肩難產與臂神經叢麻痹因果關係之醫學觀點

 

一般生產分娩有千分之六的機率會發生肩難產,而肩難產時有百分之八至二十三合併發生新生兒臂神經叢麻痹。新生兒臂神經叢麻痹有兩種型態,一是Erb’s Palsy佔了百分之八十,百分之九十在一年內自癒,只有百分之五到八會造成永久性神經損傷,二是klumpke克隆普式麻痺則較少見,只佔百分之二,百分之四十在一年內自癒。

肩難產是一種嚴重的分娩併發症,肩難本身即不可預測,傳統上把肩難產,胎兒巨體症,母親妊娠糖尿病,母親過度肥胖,第二產程延遲等等視為臂神經叢麻痹之危險因子,但在臨床上近乎一半臂神經叢麻痹的病例中,產婦並無合併上述危險因子;也就是說而所謂的危險因子根本不具預測價值,哪些胎兒產後較易有永久性神經損傷也無法預測(註一)。因為縱使生產過程順利無肩難產現象,或在產痛早期便施以無傷害性剖腹生產,甚至在根本沒有醫護人員與胎兒手臂的接觸下,一樣有臂神經叢麻痹的病例出現(註二)因此有許多臂神經叢損傷在臨床上是不可避免的,而且是子宮內因素,即子宮內傷害utero injury所引起者(註三)。也就是說並不是所有臂神經叢麻痹都是因為牽引胎兒頭頸部造成,將近百分之五十的臂神經叢麻痹是歸因於不可避免,在生產前或生產中便已經發生的醫療意外 (註四)

新生兒臂神經叢麻痹的治療方式,一般來說先予以物理治療觀察至4個月再說,有90% to 95% 會自然痊癒,且一般到4個月時就會有明顯改善,亦即 Erb氏傷,而klumpke氏麻痺百分之四十在一年內自癒,也就是說只有 5-10%會有永久機能障礙 ,這些新生兒患者一直物理治療到 3-4月時都無任何恢復的徵兆sign of recovery者 ,所以臨床上若新生兒臂神經叢麻痹復健治療觀察6 to 9個月,仍無明顯進展時,就要考慮早期手術治療,日後恢復的機會較大。

[參考文獻]

[註一]

In macrosomic newborns, shoulder dystocia was associated with brachial plexus injury, but in low- and normal-weight infants, "other malpresentation" was diagnosed more frequently than shoulder dystocia. Our study findings suggest that brachial plexus injury has causes in addition to shoulder dystocia and might result from an abnormality during the antepartum or intrapartum period.(Associated factors in 1611 cases of brachial plexus injury. Obstet Gynecol 1999 Apr;93(4):536-40 .Comment in: Obstet Gynecol. 1999 Sep;94(3):482-3)

[註二]

一.   Brachial plexus palsy can be associated with cesarean delivery. Such palsies appear to be of intrauterine origin and are more likely to persist.( Am J Obstet Gynecol 1997 Nov;177(5):1162-4.)。

二.   剖腹生產C/S並不會減少Brachial plexus injury的機會.(Am J Obstet Gynecol 2000 Nov;183(5):1296-300)

[註三]

Brachial plexus palsy can be associated with cesarean delivery. Such palsies appear to be of intrauterine origin and are more likely to persist. (Brachial plexus palsy associated with cesarean section: an in utero injury?Am J Obstet Gynecol 1997 Nov;177(5):1162-4)

[註 四]

一.   Recent evidence has suggested that not all cases of brachial plexus palsy are attributable to traction. These data further support the notion that the etiology of permanent brachial plexus palsy associated with birth may not be related to traction.( Permanent Erb palsy: a traction-related injury? Obstet Gynecol 1997 Jan;89(1):139-41)

二.  Neonatal brachial plexus injury is not a priori explained by iatrogenically induced excessive traction. Spontaneous endogenous forces may contribute substantially to this type of neonatal trauma.( Mathematic modeling of forces associated with shoulder dystocia: a comparison of endogenous and exogenous sources. Am J Obstet Gynecol 2000 Mar;182(3):689-91)

titles.gif (2030 bytes)
www.drkao.com
本站純為服務性質
本頁資料只供參考