Instrumental delivery


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Instrumental delivery

  1. 1. Instrumental Delivery Dawit Desalegn November, 2010
  2. 2. Introduction • Operative vaginal delivery refers to a delivery in which the operator uses forceps or a vacuum device to assist the mother in transitioning the fetus to extra uterine life. • The instrument is applied to the fetal head and then the operator uses traction to extract the fetus, typically during a contraction while the mother is pushing.
  3. 3. • The first instrumental deliveries were performed to extract fetuses from parturient who were at high risk of maternal mortality due to prolonged and/or obstructed labor. • In these cases, saving the mother's life took precedence over possible harm to the fetus. • The focus of these procedures has changed
  4. 4. • Decisions regarding use of instrumental delivery are now based primarily upon • the fetal/neonatal impact • Decisions are also weighed against the alternative options :- – cesarean birth, – prolonging the second stage, – second stage augmentation
  5. 5. • Incidence:- • 10-12% of all deliveries
  6. 6. CHOICE OF INSTRUMENT • The choice of instrument is determined by level of training with the various forceps and vacuum equipment. • Factors that might influence choice are:- the availability of the instrument, the degree of maternal anesthesia, and knowledge of the risks and benefits associated with each instrument.
  7. 7. • In general, vacuum devices are:- easier to apply, place less force on the fetal head, require less maternal anesthesia, result in less maternal soft tissue trauma, do not affect the diameter of the fetal head compared to forceps.
  8. 8. • The advantages of forceps :- are unlikely to detach from the head, can be sized to a premature cranium, may be used for a rotation, result in less cephalohematoma and retinal hemorrhage, and do not aggravate bleeding from scalp lacerations.
  9. 9. Summary • Vacuum delivery is probably safer than forceps for the mother, while forceps are probably safer than vacuum for the fetus.
  10. 10. Forceps Delivery • True forceps were first devised in the late 16th or beginning of the 17th century. • Hundreds of different forceps available • Special Vs Classic
  11. 11. Design of Forceps • basically consist of two crossing branches. • Each branch has four components: 1. blade, 2. shank, 3. lock, 4. handle.
  12. 12.  Each blade has two curves :- • The cephalic curve conforms to the shape of the fetal head, and • The pelvic curve corresponds more or less to the axis of the birth canal • Some varieties are – fenestrated or – pseudofenestrated to permit a firmer hold on the fetal head.
  13. 13. The blades are connected to the handles by the shanks, which are either – Parallel as in Simpson forceps, or – Crossing as in Tucker–McLane forceps. The common method of articulation, 1. The English lock, consists of a socket located on the shank at the junction with the handle, into which fits a socket similarly located on the opposite shank 2. A sliding lock is used in some forceps, such as Kielland forceps
  14. 14. Tucker-McLane
  15. 15. Kielland Forceps
  16. 16. PIPER Forceps
  17. 17. CLASSIFICATION OF FORCEPS DELIVERIES • ACOG redefined the classification of forceps delivery in 1988 to better reflect the degree of difficulty and attendant risk • eg, lower fetal station and smaller degrees of head rotation are associated with reduced maternal and fetal injury • classification emphasizes two most important factors: Station (O to +5) and rotation (< / > 45 degree )
  18. 18. CLASSIFICATION OF FORCEPS DELIVERIES I = Outlet Forceps • Scalp is visible at introitus without separating the labia • Fetal skull has reached pelvic floor • Sagittal suture is in anteroposterior diameter or right or left occiput anterior or posterior position • Fetal head is at or on the perineum • Rotation does not exceed 45 degrees
  19. 19. II = Low Forceps • Leading point of fetal skull is at station +2 cm, and not on pelvic floor • Rotation is 45 degrees or less (left or right occiput anterior to occiput anterior, or left or right occiput posterior to occiput posterior) • Rotation is greater than 45 degrees
  20. 20. III = Midforceps • Station above +2 cm but head is engaged IV = High Forceps • Not included in classification
  21. 21. Function of Forceps • The most important function = Traction, • may also be invaluable = Rotation, (OT &OP).  In general, • Simpson forceps are used to deliver the fetus with a molded head, as is common in nulliparous women. • Tucker–McLane instrument is often used for the fetus with a rounded head, which more characteristically is seen in multiparas. • In most situations, however, either instrument is appropriate.
  22. 22. Indications for forceps delivery • Maternal exhaustion • Inadequate maternal expulsive efforts – E.g. - spinal cord injuries or neuromuscular diseases • Need to avoid maternal expulsive efforts – E.g. – cardiac or cerebrovascular diseases • Lack of maternal expulsive effort • Fetal distress (NRFHRP) • Prolonged 2nd stage of labor
  23. 23. Contraindications – Are related to the potential for unacceptable fetal risks. • Fetal prematurity – is a relative contraindication. • Known fetal demineralizing diseases – (eg, osteogenesis imperfecta), • Fetal bleeding diatheses – (eg, hemophilia, alloimmune thrombocytopenia), • Unengaged head, • Unknown fetal position, • Malpresentation – (eg, brow, face), and • Suspected fetal-pelvic disproportion
  24. 24. Pre-requisites for forceps delivery 1. Presentation must be vertex or by face with the chin anterior (L/R MA) 2. Head must engaged. 3. The position of the head must be known 4. The cervix must be fully dilated. 5. The membranes should be ruptured 6. Adequate pelvis
  25. 25. • Other prerequisites include: - Informed consent - Emptying the urinary bladder - Appropriate analgesia - Adequate facilities and back up personnel - Knowledge, experience and skill in the use of the instrument and manage complications!!!!!
  26. 26. Forceps application • The long axis of the blades should corresponds to the occipitomental diameter • Three forms of application or grip are recognized 1. Biparieto-malar – Optimal 2. Front-mastoid – Suboptimal - compresses the mastoid area and the origin of the facial nerve. 3. Fronto-occipital – is asymmetric, unsafe and should not be used.
  27. 27. Steps in Outlet forceps delivery • Precise knowledge of the position of the fetal head is essential to a proper cephalic application. • Insert the left blade first.
  28. 28. 1. Two or more fingers of the right hand are introduced inside the left, posterior portion of the vulva and into the vagina beside the fetal head. 2. The handle of the left branch is grasped between the thumb and two fingers of the left hand, and the tip of the blade is gently passed into the vagina between the fetal head and the palmar surface of the fingers of the right hand (serves as a guide). -The handle and branch are held at first almost vertically, but they are depressed as the blade adapts to the fetal head, eventually to a horizontal position.
  29. 29. 3.Similarly, two or more fingers of the left hand are then introduced into the right, posterior portion of the vagina to serve as a guide for the right blade, which is held in the right hand and introduced into the vagina. 4.Then the horizontally positioned branches are articulated. 5.If necessary, one and the other blade should be gently maneuvered until the handles are repositioned to effect easy articulation.
  30. 30. Traction • The pelvis is curved in a J-shape, and it is in this direction that the series of force vectors should be applied. • Traction is always applied gently and never with excessive force. • More horizontal traction is applied, and the handles are gradually elevated, eventually pointing almost directly upwards as the parietal bones emerge. • As the vulva is distended by the occiput, episiotomy may be done if indicated. • It is preferable to apply traction with each uterine contraction, except when delivery is urgently indicated.
  31. 31. Complications of forceps delivery 1.Maternal lacerations 2.Minor external ocular trauma 3.Retinal hemorrhage 4.Fetal skull fractures 5.Facial nerve palsies 6.Cephalhematoma 7.Subaponeurotic hemorrhage 8.Intracranial hemorrhage 9.Scalp laceration
  32. 32. • Documentation of Procedure - Indication, date and time - The prerequisites - The estimated fetal weight and the maternal pelvis - Statement about the FHR and maternal contractions - Maternal condition and type of anesthesia - Record of discussion with the woman of the risks, benefits and options. - Number of application of forceps, ease of application and any complication with the application - Duration and force of each traction attempt and the number of traction attempts - Description of maternal or neonatal injuries - Cord blood gases and Apgar scores
  33. 33. VACUUM DELIVERY • Is an operative vaginal procedure to facilitate vaginal delivery with an application of a cup over the fetal head for brief duration and minimal traction forces. • In the United States, the device is referred to as the vacuum extractor, • In Europe it is commonly referred to as a ventouse (from French, literally, soft cup).
  34. 34. Principle • traction on a metal cap designed = so that the suction creates an artificial caput, or chignon, within the cup that holds firmly and allows adequate traction. • use a metal or a soft cup (Silastic cap) Malmstrom = Metal Mitavac = Soft CMI tender touch = Soft Difference?
  35. 35. • Indications and pre-requisites • -Are generally like that for forceps delivery – except for :- face and after –coming head
  36. 36. • Contra indications 1. Cephalopelvic disproportion 2. High station (above 0-station) 3. Non- vertex presentations 4. Extreme prematurity 5. Known macrosomia 6. Recent scalp blood sampling
  37. 37. Application of Vacuum Cups • Proper cup placement is the most important determinant of success in vacuum extraction
  38. 38. Ideal application “Flexing Median” is when :- • the center of the cup is superimposed on the flexion point (3 cm infront of the posterior fontanelle on the sagittal suture) • the cup is symmetrically placed over the sagittal suture. • If the center of the cup = more than 1cm to either side of the sagittal suture, the application is described as paramedian, and • when the application distance is less than 3cm, it is called deflexing.
  39. 39. • Thus, there are four types of cup applications:- 1.Flexing median ( correct/ideal application) 2.Flexing paramedian 3.Deflexing median 4.Deflexing paramedian • -Deflexing and paramedian applications promote:-  extension and  asynclitism of the head and  effectively increase or fail to decrease the size and the area of the presenting part.
  40. 40. Technique for Application of Vacuum cup. • First, test the instrument • Recheck the position of the occiput and locate the flexion point. • Connect cup tubing to the tube of the vacuum pump. • Smear the outside of the cup lightly with obstetric cream. • Press the cup against the fetal head and maneuver until its center lies over the flexion point • Check that there is no maternal tissue / fetal electrode trapped.
  41. 41. Cont… • Induce a vacuum pressure of 20 kpa (0.2 kg/cm2) and recheck the cup position. • Then increase the vacuum in one step to the recommended pressure of 80 kpa (0.8 kg/cm2) • Delay traction for 2 minutes to allow chignon to form although gentle traction may be commenced sooner if necessary. • 0.2kg/2min = rigid cap • 0.8kg/1min = soft cap
  42. 42. Traction • Should be directed in such a way that the flexion point on the head is aligned with the axis of the pelvis • Traction should be a 2- handed exercise 1.The right hand holds the traction handle and pulling in the direction of descent 2.The thumb of the non- pulling hand presses against the dome of the cup
  43. 43. “3Ds” 1st pull → should cause flexion of the head and some descent = Dislodge 2nd pull → the head should be on the pelvic floor = Descent 3rd pull → delivery of the head should be complete or imminent = Deliver
  44. 44. Cont… • Traction is discontinued – between contractions or – if an audible hiss is heard signaling loss of vacuum. • After delivery of the head, the vacuum is released, the cup eased off the scalp and the birth completed in the normal manner. • Vacuum extraction should be considered a trial, if there is no evidence of descent, consider C/S = “3Ds”
  45. 45. Complications • Scalp laceration or bruising • Subgaleal hematoma • Cephalhematoma • Intra-cranial hemorrhage • Neonatal jaundice • Subconjunctival hemorrhage • Clavicular fracture • Shoulder dystocia • Injury to 6th and 7th cranial nerves
  46. 46. Recommendations Regarding Vacuum Delivery  The classification of vacuum deliveries should be the same as that utilized for forceps  The same indications and contraindications utilized for forceps deliveries should be applied  The vacuum should not be applied to an unengaged vertex, that is, above 0 station.  The individual performing or supervising the procedure should be an experienced operator.  The operator should be willing to abandon the procedure if it does not proceed easily or if the cup pops off more than three times.
  47. 47. DESTRUCTIVE VAGINAL DELIVERY (EMBRYOTOMY) • Definition: Reductive surgical procedure performed on the dead fetus to reduce its size and make vaginal delivery possible
  48. 48. Important features • Need few instruments • Leaves the mother with intact uterus • If she is already infected, low risk of spread of infection to the peritoneum • Shorter time in bed
  49. 49. Types • Craniotomy • Decapitation • Evisceration • Cleidotomy
  50. 50. Rate of DVD in Eth • Study done in TAH (1997-2002) • 7.8 DVDs per 1000 deliveries • Craniotomy (94%) & for CPD(89%) • Average BW -2957gm • preterm(13%), post term(7%), term (54%) • Labor >24hrs in 88% – Fistulas , infection & genital trauma • Currently almost never practiced in the developed world
  51. 51. • Indications of DVD :- CPD- Breach delivery- Transverse lie
  52. 52. Prerequisites for DVD • Dead fetus • exceptions (malformation or tumor incompatible with life, Cleidotomy & needle aspiration for hydrocephalus) • Fully dilated cervix • No gross pelvic contracture • No risk of uterine rupture • 2/5 or less of his head must be above the brim • Back up operative facilities
  53. 53. CRANIOTOMY • Perforation of the skull and emptying the head of brain tissue so that the head collapses. • It is used when the fetus presents with the head or in a case of retained head in a breech
  54. 54. CRANIOTOMY INDICATIONS • Obstructed labor with a vertex or face – • Arrested after coming head – • Hydrocephalus- • Interlocked head of twins – • Contracted pelvis is the most common indication
  55. 55. CRANIOTOMY • Scalp is held with a tissue forceps and incision is made with a perforator and contents of the brain are evacuated. • Sites-  vertex- parietal bone  face- orbit/hard palate  brow- frontal bone  After coming head- foramen magnum  Hydrocephalus- encephalocentesis
  56. 56. Decapitation • Cutting the neck and separating the head from the truncus followed by version and extraction • Indication :- 1. obstructed labor in shoulder presentation when the neck is easily accessible, 2. locked twins • Instrument- – decapitating wire
  57. 57. Evisceration • Perforation of the truncus (chest or abdomen) with removal of all internal organs so that the body collapses and a version and extraction can be done without the risk of rupturing the uterus. • Indication- 1. Shoulder presentation where it is difficult to reach the neck 2. Fetal malformation - (ascites , huge distended bladder , hydronephrosis)
  58. 58. Evisceration Procedure • Pull on the prolapsed arm & his axilla • protect the vaginal wall with speculum • make an opening in the chest or abd. wall • Remove the viscera – (liver, heart, and lungs) • If necessary perforate his diaphragm with scissors
  59. 59. Cleidotomy • Cutting of one or both clavicles to reduce the width of the shoulder • Indication :- • Shoulder dystocia and other maneuvers for shoulder dystocia have been unsuccessful
  60. 60. COMPLICATIONS Trauma to birth canal PPH Shock Puerperal sepsis Injury to adjacent organs- VVF,UVF or RVF Iatrogenic Ux rupture
  61. 61. Thank You All