Revised Proposal
Effects of Using a Blunt versus Sharp Instrument in a Low Transverse Uterine Incision Expansion in a Cesarean Section for Women Ages 18-30
This review will seek to analyze available evidence regarding the outcomes of using blunt or sharp instruments to perform a uterine incision expansion when confronted with a cesarean birth. This will be measured by estimated blood loss, hemoglobin levels, need for blood transfusion, length of operative time, maternal death rate, infant mortality rate of these procedures, as well as any injury sustained by the neonate as a result of the expansion. The group of the women being studied is from 20-30 years of age who are giving birth through cesarean section for the first time and are between their 37th and 41st week of pregnancy. Only operations that use a transverse uterine incision will be considered. A transverse incision is when the incision is made horizontally across the lower abdomen, across the ilium, and obstetricians and gynecologists agree it is the safest method of initial incision. Obstetrics and gynecology will be the sciences used because they both deal with the medical and surgical care of women with particular emphasis on pregnancy, childbirth, and disorders of the reproduction system.
Blunt versus sharp expansion of the uterine incision in a cesarean delivery is being debated as a technique to reduce the possibility of blood loss through internal hemorrhaging and possibly decrease the need for subsequent blood transfusions as a result. This means that once a doctor makes the initial incision necessary for a cesarean section, the doctor then needs to use another instrument to expand the incision so that the infant can be delivered. The debate is over whether that instrument should be something sharp, such as bandage scissors, or something blunt, such as the surgeon’s fingers. Obstetricians are still debating this with an equal split on both sides.
Working thesis: A blunt instrument will cause less intraoperative blood loss and will decrease the need for subsequent transfusion. Likewise, the infant will be negatively impacted by the use of a sharp instrument.
Annotated Bibliography
Asıcıoglu, O., Gungorduk, K., Asıcıoglu, B., Yıldırım, G., Gungorduk, O., & Ark, C. (2014). Unintended extension of the lower segment uterine incision at cesarean delivery: A randomized comparison of sharp versus blunt techniques. American Journal of Perinatology, 837-844. DOI: 10.1055/s-0033-1361934
The purpose of this study was to compare the two methods, sharp or blunt, of expanding the uterine incision in the case of a cesarean delivery. It was a randomized trial consisting of 1,076 women ages 18-40, who underwent elective cesarean surgery, which means that the mother requested for the neonate to be born via cesarean section, but nothing happened with the birth that would make it necessary. They also had to be past their 37th week of pregnancy.
The study measured the success of each instrument by the amount of unintended uterine expansions in each case. The groups used for the sharp and blunt groups were of similar demographics and their deliveries had similar clinical characteristics. The amount of unintended expansions and the incidence of surgeon-estimated blood loss were significantly lower in the blunt group when compared to the sharp group. However, the number of blood transfusions needed was unaffected by either method as was injury to the neonate.
The study concluded that blunt instruments should be used to expand the uterine incision during a cesarean delivery, because sharp instruments were linked to a higher risk for unintended uterine extensions and higher maternal blood loss. Therefore, blunt instruments are the safest option.
Saad, A., Rahman, M., Constantine, M., & Saade, G. (2014). Blunt versus sharp uterine incision expansion during low transverse cesarean delivery: A metaanalysis. American Journal of Obstetrics and Gynecology, Vol.211, 684. e1-684.e11. DOI: 10.1016/j.ajog.2014.06.050
This study included six randomized clinical trials and was comprised of 2,908 patients. The primary focus was on unintended extension of the uterus, and the secondary focuses were changes in hemoglobin and hematocrit levels, estimated blood loss, blood transfusion, length of operation, and neonatal injuries.
The blunt expansion technique was associated with less of a change in both hemoglobin and hematocrit levels and fewer accidental uterine tears. There was slightly less blood loss when the blunt instrument was used but not enough to be significant. Virtually no change was noted in the rates of blood transfusion, neonatal trauma or cord injuries.
The conclusion that the study came to was that although the results favor the blunt instrument over the sharp instrument, the difference may not be significant enough to be clinically relevant. In any case, the blunt instrument was recommended.
Sekhavat, L., Firouzabadi, R., & Mojiri, P. (2010). Effect of expansion technique of uterine incision on maternal blood loss in cesarean section. Archives of Gynecology and Obstetrics, 475-479. DOI: 10.1007/s00404-009-1251-5
The purpose of this study was to examine the difference between using sharp and blunt techniques during a low transverse cesarean section. The focus was predominantly on intraoperative, meaning during the procedure, maternal blood loss levels and how to decrease them. The secondary focus was on uterine extension into the cervix, vagina, or nearby ligaments.
200 women in total were studied. 100 women had the blunt expansion of the initial uterine incision by the surgeon’s fingers and the other 100 women had the sharp expansion by a pair of bandage scissors. Every procedure was that of an elective cesarean section. Women with severe surgical and medical disorders were excluded from the trials, as were women that required emergency cesarean procedures. All of the patients were between ages 20 and 30, and were in week 37-41 of their pregnancy. All of the BMIs were between 22 and 30.5.
The groups were compared in terms of uterine extension, blood loss, blood transfusions, and haematocrit change, which means change in the ratio of red blood cells to the total amount of blood.
The results showed that levels of maternal blood loss as estimated by the surgeon and the drop in hematocrit were higher in the sharp expansion group. The number of unintended extensions were affected similarly, though to an inconsequential extent. The number of blood transfusions required after the operation had no significant difference between each group. The study indicated that using a blunt instrument during a uterine incision expansion is easier and safer for the mother than using a sharp instrument (Sekhavat et al., 2010).
Effects of Using a Blunt versus Sharp Instrument in a Low Transverse Uterine Incision Expansion in an Elective Cesarean Section for Women Ages 18-30
Caroline Lambert
University of Texas at Dallas
This paper will seek to review available evidence regarding the outcomes of using blunt or sharp instruments to perform a uterine incision expansion when confronted with an elective cesarean birth. The efficacy of each option is measured by estimated blood loss, hemoglobin levels, changes in hematocrit, need for blood transfusion, unintended uterine extension, as well as any injury sustained by the neonate as a result of the expansion. The group of the women being studied is from 18-30 years of age who are giving birth through an elective cesarean section for the first time in between their 37th and 41st week of pregnancy. An elective cesarean section is when the woman chooses to have a cesarean section rather than a vaginal birth, and is not under any high risk or emergency circumstances. Only operations that use a transverse uterine incision are being considered. A transverse incision is when the incision is made horizontally across the lower abdomen, across the ilium, and obstetricians and gynecologists agree it is the safest method of initial incision. Obstetrics and gynecology are the sciences involved because they both deal with the medical and surgical care of women with particular emphasis on pregnancy, childbirth, and disorders of the reproduction system.
Blunt versus sharp expansion of the uterine incision in a cesarean delivery is being debated as a technique to reduce the possibility of blood loss through internal hemorrhaging and possibly decrease the need for subsequent blood transfusions as a result. This means that once a doctor makes the initial incision necessary for a cesarean section, the doctor then needs to use another instrument to expand the incision so that the infant can be removed. The question is whether that instrument should be something sharp, such as scissors, or something blunt, such as the surgeon’s fingers. Obstetricians are still debating this with an equal split on both sides. However, in a cesarean delivery, a blunt instrument causes less intraoperative blood loss and decreases the need for subsequent transfusion, and any injuries caused, either to the mother or the neonate, will be negligible.
In 2005, there was a study, which consisted of several smaller studies all of which sought to provide information on several decisions in the cesarean method of delivery. One of these smaller studies was focused on the comparison of sharp and blunt instruments when performing a uterine incision expansion. The focus of this comparison was the result on both the mother and the infant (Berghella, Baxter, & Chauhan, 2005).
Two randomized trials took place in order to test each method. In the first trial, 147 women were in the group where sharp instruments were used and 139 women were in the group where blunt instruments were used. The second trial tested 470 women in the sharp group and 475 women were in the blunt group. These women were all from age 18-35, had nonemergency singleton pregnancies, had no serious health issues, and were in between week 37-41 of their pregnancies. The race and BMI of the women were also similar between all of the groups. The efficacy of each method was measured by unintended uterine extensions, which is where the uterus tears accidentally, estimated blood loss, number of needed blood transfusions, and postpartum hemoglobin levels (Berghella et al., 2005).
According to these trials, sharp instruments were highly linked with blood loss, extensions, and the need for blood transfusions. Blunt instruments were also less likely to cut either the neonate or the cord during the operation. The study concluded that the incidence of these problems was high enough to recommend the use of blunt instruments in all uterine incision procedures (Berghella et al., 2005)
Cromi et al., (2007) also speculated that the use of a blunt instrument would minimize trauma to the wall of the uterus. All of the patients involved in the study had been scheduled for elective cesarean operations. The women were also required to be passed the 30th week of gestation. There was no age, race, or BMI requirement. The trial also included women who had multiple pregnancies, but no women who had pressing medical conditions, such as preeclampsia, that would lead to excess bleeding were permitted to participate. Women were excluded from the study if the cesarean section was not their first. Also, none of the women who entered the hospital requiring emergency cesareans were considered. There were a total of 811 women who participated in the study.
Both techniques were measured by uterine artery injury, the need for additional stitches, excessive bleeding, hemoglobin decrease, blood transfusions, and uterine extension caused by the operation.
The study found that, while the sharp technique did tend to cause a higher amount of blood loss than the blunt technique, it was rarely enough to require any change in the number of blood transfusions and the study was overall inconclusive. The sharp technique was, however, linked with unintended uterine extension (Cromi et al., 2007).
Another study came out in 2010 that examined the difference between using sharp and blunt techniques during a low transverse cesarean section. The focus was predominantly on intraoperative, meaning during the procedure, maternal blood loss levels and how to decrease them. The secondary focus was on uterine extension into the cervix, vagina, or nearby ligaments (Sekhavat, Firouzabadi, & Mojiri, 2010).
200 women in total were studied. 100 women had the blunt expansion of the initial uterine incision by the surgeon’s fingers and the other 100 women had the sharp expansion by a pair of bandage scissors. Every procedure was that of an elective cesarean section. Women with severe surgical and medical disorders were excluded from the trials, as were women that required emergency cesarean procedures. All of the patients were between ages 20 and 30, and were in week 37-41 of their pregnancy. All of the BMIs were between 22 and 30.5 (Sekhavat et al., 2010).
The groups were compared in terms of uterine extension, blood loss, blood transfusions, and haematocrit change, which means change in the ratio of red blood cells to the total amount of blood (Sekhavat et al., 2010).
The results showed that levels of maternal blood loss as estimated by the surgeon and the drop in hematocrit were higher in the sharp expansion group. The number of unintended extensions were affected similarly, though to an inconsequential extent. The number of blood transfusions required after the operation had no significant difference between each group. The study indicated that using a blunt instrument during a uterine incision expansion is easier and safer for the mother than using a sharp instrument (Sekhavat et al., 2010).
The study by Pandit and Khan (2013), much like the Berghella et al., (2005) study, was about more than uterine incision expansion. The purpose of the study was to observe different decisions to be made during a cesarean delivery and to indicate the best course of action for each. Uterine incision expansion was one of the parts of the study and is the only part relevant in this case. The focus was primarily on estimated blood loss.
945 patients were deemed eligible; 470 of them were randomly assigned to the sharp instrument group and the other 475 women were in the blunt instrument group. The women were all ages 18-31 and a significant majority of them were African American. The patients were excluded from the study if they had any prior cesarean sections. Not all of the women underwent elective cesarean sections, but those are the only patients considered here (Pandit & Khan, 2013).
The results indicated that a blunt instrument should be used for uterine incision expansion over a sharp instrument because a blunt instrument reduces blood loss, blood transfusion, and postpartum hemorrhaging. Neither technique tended to lead to any significantly higher risk of injury to the neonate. Sharp instrument expansion was also associated with a greater drop in hematocrit levels (Pandit & Khan, 2013).
The study concluded that intraoperative blood loss and blood transfusions were less when a blunt instrument was used during a uterine incision expansion during a cesarean section operation, and that it is the safest, most effective method to use (Pandit & Khan, 2013).
One of the largest metaanalyses on the subject of blunt versus sharp instruments for uterine expansion was conducted in 2014. It involved six randomized clinical trials and included 2,908 patients. The primary focus was on unintended extension of the uterus, and the secondary focuses were changes in hemoglobin and hematocrit levels, estimated blood loss, blood transfusion, length of operation, and neonatal injuries (Saad, Rahman, Constantine, & Saade, 2014).
The blunt expansion technique was associated with less of a change in both hemoglobin and hematocrit levels and fewer accidental uterine tears. There was slightly less blood loss when the blunt instrument was used but not enough to be significant. Virtually no change was noted in the rates of blood transfusion, neonatal trauma or cord injuries (Saad et al., 2014).
The conclusion that the Saad et al., (2014) study comes to is that although the results favor the blunt instrument over the sharp instrument, the difference may not be significant enough to be clinically relevant. In any case, the blunt instrument is recommended.
The most recent study was a randomized trial consisting of 1,076 women ages 18-40 who underwent elective cesarean surgery. Each woman had been pregnant for over 38 weeks and women who required emergency cesarean sections, had abnormal birth presentation, were giving birth to multiple infants, or had any conditions that resulted in unusually heavy blood loss were not able to participate. The women in both the sharp and blunt groups all had similar health characteristics (Asıcıoglu et al., 2014).
The purpose of the study was to compare the blunt and sharp instrument techniques, the success of which they measured by considering unintended uterine tearing during the operation and maternal blood loss for up to 48 hours after the procedure. The unintended uterine tearing was the primary focus of the study (Asıcıoglu et al., 2014).
The number of unintended uterine tears as a result of the expansion and the incidence of surgeon -estimated blood loss were significantly lower in the blunt group as compared to the sharp group. However, the number of blood transfusions required was unaffected by the use of either instrument (Asıcıoglu et al., 2014).
The study concluded that blunt instruments should be used to expand the uterine incision during a cesarean delivery because sharp instruments were linked to a higher risk of unintended uterine extensions and a higher rate of maternal blood loss (Asıcıoglu et al., 2014).
When all of the evidence is considered, when performing a uterine incision expansion during a low transverse cesarean section, a blunt instrument is safer to use than a sharp instrument because they are safer and more effective than their sharper counterparts. They lead to less blood loss, fewer blood transfusions, smaller incidence of injury to the neonate, and fewer changes to hemoglobin and hematocrit levels. There is strong evidence to suggest that the cesarean operation will be less risky if a blunt instrument is used.
There are restrictions with this research, of course. The difference between the sharp and blunt instruments is there, but it is usually not enough to significantly impact the mother. Often, the woman will not even lose enough blood to require a blood transfusion in either case. Also, the cesarean sections that are performed for these studies are often performed by inexperienced doctors, meaning doctors that have performed less that 100 cesarean sections in their career.
Similarly, these studies have been rare until the last couple of years because it can be difficult to find enough women who fit all the parameters needed to perform a good study. Elective cesarean sections may be rising in popularity, but when it is compounded with the requirement that the pregnancy be a completely normal and healthy one, the pool becomes much smaller.
Another limitation to the argument stated here is that, while blunt instruments are marginally better where blood loss and uterine extension are concerned, sharper instruments such as bandage scissors are often faster and more precise. This can decrease the length of the operation, which is sometimes not measured at all.
One question that these studies left unanswered was whether the uterine incision, once made, should be expanded laterally or vertically. The type of blunt technique to use when expanding the incision also remains an unsolved problem. In the future, studies should seek to answer these questions and put more emphasis on keeping the patients the same demographic, measuring the length of the operation, increase the number of test subjects and further addressing and assessing any injuries to the neonate and trauma to the cord.
Asıcıoglu, O., Gungorduk, K., Asıcıoglu, B., Yıldırım, G., Gungorduk, O., & Ark, C. (2014). Unintended extension of the lower segment uterine incision at cesarean delivery: A randomized comparison of sharp versus blunt techniques. American Journal of Perinatology, 837-844. DOI: 10.1055/s-0033-1361934
Berghella, V., Baxter, J., & Chauhan, S. (2005). Evidence-based surgery for cesarean delivery.American Journal of Obstetrics and Gynecology, 1607-1617. DOI: 10.1016/j.ajog.2005.03.063
Cromi, A., Naro, E., Siesto, G., Uccella, S., Caringella, A., Uboldi, V., & Ghezzi, F. (2007). 79: Expansion of uterine incision at cesarean delivery: A randomized comparison of two techniques. American Journal of Obstetrics and Gynecology, S36-S36. DOI: 10.1016/j.ajog.2007.10.089
Pandit, S., & Khan, R. (2013). Surgical techniques for performing caesarean section including CS at full dilatation. Best Practice & Research Clinical Obstetrics & Gynaecology, 179-195. DOI: 10.1016/j.bpobgyn.2012.12.006
Saad, A., Rahman, M., Constantine, M., & Saade, G. (2014). Blunt versus sharp uterine incision expansion during low transverse cesarean delivery: A metaanalysis. American Journal of Obstetrics and Gynecology, Vol.211, 684. e1-684.e11. DOI: 10.1016/j.ajog.2014.06.050
Sekhavat, L., Firouzabadi, R., & Mojiri, P. (2010). Effect of expansion technique of uterine incision on maternal blood loss in cesarean section. Archives of Gynecology and Obstetrics, 475-479. DOI: 10.1007/s00404-009-1251-5
No comments:
Post a Comment