Clinical predictors of Covid-19 mortality in a tertiary hospital in Lagos, Nigeria: A retrospective cohort study.

Background: The predictors of mortality among patients presenting with severe to critical disease in Nigeria are presently unknown. Aim: The aim of this study was to identify the predictors of mortality among patients with COVID-19 presenting for admission in a tertiary referral hospital in Lagos, Nigeria. Patients and Methods: The study was a retrospective study. Patients' sociodemographics, clinical characteristics, comorbidities, complications, treatment outcomes, and hospital duration were documented. Pearson's Chi-square, Fischer's Exact test, or Student's t-test were used to assess the relationship between the variables and mortality. To compare the survival experience across medical comorbidities, Kaplan Meir plots and life tables were used. Univariable and multivariable Cox-proportional hazard analyses were conducted. Results: A total of 734 patients were recruited. Participants' age ranged from five months to 92 years, with a mean ± SD of 47.4 ± 17.2 years, and a male preponderance (58.5% vs. 41.5%). The mortality rate was 9.07 per thousand person-days. About 73.9% (n = 51/69) of the deceased had one or more co-morbidities, compared to 41.6% (252/606) of those discharged. Patients who were older than 50 years, with diabetes mellitus, hypertension, chronic renal illness, and cancer had a statistically significant relationship with mortality. Conclusion: These findings call for a more comprehensive approach to the control of non-communicable diseases, the allocation of sufficient resources for ICU care during outbreaks, an improvement in the quality of health care available to Nigerians, and further research into the relationship between obesity and COVID-19 in Nigerians.

Ivermectin shows clinical benefits in mild to moderate COVID19: a randomized controlled double-blind, dose-response study in Lagos.

INTRODUCTION: In vitro studies have shown the efficacy of Ivermectin (IV) to inhibit the SARS-CoV-2 viral replication, but questions remained as to in-vivo applications. We set out to explore the efficacy and safety of Ivermectin in persons infected with COVID19. METHODS: We conducted a translational proof of concept randomized, double blind placebo controlled, dose response and parallel group study of IV efficacy in RT-polymerase chain reaction proven COVID 19 positive patients. Sixty-two patients were randomized to three treatment groups. (A) IV 6 mg regime, (B) IV 12 mg regime (given Q84 h for 2 weeks) (C, control) Lopinavir/Ritonavir. All groups plus standard of Care. RESULTS: The Days to COVID negativity (DTN) was significantly and dose dependently reduced by IV (P = 0.0066). The DTN for Control were, = 9.1+/-5.2, for A 6.0 +/- 2.9 and for B 4.6 +/-3.2. Two way repeated measures ANOVA of ranked COVID 19 +/- scores at 0, 84, 168 and252h showed a significant IV treatment effect (P = 0.035) and time effect (P < 0.0001). IV also tended to increase SPO2% compared to controls, P = 0.073, 95% CI-0.39 to 2.59 and increased platelet count compared to C (P = 0.037) 95%CI 5.55-162.55 × 103/ml. The platelet count increase was inversely correlated to DTN (r = -0.52, P = 0.005). No SAE was reported. CONCLUSIONS: 12mg IV regime given twice a week may have superior efficacy over 6mg IV given twice a week, and certainly over the non IV arm of the study. IV should be considered for use in clinical management of SARS-COV2, and may find applications in prophylaxis in high risk areas.

Development and practice of laparoscopic surgery in a Nigerian tertiary hospital.

BACKGROUND: For the benefits of less postoperative pain, early recovery and discharge, and better cosmesis, laparoscopic surgery is rapidly gaining acceptance amongst surgeons as a better alternative to traditional open procedures. In January 2015, bookings for laparoscopic surgery became a more regular feature on our operation list. AIMS: We reported the indications, management outcome, and challenges in patients who had laparoscopic surgery in our institution. This is to document the trends in our surgical practice. METHODOLOGY: This is a descriptive study of 137 patients who had laparoscopic surgery for general surgical indications in our institution over a period of 5 years. Patients data as collected from the records department were evaluated for demographic characteristics, medical comorbidities, type of procedures done, and perioperative outcome. Data analysis was performed using Statistical Package for Social Sciences (SPSS). RESULTS: A total of 137 Patients had laparoscopic general surgery between January 2015 and December 2019. There were 48 males and 89 females with a male-to-female ratio of 1:1.9. The mean age of the patients was 38.8 ± 3.4 years (range 16-87 years). Laparoscopic cholecystectomy (35%) and laparoscopic appendicectomy (29.9%) were the most common procedures performed. Five (3.7%) cases were converted to open surgery. Superficial surgical site infection (5.8%) following laparoscopic appendicectomy was the most common postoperative complication. There was no 30-day postoperative mortality. CONCLUSION: Laparoscopic surgery is safe and can be applied to wide variety of general surgical conditions in developing countries. Minimal postoperative morbidity of laparoscopy is a major benefit to the patients.

Routine hemoglobin electrophoresis for pediatric surgery day case in at-risk populations: Suggested algorithm for screening using clinical risk factors.

BACKGROUND: Hemoglobin electrophoresis (HBE) is a part of the preoperative routine requested by anesthetists. However, the prevalence of hemoglobinopathy in the population is low. This study aims to determine the clinical risk factors for hemoglobinopathies and propose clinical guidelines for preoperative screening of patients for pediatric day care surgery. PATIENTS AND METHODS: A prospective study carried out over 12 months. Consecutive patients aged 6 months and older who had day case surgery were recruited to the study. Biodata and relevant clinical data were collated and documented in a proforma and analyzed using a statistical package for social sciences version 17. RESULTS: There were 124 patients106 boys and 18 girls. The median age was 3 years. Scrotal lesions were the most common conditions managed (71.7%). Seventy-eight percent of patients had HbAA, 15.3% had HbAS, and 4.8% had HbAC while 0.8% each had both HbSC and HbSS. At least one parent of 78.2% knew their Hb phenotype, of which, 79% were HbAA. A history of jaundice (P = 0.0001), hand and foot syndrome (P = 0.0001), frontal bossing (P = 0.0001), and low packed cell volume at surgery (P = 0.001) were found significant in predicting hemoglobinopathies. There was no mortality. CONCLUSION: Risk factors for hemoglobinopathies from this study included a positive history of jaundice, hand and foot syndrome, frontal bossing, and anemia. Proposed guidelines for HBE screening include the presence of hemoglobinopathy in one parent if one parent has sickle cell trait, and the other parent's genotype is unknown or if any of the risk factors is present.

Preoperative localization of undescended testes in children: comparison of clinical examination and ultrasonography.

BACKGROUND: Preoperative localization of the testis aids effective management of undescended testes. Various diagnostic techniques have been applied in the localization of undescended testes with varying results. The aim of this study was to compare clinical assessment and ultrasound evaluation in the preoperative localization of undescended testes in children. METHODS: A prospective evaluation of all boys undergoing operation for undescended testes at the Lagos University Teaching Hospital, Idi Araba, from July 2010 to June 2011 was carried out. The findings on preoperative clinical and ultrasound examinations were compared with intraoperative findings. RESULTS: Forty boys with 52 undescended testes were studied. The median age of the boys at the time of surgery was 4 years (range 1-11 years). Forty-five testes (86.5%) were accurately localized preoperatively by ultrasound while 25 testes (48.1%) were accurately localized on clinical examination. Ultrasound evaluation had an accuracy of 86.5% in preoperative localization of undescended testes. Clinical examination had an accuracy of 48.1% in preoperative localization of undescended testes. Ultrasound was more accurate than physical examination (p < 0.001). CONCLUSIONS: Ultrasonography is more accurate than clinical examination in the preoperative localization of undescended testes in children and could play a role in preoperative evaluation of patients with undescended testes.

H-type tracheo-oesophageal fistula: a diagnostic challenge in a resource-poor country. A case report.

H-type fistula is a rare form of congenital tracheo-oesophageal fistula accounting for 4% of all cases of Tracheo-oesophageal fistula. The typical picture is that of recurrent chest infection due to both missed and delayed diagnosis as well as cyanosis and choking during feeds. In resource poor countries this problem is further exaggerated by ignorance, poverty and lack of access to basic investigative modalities. This is the case of [abstract incomplete].

Has the middle-level anaesthesia manpower training program of the West African College of Surgeons fulfilled its objectives?

An audit of the West African College of Surgeons' middle-level Diploma in Anaesthesia program was carried out to determine the current status of the diplomates. Using the West African College of Surgeons' database, social media and personal communications, the current status of Diploma in Anaesthesia graduates spanning 20 years was determined. A total of 303 (97%) out of 311 of graduates were traced. Eighty percent were still practising anaesthesia, while 5% were now in other disciplines. Two hundred and four (67.3%) still resided in West Africa (183 in Nigeria, 50 in Ghana, one in Sierra Leone), while 69 (22.7%) were abroad: 35 (11.5%) in the United Kingdom, 21 (6.9%) in the United States of America and four (1.3%) in Canada. More Ghanaian than Nigerian graduates had emigrated (41 vs 14%, respectively). Only 9% of diplomates remained in rural communities (as originally envisaged), while 31% were now consultants (as fellows) and 30% were registrars in fellowship training. These findings indicate that most diplomates moved on to acquire further qualifications and a significant proportion migrated. The program did not appear to have achieved the objectives of meeting rural middle-level manpower needs in anaesthesia as envisaged. It has, however, boosted the recruitment drive for residency training in anaesthesia. Perhaps a less migrant cadre such as nurses may better serve this function if recruited into a suitably designed training program in countries desiring to use middle-level manpower in anaesthesia.

Routine haemoglobin electrophoresis screening in day case herniotomy in Nigerian children: Is it evidence-based?

BACKGROUND: To determine the prevalence of haemoglobinopathies in children who require day case herniotomy in our centre and ascertain if routine screening is necessary in all patients who require herniotomy. MATERIALS AND METHODS: A 12-month retrospective analysis of patients requiring herniotomy in our centre. Data including age, sex, diagnosis, haemoglobin electrophoresis status, surgical outcome and hospital stay were analysed. RESULTS: Ninety-five patients had complete records. There were 84 boys and 11 girls. M:F ratio: 7.6:1. The mean age was 3.2 ± 0.6 years. Fifty-five point eight per cent of the patients had right inguinal hernias while 35.8% had left inguinal hernias. Eight patients (8.4%) had bilateral inguinal hernias. Twenty-six patients (27.4%) had haemoglobinopathies while 69 patients (72.6%) had homozygous Haemoglobin A. The Sickle Cell trait (HbAS) was found in 22 patients (23.2%) while the HbAC was found in three patients (3.2%). One patient (1.1%) had Sickle Cell disease (Haemoglobin SS). He had had blood transfusion and previous history of jaundice. All patients survived and all patients were discharged on the day of surgery (mean hospital stay: 4hrs (range: 2.5 hrs-12 hrs)) except the patient with Sickle Cell disease who was admitted a day before surgery and discharged a day after the operation. CONCLUSION: One in four children coming for day case herniotomy in our centre had the Sickle Cell trait while only 1% had the Sickle Cell disease. These findings are in keeping with the prevalence in the Nigerian population. Routine screening may not be necessary for all patients coming for herniotomy in our centre. Clear indication(s) should be outlined for screening.

Accreditation of Training Programmes by the West African College of Surgeons.

The establishment of surgical training programmes of the West African College of Surgeons started in six teaching hospitals the early 1970s in Nigeria and Ghana; it was championed by College Fellows, surgeons who had returned to the sub-region after having trained in Europe and America. Surgical programmes accreditation, captured in the College's constitution and mission statement, uses objective guidelines in the identification and encouragement of suitable institutions for surgical training through periodic peer-review audits of installed manpower, facilities, clinical services and academic programmes. This pan-regional model adopted by the five Anglophone countries of West Africa has standardized and nurtured surgical training in the disciplines of surgery, obstetrics and gynaecology, ophthalmology, otorhinolaryngology, dental surgery, radiology and anaesthesia. It has also proven to be a useful template in the current drive for the ongoing harmonization of surgical training programmes with Francophone West African as a prelude to an integrated sub-regional accreditation body. This paper details the evolution of surgical programmes accreditation in West Africa, its progress, challenges, opportunities and future trends.

Swenson's pull-through in older children and adults: peculiar peri-operative challenges of surgery.

INTRODUCTION: The definitive treatment of Hirschsprung's disease is removal of the aganglionic bowel by a pull-through surgery. In most cases this surgery is performed in infancy or the neonatal period as presentation in older children and adulthood is rare. Nevertheless, pull-through in this age group may be necessary and present peculiar challenges. MATERIALS/METHODS: A prospective study of patients above 5 years with Hirschsprung's disease who presented at LUTH, Lagos between January 2007 and July 2010. RESULTS: There were fourteen patients (10 males and 4 females). The median age was 9 years (range 5-31 years). All the patients presented with constipation and abdominal distension. Seven patients presented with intestinal obstruction necessitating colostomy. Thirteen patients had short segment Hirschsprung's disease limited to the rectosigmoid. The only exception had long segment disease with the transition zone located at the transverse colon. Ten patients (71.4%) had colostomy before definitive pull-through while four patients (28.6%) had primary pull-through procedure without a colostomy. The definitive pull-through procedure done in all the patients was Swenson's abdomino-perineal pull-through and all the patients had a 2-layered colo-anal anastomoses. Due to the rigid pelvis in these patients, as well as possible scarring, simple blunt dissection was difficult in these cases. The median length of follow up was 11 months (range 6-28 months). There was one case (7.1%) of mortality. CONCLUSION: Older patients with Hirschsprung's disease present with intestinal obstruction and poor nutritional status that may necessitate preoperative colostomy. Swenson's pull-through in them poses peculiar challenges of mobilization of bowel and achieving a reliable colo-anal anastomosis, however, outcome is comparable with surgery in younger children if these challenges are overcome.

Penile injuries from proximal migration of the Plastibell circumcision ring.

BACKGROUND: Although circumcision is the commonest surgical procedure performed on male neonates, complications still arise from all methods used by operators. PATIENTS AND METHOD: This was a prospective study of penile injuries resulting from proximal migration of the Plastibell device in neonate boys referred to the Lagos University Teaching Hospital, Lagos, Nigeria. The parameters measured were patients' biodata, presentation, management and treatment outcome. RESULTS: Twenty-three injuries resulting from circumcision with the Plastibell device all occurred from prolonged retention of the ring. In each case, the ring was retained and had migrated proximally. There was extensive skin loss in 17 (74%) babies. Urethrocutaneous fistulae were the result in nine (39%) of these cases, while partial necrosis of the glans penis occurred in four (17%). These complications resulted from the use of wrong-sized Plastibell kits, lack of follow-up by the medical staff, and inadequate maternal knowledge of ring fall-out time. CONCLUSION: Proximal migration of the Plastibell ring can result from employment of an inappropriate size, causing grievous penile injury. Adequate information should be provided to mothers of circumcised babies about possible complications of the Plastibell kit when employed. There is a need to redesign the Plastibell kit to eliminate its migration up the penile shaft.

Appropriateness of intra-operative blood transfusion in children at the Lagos University Teaching Hospital--an initial survey.

BACKGROUND: The decision to transfuse intra-operatively is based on preoperative haemoglobin (Hb), estimated blood loss and physiological variables. The visual estimate of blood loss is notoriously unreliable especially with small volumes of blood losses in children. OBJECTIVES: We sought therefore to determine the appropriateness of intra-operative blood transfusion in a sample of children METHODS: All children requiring intra-operative blood transfusion between May and June 2008 were prospectively studied. Neonates and children already on blood transfusion at induction were excluded. Transfusion was prescribed at the discretion of the attending anaesthetist. The Estimated blood volume (EBV) and estimated blood loss (EBL)were determined. Appropriate transfusion was defined as blood transfusion at EBL > 15% of EBV, maximum allowable blood loss to PCV of 27% and pre-transfusion Hb < 8g/dl. RESULTS: Twenty-five patients were studied with a mean age of 4.16 +/- 3.59 years (Range 0.33-11 years). The mean preoperative PCV was 31.14 +/- 3.53% (range 25-34%). Twelve patients (48%) were appropriately transfused when MABL was calculated to PCV of 27%. Nine patients (36%) had appropriate blood transfusion at an EBL greater or equal to 15% of the EBV. Of the 12 patients that had pre-transfusion Hb measured, 2 (16.6%) were appropriately transfused at Hb < 8 g/dl. CONCLUSION: The use of near patient monitoring devices should be encouraged as this will give an accurate assessment of Hb and appropriate indication for transfusion. Equipment should be made available to perform gravimetric estimation of blood loss as the visual method is notoriously unreliable.

Meconium peritonitis in Nigerian children.

BACKGROUND: Meconium peritonitis is a rare disease with a fatal outcome. In Nigeria and Africa, there are only the occasional case reports on the subject matter. METHODS: This is a 10-year retrospective study of all patients with meconium peritonitis treated at the University of Maiduguri Teaching Hospital, Maiduguri, Borno State, the Lagos University Teaching Hospital, Lagos State, Obafemi Awolowo University Teaching Hospitals complex, Ile-Ife, Osun State and the Federal Medical Centre Gombe, Gombe State, Nigeria. RESULTS: There were 10 neonates comprising 6 girls and 4 boys. The median age at presentation was 4 days (range 2-6 days). Six of the mothers of the children with meconium peritonitis had a supervised antenatal care and 4 had antenatal ultrasonography but meconium peritonitis was missed. The most common clinical presentation was abdominal distension at birth in 9 of 10 patients. The abdominal X-rays showed calcification and homogenous opacity in 4 patients and pneumoperitoneum in 2 patients. At laparotomy, all the patients had inflammatory adhesion bands and matted bowel loops. The generalized type was the commonest form observed (7 patients) and giant pseudocyst was noted in 2 patients. The commonest sites of perforation were the ileum in 4 patients and jejunum in 3 patients. In one patient the perforation had sealed at laparotomy. Intestinal obstruction was the commonest cause of meconium peritonitis in 7 of 10 patients. In the remaining 3 patients the cause is unknown. The commonest procedure performed was resection and anastomosis (4 patients). The mortality rate was high (50%). CONCLUSION: Our data revealed the rarity of meconium peritonitis and intestinal obstruction as the commonest cause. It is recommended that in patients with an unidentifiable cause a rectal biopsy should be done to rule out Hirschsprung's disease. Early diagnosis, proper operative procedure and meticulous post-operative care should improve their survival.

Presentation and management outcome of childhood intussusception in Lagos: a prospective study.

BACKGROUND: Intussusception is the commonest cause of bowel obstruction in infancy and childhood. Early diagnosis and effective management have reduced its morbidity and mortality in developed countries. AIM: To document the presentation, management and treatment outcome of intussusceptions at the Lagos University Teaching Hospital (LUTH). PATIENTS AND METHODS: One hundred seventy-four consecutive cases of this condition seen in children presenting at LUTH over a 5-year period were prospectively studied. Details of symptoms and signs, pre-hospital care, treatment, and outcome in LUTH were documented. RESULTS: The triad of abdominal pain, bloody mucoid stools and palpable abdominal mass was seen in 106 (61%) of the cases. One hundred thirty-five (77.6%) had been admitted and treated with antibiotics and intravenous fluids in primary healthcare centers for an average of 3 days before referral to the LUTH. Prolonged mean duration of recognizable symptoms of 3 days accounted for a 70.4% bowel resection rate. Wound infection occurred in 61 (36.1%), whereas fecal fistulae developed in six (3.6%), and burst abdomen in five (3%) of cases. Seven (4.1%) patients developed incisional herniae. Overall, mortality rate was 12.1%. CONCLUSION: The early symptoms of intussusception would seem to be missed by primary healthcare workers in Lagos, with consequently high morbidity and mortality. There is an urgent need to re-emphasize these symptoms to first-line healthcare providers and parents through public enlightenment campaigns.

Meconium peritonitis in nigerian children

Background: Meconium peritonitis is a rare disease with a fatal outcome. In Nigeria and Africa; there are only the occasional case reports on the subject matter. Methods: This is a 10-year retrospective study of all patients with meconium peritonitis treated at the University of Maiduguri Teaching Hospital; Maiduguri; Borno State; the Lagos University Teaching Hospital; Lagos State; Obafemi Awolowo University Teaching Hospitals complex; Ile-Ife; Osun State and the Federal Medical Centre Gombe; Gombe State; Nigeria. Results: There were 10 neonates comprising 6 girls and 4 boys. The median age at presentation was 4 days (range 2-6 days). Six of the mothers of the children with meconium peritonitis had a supervised antenatal care and 4 had antenatal ultrasonography but meconium peritonitis was missed. The most common clinical presentation was abdominal distension at birth in 9 of 10 patients. The abdominal X- rays showed calcification and homogenous opacity in 4 patients and pneumoperitoneum in 2 patients. At laparotomy; all the patients had inflammatory adhesion bands and matted bowel loops. The generalized type was the commonest form observed (7 patients) and giant pseudocyst was noted in 2 patients. The commonest sites of perforation were the ileum in 4 patients and jejunum in 3 patients. In one patient the perforation had sealed at laparotomy. Intestinal obstruction was the commonest cause of meconium peritonitis in 7 of 10 patients. In the remaining 3 patients the cause is unknown. The commonest procedure performed was resection and anastomosis (4 patients).The mortality rate was high (50). Conclusion: Our data revealed the rarity of meconium peritonitis and intestinal obstruction as the commonest cause. It is recommended that in patients with an unidentifiable cause a rectal biopsy should be done to rule out Hirschsprung's disease. Early diagnosis; proper operative procedure and meticulous post-operative care should improve their survival

A comparative study of the haemodynamic effects of atropine and glycopyrrolate at induction of anaesthesia in children.

BACKGROUND: Bradycardia following administration of halothane and suxamethonium in children leads to reduced cardiac output, which can be prevented with prophylactic anticholinergics. Anticholinergics may result in tachycardia and arrhythmias. This study was designed to compare haemodynamic changes and incidence of cardiac arrhythmias following intravenous atropine and glycopyrrolate. STUDY DESIGN: Ninety ASA I and II children between one month and twelve years were studied. Premedication was with oral promethazine 1mg/kg. Anaesthesia was achieved with 3 % halothane in 33 % oxygen and nitrous oxide. Patients were randomly allocated to receive atropine 0.01mg/kg (Group I) or glycopyrrolate 0.005mg/kg (Group II). Tracheal intubation was facilitated with suxamethonium 1.5mg/kg. RESULTS: Patients in Group I had a 35.7% rise in heart rate from baseline, compared to 22.5 % in Group II two minutes after anticholinergic administration (p=0.001). Following intubation, heart rate rose by 9.7 % and 13.2 % (p<0.05) in Groups I and II respectively. MAP rose similarly in both groups. Arrhythmia occurred in 44.4 % of patients in Group I and 11.1% in Group II (p=0.001) and were mainly sinus tachycardia. 2.2% of patients in Group I exhibited bigemini. No patient experienced bradycardia. Hypoxia occurred in 2.2 %, hypotension in 13.3% and mild laryngeal spasm in 0% of Group I and 11.1%, 4.4% and 4.4% of Group II respectively. CONCLUSION: The use of glycopyrrolate compared to atropine, offered better cardiovascular stability in Nigerian children. Arrhythmias occurred more in patients who had atropine and occurred most frequently after tracheal intubation.

Surgical swab foreign bodies--observations on 7 cases in Lagos.

Foreign bodies inadvertently left in body cavities are a rare complication of abdominal and other surgeries. The true incidence of this condition is not known. The author reports on 7 such cases occurring over a 16-year period and comments on preventive measures, early diagnosis, tactful handling and the need for damage control when dealing with this unwelcome issue in a surgical setting.

Endothelin-like action of Pausinystalia yohimbe aqueous extract on vascular and renal regional hemodynamics in Sprague Dawley rats.

The bark of the African tree Pausinystalia yohimbe has been used as a food additive with aphrodisiac and penile erection enhancing properties. The effect of an aqueous extract of P. yohimbe (CCD-X) on renal circulation was assessed in order to test the hypothesis that it possesses additional effects on nitric oxide production and/or endothelin-1 (ET-1)-like actions. In vivo studies with CCD-X in Sprague Dawley rats demonstrated a dose-dependent (1-1000 ng/kg) increase in mean blood pressure (p < 0.001) and an increase in medullary blood flow (MBF) (p < 0.001). Both the pressor action and renal medullary vasodilation were blocked by endothelinA (ETA) receptor antagonist BMS182874 and endothelinB (ETB) receptor antagonist BQ788 in combination. L-Nomega-nitro-l-arginine methyl ester (L-NAME; 10 mg/kg) also inhibited the increase in MBF induced by CCD-X. In vitro studies in isolated perfused kidney and in pressurized renal microvessels confirmed the dose-dependent vasoconstrictor action of this extract. ETA receptor antagonist BQ610 and ETB receptor antagonist BQ788 separately and significantly attenuated the renal vasoconstrictor actions of the extract (p < 0.001 ANOVA). These preliminary observations indicate that, in addition to the alpha-adrenergic antagonist actions that characterize yohimbine, CCD-X possesses endothelin-like actions and affects nitric oxide (NO) production in renal circulation. These findings suggest a strong possibility of post-receptor cross-talk between alpha2-adrenoceptors and endothelin, as well as a direct effect of alpha2-adrenoceptors on renal NO production.