Comparison of Intrathecal Dexmedetomidine and Nalbuphine as an Adjuvant in Hyperbaric Bupivacaine for Saddle Block and Postoperative Analgesia in Patients Undergoing Perianal Surgeries.

Saddle block is the most commonly used anaesthetic technique for perianal surgeries in adults. Perianal surgeries under saddle block are considered as day care surgeries. Major disadvantage is that the low volume of spinally given drug won’t prolong duration of postoperative analgesia. Inj. Dexmedetomidine (α2-Adrenoceptor agonist) and Inj. Nalbuphine (opioid agonist-antagonist) were studied as an adjuvant as to whether they increase the duration of post-operative analgesia. Secondary objectives of this study were to compare hemodynamic stability and side effects among Inj. Dexmedetomidine and Inj. Nalbuphine. METHODSA total of 60 patients with American Society of Anaesthesiologist physical Status I and II scheduled for elective perianal surgeries were randomly allocated into two equal groups in this randomized prospective comparative study. Group D received 0.5% hyperbaric bupivacaine 0.8 mL + 5 mcg dexmedetomidine and group N received 0.5% hyperbaric bupivacaine 0.8 mL + 0.6 mg nalbuphine. Onset and duration of sensory and motor blockade, and duration of analgesia were recorded. Post-operative analgesic consumption and side effects were studied for 24 hours. Statistical analysis was done by using descriptive and inferential statistics using Chi- square test and Student’s t-test. RESULTSDemographic characteristics, duration of surgery, onset of sensory and motor block were comparable. Duration of analgesia was 320.26 ± 89.52 min for dexmedetomidine (D) whereas it was 222.23 ± 25.43 min for nalbuphine (N) with a P value of <0.05. No side effects were noted. CONCLUSIONA dose of 5 mcg dexmedetomidine as an adjuvant seems to be optimal for providing postoperative analgesia with better hemodynamic stability.

Is It Useful and Safe to Maintain the Sitting Position During Only One Minute before Position Change to the Jack-knife Position?

BACKGROUND: Conventional spinal saddle block is performed with the patient in a sitting position, keeping the patient sitting for between 3 to 10 min after injection of a drug. This amount of time, however, is long enough to cause prolonged postoperative urinary retention. The trend in this block is to lower the dose of local anesthetics, providing a selective segmental block; however, an optimal dose and method are needed for adequate anesthesia in variable situations. Therefore, in this study, we evaluated the question of whether only 1 min of sitting after drug injection would be sufficient and safe for minor anorectal surgery. METHODS: Two hundred and sixteen patients undergoing minor anorectal surgery under spinal anesthesia remained sitting for 1 min after completion of subarachnoid administration of 1 ml of a 0.5% hyperbaric bupivacaine solution (5 mg). They were then placed in the jack-knife position. After surgery, analgesia levels were assessed using loss of cold sensation in the supine position. The next day, urination and 11-point numeric rating scale (NRS) for postoperative pain were assessed. RESULTS: None of the patients required additional analgesics during surgical manipulation. Postoperative sensory levels were T10 [T8-T12] in patients, and no significant differences were observed between sex (P = 0.857), height (P = 0.065), obesity (P = 0.873), or age (P = 0.138). Urinary retention developed in only 7 patients (3.2%). In this group, NRS was 5.0 +/- 2.4 (P = 0.014). CONCLUSIONS: The one-minute sitting position for spinal saddle block before the jack-knife position is a safe method for use with minor anorectal surgery and can reduce development of postoperative urinary retention.

Effect of the Sitting Position after Spinal Anesthesia on the Incidence of Postdural Puncture Headaches: Saddle Block versus Low Spinal Anesthesia

PURPOSE: Postdural puncture headache is one well-known complications of spinal anesthesia. The development of postdurals puncture headaches is related to needle size, the direction of the needle bevel, the number of dural punctures and the age of the patient. However, the effect of the sitting position after spinal anesthesia (saddle block) on the incidence of postdural puncture headaches is not yet known. This study was performed to compare the incidence rates of headaches between a saddle block group (sitting position group) and a low spinal anesthesia group (supine position group). In addition, this study was performed to identify the predisposing factors influencing postdural puncture headaches (age, sex, seasonal variation, onset of headache, location of headache). METHODS: The authors analyzed 960 anal-surgery patients who were operated on using a saddle block or low spinal anesthesia at Hang Cinic from Jan. 2000 through Dec. 2000. The authors compared the incidence rates of headaches between the saddle block group (480 cases) and the low spinal anesthesia group (480 cases). RESULTS: 1) The incidence of postdural puncture headaches was not significantly different between the two groups (2.5% in the saddle block group, and 2.3% in the low spinal anesthesia group) (P>0.05). 2) The postdural puncture headache incidence rate was higher for younger patients (20~30 years) and for females. (M:F=7:16) (P<0.05). 3) The onest of postdural puncture headaches was at the postoperative 2nd day in 16 cases (70%) and at the postoperative 3rd day in 6 cases (26%). 4) The incidence rate of postdural puncture headache was higher in the summer (5 cases in June, and 3 cases in July, 4 cases in August). 5) The headache were located in the frontal region in 16 cases (70%) and in the occipital region in 3 cases (13%). CONCLUSIONS: There is no significant difference in the incidence rates of postdural puncture headaches between the saddle block group and the low spinal anesthesia group. Postdural puncture headaches had a tendency to occur more frequently in young female patients and during the summer season. In addition, a more intensive study of the use of saddle block anesthesia for ambulatory anal surgery is required.

Comparison of the Analgesic Duration of Clonidine and Epinephrine Mixture with Tetracaine on Saddle Block / 대한마취과학회지

Clonidine, a2 adrenergic agonist, has a vasoconstrictive property like epinephrine when injected into the subarachoid space. Thus duration of anesthesia would be prolonged in regional block. Besides this effects clonidine also produces direct analgesic effect at spinal cord level and potentiates the effect of local anesthetics injected into intrathecal space. In this study saddle blocks were induced in sitting position by the intrathecal injection of tetracaine for the perianal procedures. 45 patients were classified randomly into three groups. In group I (control) 0.5% tetracaine 4 mg (0.8 ml) and normal saline 0.2 ml was injected intrathecally at L4-5 interspace. In group II (epinephrine) epinephrine 0.2 mg (0.2 ml) was added to 0.5% tetracaine 4 mg and in group III (clonidine) clonidine 30 ug (0.2 ml) was added to tetracaine 4 mg. After intrathecal injections, sensory block level and motor impairment was checked at 5 min and 50 min, The duration of analgesia was defined by the patients who complain the postoperative pain at the incision site. The results in each group were as follows. Sensory block level was Sl (control), L51 (epinephrine) and L5+/-1 (clonidine) at 50 min after injections. The duration of analgesia was significantly prolonged in epinephrine group (369.6+/-64.1 min) and clonidine group (297.9+/-33.8 min) compared with control group (194.3+/-18.2 min). The number of patients with motor block was 12 in epinephrine group, 4 in clonidine group and 1 in control group. In conclusion, tetracaine plus clonidine 30 ug to prolong the duration of analgesia is considered as adequate and safe dosage without significant adverse effects in saddle block.