アルブミン値とCRPで胃瘻造設後短期の死亡率を予測

アルブミン値とCRPで胃瘻造設後短期の死亡率を予測できるという前向きコホート研究の論文を紹介します。

Blomberg J, Lagergren P, Martin L, Mattsson F, Lagergren J. Albumin and C-reactive protein levels predict short-term mortality after percutaneous endoscopic gastrostomy in a prospective cohort study. Gastrointest Endosc. 2010 Nov 11. [Epub ahead of print]

胃瘻造設した484人の患者を対象に評価したところ、造設後30日以内に死亡したのは58人(12%)でした。死亡リスクに関連したのは以下の要因です。

Albumin <30 g/L （アルブミン3.0g/dl未満）(hazard ratio [HR], 3.46; 95% CI, 1.75-6.88)
CRP ≥10 mg/L （CRP1mg/dl以上）((HR, 3.47; 95% CI, 1.68-7.18)
age ≥65 years (HR, 2.26; 95% CI, 1.20-4.25)
body mass index <18.5 (HR, 2.04; 95% CI, 0.97-4.31)：これだけ統計学的有意差は微妙です。

低アルブミン値と高CRP値の療法に該当する場合、死亡率は20.5％でした。どちらにも該当しない場合の死亡率は2.6％で、ハザード比が7.45(95% CI, 2.62-21.19)でした。

以下、私の解釈です。アルブミン3.0g/dl未満でCRP1mg/dl以上の患者に胃瘻造設するときは、かなりの注意を要します。CRPを陰性化することは悪液質の存在下では難しいですが、侵襲によるCRP陽性であれば陰性化後に胃瘻を造設することが望ましいといえます。年齢はどうしようもありません。

アルブミンはここでも予後指標として有用です。目安はやはり3.0g/dl未満でした。リハ効果を期待できるかどうかの1つの目安も3.0g/dlですね。可能であればアルブミンを3.0g/dl以上、BMIを18.5以上まで栄養改善してから胃瘻造設することが望ましいかもしれません。

Abstract
BACKGROUND: Percutaneous endoscopic gastrostomy (PEG) is a procedure with many complications that sometimes can be devastating. To give better advice to patients referred for PEG regarding risk of complications, important risk factors should be known.

OBJECTIVE: To evaluate whether age, body mass index, albumin levels, C-reactive protein (CRP) levels, indication for PEG, and comorbidity influence the risk of mortality or peristomal infection after PEG insertion.

DESIGN: Prospective cohort study from 2005 to 2009. Follow-up 14 days after PEG.

SETTING: University hospital.

PATIENTS: This study involved 484 patients referred for PEG.

INTERVENTION: PEG.

MAIN OUTCOME MEASUREMENTS: Mortality within 30 days and peristomal infection within 14 days after PEG insertion. All risk estimates were calculated with 95% CIs and adjusted for confounding.

RESULTS: Among 484 patients, 58 (12%) died within 30 days after PEG insertion. Albumin <30 g/L (hazard ratio [HR], 3.46; 95% CI, 1.75-6.88), CRP ≥10 (HR, 3.47; 95% CI, 1.68-7.18), age ≥65 years (HR, 2.26; 95% CI, 1.20-4.25) and possibly body mass index <18.5 (HR, 2.04; 95% CI, 0.97-4.31) were associated with increased mortality. Patients with a combination of low albumin and high CRP levels had a mortality rate of 20.5% compared with 2.6% among patients with normal values, rendering an over 7-fold increased adjusted risk of mortality (HR, 7.45; 95% CI, 2.62-21.19).

LIMITATIONS: Missing data in some study variables. Although the sample size was large, weaker associations could not be established.

CONCLUSION: The combination of low albumin and high CRP levels indicates a substantially increased short-term mortality risk after PEG, which should be considered in decision making.