Spinal Ropivacaine in fast-track TURP

Transcription

1 1 Spinal Ropivacaine in fast-track TURP Saad A. Sheta, MD*, Essam A. Eid, MD**, Ashraf A Moussa, MD. *** *Ass. Professor of Anaesthesia, faculty of Medicine, University of Alexandria, ** Ass. Professor of Anaesthesia, National Liver Institute, Menofia University, ***Lecturer of Anaesthesia, National Liver Institute, Menofia University. ABSTRACT Background: The addition of fentanyl to spinal ropivacaine anaesthesia has been shown to improve the quality of block, increase duration of sensory block, and provide postoperative analgesia without affecting motor function. In a randomized controlled, double blind study, we examined the efficacy and the adverse effects of three different regimen of spinal anesthesia. Methods: Forty-five patients scheduled for transuretheral resection of the prostate (TURP) under sudarachnoid anesthesia. Patients were randomly assigned to Group I (G I) hyperbaric bupivacaine 1 mg, Group II (G II) 15 mg heavy ropivacaine, and Group III (G III) ropivacaine 1 mg with 2 µg fentanyl. Evaluation of the block and side effects were performed after spinal anaesthesia. Results: Three patients in bupivacaine group, three patients in ropivacaine group and one patient in fentanyl group required sedative / analgesic supplementations. Patients of fentanyl group showed significant prolonged sensory block and significant decrease in the motor block. Time to walk was significantly shortened in fentanyl group, it was 15 min versus 197 and 162 min in bupivacaine and ropivacaine groups respectively. The visual analogue score for pain at 3, 6 and 12 hours after intrathecal anaesthesia in G II and III were significantly less than G I. No patient experienced respiratory depression, hypoxemia, hypotension or bradycardia during the postoperative period. Pruritus was reported in 12 patients (8%) of fentanyl group, but it was mild and did not necessitate medical treatment. Shivering was significantly less in the patients of fentanyl group. Conclusion: Intrathecal ropivacaine 1 mg plus 2 ug fentanyl resulted in sufficient analgesia comparable to 15 mg ropivacaine or 1 mg bupivacaine with better analgesia and discharge criteria for fast-track TURP. Key words: spinal blockade; fast-track transurethral resection of prostate, ropivacaine, intrathecal fentanyl. INTRODUCTION Spinal anaesthesia is an established technique for TURP and indeed is considered by many as the technique of choice. Recently, TURP has been managed as day case surgery, where the hypertrophied prostate of less than 4 gm is removed. 4 hours after finishing the procedure, if the urine flow is clear and the patient haemodynamics were stable, the urinary catheter was removed and patients discharged home with the postoperative instructions (1). The ideal spinal anaesthetic for day case surgery would combine rapid and adequate surgical anaesthesia with rapid achievement of discharge criteria such as ambulation and urination. The most important determinant of both successful surgical anaesthesia and time until recovery is the dose of local anesthetic (2). Neither volume of injectate nor concentrations of solution within a 1-fold range (.5-5% lidocaine) have significant effects (3). Unfortunately, selection of dose for ambulatory spinal anaesthesia will inherently result in variable individual patient response. Both pharmacokinetics and pharmacodymanics of individual patients are highly variable and are not easily predicted by individual patient demographics (e.g., age, height). Hyperbaric 5% lidocaine has been AJAIC-Vol. (8) No. 2 June 25

2 11 reported to be associated with transient radicular irritation following single-dose spinal anaesthesia. These observations prompted the search for alternative drugs, particularly for ambulatory surgery. Several investigators tested the efficacy of low dosage bupivacaine, but still the residual detrosor muscle weakness and difficulty to urinate delay patient discharge from the hospital. It is particularly important to select small doses of bupivacaine ( 1 mg) to avoid prolonged detrosor block, inability to void, and excessively prolonged time for discharge as compared with equipotent doses of lidocaine (4). Ropivacaine is a new local anaesthetic released in the United States in It is a lipid-soluble agent that is approximately 5-6% as potent as spinal bupivacaine. Its pharmacological profile is similar to bupivacaine; however it is of less muscle blockade and a less cardio toxic (5). The decreased potency of ropivacaine offers the potential for more rapid recovery and better suitability as an outpatient spinal anaesthetic (6). Intrathecal opioids selectively decrease nociceptive afferent input from Aδ and C fibers without affecting dorsal root axons or somatosensory evoked potentials. Lipophilic opioids have a more favorable clinical profile of fast onset (minutes), modest duration (1-4 h), and little risk of delayed respiratory depression (7). The addition of intrathecal fentanyl to spinal anaesthesia has been shown to improve the quality of block, increase duration of sensory block, and provide postoperative analgesia without affecting motor function (8). Fentanyl is less lipid soluble than sufentanil and will maintain modest spinal selectivity when injected intrathecally (9). Dose-response data indicate that spinal fentanyl alone provides dosedependent analgesia with a minimally effective dose of approximately 1 μg (7). Risk of early respiratory depression is also dose-dependent, with significant risk occurring with doses greater than 25 μg (1). Addition of fentanyl to spinal anaesthesia produces synergistic analgesia for somatic and visceral pain without increased sympathetic block (11). In addition, mixture of fentanyl with local anaesthetic solution decreases barecity and may alter distribution of agents in CSF (12). Taken as a whole, the best riskbenefit dose range would be addition of 1-25 μg fentanyl. Side effects will be limited to easily treated pruritus (6%), while risk of early respiratory depression and urinary retention will be minimized (13). This study was designed to examine the efficacy of two regimens of spinal ropivacaine in performing fast-track TURP. We tested either 15 mg heavy ropivacaine or 1 mg ropivacaine plus 2 ug fentanyl against the commonly used regimen of 1 mg bupivacaine. METHODS In a prospective, randomized, double blind investigation, 45 patients classified as American Society of Anesthesiologists physical status II, scheduled for fast-track TURP were enrolled in the study. No premedication was given the day of surgery. An intravenous bolus of at least 25 ml normal saline solution was administered followed by infusion of 1 ml/h. Spinal technique was performed at the L3-L4 interspaces using a midline approach while the patient in the lateral position. Dural puncture was performed using a 27-gauge pencil-point Quincke needle. The level and duration of sensory anaesthesia {defined as the loss of sharp sensation by using a pinprick test (2-gauge hypodermic needle)} were recorded bilaterally at the midclavicular level. This assessment was performed at 6, 8, 1, 12, 14, 16, 18, 2, and 3 min after intrathecal injection and every 15 min until regression to S2. A dose was considered effective if an upper AJAIC-Vol. (8) No. 2 June 25

3 12 sensory level to pin prick of T1 or above was achieved. Motor block in the lower limb was assessed using a modified Bromage scale (14), (1= complete motor blockade; 2=the patient is able only to move the feet; 3= the patient is able to move the knees; 4= detectable weakness of hip flexion, the patient can not keep the leg raised; 5=no detectable weakness of hip flexion; 6= no detectable weakness at all). These measurements were performed at 1, 15, 2, and 3 min before surgery and every 15 min after surgery. When no motor blockade could be detected (modified Bromage scale 6) and when the patient was ready they were asked to walk. The time elapsed between intrtathecal injections and walking and the time elapsed between intrathecal injection and spontaneous micturition was recorded. During surgery, the surgeon assessed the quality of the motor blockade as perfect, adequate, poor or inadequate. The same surgeon performed all procedures. The quality of intraoperative analgesia was evaluated by the patient using a two-point scale (1=adequate analgesia: no sensation at all from the surgical site; 2=inadequate analgesia or discomfort) Heart rate and blood pressure were measured at 5-min intervals before and during induction, surgery and recovery using automated oscillometery. Arterial oxygen saturation was registered continuously by pulse oximetery (Solar 8M GE Adult CDA15). After free flow of clear cerebrospinal fluid was obtained, 3 ml of the following intrathecal hyperbaric solutions was injected according to a computer-generated list of random numbers. The patients were randomly allocated into three even groups, 15 each, according to a list of random numbers. Groups were categorized according to the anaesthetic solution used: Patient in group I (Bupivacaine group) received 1 mg.5% bupivacaine; Patients in group II (Ropivacaine group) received 15 mg.5% ropivacaine (Naropin,Astra Zeneca, USA Inc); Patients in group III: (Fentanyl group) received 1 mg ropivacaine plus 2 ug (.4 ml) fentanyl. Fentanyl dose was adjusted according to the recommendations of Chilvers et al (15) All injections were made with cephalic orientation of the spinal needle bevel and by using a Luer-Lock syringe (Terumo, Tokyo, Japan), which made it possible to inject the dose in 35 s. The anaesthetic solution was injected without barbotage or aspiration at the beginning or at the end of the injection. A senior anesthesiologist not involved in the patient care prepared the study solutions, and the patient and the anesthesiologist who delivered analgesia were blind to the study solutions. Patients were returned to the supine position immediately after completion of the block, and the patient s legs were wrapped with elastic bandage and placed in the lithotomy position. Immediately after positioning, O2 (4 L/min) via face mask was applied. If systolic arterial pressure decreased more than 5 mmhg from the initial or below 7 mmhg, a vasopressor (ephedrine) was administered intravenously. Bradycardia (heart rate < 5 beats/ min) was treated with intravenous atropine. Blood pressure, SpO 2, respireatory rate, electrocardiograph and heart rate were monitored continuously during anaesthesia and the next 6 hours after surgery and before discharge. The highest dermatome level of sensory blockade, duration of sensory blockade (from onset of spinal anaesthesia to regression to L4 level), and duration of motor blockade ([from onset of spinal anaesthesia to Bromage scale 1 (7) (full ability to flex the knees and resist gravity with full movement of the feet]) were recorded. Patient s ability to ambulate was assessed 6 minutes AJAIC-Vol. (8) No. 2 June 25

4 13 after completion of the procedure and then every 3 min until free ambulation. Postoperative pain was evaluated by using the visual analogue scale (VAS) ranging from to 1 mm. Assessment were recorded every 1 min intraoperatively and hourly till discharge. If VAS is more than 4, patient received an intravenous bolus of 5 mg tramadol.if VAS is more than 7 or the surgeon reported difficult operative condition (because of lack of motor blockade), general anaesthesia was induced. Incidence of pruritus and nausea were also recorded. The protocols to treat patients symptoms included granisetrone 1. mg IV for vomiting, Naloxone,.1 mg IV for severe Pruritus. Post-operative shivering was assessed by using Wrench score (16). If 2 score points or more were reached, 2 mg intravenous pethedine was given. Data were analyzed using one-way factorial analysis of variance and multiple comparisons test and Kruskal- Wallis test as applicable. Post hoc analysis was performed using Mann- Whitney U test when necessary. The comparison of the three groups in demographic data and the duration of surgery were done with parametric oneway analysis of variance. P values <.5 were interpreted as statistically significant. The computations were performed with SAS System for Windows, release 6.12/1996 (SAS, Cary, NC). Adverse effects and treatments were compared with X 2 test. Results were expressed as means ± SD, and P <.5 was considered significant. RESULTS Demographic data showed no difference among study groups (Table 1). The spinal technique was easy and uneventful in all patients. The relevant aspects of the spinal block are presented in (Table 2). The duration of sensory and motor block was signifycantly shorter in patients treated with ropivacaine 15 mg and those treated with ropivacaine1 mg plus 2 ug fentanyl (group II and III) compared with bupivacaine (group I). Time to walk was significantly decreased in groups II and III compared to group I. Three patient in group I, three patients in group II and one patient in group III required sedation analgesia during the intraoperative course (those matched grade 3 on modified Bromage scale), they were given propofol infusion 4. mg/ kg / hr.(table 3). However, no patients in all the study groups required induction of general anaesthesia. Quality of intraoperative motor blockade was assessed as excellent by the surgeon in 14 patients in group I, 13 patients in group II and 12 patients in group III (Table 3). All patients of the study groups evaluated their intraoperative analgesia as adequate. Postoperatively, visual analogue scores showed significant increase in group I and II compared to GIII. From 3 hours postoperatively all patients in group I and 12 patients in group II experienced mild pain of VAS > 4. Patients of group III showed no pain during the recovery period (Table 4 & Figure 1). Three patients in group I, one patient in group II and no patient in group III received intravenous ephedrine for hypotension. Two patients in group I developed bradycardia and treated with intravenous atropine. None of the patients developed postdural puncture headache or reported any complaint suggestive of transient neurological symptoms at the early and late postoperative interview. No patient experienced respiratory depression, hypoxemia, hypotension or bradycardia during the postoperative period (Table 5). No patient had pruritus in group I and II in comparison to 12 patients (8%) in group III. However, pruritis was mild, in the form of nasal itching and no patient requested treatment (Table 5). AJAIC-Vol. (8) No. 2 June 25

5 14 There were no significant differences in the intensity of nausea and consumption of ant emetic (Table 5). Shivering was significantly less in the patients of group III who received intrathecal fentanyl in comparison to those who did not (group I and II), however, it fades without treatment as it responds to warming and oxygen therapy (Table 5). DISCUSSION Spinal anaesthesia is especially useful during TURP surgery, as it allows the patient to detect side effects of the washing solution used in the bladder (it makes their vision fade temporarily) and it encourages clotting in the cut blood vessels (17). The results of this study demonstrated that adding 2 ug fentanyl to small dose (1 mg) hyperbaric ropivacaine spinal anaesthesia during TURP, decreased the need for drug supplementation, improved intraoperative patient and urosurgeons satisfaction and did not prolong recovery. Also, the study proved the efficacy of heavy ropivacaine as a sole spinal anaesthetic in comparisons to equipotent doses of bupivacaine. However, 2% of the patients of groups I and II needed sedative/analgesic supplementations to achieve intra-operative patient/surgeon satisfaction. This finding goes parallel with the results of other investigators. Ben David et al (18) have demonstrated that addition of 1-25 μg fentanyl improves success of spinal anaesthesia, allows use of less local anaesthetic, and does not prolong duration until discharge. They found that, 1 μg fentanyl added to 5 mg hyperbaric bupivacaine for outpatient knee arthroscopy improved anaesthetic success from 75% with plain bupivacaine to 1%, intensified and increased the sensory blockade without increasing the intensity of motor block or prolonging recovery of micturition or street fitness. A dose of 7.5 mg plain bupivacaine is needed to achieve similar success, with resultant prolongation of time until discharge of min when compared with 5 mg plus fentanyl. Chiari and Eisenach (19) reported that the use of small dose spinal anaesthesia in TURP (5-7.5 mg bupivacaine) is still a matter of controversy and lead to a high failure rate. Reuben et al (2) in a dose-response study of the optimal dose of intrathecal fentanyl concluded that analgesia is derived from doses of 1 µg to a maximum of 25 ug, and above with these doses pruritis, urine retention and respiratory depression are likely to occure. (21) Goel et al compared different doses of fentanyl added to bupivacaine for spinal anaesthesia reported that the addition of increasing doses of fentanyl significantly improved the quality and duration of analgesia and decrease the dose requirements of bupivacaine by 25%. In the present study, we found that addition of 2 µg fentanyl to 1 mg ropivacaine produced anaesthesia comparable to the anaesthesia produced by either 1 mg bupivacaine or 15 mg ropivacaine. Table 1: Patient characteristics and duration of surgery G I G II Group III Number of patients Age (year) 72 ± ± ±7.5 Weight (Kg) 71± ± ± 11 Height (cm) 168 ± ± 7 17 ± 6 Duration of surgery (min) 66 ± ± ± 21 Data are presented as mean ± SD. AJAIC-Vol. (8) No. 2 June 25

6 15 Table 2: Characteristics of spinal Block Group I Bupivacaine(1mg) Sensory block: Median peak dermatome level Time to peak sensory level (min) Time to sensory block to S2 (min) Motor block: Maximum motor block (number of patients) Bromage scale 1 Bromage scale 2 Bromage scale 3 Bromage scale 4 Group II Ropivacaine (15mg) Group III Rupiv.1+fent.2 Th 8 (Th 4-9 ) Th 9 (Th 5-1) Th 8 (Th 4-1) 14±6 15±8 16±7 18±39 176±44 27±56* Time to maximum motor blockade (min) 15±7 16±9 18±11 Duration of motor blockade (min) 169±39 153±46* 141±48* Time to walk (min) 197±5 162±38* 15±29* 13 2 P<.5: Significantly different from bupivacaine group (group I). Table 3: Quality of intraoperative analgesia Group I Group II Group III Surgeon evaluation: Excellent (number) Good Fair Bad Patient evaluation: Adequate Inadequate VAS GI GII GIII Time (hours ). Fig. 1. Postoperative VAS AJAIC-Vol. (8) No. 2 June 25

7 16 Table 4: Incidence of intra- and postoperative pains G I (n=15) G II (n=15) G III (n=15) Intra-operative sedative/analgesia 3 (2%) 3 (2%) 1 (6.6%)* Pain (%) 15 (1) 12 (8) (o)* Time to first request of analgesics (min) 189 ± ± 29*. ± * P <.5 compared to G I Table 5: Incidence of postoperative complications: GI (n=15) G II (n=15) G III (n=15) Pruritus (%) 12 (8)* Shivering (%) 3 (2) * 2 (13)* Hypotension (%) 3 (2) * 1(6.6) Bradycardia (%) 2 (13) * Respiratory depression (%) P <.5 (22) Chung et al successfully used 1 µg fentanyl and 18 mg hyperbaric ropivacaine for spinal anaesthesia in cesarean delivery, and observed that the quality of intraoperative analgesia and the duration of analgesia were significantly improved in the early postoperative period. In TURP, Chen et al (23) reported that as small dose as 4 mg hyperbaric tetracaine plus 1 µg fentanyl, with or without.2 mg epinephrine, provided adequate anaesthesia and fewer side effects. In the present study we aimed to provide central block to T1 sensory to provide adequate anaesthesia for both the surgeon and the patient. A subarachnoid sensory block extending to the T1 is necessary to provide adequate anaesthesia during TURP. In (14) 1994, Beers et al assumed that a midlumbar block level (L1) provided adequate anaesthesia for TURP. However, they reported that bladder distension elicited pain under a low or intermediate block. They suggested monitoring and controlling bladder pressure during TURP for block levels lower than T1. Khaw et al (24) found that hyperbaric ropivacaine produced spinal anaesthesia with a more frequent success rate and a less frequent incidence of intraoperative pain compared to plain solution. The results of the present study showed that, 15 mg of.5% heavy ropivacaine produces better spinal analgesia for fast-track procedures than equipotent doses of bupivacaine (1 mg of.5% bupivacaine ). Whatever the explanation; this challenges our earlier assumption that an opioid is necessary to minimize local anaesthetic dose requirements, and to maximize efficacy and satisfaction. Although the decreesed motor block in the ropivacaine group compared to the other two groups was not statistically significant, but the study was probably underpowered for this point. However, even if the ropivacaine regimen did cause more motor block, this did not adversely affect patient satisfaction. Thus another widely held assumption, that satisfaction is strongly related to mobility, is challenged (18). In the present study, intrathecal fentanyl significantly prolonged the recovery of sensory block to S2 to 27 min compared to 18 and 176 min in groups I and II respectively. Simillar results were obtained by Yegi et al (25) who used hyperbaric ropivacaine with fentanyl in TURP. They found the prolongation of sensory block with rapid motor recovery improved the overall recovery and discharge criteria. AJAIC-Vol. (8) No. 2 June 25

8 17 Patients of fentanyl group (III) showed significant decrease in motor block duration (141 min) compared to patients of groups I and II (169 and 153 min). There was a significant decrease in group II compared to group I. Time to walk showed significant decrease in fentanyl group (15 min) compared to bupivacaine and ropivacaine groups (197 and 162 min), still patients of ropivacaine group showed significant decrease in time to walk in comparison to bupivacaine group. Beers et al (26) and Yegi et al (25) have got results very close to ours and they highly recommended the use of small dose hyperbaric ropivacaine plus 2 ug fentanyl for ambulatory TURP. It was difficult to assess the time to micturate, as all patients till 6 hours postoperatively were still catheterized. Times to the first dose of analgesic administration were significantly longer in the fentanyl groups compared with the other groups. These effects of intrathecal fentanyl seem similar to those reported in different studies in which fentanyl was used in combination with hyperbaric ropivacaine or bupivacaine (1, 4). In the present study, Although 12 patients of fentanyl group developed pruritis but it was very mild in the form of nasal itching and did not need any intervention. This incidence of pruritis agreed with the observation of Liu et al (12) who found that the addition of 2 µg of fentanyl intrathecally led to pruritus in all patients. No patients in the three study groups suffered ventilatory depression or delayed discharge. As fentanyl is much more lipid-soluble than morphine and hence does not tend to migrate intrathecally to the fourth ventricle in sufficient concentrations to cause respiratory depression. (24) Varassi et al demonstrated that the subarachnoid administration of 25 µg of fentanyl during spinal anaesthesia in non-premeditated elderly men did not alter respiratory rate, end-tidal tension of CO 2, minute ventilation, respiratory drive, respiratory timing, or the ventilatory response to CO 2. Moreover, addition of fentanyl to intrathecal local anesthetics might decrease the incidence of nausea (25). In the present study, the incidence of nausea was minimal, and similar in the all study groups. Shivering was reported in 2 cases of ropivacaine group and 3 patients of bupivacaine group and no case in fentanyl group. Shivering is one of the leading causes of distress of patients undergoing TURP and sometime might delay discharge. The occurrence of shivering may be due to decreased core temperature secondary to peripheral vasodilatation from sympathetic blockade and cold irrigation fluid. In the present study, intrathecal fentanyl significantly decreased the incidence of shivering. This came in accordance to a previous report about intrathecal fentanyl and shivering (27). In conclusion, heavy ropivacaine 15 mg and 1 mg plus 2 ug fentanyl proved to be effective and potent as 1 mg heavy bupivacaine. Moreover both doses showed less motor blockade, early ambulation and discharge. The addition of fentanyl in a dose of 2 µg to intrathecal ropivacaine 1 mg resulted in fewer requirements of analgesics with-out significant side effects. This study recommended the use of 15 mg ropivacaine or 1 mg ropivacaine plus 2 ug fentanyl for spinal anaesthesia for TURP REFERENCES 1. Karamaz A, Kaya S, Turhanoglu S, Ozyilmaz MA. Low-dose bupi-vacainefentanyl spinal anaesth-esia for transurethral prost-atectomy. Anaesthesia 23; 58: Liu SS: Optimizing spinal anesthesia for ambulatory surgery. Reg Aneth 1997; 22: 5-1. AJAIC-Vol. (8) No. 2 June 25

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10 Beers RA, Kane PB, Nsouli I, Krauss D. Does a mid-lumbar block level provide adequate anesthesia for transurethral pro-statectomy? Can J Anaesth 1994; 41: Chow TC, Cho PH. The influence of small dose intrathecal fentanyl on shivering during transurethral resec-tion of prostate under spinal anes-thesia. Acta Anesthesiology Scandn 1994; 32(3): AJAIC-Vol. (8) No. 2 June 25