6.8x30)=66+822+800-204=1484
(比較！簡易心法 2：25kcal/kg/day-＞60x25=1500kcal/day)
patient’s TEE=1484x1.4 = 2077.6kcal/day
fluid requirement = 2300 ml (via 100-50-20 rule, or 4-2-1 rule)
2.find the daily protein requirement
設每日需要量為 1.5g/kg/day –＞ patient requirement = 60x1.5 = 90g
energy supply = 90x4 = 360kcal
(一般而言,protein 不應當作能量來源,只作為維持 nitrogen balance！！但實
際上,在計算能量時, 我們仍將其產生能量計入 total calories 之中！)
3.find the daily fat requirement
設每日需要量為 1g/kg/day –＞ patient requirement = 60x1 = 60g
假設我們以 intralipid 20％ (20g/100ml/bt, 2kcal/ml) 作為脂肪來源,
則其 energy supply = 300ml 20％ intrlipid = 2x300ml = 600kcal
4.find the residual calories provided by carbohydrate
dextrose calories = total amount - protein supply - fat supply
= 2077.6 - 360 - 600 =1117.6kcal
換算為重量, dextrose = 1117.6/3.4 = 328.7 g
5.check the formula with C/N ratio
non-protein calories = 1117.6 + 600 kcal = 1717.6
protein 90 g = nitrogen 14.4 g
C/N ratio is 1717.6/14.4 = 119.2：1(acceptable！)
最後呢, 計算 protein and dextrose 濃度, 並填入 TPN 處方籤中：
total fluid requirement 2300ml - intralipid 20％ 300 ml = 2000ml
dextrose 328.7g/2000ml = 16.4％
protein 90g/2000ml = 4.5％
輸注速率為：2300/24=95.8ml/hr (including the fat emulsion)
泡製完成, 大功告成, 如何使用呢？
Initiating:
a. 1st day 1000ml-＞2nd day 2000ml -＞3rd day 3000ml
b. 1st day 1000kcal, increased by 500kcal/day till reached your goal
c. 50ml/hr-＞75ml/hr-＞100ml/hr
tapering and discontinuing:
tapered over 48 hours, reduced to 50ml/hr for 30-60 mins, then DC.
Halved for 1 hour, halved for a second hour, then DC.
TPN supply ＜1000kcal/day, no need to taper the infusion rate.
2-3 days later, 可開始 Lab survey; 記得要 check UUN for nitrogen balance！！！
The last dance……
Complication:
Catheter-related infection
Metabolic complication (sugar, electrolyte and others..)
Hepatic dysfunction
Acaculous cholecystitis
Venous access:
The catheter entered via subclavian v. and int. jugular v. is much better
Appendix:
(*1) C/N ratio : non-protein calorie / nitrogen (kcal/g), explained subsequently.
(*2)insulin 會與 plastic bag or drip set 結合, 估計損失量約 5-10u, 添加 RI 時需
考量之！