Re: Article
Posted: Tue Mar 18, 2003 10:24 am
Well, our dear Dr. Gherman strikes again. I found this article that he published just last month...
A Guest Editorial: New Insights to Shoulder Dystocia and Brachial Plexus Palsy
Obstetrical and Gynecological Survey Vol 58 No 1
Shoulder dystocia is a relatively uncommon event that the general obstetrician may encounter just a few times, during an entier career that spans several decades. Only 0.2% to 3% of all vaginal deliveries are complicated by a failure of the fetal shoulder(s) to spontaneously deliver. Fetal morbidity associated with shoulder dystocia, mainly consisting of transient brachial plexus palsy, is even more unusual. Among 1,094,298 women who delivered over 2 years in 300 civilian acute care hospitals in California, Gilbert et al. found 1611 (0.15%) cases of brachial plexus palsy. Transient brachial plexus palsy has been reported to complicated on 15% of all shoulder dystocial cases. Permanent brachial plexus palsy after a shoulder dystocia episode, however, is exceedingly rare (0.54 - 1.4%).
A commonly held misconception is that these brachial plexus palsies result from excessive lateral traction applied by the accoucheur. Res ipsa loquiteur ("the thing speaks for itself") has implied that there is simply a single mechanism for this injury. The case control study by McFarland et al. provided an unreferenced statement that 'injuries to the brachial plexus occur when there is a strong lateral traction on the head and neck or a downward traction on the shoulders'. The textbook by O'Leary likewise provided an unsupported claim that "... the vast majority of Erb palsy in patients with shoulder dystocia are caused by the care provider to a statistical probability of 95% to 98%". In a study that described two shoulder dystocia cases (one of which was associated with clavicular fracture and transient brachial plexus injury), Allen et al. mysteriously concluded that there was a 'possible threshold for the likelihood of birth injury'. Hwwever, note that there were no statistically significant differences between the uninjured and injured neonates concerning the peak and average clinician-applied forces. The same author also studied 39 physicians and found that "injury-inducing" force levels are reached in 82% of shoulder dystocia cases but also in 31% of routine deliveries. Simply put, the findings from this nonclinical laboratory model are inconsistent with the fact that brachial plexus palsy has been found in only 0.5 to 3 cases per 1000 births.
Over the last several years, multiple lines of evidence have emerged that have supported the concept that not all brachial plexus injuries are traction-mediated events. A recent review article which extracted data from 14 published reports of neonatal brachial plexus palsy, found that slightly more than half of all brachial plexus injuries are associated with uncomplicated vaginal deliveries. Brachial plexus palsy has also been found to occur in the posterior arm of infants whose anterior shoulder was impacted behind the symphsis pubis and in vertex-presenting fetuses delivered by atraumatic cesarean delivery. If brachial plexus palsy resulted from excessive traction by the clinician, then the overwhelming majority of injuries should affect the anterior fetal shoulder. Walle and Hartikainen-Sorri, however, found that one third of all injuries were located in the posterior shoulder. Rapid second state and disproportionate descent of the head and body of the fetus have also been implicated in the pathogenesis of the injury. Finally, Gonik et al. has compared the endogenous and exogenous sources of forces associated with shoulder dystocia. From his mathematic model, the estimated pressures that originated from maternal and uterine forces were found to be four to nine times greater than those generated from clinical-applied forces.
Throughout modern medicine, misconception has often plagued our understanding of common problems. The main culprit for duodenal ulcers is now known to be Helicobacter pylori, rather than a stressful lifestyle or improper diet. Cerebral palsy does not simply occur as an acute intrapartum event; its pathogenesis is complex and may be related to metabolic, genetic, thrombophilic, or infectious causes. Most cases of severe meconium aspiration syndrome are not causally related to the aspiration of meconium but rather to chronic asphyxia and infection. As evidence-based scientific research continues to provide new insights, the myth that brachial plexus palsy results from clinician-applied 'excess' traction will hopefully be dispelled. In its place will come a realization that the etiology of brachial plexus palsy is multifactorial and results from antenatal events: the shoulder dystocia impaction itself, the forces inherent in the normal birth process, or from impingement of the posterior fetal arm on the sacral promontory.
I didn't include the reference list, but I find it very amusing that in the 19 citations in the list, he is quoting HIS OWN RESEARCH in 8 of them. I'm just now starting to read most of his articles and they are making me wonder how in the world he can actually think these things are legitimate. Points to ponder I guess..
Cherie
A Guest Editorial: New Insights to Shoulder Dystocia and Brachial Plexus Palsy
Obstetrical and Gynecological Survey Vol 58 No 1
Shoulder dystocia is a relatively uncommon event that the general obstetrician may encounter just a few times, during an entier career that spans several decades. Only 0.2% to 3% of all vaginal deliveries are complicated by a failure of the fetal shoulder(s) to spontaneously deliver. Fetal morbidity associated with shoulder dystocia, mainly consisting of transient brachial plexus palsy, is even more unusual. Among 1,094,298 women who delivered over 2 years in 300 civilian acute care hospitals in California, Gilbert et al. found 1611 (0.15%) cases of brachial plexus palsy. Transient brachial plexus palsy has been reported to complicated on 15% of all shoulder dystocial cases. Permanent brachial plexus palsy after a shoulder dystocia episode, however, is exceedingly rare (0.54 - 1.4%).
A commonly held misconception is that these brachial plexus palsies result from excessive lateral traction applied by the accoucheur. Res ipsa loquiteur ("the thing speaks for itself") has implied that there is simply a single mechanism for this injury. The case control study by McFarland et al. provided an unreferenced statement that 'injuries to the brachial plexus occur when there is a strong lateral traction on the head and neck or a downward traction on the shoulders'. The textbook by O'Leary likewise provided an unsupported claim that "... the vast majority of Erb palsy in patients with shoulder dystocia are caused by the care provider to a statistical probability of 95% to 98%". In a study that described two shoulder dystocia cases (one of which was associated with clavicular fracture and transient brachial plexus injury), Allen et al. mysteriously concluded that there was a 'possible threshold for the likelihood of birth injury'. Hwwever, note that there were no statistically significant differences between the uninjured and injured neonates concerning the peak and average clinician-applied forces. The same author also studied 39 physicians and found that "injury-inducing" force levels are reached in 82% of shoulder dystocia cases but also in 31% of routine deliveries. Simply put, the findings from this nonclinical laboratory model are inconsistent with the fact that brachial plexus palsy has been found in only 0.5 to 3 cases per 1000 births.
Over the last several years, multiple lines of evidence have emerged that have supported the concept that not all brachial plexus injuries are traction-mediated events. A recent review article which extracted data from 14 published reports of neonatal brachial plexus palsy, found that slightly more than half of all brachial plexus injuries are associated with uncomplicated vaginal deliveries. Brachial plexus palsy has also been found to occur in the posterior arm of infants whose anterior shoulder was impacted behind the symphsis pubis and in vertex-presenting fetuses delivered by atraumatic cesarean delivery. If brachial plexus palsy resulted from excessive traction by the clinician, then the overwhelming majority of injuries should affect the anterior fetal shoulder. Walle and Hartikainen-Sorri, however, found that one third of all injuries were located in the posterior shoulder. Rapid second state and disproportionate descent of the head and body of the fetus have also been implicated in the pathogenesis of the injury. Finally, Gonik et al. has compared the endogenous and exogenous sources of forces associated with shoulder dystocia. From his mathematic model, the estimated pressures that originated from maternal and uterine forces were found to be four to nine times greater than those generated from clinical-applied forces.
Throughout modern medicine, misconception has often plagued our understanding of common problems. The main culprit for duodenal ulcers is now known to be Helicobacter pylori, rather than a stressful lifestyle or improper diet. Cerebral palsy does not simply occur as an acute intrapartum event; its pathogenesis is complex and may be related to metabolic, genetic, thrombophilic, or infectious causes. Most cases of severe meconium aspiration syndrome are not causally related to the aspiration of meconium but rather to chronic asphyxia and infection. As evidence-based scientific research continues to provide new insights, the myth that brachial plexus palsy results from clinician-applied 'excess' traction will hopefully be dispelled. In its place will come a realization that the etiology of brachial plexus palsy is multifactorial and results from antenatal events: the shoulder dystocia impaction itself, the forces inherent in the normal birth process, or from impingement of the posterior fetal arm on the sacral promontory.
I didn't include the reference list, but I find it very amusing that in the 19 citations in the list, he is quoting HIS OWN RESEARCH in 8 of them. I'm just now starting to read most of his articles and they are making me wonder how in the world he can actually think these things are legitimate. Points to ponder I guess..
Cherie