Feline penile erection induced by transurethral administration of sodium nitroprusside

Nitric oxide (NO) is an important mediator in the relaxation of cavernosal smooth muscle. The aim of this study was to investigate the in vivo feline erectile response after transurethral administration of sodium nitroprusside (SNP), a NO donor drug. Erectile responses after administration of transurethral SNP were compared with those elicited by an intracavernosal control triple-drug combination (1.65 mg papaverine, 25 μg phentolamine, and 0.5 μg prostaglandin E₁). SNP was administered via a 20-gauge Jelco intravenous catheter in a volume of 200 μl and changes in intracavernosal pressure, penile length, and systemic blood pressure were monitored. The control triple-drug combination was administered via a 30-gauge needle at the end of each experiment to serve as a control reference. Transurethral administration of SNP (1–4 mg) induced penile erection in a dose-dependent manner with minimal changes in systemic blood pressure. The maximum increase in intracavernosal pressure and penile length after transurethral administration of SNP (4 mg) was significantly less than after the intracavernosal injection of the control triple-drug combination (P < 0.01). These data suggest that transurethral administration of SNP can induce an erectile response in cats with minimal side effects. Received: 17 December 1998 / Accepted: 14 April 1999     

COMPARISON OF LONG-TERM OUTCOMES OF PENILE PROSTHESES AND INTRACAVERNOSAL INJECTION THERAPY

Purpose

Intracavernosal injection therapy is one of the most popular therapies for erectile dysfunction today. Yet, most clinicians consider intracavernosal injection a palliative treatment for erectile dysfunction because of the high patient initiated dropout rate. In contrast, penile prostheses appear to offer a more permanent cure for erectile dysfunction. We compare the long-term outcomes of both therapies in contemporaneously treated patients and determine the reasons for failure of each.

Materials and Methods

Telephone survey and chart review was conducted on the first 115 patients treated with intracavernosal injection and 65 patients undergoing insertion of a penile prosthesis during the same period at our institution. Mean patient age was 57 and 60 years, respectively, and mean followup of all patients was 5.4 years (range of 3.3 to 16).

Results

An equal percentage of patients were lost to followup in both groups, including 19% of the intracavernosal injection group and 18% of the penile prosthesis group. Of the intracavernosal injection patients 6 (6%) died during followup and 10 (19%) of the prosthetic patients died (p <0.05). At the time of contact only 41% of the patients were still using intracavernosal injection. In contrast, 70% of the patients were still sexually active with the prosthesis (p <0.01). Mean duration of use of the penile prosthetics was 63 months compared to 37 months for intracavernosal injection (p <0.001). The most common reasons for discontinuing intracavernosal injection were inadequate erections (16 cases), lack of spontaneity (14), side effects (12), lack of partner (10), loss of sexual interest (6) and spontaneous return of normal erections (4). More than half of the patients (61%) who discontinued intracavernosal injection remain sexually active with other therapies, including penile prosthesis in 11, vacuum devices in 4, vascular surgery in 1 and oral medication in 1, and 14 without any therapy. We could not identify any significant clinical parameters that would accurately predict which patients most benefited by the long-term use of intracavernosal injection therapy. In contrast, only 6 patients discontinued use of the implant because of complications (infection, erosion and malfunction) and 7 for reasons independent of the implant (that is lack of partner, loss of sexual interest and co-morbidity).

Conclusions

Intracavernosal injection serves as only a palliative therapy for the majority of patients with erectile dysfunction but there exists a core group who derives long-term satisfaction with its use. The majority of patients who discontinue intracavernosal injection remain sexually active yet do not progress to more invasive or effective therapies. The reason for discontinuing therapies for erectile dysfunction is often unrelated to the actual therapeutic modality. Our findings suggest that further improvements in intracavernosal injection therapy and the development of alternative methods of delivery of vasoactive agents will have only a limited impact on the overall outcome of therapy for erectile dysfunction and that increased attention to issues separate from the erection is warranted.     

Significance of phentolamine redosing during prostaglandin E1 penile color Doppler ultrasonography in diagnosis of vascular erectile dysfunction

Recently, it was reported that phentolamine redosing during penile duplex can abolish a false diagnosis of venous leakage in patients with impotence. The aim of this study is to identify any useful role of phentolamine redosing in diagnosis of venogenic impotence. Sixty-seven consecutive patients complaining of weak erection for at least 6 months were included in this study. Penile color Doppler ultrasound (CDU) was performed using a 7.5 MHz linear array transducer with a color flow mapping capability. Following intracavernous injection of 20 microg prostaglandin E1 (PGE1), all patients with persistent end diastolic velocity (EDV) >5 cm/sec with an erectile response of E3 or lower, 20 min after intracavernosal injection of PGE1, were asked to revisit our clinic for a second CDU, 2 weeks later. During initial CDU examination, all 67 patients experienced poor response to 20 microg PGE1 with their average peak systolic velocity (PSV) and EDV being 42.8 and 6.6 cm/sec, respectively. The second CDU examination had similar results to the first one. Addition of 2 mg phentolamine did not significantly change the PSV and EDV of cavernosal arteries in any of the 67 patients. In conclusion, addition of intracavernous phentolamine during PGE1 CDU examination carries no advantage over the use of PGE1 alone regarding cavernosal artery response in patients with suspected venogenic EDV.     

Colour penile Doppler ultrasonography with intraurethral prostaglandin-E2: Preliminary results

Intraurethral instillation was used in place of intracavernosal injection of vasoactive agents for the colour Doppler investigation of patients with erectile dysfunction. A total of 19 patients were enrolled in this study. Colour penile Doppler ultrasonography was done with intracavernosal injection of papaverine-HCl 60 mg and intraurethral instillation of prostaglandin-E₂ 0.5mg. Arterial diameter, peak systolic velocity and end diastolic velocity were measured before and after papaverine injection and prostaglandin-E₂ instillation. Colour penile Doppler parameters increased statistically significantly after papaverine injection and prostaglandin-E₂ instillation (p<0.01). But we did not observe differences between the results after papaverine-HCl and prostaglandin-E₂. We believe that prostaglandin-E₂ may be used with colour Doppler ultrasonography in the evaluation of patients with erectile dysfunction.     

Usefulness of power Doppler ultrasonography in evaluating erectile dysfunction

OBJECTIVE: To evaluate deep penile arterial flow after an intracavernosal injection with papaverine in patients with erectile dysfunction (ED). PATIENTS AND METHODS: Twenty patients with ED were evaluated using power Doppler ultrasonography with a linear probe (8 MHz). Diagnostic tests were undertaken after an intracavernosal injection with 40 mg papaverine. The peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistive index (RI) were analysed. RESULTS: After injecting papaverine, seven patients had a normal erection and appropriate waveform patterns; their mean PSV was 30.7 cm/s, the EDV 4.42 cm/s and the RI 0.85. There was tumescence and elongation of the penis with no rigidity in eight patients; their mean PSV was 23.9 cm/s, the EDV 7.34 cm/s and the RI 0.72. There was no erection in five patients. The abnormal flow values showed insufficient arterial vessels in a quarter of the men, venous leakage in 15% and mixed ED in 20%. CONCLUSION: The power Doppler technique allows the accurate location and evaluation of deep penile arteries. Vascular pathology may be differentiated after an intracavernosal injection with a vasomotor agent. Recognising the pathological pattern assists in choosing the best method of treatment.     

The effect of vascular endothelial growth factor and brain-derived neurotrophic factor on cavernosal nerve regeneration in a nerve-crush rat model

OBJECTIVE: To test the hypothesis that an intracavernosal injection with brain-derived neurotrophin factor (BDNF) and vascular endothelial growth factor (VEGF) can facilitate nerve regeneration and recovery of erectile function after cavernosal nerve injury. MATERIALS AND METHODS: The study included 25 Sprague-Dawley rats; four had a sham operation, seven bilateral nerve crushing with no further intervention, and 14 bilateral nerve crushing with either an immediate (seven) or delayed for 1 month (seven) intracavernosal injection with BDNF+VEGF. Erectile function was assessed by cavernosal nerve electrostimulation at 3 months, and neural regeneration by NADPH-diaphorase staining and tyrosine hydroxylase (TH) staining of penile tissue and major pelvic ganglia (MPG). RESULTS: After nerve crushing, the functional evaluation at 3 months showed a lower mean (SD) intracavernosal pressure (ICP) with cavernosal nerve stimulation, at 33.9 (15.3) cmH2O, than in the sham group, at 107.8 (18.1) cmH2O. With an immediate injection with BDNF+VEGF the ICP was significantly higher than in the controls, at 67.8 (38.5) cmH2O. Even delayed injection with BDNF+VEGF improved the ICP, to 78.0 (21.8) cmH2O. Histological analysis of specimens stained for NADPH and TH showed a significant change in the morphology of terminal branches of the cavernosal and dorsal nerves, and the staining quality of the neurones in the MPG. The number of positively stained nerve fibres tended to revert to normal after treatment with BDNF+VEGF. CONCLUSION: An intracavernosal injection with BDNF+VEGF appears to both prevent degeneration and facilitate regeneration of neurones containing neuronal nitric oxide synthase in the MPG, dorsal nerve and intracavernosal tissue. Therefore it might have therapeutic potential for enhancing the recovery of erectile function after radical pelvic surgery.     

Clinical course of penile fibrosis in intracavernosal prostaglandin E1 injection therapy: a follow-up of 44 patients

A study was undertaken of 44 patients who had developed fibrotic changes in the penis in the course of intracavernosal prostaglandin E1 (PGE1) injection therapy for erectile dysfunction. Of these patients, 75.0% (n=33) were followed up for more than 24 months, and 59.1% (n=26) for more than 36 months. Of the patients, 52.3% (n=23) had clinical improvement of the fibrotic changes without therapeutic intervention and despite most (91.3%) continuing intracavernosal PGE1 injection therapy. These included 25.0% (n=11) no longer having clinically detectable penile fibrosis (PF). The presence of penile curvature or pain did not significantly influence this outcome. The ages of men who showed improvement and the duration of their injection therapy were similar to those who did not improve. It would be prudent to defer therapeutic intervention for PF in the course of intracavernosal PGE1 injection therapy in anticipation of possible spontaneous improvement.     

彩色多普勒超声检查在血管性勃起功能障碍诊断中的应用

目的:评估彩色多普勒超声在诊断血管性勃起功能障碍中的临床价值。方法:应用彩色多普勒超声技术,检测527例疑似血管性勃起功能障碍患者,海绵体注射血管活性药物前、后阴茎海绵体动脉血流动力学。结果:动脉性勃起功能障碍207例(49.88%),静脉性勃起功能障碍144例(34.70%),动静脉性勃起功能障碍64例(15.42%),非血管性勃起功障碍112例(26.99%)。结论:彩色多普勒超声技术是目前诊断血管性勃起功能障碍的一种微创而可靠的检查方法,其能够定量反映阴茎的血流动力学状态,为合理的治疗勃起功能障碍提供有价值的依据。     

Intracavernosal sildenafil facilitates penile erection independent of the nitric oxide pathway.

Sildenafil, in nanomolar serum levels, is an effective phosphodiesterase type 5 inhibitor, and facilitates penile erection only during sexual stimulation. However, there is limited information on the pharmacological activity of this agent when tissue levels approach millimolar concentrations following intracavernosal injection. The aim of this study was to investigate whether sildenafil causes penile erection in the absence of active neurogenic input. Organ bath preparations of rabbit penile cavernosal tissue strips were contracted with 1 microM phenylephrine and exposed to increasing concentrations of sildenafil in the absence or presence of the nitric oxide (NO) synthase inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME; 0.6 mM). Sildenafil caused dose-dependent relaxation of rabbit cavernosal smooth muscle at high concentrations (>0.1 microM) with little or no effect at concentrations below 0.1 microM. The addition of L-NAME did not affect this response. In a separate protocol, sildenafil dose response determinations were performed in the presence of the guanylyl cyclase inhibitor, 1H-[1,2,4]-oxadiazolo-[4,3-a]-quinoxalin-1-one (ODQ; 3 microM) or vehicle (50% dimethyl sulfoxide [DMSO]). Relaxation to sildenafil in the presence of DMSO was significantly enhanced relative to sildenafil alone. ODQ treatment partially attenuated relaxation to sildenafil, but failed to completely inhibit the response. In cavernosal tissue strips, sildenafil elevated basal cyclic guanosine monophosphate (cGMP) levels twofold (0.54 vs. 1.10 pmol/mg prot). To further investigate these observations, anesthetized rabbits were injected intracavernosally with sildenafil (0.3-1.3 mg). In the absence of pelvic nerve stimulation, the magnitude and duration of the intracavernosal pressure increased in a dose-dependent fashion in response to sildenafil, approaching the systemic arterial pressure at higher doses. Intracavernosal administration of L-NAME, at doses that inhibited pelvic nerve stimulated penile erection, did not alter the response to intracavernosal sildenafil at 1.3 mg. Sildenafil, at the doses tested, did not significantly change the systemic arterial pressure. These data suggest that intracavernosal sildenafil, at tissue levels approaching millimolar concentrations, can cause relaxation of vascular smooth muscle and penile erection by a novel mechanism independent of the classical NO/cGMP pathway.     

前列腺素E1与西地那非治疗ED的比较

目的 :比较口服西地那非与阴茎海绵体内注射前列腺素E1(PGE1)治疗勃起功能障碍 (ED)的疗效。　方法 :5 4例ED病人随机分为两组 ,A组口服西地那非 ,B组行海绵体内注射PGE1,均治疗 4～ 9个月 ,平均 6个月。结果 :A、B两组的有效率分别为 80 0 %和 83 3% ,两者差异无显著性 (P >0 0 5 )。A组 6例无效病人经海绵体内注射PGE1治疗 ,2例获得满意勃起 ;而B组 4例无效病人经口服西地那非治疗 ,无 1例勃起。　结论 :口服西地那非与海绵体内注射PGE1对各种病因所致的ED均有良好的治疗作用 ,对西地那非治疗无效者 ,可试用海绵体内注射PGE1,有时也能获得满意的效果     

Are women more sensitive to a pre‐curarization dose of rocuronium than men?

Background: There is increasing evidence that there are gender-related differences in the pharmacodynamics of neuromuscular blocking drugs. However, it is not known whether gender influences the pharmacodynamics of a pre-curarizing dose.
Methods: In the first part, we measured the neuromuscular blockade after administration of rocuronium 0.03 mg/kg (10% of ED₉₅) after induction of anaesthesia in 20 patients (10 female and 10 male patients) by electromyography. In the second part, 40 female and 40 male patients were observed for signs and symptoms of muscle weakness 2.5 min after injection of rocuronium 0.03 mg/kg before loss of consciousness. Succinylcholine-associated post-operative myalgia (POM) was also assessed.
Results: Median twitch heights were comparable between the two groups: 95.5 (range: 85–97; female) vs. 96.0 (range: 85–99; male), (NS). Train-of-four ratios were 97.5 (range: 64–100; female) vs. 99.0 (range: 52–100; male) (NS). Signs and symptoms of muscle weakness were observed in 64 (80%) patients, but there were no gender-related differences. The incidence and severity of POM did not differ significantly between the study groups.
Conclusions: Pre-curarization with rocuronium 0.03 mg/kg affected men and women equally. Nor was the incidence and the severity of muscle weakness affected by gender.     

Intracavernosal prostaglandin E1 self vs office injection therapy in patients with erectile dysfunction

We have investigated the reliability of intracavernosal prostaglandin E1 (PGE1) office vs self-injection therapy in patients with erectile dysfunction (ED). A total of 298 male patients with ED were enrolled in this study. In all patients, intracavernosal titration of the PGE1 dose was performed. A total of 106 patients were enrolled in the self-injection program, and 192 patients were enrolled in the office injection program. There were significant differences between number of injections and amount of PGE1 per month, total number of injections, and total amount of PGE1 on office and self-injection programs (P < 0.05 for each). There was a significant increase in the dropout rate in the office injection group compared with the self-injection group (P < 0.05). There was an increase in penile fibrosis in the self-injection program compared with the office program (P < 0.05). A self-injection program is reliable. Office injection program can be reserved for a subset of ED patients with special preferences.     

Feline penile erection induced by topical glans penis application of combination alprostadil and SEPA (Topiglan)

The objective of this study was to evaluate the efficacy of topically applied prostaglandin E1 (PGE(1))+5% SEPA (soft enhancement of percutaneous absorption) on the glans penis in a feline erection model. Erectile response after glans penis administration of PGE(1)+5% SEPA cream (Topiglan, MacroChem Co., Lexington, MA, USA) was compared to the erectile response after intracavernosal administration of the triple-drug combination (1.65 mg papaverine, 25 microg phentolamine, and 0.5 microg PGE(1)). The placebo cream and increasing concentrations (0.25%, 2.5 mg/ml; 0.5%, 5 mg/ml; and 1%, 10 mg/ml) of PGE(1)+5% SEPA were applied in a total volume of 0.1 ml via a plastic needle-less syringe. The control triple-drug combination was administrated intracavernosally via a 30-gauge needle at the completion of each experiment to serve as a control reference. With each application of placebo, PGE(1)+SEPA, and the triple-drug combination, changes in intracavernosal pressure and systemic blood pressure were continuously monitored. Topical application of PGE(1)+SEPA induced increases in intracavernosal pressure in a dose-dependent manner, with minimal effects on systemic blood pressure. The increases obtained with 1% PGE(1) Topiglan cream were similar to the intracavernosal pressure values elicited by the standard intracavernosal triple-drug combination. These data demonstrate that topical glans penis application of PGE(1)+SEPA can induce an erectile response in cats with minimal systemic adverse effects. Oral pharmacological agents are the first-line treatment for male ED. Studies investigating the effectiveness of noninvasive modalities such as topical therapy should continue, because these agents have the potential to avoid the systemic effects commonly seen with oral therapies. Additionally, topical therapy may also benefit patients who are unresponsive to oral agents or have explicit contraindications. Topical PGE(1) application to the glans penis may become an important treatment option in selected patients suffering from erectile dysfunction.     

TREATMENT OF ERECTILE DYSFUNCTION AFTER KIDNEY TRANSPLANTATION WITH INTRACAVERNOSAL SELF-INJECTION OF PROSTAGLANDIN E1

Purpose

We evaluate the results of treatment of erectile dysfunction in kidney transplant patients with intracavernosal self-injection of vasoactive drugs.

Materials and Methods

We evaluated and treated 26 male kidney transplant patients for erectile dysfunction. All patients had stable kidney function 6 to 75 months (mean 26.6 +/− 9) after transplantation. Each patient received an intracavernosal injection of 20 micro g. prostaglandin E1 (PGE1), and after 20 to 30 minutes the response was assessed. Nonresponders received 40 micro g. PGE1 at another visit, and those who showed no response were reinjected with 40 micro g. PGE1 plus 30 mg. papaverine hydrochloride. A total of 21 patients were enrolled in a self-injection program and have been followed between 3 and 21 months (mean 11.6 +/− 2.7).

Results

Hormonal alterations were seen in 7 patients with serum testosterone as low as 16.6 ng./ml. (normal 33 to 100), and testosterone infections gave only marginal response in 2. Intracavernosal injection of 20 micro g. PGE1 provided good response in 15 patients (57.7%), while 40 micro g. PGE1 alone or in combination with 30 mg. papaverine resulted in good response in another 6 and 2 patients, respectively. Among the 21 patients who were enrolled in the self-injection program 19 (90.5%) reported complete satisfaction with no adverse local or systemic complications except for local pain at the injection site in 4. There has been no change in serum creatinine, cyclosporine level or doses of immunosuppression medications during the observation period.

Conclusions

Intracavernosal self-injection of PGE1 is well accepted and tolerated by kidney transplant patients. It poses no apparent risks to the transplanted kidney and could be a good modality to treat erectile dysfunction in kidney transplant recipients.     

生长激素补充对老龄大鼠勃起功能及阴茎海绵体nNOS表达的影响

目的探讨生长激素(GH)补充对老龄大鼠勃起功能及阴茎海绵体神经型一氧化氮合酶(nNOS)表达的影响。方法20只18月龄SD大鼠随机均分成A、B两组,10只2月龄SD大鼠为C组。A组给予GH1U/(kg·d),B、C组给予相同剂量的生理盐水,均皮下注射8周。于8周末观察阿朴吗啡(APO)皮下注射与大鼠海绵体内注射罂粟碱诱导的阴茎勃起情况,并用免疫组化SP法检测阴茎海绵体组织中nNOS神经纤维的数目。结果8周末时,A、C组大鼠APO诱导的勃起次数、海绵体内注射罂粟碱诱导的最大海绵体内压以及阴茎海绵体组织中nNOS神经纤维数目均显著高于B组(P<0.05或P<0.01)。结论老龄大鼠勃起功能及阴茎海绵体nNOS表达较成年大鼠明显下降,GH补充可以部分改善老龄大鼠的勃起功能,其机制之一可能与GH补充增加了老龄大鼠阴茎海绵体组织中nNOS神经纤维数目有关。     

阴茎异常勃起的诊断与处理(附13例报告)

目的　提高阴茎异常勃起的诊治水平。　方法　阴茎异常勃起患者 13例 ,其中血管活性药物所致 9例 ,会阴外伤所致 1例 ,原因不明 3例。经体检、海绵体血气分析、阴茎彩色双功能超声等检查 ,分别行阿拉明海绵体注射及海绵体减压等治疗。　结果　 12例为低流量型异常勃起 ,1例为高流量型 ,经上述处理后 ,异常勃起均缓解。随访 3～ 4 3个月 ,勃起功能减退 4例 ,9例患者勃起功能无显著改变 ,无明显阴茎海绵体纤维化。　结论　海绵体血气分析和彩色双功能超声等检查有助于阴茎异常勃起准确及时的诊断。海绵体减压和阿拉明注射适用于多数患者 ,治疗时尽量避免对全身的影响。     

Erectile dysfunction after kidney transplantation: our 22 years of experience

AIM: To evaluate the results of treatment of erectile dysfunction (ED) in kidney transplant recipients before and after the advent of sildenafil. MATERIALS AND METHODS: From 1981 through 2002, 971 male patients of mean age 53.4 years received a renal graft. Erectile dysfunction (ED) was investigated in all patients at the first urologic visit posttransplantation. Psycho-sexual support was offered to all patients. Before sildenafil use (1998), our diagnostic approach was complex. From 1998 we tested: serum levels of testosterone, prolactin, and glucose with penile duplex ultrasonography and NPT reserved for selected cases. RESULTS: From 1981 through 1998, 365 male kidney transplant recipients (45%) reported ED. Only 169 patients chose to be treated: 27 responded to psycho-sexual therapy; 3 received testosterone with benefit; 133 had a good results from intracavernosal injection of vasoactive drugs; and 6 received a penile prosthesis. Since 1998, 126 patients reported ED (78.3%). Only 78 chose treatment: 24 patients had a satisfactory response to sildenafil (65% with 50 mg and 35% with 100 mg). PGE1 alone or in combination with papaverine and phentolamine produced a good response in 37 patients; 17 patients did not respond to pharmacotherapy; and 5 received a tricomponent penile prosthesis without complications. The side effects of sildenafil and PGE1 therapy were similar to those reported in the literature. CONCLUSIONS: ED is an important problem in male renal transplant recipients. Cultural resistance to treatment is common. However, treatment with sildenafil citrate and intracavernosal self-injection of PGE1 are well accepted, and prosthetic devices may help in resistant cases.     

Intracavernosal adrenalin injection in priapism.

Prolonged erection is a rare problem in urology but it must be treated effectively. The most common etiological factor is intracavernosal vasoactive agent injection for diagnosis or treatment of erectile dysfunction. The aim of this study was to evaluate the efficacy of intracavernosal adrenalin injection alone in the treatment of priapism. Nineteen patients with prolonged erection were evaluated. Seventeen out of the 19 prolonged erections were due to intracavernosal vasoactive agent injection and the remaining two were idiopathic. In all cases 2 ml adrenalin (1/100 000) was injected in each cavernosal body. In the patients who did not respond to the first injection, repeated adrenalin injections were performed at 20 min intervals. Blood pressure and heart rate were monitored during the injections. Detumescence was achieved in ten (53%) patients after the first injection. Repeated adrenalin injections (2-5 injections) were required in nine patients and eight (42%) of them achieved detumescence. Only one (5%) patient who had 26-h prolonged erection could not achieve detumescence. There was no significant difference in blood pressure and heart rate during the monitoring of the patients when compared to the initial values. No standard treatment method has yet been described for prolonged erection. Repeated aspirations and irrigations for treatment of prolonged erection are problematical applications both for patients and urologist. Intracavernosal adrenalin injection alone can be used with high efficacy and safety for the treatment of prolonged erection especially in patients with a short duration of erection.     

Pain on injection of propofol. A comparison of cold propofol with propofol premixed with lignocaine

Propofol is frequently associated with pain on injection. Previous studies have suggested that chilling of the propofol decreases pain significantly. This prospective, randomised, double-blind trial was designed to assess the effectiveness of cold propofol compared with propofol premixed with lignocaine in minimising pain on injection. Patients were allocated to one of four groups: propofol + lignocaine 0.1 mg.kg⁻¹, propofol + lignocaine 0.2 mg.kg⁻¹, cold propofol and a control group consisting of propofol premixed with normal saline and maintained at room temperature. The results of this study show that cold propofol is associated with a very high incidence of injection pain while lignocaine 0.1 mg.kg⁻¹ premixed with propofol significantly decreases the incidence of pain (p < 0.001). Increasing the dosage of lignocaine above 0.1 mg.kg⁻¹, however, does not significantly decrease the incidence of pain further. The addition of lignocaine also significantly decreases the incidence of excitatory side-effects.