ANALGESIA IN LABOUR:
COMBINATED TECHNIQUE (needle through needle and/or needle of ELDOR)
Maurizio Pintore, Fernando Chiumiento, Vincenzo Galdo, Errico Miele, Paolo Paganelli.
CAMPANIA REGION A.S.L. Salerno 2
Department of Anaesthesia and Reanimation - Hospital "S. Francesco dAssisi" OLIVETO CITRA (SA) , Italy
Chief physician: Dr. Giuseppe Visciani
Dr. Maurizio Pintore, Department of Anaesthesia and Reanimation - Hospital "S. Francesco dAssisi"
P.zza Bergamo - 84025 Oliveto Citra (SA) , Italy tel. : +39.828 .797230 tel/fax 089/954285
The scope of the present study is to optimize a technique of analgesia during a spontaneous delivery or an instrumental delivery, that responds well to the following needs:
Observance of the physiology of the delivery;
Secure and complete analgesia that starts from the primary stages of the delivery (with respect to the traditional peridural techniques) and which effect is extended to the hours after the final part of the delivery (seconding);
Complete wellbeing of the fetus;
Reduction of the risks - the side effects - that can be the result of an operative delivery.
107 women in labour have been subject to an analgesia in labour during which subarachnoid fentanyl has been used linked to the classical peridural technique.
No side effect of any importance has been found with the exeption of pruritus, and no modification of the uterine kinetics has been found.
KEY WORDS : Analgesia in labour, Intratecal oppioides, Combinated anaesthesia, Needle of Eldor.
Childbirth, which is a physological process, begins with painful, ritmical contractions of the uterus combined with modifications of the neck of the uterus and the cervix uteri. The foetus (mobile body), accomplishes his passage through the womans delivery channel , which is composed of a bone structure of maternal pelvis and of weak parts constituted by fascial and vaginal-perineal muscles.
Traditionally the labour process is subdivided in three fases or stages (1):
The first stage or stretching period, starts with the beginning of contractions until the complete dilatation of the cervix uteri of about 10 cms.
During this first stage, the pain is tipically visceral with a "cervical" origin, which is caused by the relaxation and straining of the inferior parts of the neck of the uterus and of the cervix uteri. These kind of painfull stimulations, through sensitive sympatetic fibres coming from the body and the neck of the uterus, are lead to the metameres T10-L1, through plexuses: uterus, cervix, pelvis, lower hypogastric, medium hypogastric and higher hypogastric.
Another relevant innervative component is the sympathetic one of the lower segment, in case of hyperstimulation of the latter occurs an hypertonia of the neck of the uterus that prolongs and hinders the conclusion of the first fase; rachidian analgesia diminishing the sympathetic tone associated to it, resolves the hypertonia of the neck of the uterus, making its dilatation easier.
The second part of the labour process or expulsive stage, starts with the completion of the dilatation, and is caracterised by more painfull and stronger contractions that with the help of auxiliary forces lead to a reduction of the volume of the uterus by making descend the foetus (mobile body) through the delivery channel.
The third and last stage, also called seconding, after the expulsion of the foetus, includes the emission of the placenta and of the membranes.
The pain during the second fase of the delivery, loses gradually the charateristics of visceral pain to transform slowly into a more somatic pain, caused by an abrupt spraining fascial muscle structure of the pelvic perineal pavement and of the compression that the mobile body , while descending, exercises on it. The painfull stimulations related to these algid components, lead as a rule to the sacral metamers S2-S4, with an association of stimulating signals that arrive at T8 (stretching of the adnexal structures), to L5 (compression of the lumbo-sacral muscles), to T10-L1 (compression of the visceral structure like the vesical, urethra and rectrum).
To the labour process are also linked a series of modifications to the cardiocirculatory system (tachycardia, increase of the cardiac output) and the respiratory system (hyperventilation with respiratory alkalosis) in relation to the overproduction of catecolamine, ACTH., cortisolo, beta-endorfine, linked partially also to the pain stiumulations.
An "ideal" analgesia for delivery should therefore abolish the pain without interfering in the uterine kinetics which are necessary for the expulsion of the foetus.
This reasoning is at the basis for the use of opiates (2) because they dont effect :
the motoric system;
the sympathetic nervous system;
the proprioceptive nerves.
Fentanyl, in particular because it is in clearly liposoluble with respect to morfine, can be considered according to us at this moment the ideal opioide for intratecal use, because it remains little time in the L.C.R., and it attaches quickly and solidly to the lipides of the medullar sites (receptor action p synapse between 1°-2° sensitive neurone).
This aspect ensures a latency of short action and a sufficient duration of action (3).
Moreover, the passage through the placenta of opiates is irrelevent with side-effects clinically neglectable with respect to the foetus and the Apgar of the new-born, thanks to strong protein - farmaco binding of the molecules.
The authors, after a period of experienc with analgesia in labour, with the traditional technique of continued peridural treatment, carried out with the well-known concentrated local anaesthesia publicized in recent literature (especially marcaina 0,125% dose + fentanyl), retain that the farmodynamic and kinetic characteristics of an opioid like intratecal fentanyl, take away many obstacles and resolve many problems related to isolated peridural techniques, in particular:
Possibility to initiate the analgesia in a very early stage of the labour process with respect to the techniques of continuous peridural infusion (when the head of the foetus can still be moved);
Latency of shorter action;
Immediate and garanteed analgesia;
Complete absence of motoric and sympathetic blockage;
No interference on the uterine kinetics;
No emodynamic repercussions on the mother and on the foetus (hypertension bradycardia);
Analgesia extended also to the hours after the childbirth.
MATERIAL AND METHODS
Our record consists of 107 women in labour, of which 55 are pluripare and 52 primipare, ASA rating 1 - 3. Table 1 gives the characteristics of the patients.
During the anaesthetic visit has been given priority to the psychological aspect of the relationship between the physisian and the patient, offering to the former a clear, simple and complete picture of the analgesic treatment during the labour process, mentioning in particular the advantages and disadvantages, ways of carrying out the treatment, importance of the patients active involvement, potential risks, possibilty expressed in percentage of an operative childbirth, linked to obstetrical and /or anaesthesiologic motives.
To all these well-informed women has been asked consensus.
At the beginning of the resolute labour, upon clinical signalling of the gyneacologist and upon the cardiografic confirmation, the patients (after rhythm verification, of the F.C. and PA), have been premedicated with 0,5-1 mg. of atropina IM.
Before entering with an annula needle 18-16 G into a basilic or cephalic vein at the elbow was practised a pre-filling with 500 ml dose of plasma-expanders.
During the childbirth was shown on the monitor the cardiotocografic tracing, ECG, F.C, P.A. without bloodshed, SA=2, diuresis of the woman in labour.
The intrarachidian analgesia was carried out after the presuppositions mentioned in Table 2 had been fulfilled.
The first presupposition is considered to be the only one really necessary, the second one is only indicative, while with regard to the third one, engagement of the head, has to be considered that the use of intratecal opioide, exempted from motoric block, makes it possible to start at a relative early stage , when the head of the foetus even if ready to be engeged, can still be moved.
To carry out the block the patient was put in left side decubitus, while she was informed that if the contractions would already be very painfull , the dural punture and the installation of peridural catheter would be carried out during a pause between one contraction and another. After the preparation of a sterile piece in asepsis, the intervertebral space L3-L4 was traced; followed by an accurate local anaesthetic infiltration and after this by the identification of the peridural space by using an air mandrintechnique.
The tracing of the subarachnoid space on the contrary is carried out with two different techniques in different stages of our study:
Technique with the needle of Eldor (Fig. 1)
With the needle through -needle technique (69 patients), already well-known, after the tracing of the peridural space with a needle of Touhy, was introduced through the same needle a G27 4 Whitacre needle, which is used to administrate the subarachnoid bolus. Subsequently the peridural catheter is introduced until not more then 2.5 cm towards the superior metamers.
The only needle of Eldor (38 patients) is a Touhy needle which has on the lateral side a little accessory track, and its hollow inside, even if it is one piece with the main needle, is completely seperated from it; after the tracing of the peridural space the peridural catheter is positioned, so after the necessary checks, a G 27 3, ½ Whitacre is introduced into the accessory lateral hollow part, which enables the administration of the subarachnoid bolus.
The procedure implements the initial administration of the subaracnoid space of a bolus of 125 grams of fentanyl + 0,8 mg of bupivacaina 0,25% dose + 1 ml. glucose 10% dose.
After the initial bolus we observed the analgesia starting being effective, with a latency time of 3 - 5 min.; this analgesia was completed in a time that varied from 8 to 10 min.
The women in labour defined the contraction like "a not painfull sensation of inter-abdominal movement and pressure".
After we asked the patients to give an indication of the intensity of the pain, using an analogical scale from 0 to 10 (10=maximum pain, incoercible, unbearable), we received in most cases scores from 0 to 3.
Table 3 shows the obtained results.
From the beginning until the end of the treatment, the P.A., the F.C. and the SaO2 of the mother have been steady; moreover we observed a diminuation of anxiety and stress and related symtoms (hyperventilation, perspiration, muscular hypertonia etc.) in some cases we found initial decrements of P.A. and F.C.which were not more then 10-15% with respect to the basic values; considering the exiguity of these decrements, we thought the phenomenon was mainly connected to the diminished catecolaminergic production being a consequence of the analgesia, and not to the possible pharmacology reducing the sympathetic tone being a subsequence of the rachidian analgesia, which doesnt occur with the use of intratecal opiates.
Moreover, we didnt find respiratory depression and/or somnolence of the mother.
What instead has been a frequent side effect (in 97% of the cases) was pruritus.
According to our experience the latter responded well to a pharmalogical treatment with 10-20 mg of entraveinal propofol , or alternatively 0.1 mg of naloxone.
With regard to propofol, apart from a possible light effect as a tranquilizer becaus it is a sedative (profitable to the patient), the way it has an effect on pruritus is not yet known; instead the use of naloxone can be pharmalogically rationalized being a receptor which is useful for the symptom, but which doesnt invalidate an effective analgesia of the opiates.
In general we didnt find any negative effects on the foetus and the new-born which were clinically noticeable, with the APGAR valuation, if not linked to intrinsic obstetrics (compression of the head, turns of the umbilical cord etc.).
Of the 1017 cases, we found 6 cases of foetal bradycardia (foetal F.C. 90-100 min.) transitory, improved with decubitus on the left side of the patient, not linked to emodynamic variations of the mother (P.A., F.C., Sao2), neither to plausibel obstetrics. We didnt find negative quantative and qualitative interferences of kinetic contractibility of the uterus. We left however the opportunity to use and to chose dosages of entraveinal infusion with ossitocic to the competence of the obstetrician. We found 4 cases (linked to obstretical motives) of insrtrumental deliveries (cupping-glass application) and 2 cases in which it was necessary to carry out an operative delivery, T.C. was done with continuous epidural infusion.
Generally we think the use of subaracnoid fentanyl is satisfying for analgesia in labour. We stress that the addition of bupivacaina to the mixture is not indispensable but we experienced that it diminishes the duration of the latency of the block, and in this way makes the analgesic effect of Fentanyl stronger without interfering in the motoric e sympathetic block.
In the procedure has been included the insertion of the epidural catheter because of two reasons: the first is linked to a percentage of cases (almost the total amount of cases primipare with a long delivery time) in which the duration of the intratecal analgesia was insufficient (it was necessary in the course of time to use an epidural treatment), the second is linked to the necessity to carry out in a certain percentage of the cases an operative delivery (ceasarian section), which in that case can be carried out with peripheral anaesthesia.
The necessity of an additional peridural bolus depends from the contingent variable elements:
Duration of the delivery;
Threshold of personal awareness of pain;
Possible necessity of an instrumental delivery;
The determining element to use the support of a peridural infusion has been however the total time of expulsion and infact it has been necessary in 65% of the cases of primipare, for which the delivery takes considerably more time, against 20% of the pluripare.
As far the technical side is concerned, the needle of ELDOR seems to be a usefull technical innovation because it offers a number of advantages:
It makes it possible to position with the required calmness the peridural catheter, without being in a hurry because the subarachnoid block has already been carried out; (hyperbaric solutions > lateral decubitus > analgesia of a hemisoma).
One can avoid the positioning of one needle into another one, which creates the potential risk to put at the internal of the subarachnoid space metallic microcomponents.
It is not possible that the peridural catheter which has been positioned after the aracnoid puncture, can be displaced into the subarachnoid space.
Moreover, the 27 Whitacre needle inserted through the acessory hollow inside the needle of Eldor, is more solid with respect to the needle-in-needle technique, because the little movements during the injection are avoided, which at times are the cause of displacement of the needle in the subaracnoid space causing a failure of the block.
When the puncture of the arachnoid proceeds the insertion of the catheter, it happens often that from this catheter leaks liquor that can lead to a wrong diagnoses of a subarachnoid displacement of the catheter.
Tabella 1 : Patients characteristics
N° women 107, Primiparae 52 women ,Multiparae 55 women
Age 20 - 35 years
Weight 65 - 82 Kg
A.S.A. 1 - 3
Obesity 11 women
Non severe preeclampsia 7 women
Hypertension 8 women
Allergic asthma 3 women
Thyroid pathology 2 women
Tabella 2 : Required conditions to begin rachidian analgesia.
Resolute labour, true swelled tage
Dilatation of 2 cm for multipare
Dilatation of 3 - 4 cm for primipare
Disposition of the fetal head to engagement
Tabella 3 : Results
Time of labour 3 - 7 hours
Onset of subarachnoid bolus 3 - 5 minutes
Lenght of subarachnoid analgesia 3 - 4 hours
Women that have requested epidural bolus 44 (47%)
Primiparae 33 (65%)
Multiparae 11 (20%)
Bupivacaine 0,125 % dose in 8 ml volume
administred 5-10 mg
Instrumental labours 4 women
Cesarean section 2 women
Friedman EA : Labor : clinical evaluation and management2nd ed. New York : Appleton - Century - Crofts, 1968
Nordberg G., Hedner T., Mellstrand T. e al. :Pharmacokinetics aspects of epidural morphine analgesia.Anaesthesiology 1983 ; 58 :545
Carrie LES., OSullivan GM., Sugobin R. :Epidural fentanyl in labourAnaesthesia, 1981 ; 36 : 965
Rosenblatt R., Wright R., Denson D. e al :Continous epidural infusion for obstetric analgesiaReg. Anaesth. 1983 ; 8 : 10
Youngstrom P., Eastwood D., Pate H. e al. :Epidural fentanyl and bupivacaine in labour.Anaesthesiology 1987 ; 67 : A461
Stacey RGW., Wam S., Cadim MJ. E al :Single space combined spinal-extradural technique for analgesia in labour.Br. J. Anesth. 1993 ; 71 :499
The undersigning Authors declare that the research at the basis of this study has been carried out in accordance with the Declaration of Helsinki and/or the international Principles that regolate the research on animals.