Ml Of Anesthetic Solution Research Articles

EPIDURAL BLOCK FOR CESAREAN SECTION (C/S)

S364 It is a common practice to insert the epidural catheter into the epidural space and to inject the local anesthetic solution through the catheter. Our practice has been to initiate epidural block through the needle by gravity technique and then to insert the catheter [1] (Figure 1). To determine whether administration of local anesthetic solution by gravity via the needle into the epidural space is associated with fewer adverse effects than the traditional injection through the catheter technique, we conducted, with IRB approval, a prospective, randomized double blind study of 104 consenting parturients who received epidural block for elective C/S.Figure 1: Gravity techniqueMethods: The patients were randomly allocated to two groups. Group I (n=52) received the anesthetic solution through the epidural catheter. Group II (n=52) received the anesthetic solution by gravity before insertion of the catheter. Following a standard lumbar epidural approach, Group I patients received incremental doses of 3ml, 5ml, 5ml, 5ml, 3ml to a total of 21 ml of 2% lidocaine with 5 [micro sign]g/ml epinephrine and 5 [micro sign]g/ml fentanyl. Group II received 3 ml, 5 ml, 5ml and 5ml of anesthetic solution administered by gravity through the needle, followed by catheter insertion and administration of 3ml of the anesthetic solution via the catheter to a total of 21 ml. Results: Values are mean +/- SD. Groups did not differ in age, height or parity. Average weight in Group I was slightly less than Group II (171 +/- 35 vs 188 +/- 37 kg, p<0.02). The groups did not differ in number of previous epidural or spinal blocks. No patient had a prior inadvertent dural puncture or blood patch. Groups did not differ in distance of epidural space from skin, duration of surgery or incidence of nausea or sedation. Apgar scores of babies in Groups I and II were similar at both 1 and 5 minutes. Incidence of blood vessel puncture was greater in Group I than Group II (8 vs 1, p<0.04). Group I required more additional local anesthetic than Group II to achieve T4-S5 level of anesthesia (2.2 +/- 3.6 ml vs 0.0 +/- 0.0, p<0.001) and had a greater incidence of discomfort from paresthesia (33 vs 21, p<0.03). There were 13 patients in Group I and none in Group II for whom the epidural block alone did not provide satisfactory analgesia p<0.001). Conclusion: These data show that epidural administration of local anesthetic solution for C/S by gravity via the needle is associated with a higher success rate, fewer paresthesias, and fewer epidural blood punctures than the traditional injection through the epidural catheter.

The optimal dose of local anaesthetic in the orthogonal two-needle technique. Extent of sensory block after the injection of 20, 30 and 40 mL of anaesthetic solution

The optimal dose of local anaesthetic in the orthogonal two-needle technique. Extent of sensory block after the injection of 20, 30 and 40 mL of anaesthetic solution

Retrobulbar Anesthesia With a Flexible Catheter

The authors describe a method that seeks to improve the administration of local anesthesia for intraocular surgery, avoiding the risk of potential complications associated with retrobulbar and peribulbar techniques and eliminating the inconveniences of the new methods such as subconjunctival and limbal infiltration. The authors demonstrate the safety and effectiveness of this technique in 50 consecutive cases. This technique consists of a small, blunt dissection of the conjunctiva, Tenon's capsule, and intermuscular septum in the inferior nasal quadrant, followed by the insertion of a flexible catheter that is guided to the retrobulbar space, where 3.0 ml of anesthetic solution is injected. All of the patients (100%) felt that this procedure was comfortable and painless. No complications were observed. Ultrasonography demonstrated the exact catheter position in the retrobulbar space; therefore, the authors could be sure that this anesthetic infiltration was done in the appropriate and safe place. This is a direct sub-Tenon's technique that is simple, effective, and safe and that avoids introducing a sharp or metallic instrument into the orbit.

Isolation of HIV‐1 from experimentally contaminated multidose local anaesthetic vials

To investigate the hypothesis that HIV can be transmitted via contamination of multidose vials of local anaesthetic solution through reuse of needles and syringes. Laboratory study. (1) By experiments with multidose vials and disposable needles and syringes, we identified a sequence of events in which HIV could contaminate the anaesthetic solution. (2) Three anaesthetic solutions were contaminated with a laboratory strain of HIV and tested by viral culture and p24 enzyme immunoassay one, two and four hours later to see how long the virus remained active. (1) Needles and syringes retained small volumes of fluid after use (mean, 25 microL; in syringe alone, mean 16 microL) which could be transferred to multidose vials of local anaesthetic. (2) 10 mL of anaesthetic solution contaminated with 8 microL of HIV-infected solution (equivalent to 1% infected lymphocytes in vivo) contained active virus one hour later. In some settings, HIV could be isolated four hours after exposure. When inadvertently contaminated with HIV, multidose solutions represent a potential source of transmissible virus.

Isolation of HIV-1 from experimentally contaminated multidose local anaesthetic vials.

To investigate the hypothesis that HIV can be transmitted via contamination of multidose vials of local anaesthetic solution through reuse of needles and syringes. Laboratory study. (1) By experiments with multidose vials and disposable needles and syringes, we identified a sequence of events in which HIV could contaminate the anaesthetic solution. (2) Three anaesthetic solutions were contaminated with a laboratory strain of HIV and tested by viral culture and p24 enzyme immunoassay one, two and four hours later to see how long the virus remained active. (1) Needles and syringes retained small volumes of fluid after use (mean, 25 microL; in syringe alone, mean 16 microL) which could be transferred to multidose vials of local anaesthetic. (2) 10 mL of anaesthetic solution contaminated with 8 microL of HIV-infected solution (equivalent to 1% infected lymphocytes in vivo) contained active virus one hour later. In some settings, HIV could be isolated four hours after exposure. When inadvertently contaminated with HIV, multidose solutions represent a potential source of transmissible virus.

PH-Adjusted 2-Chloroprocaine for Epidural Anesthesia in Patients Undergoing Postpartum Tubal Ligation

Thirty patients scheduled for postpartum tubal ligation under epidural anesthesia received either a commercial preparation of 3% 2-chloroprocaine or one with pH adjusted by the addition of NaHCO3 shortly before block placement. The administrators of the epidural were blinded as to the solution employed and were scheduled to administer up to 23 ml of anesthetic solution via an epidural catheter in divided doses. Data collected included time to onset of blockade, time to attainment of T4 level, maximal dermatomal spread, and time to 2-segment regression. The need for intravenous sedatives and analgesics was recorded.

A Single Dose Epidural Technique for Cesarean Section

Forty healthy women scheduled for elective cesarean section under epidural anesthesia were randomly allocated to receive, in a double-blind manner, either 0.5% plain bupivacaine or 0.5% bupivacaine with 1:200,000 epinephrine. The drug was injected entirely through a Tuohy needle in fractionated doses: a 2 ml test dose followed by 18 ml injected over 5 minutes. Thereafter an epidural catheter was inserted and anesthesia and surgery managed routinely. Assessment was made of onset and spread of sympathetic, sensory and motor blockade. If sensory block was below T6 after 20 minutes, an additional 7 ml of anesthetic solution was injected via the catheter. Intra-operative discomfort was managed with intravenous narcotics (after delivery), further epidural drug, or inhalation agents.