Perceived barriers of migrants and refugees to vaccinate their children against Measles and polio: a study in Iran.

BACKGROUND: This study examined the perceived barriers of migrants and refugees to vaccinating their children against measles and polio in Iran. METHODS: First, an instrument was developed and validated through several steps. Next, 1,067 parents who had not vaccinated their children against polio and measles or had delayed receiving any dose of these two vaccines until the age of 15 were selected from 16 provinces and completed the instrument. Finally, the data were analyzed. RESULTS: The results of the explanatory factor analysis showed that the perceived barriers affecting vaccination against polio and measles vaccines were categorized into five factors: low knowledge, negative attitude, communication challenges, lack of participation in vaccination programs, and problems related to migration and refugees. Additionally, the results indicated a significant difference in the mean score of perceived barriers based on participants' level of education, economic status, and nationality. CONCLUSION: The identified barriers may provide a perspective for developing effective efforts in this area. Interventions should focus on parents with low education and poor economic status.

COVID-19 in Older Adults: Iran Health Care System Response.

Cite this article as: Shati M, Mortazavi SS, Moghadam M, Solbi Z, Barakati SH, Rezaei F. COVID-19 in Older Adults: Iran Health Care System Response. Med J Islam Repub Iran. 2022 (25 Apr);36:41. https://doi.org/10.47176/mjiri.36.41.

Imported cases of Chikungunya virus in Iran.

BACKGROUND: Chikungunya virus (CHIKV) is a widespread mosquito-borne virus representing a serious challenge to public health. The largest outbreak in the Middle-East was recorded in 2016-2017 in Pakistan. Sistan and Baluchistan Province of Iran shares a wide border with Pakistan; accordingly, introduction of CHIKV from Pakistan to Iran seems to be probable. The current study is aimed at investigating CHIKV infection in Sistan and Baluchistan Province. METHODS: Between April 2017 and June 2018, a total of 159 serum samples of CHIK suspected cases from 10 cities of Sistan and Baluchistan Province were tested by molecular and serological assays. Samples obtained up to 4 days after onset of illness were tested by real time PCR (n = 8). Samples collected 5-10 days after disease onset were subjected to ELISA, as well as real time PCR tests (n = 72). Samples obtained after the 10th day of disease onset were tested by only ELISA (n = 79). Phylogenetic analysis of real time PCR positive samples was carried out by sequencing of a 1014-bp region of Envelope 1 gene (E1 gene). Chi-square and independent t tests were used to evaluate the association between variables and CHIKV infection. RESULTS: In total, 40 (25.1%) out of 159 samples tested positive either by real time PCR or ELISA tests.Out of 151 samples serologically analyzed, 19 (12.6%) and 28 (18.6%) cases were positive for anti-CHIKV IgM and anti-CHIKV IgG antibodies, respectively. Of 80 samples tested by real time PCR, CHIKV RNA was detected in 11 (13.7%) sera, all of them had recent travel history to Pakistan. Additionally, phylogenetic analysis of 5 samples indicated their similarity with recent isolates of Pakistan outbreak 2016-2017 belonging to Indian Ocean sub-lineage of ECSA genotype. A significant correlation between abroad travel history and CHIKV infection was observed (P < 0.001). The most common clinical symptoms included fever, arthralgia/arthritis, myalgia, headache, and chill. CONCLUSIONS: These results present substantial evidence of CHIKV introduction to Iran from Pakistan and emphasize the need for the enhancement of surveillance system and preventive measures.

Cluster of Middle East respiratory syndrome coronavirus infections in Iran, 2014.

During January 2013-August 2014, a total of 1,800 patients in Iran who had respiratory illness were tested for Middle East respiratory syndrome coronavirus. A cluster of 5 cases occurred in Kerman Province during May-July 2014, but virus transmission routes for some infections were unclear.

Metabolomic profiling of embryo culture media in patients with repeated implantation failure during assisted reproductive technology cycles.

Objective: This study investigated the metabolic status of the spent culture media from embryos of patients with repeated implantation failure (RIF) undergoing in vitro fertilization-intracytoplasmic sperm injection cycles in comparison with the embryos from healthy fertile women. Methods: Metabolite levels in spent culture media were assessed and compared between embryos from RIF patients (n=35) and oocyte donors as controls (n=15). Protein levels of insulin-like growth factor 1 (IGF-1) were determined using Western blotting. Concentrations of glucose, pyruvate, and lactate were measured using spectrophotometry. Ionic colorimetric assay kits were utilized to analyze the concentrations of sodium, chloride, calcium, and magnesium ions. High-performance liquid chromatography was employed to measure the concentrations of glutamic acid, aspartic acid, methionine, phenylalanine, and histidine. Results: Glucose consumption and lactate secretion were higher in the control group than in the RIF group. The magnesium concentration was significantly higher in the control group than in the RIF group, but glutamic acid and aspartic acid concentrations were lower in the control group than in the RIF patients (p<0.05). The levels of IGF-1, sodium, calcium, chloride, methionine, histidine, and phenylalanine did not show statistically significant differences between the two groups. Conclusion: The metabolic profile of the culture medium of the embryos in the RIF group differed from that of the control group. These findings suggest potential factors that may affect implantation capacity in RIF patients and provide a new perspective on embryo selection.

Clinical and echocardiographic evaluations of sedative and cardiovascular effects of combination of xylazine-acepromazine versus xylazine-pregabalin in horses.

The aim of this study was to compare the sedative and cardiovascular effects of the combination of xylazine-acepromazine versus xylazine-pregabalin - in horses. Four healthy crossbred horses were included in the study and assigned to two treatments. In treatment I (T1), the animals received xylazine hydrochloride (1.00 mg kg-1) in combination with acepromazine maleate (0.05 mg kg-1) intravenously. In treatment II (T2), the animals received intragastric administration of pregabalin (4.00 mg kg-1) followed by xylazine hydrochloride (1.00 mg kg-1) intravenously after 60 min. Head height above ground (HHAG) and echocardiographic indices were evaluated. In T1, recordings were made 5 minubefore and 5, 15, 30, 60, and 90 minu after drug administration. In T2, recordings were made 5 min before pregabalin, 55 minu after pregabalin administration, and then 5, 15, 30, 60, and 90 min after xylazine hydrochloride acepromazine injection. Analyses of the data showed there were no significant differences regarding HHAG and echocardiographic indices between the two treatments. Intragastric administration of pregabalin prior to xylazine could be considered as an alternative premedication regimen when acepromazine administration is contraindicated or undesirable.

Comparison of the sedative and cardiovascular effects of the combination of acepromazine-clonidine versus acepromazine-xylazine in horses.

The aim of this study was to compare the sedative and cardiovascular effects of the combination of acepromazine-clonidine versus acepromazine-xylazine in horses. Four healthy cross-bred horses were included in the study. They were assigned to two treatments. In treatment I (T1), the animals received xylazine hydrochloride (1.00 mg kg-1) in combination with acepromazine maleate (0.05 mg kg-1) intravenously (IV). In treatment II (T2), the animals received intra-gastric administration of clonidine (0.002 mg kg-1) followed by acepromazine (0.05 mg kg-1; IV) after 60 min. Head height above the ground (HHAG) and echocardiographic indices were evaluated. In T1, recordings were made 5 min before and 5, 15, 30, 60, and 90 min after drug administration. In T2, recordings were made 5 min before clonidine, 55 min after clonidine administration, and then 5, 15, 30, 60, and 90 min after acepromazine injection. Analyses of the data showed there were not significant differences regarding HHAG and echocardiographic indices between two treatments. For sedation of healthy horses, it was concluded that intra-gastric administration of clonidine and IV administration of acepromazine showed similar sedative and cardiovascular effects compared to IV acepromazine-xylazine administration.

Explaining barriers to childbearing using the risk communication and community engagement (RCCE) strategy: Based on action research.

Background and Aims: Reluctance to childbearing and then the reduction of the total fertility rate are common experiences of developed countries and many developing countries, including Iran, therefore, the purpose of this study was explaining barriers to childbearing using the risk communication and community engagement (RCCE) strategy. Methods: The study was conducted by action research and according to RCCE during 9 months in Ardabil city. The statistical population consisted of 41 married women aged 15-54 who were eligible for childbearing, these women were purposefully selected from among the people covered by Ardabil health centers and interviewed. Data were collected using open and in-depth interviews by the researcher and analyzed by content analysis. Results: The results of data analysis led to the extraction of three main categories, personal, familial, and social barriers. The "personal barriers" category was classified into three subcategories, namely mental, belief, and awareness barriers, the "familial barriers" category was classified into two subcategories, namely social and financial barriers, and the "social barriers" category was classified into two subcategories, political and managerial barriers. Conclusions: According to the results, a set of personal, familial, and social factors could affect childbearing among married women. Identification of these factors can play an effective role in designing educational and managerial programs.

Serological evidence of Yersinia pestis infection in rodents and carnivores in Northwestern Iran.

BACKGROUND: Plague may recur after several decades in its endemic regions; therefore, the continuous monitoring of wildlife is essential, even when no human cases are reported in the old foci. The present study was conducted to monitor rodents and their ectoparasites as well as carnivores to learn about the epidemiology of plague infection in an old focus of Iran. METHODOLOGY: The present study was conducted from 2019 to 2020 in Takestan county of Qazvin Province in northwestern Iran. Rodents were caught using live traps, and their fleas were separated. Blood and spleen specimens were taken from the captured rodents. Serum samples were also collected from sheepdogs and wild carnivores. The collected samples were tested by culture, serology (ELISA), and molecular methods to detect Yersinia pestis infection. FINDINGS: A total of 399 small mammals were caught, of which 68.6% were Meriones persicus. A total of 2438 fleas were collected from the rodents, 95.3% of which were Xenopsylla buxtoni. Overall, 23 out of 377 tested rodents (5.7%, CI 95%, 3.9-9.0) had IgG antibodies against the F1 antigen of Y. pestis, and all the positive samples belonged to M. persicus. Nine (4.8%) out of 186 collected sera from the sheepdogs' serum and one serum from the Canis aureus had specific IgG antibodies against the F1 antigen of Y. pestis. There were no positive cases of Y. pestis in the rodents and fleas based on the culture and real-time PCR. CONCLUSION: Serological evidence of Y. pestis circulation was observed in rodents and carnivores (sheepdogs and C. aureus). The presence of potential plague vectors and serological evidence of Y. pestis infection in the surveyed animals could probably raise the risk of infection and clinical cases of plague in the studied region. Training health personnel is therefore essential to encourage their detection of possible human cases of the disease.

Prevalence, severity, and related factors of anemia in HIV/AIDS patients.

OBJECTIVE: The prevalence of anemia in HIV infected patients has not been well characterized in Iran. This study aimed to describe the prevalence of anemia and related factors in HIV positive patients. MATERIALS AND METHODS: In a cross-sectional study, anemia prevalence and risk factors of 212 HIV positive patients were assessed, at the behavioral disease consulting center in Isfahan. The relationship between anemia, demographic variables, and clinical histories were analyzed. Mild to moderate anemia was defined as hemoglobin 8-13 g/dL for men and 8-12 g/dL for women. Severe anemia was defined as hemoglobin, 8 g/dL. RESULTS: A total of 212 HIV positive patients with a mean±SD age of 36.1 ± 9.1 years were assessed. We found that hemoglobin levels were between 4.7 and 16.5 gr/dL. In this study, the overall prevalence of anemia was 71%, with the majority of patients having mild to moderate anemia. Mild to moderate anemia and severe anemia occurred in 67% and 4% of patients, respectively. The mean absolute CD4 count was 348 ± 267.8 cells/cubic mm. Sixty one of 212 patients were at late stage of HIV infection (males=51 and female=10). Of the 212 HIV positive patients enrolled, 17 (8%) had a positive history of tuberculosis. We found a strong association between anemia and death. CONCLUSION: Normocytic anemia with decreased reticulocyte count was the most common type of anemia in overall. Prevalence of anemia in this study is relatively higher than other similar studies. Such a high prevalence of anemia needs close monitoring of patients on a zidovudine-based regimen. Better screening for anemia and infectious diseases, and modified harm reduction strategy (HRS) for injection drug users are primary needs in HIV seropositive patients.

Xanthogranulomatous osteomyelitis.

Xanthogranulomatous osteomyelitis is a rare type of inflammatory process which is characterized by composition of immune cell aggregation on histological studies. Delayed-type hypersensitivity reaction of cell-mediated immunity may be implicated in its pathogenesis. Gross and radiological examination can mimic malignancy, and differentiation should be confirmed by histopathological evaluation. We describe the case of a 14-year-old Afghan boy presenting with pain in right shoulder and left leg with prior history of trauma. Fever, limitation in right shoulder range of motion, and tenderness in right shoulder and left thigh were detected following examination. Mild leukocytosis, elevated alkaline phosphatase, and increased erythrocyte sedimentation rate with negative C-reactive protein (CRP) were revealed. X-ray imaging showed mixed density, periosteal reaction, and cortical disruption. Computed tomography (CT) scan revealed lesions involving medulla and cortex, periosteal reaction with soft tissue component, and bone marrow infiltration in right humerus and left fibula. On magnetic resonance imaging (MRI), signal abnormalities in medulla, metaphysis, and diaphysis of the left fibula associated with cortical irregularity and diffuse soft tissue hypersignal areas were demonstrated. Finally, xanthogranulomatous osteomyelitis was confirmed by histological sample. The clinical manifestations and radiographic and laboratory findings of this rare condition are discussed.

Adipose-derived stromal vascular fraction improves tendon healing in rabbits.

OBJECTIVE: To evaluate the potential effects of uncultured adipose-derived stromal vascular fraction on tendon healing. METHODS: Twenty five adult male New Zealand white rabbits weighing 2.5-3.0 kg were used. Five rabbits were used as donors of adipose tissue and the rest were divided into control and treatment groups. The injury model was completed by unilateral tenotomy through the middle one third of deep digital flexor tendon. Immediately after suture repair, either fresh stromal vascular fraction from enzymatic digestion of adipose tissue or placebo was intratendinously injected at tendon stumps in treatment and control groups, respectively. Immobilization with cast was continued for two weeks after surgery. Animals were sacrificed at eight weeks after surgery and tendons underwent histological, immunohistochemical, and mechanical evaluations. Statistical analyses of quantitative and qualitative data were assessed using one-way analysis of variance and Mann-Whitney U-test, respectively. RESULTS: Histological evaluations demonstrated superior fibrillar linearity and continuity, and decreased vascularity in treatment group indicated improved organization and remodeling of neotendons. Immunohistochemistry de- monstrated a significant increase in collagen I expression in treatment group. Ultimate load and energy absorption capacity were both significantly increased in cell-treated repairs compared with controls. CONCLUSION: The present study shows that intratendinous injection of uncultured adipose-derived stromal vascular fraction results in improved structural and mechanical properties of tendon repairs and it could be an effective modality for treating tendon injury.

Fabrication of chitosan-based electrospun nanofiber scaffold: Amplification of biomechanical properties, structural stability, and seeded cell viability.

The cell scaffolds should structurally be manufactured similar to the target tissue's extracellular matrix. This property should be maintained until cell differentiation. For this purpose, in the current study, electrospun nanofiber (EN) of chitosan (Ch)/polyvinyl alcohol (PVA), as a tissue-friend scaffold, was fabricated by electrospinning in different formulations and borax was utilized as an innovative cross-linking agent to up-regulate the structural and biomechanical properties. The weight loss, water absorbability, structural stability, tensile strength and biocompatibility of borax-included and non-included ENs were compared. The finest morphology, weight loss, water absorbability, structural stability in an aqueous environment, tensile strength and cell viability were found in the borax-included EN containing Ch50.00%v/PVA50.00%v. Moreover, The ENs exhibited appropriate antibacterial properties against Gram-positive and Gram-negative bacteria. In conclusion, borax can be used to improve the mechanical and biocompatibility features of the Ch/PVA-based ENs. Furthermore, it could be suggested that borax-included Ch/PVA ENs can exhibit high appropriate biological properties, candidate them as an appropriate scaffold in the field of tissue engineering. However, in vivo trials are needed to clearly their side effects and advantages.

Varicocoele and oxidative stress: New perspectives from animal and human studies.

BACKGROUND: Varicocoele (VCL), one of the main causes of male subfertility, negatively affects testicular function. Due to limited access to human testicular tissue, animal model studies have been used to evaluate molecular and, recently, epigenetic changes attributed to pathophysiology induced by VCL. OBJECTIVES: This review aims to provide an update on the latest findings regarding the link between VCL-induced biochemical stress and molecular changes in germ cells and spermatozoa. Endocrine and antioxidant status, testicular chaperone-specific hemostasis failure, altered testicular ion balance, metabolic disorders, and altered carbon cycling during spermatogenesis are among the many features that will be presented. DISCUSSION: Literature review coupled with our own findings suggests that ionic imbalance, hypoxia, hyperthermia, and altered blood flow could lead to severe chronic oxidative and nitrosative stress in patients with VCL leading to defective spermatogenesis and impairment of the integrity of all sperm cell components and compartments down to the epigenetic information they carry. CONCLUSION: Since oxidative stress is an important feature of the reproductive pathology of VCL, therapeutic strategies such as the administration of appropriate antioxidants could be undertaken as a complementary non-invasive treatment line.

SARS-Cov-2 and COVID-19, Basic and Clinical Aspects of the Human Pandemic: A Review.

In the last two decades, we have witnessed three major epidemics of the coronavirus human disease namely, severe acute respiratory syndrome (SARS), Middle Eastern respiratory syndrome, and more recently an ongoing global pandemic of coronavirus disease 2019 (COVID-19). Iran, a country of nearly 84 million, in the Middle East, severely involved with the COVID-19 disease. A documented multidimensional approach to COVID-19 disease is therefore mandatory to provide a well-balanced platform for the concerned medical community in our county and beyond. In this review, we highlight the disease status in Iran and attempt to provide a multilateral view of the fundamental and clinical aspects of the disease including the clinical features of the confirmed cases, virology, pathogenesis, epidemiology, and laboratory methods needed for diagnosis.

Developing a questionnaire to assess Iranian nurses' knowledge of and attitude to Middle East respiratory syndrome.

BACKGROUND: With the emergence of Middle East respiratory syndrome (MERS), health care preparedness has received increasing attention, which requires valid tools to assess the knowledge and attitude of health workers, such as nurses, with regard to this disease. AIMS: This study aimed to develop and evaluate a knowledge and attitudes questionnaire on MERS coronavirus for Iranian nurses. METHODS: A questionnaire was developed based on international and national guidelines and a literature review. Ten nurses were recruited to assess face validity and 11 experts reviewed the instrument to determine the content validity ratio and index. Exploratory factor analysis was then done with a random sample of 155 nurses in Tabriz city, Islamic Republic of Iran. RESULTS: Following determination of face and content validity, 78 items (61 knowledge and 17 attitude) were retained in the final version of the questionnaire. The knowledge scale had an average content validity index of 0.80 and the attitude scale a value of 0.91. In the exploratory factor analysis, five dimensions with eigenvalues > 1 and loading level ≥ 0.4 were extracted for the knowledge scale (46 items) and two for the attitude scale (16 items). The Kuder-Richardson 21 coefficient and intraclass correlation coefficient for the knowledge scale were 0.94 and 0.91 respectively. In the attitude scale, the Cronbach alpha coefficient and intraclass correlation coefficients were 0.82 and 0.89 respectively. CONCLUSIONS: The scale developed in this study is reliable and stable and a suitable instrument for evaluating the knowledge and attitude of nurses about MERS-CoV.

Testosterone amplifies HSP70-2a, HSP90 and PCNA expression in experimental varicocele condition: Implication for DNA fragmentation.

The DNA fragmentation and failure in post-meiotic maturation of the spermatozoa because of testosterone withdrawal can affect the fertilization potential in varicocele (VCL) patients. To find out the exact mechanism of VCL-induced failure in histone-protamine replacement process and DNA fragmentation, the correlations between the levels of expression of HSP70-2a, HSP90, PCNA, TP1/2 and PCNA genes and the patterns of DNA methylation were investigated before and after testosterone administration in rats. In total, 40 mature male Wistar rats (10 in each group) were assigned between control (with no intervention), control-sham (undergone a simple laparotomy), VCL-induced (VCL-sole), and testosterone-treated VCL-induced (VCLT) groups. The HSP70-2a, HSP90, PCNA, TP1, and TP2 genes expressions and the patterns of global DNA methylation were determined in all groups. A statistically significant (p < 0.05) reduction were found in the HSP70-2a, HSP90, PCNA, TP1 and TP2 genes expressions in VCL-sole group. In VCLT group, testosterone was shown to significantly (p < 0.05) up-regulate the HSP70-2a, HSP90, PCNA, and TP2expression levels, but TP1 expression has not been changed. Furthermore, the VCLT group exhibited higher DNA methylation rates compared to VCL-sole animals. In conclusion, testosterone, by up-regulating the HSP70-2a and HSP90 expressions and maintaining the pre-existing HSP70-2a and HSP90 proteins levels, may be the reason for the significant increment in TP2 expression during post-meiotic stage and can boost the global methylation rates of DNA via up-regulating the PCNA expression, suggesting that administration of testosterone can mitigate the VCL-impaired histone-protamine replacement and DNA methylation rates and protect the cellular DNA content from VCL-induced oxidative stress.

Effects of rabbit pinna-derived blastema cells on tendon healing.

OBJECTIVES: Tendon healing is substantially slow and often associated with suboptimal repair. Cell therapy is one of the promising methods to improve tendon repair. Blastema, a population of undifferentiated cells, represents characteristics of pluripotent mesenchymal stem cells and has the potentials to be used in regenerative medicine. The aim of this study was to investigate the use of blastema allotransplantation in rabbit tendon healing. MATERIALS AND METHODS: In this study, one rabbit was used as a blastema donor, and twenty-four rabbits were divided into control and treatment groups. Blastema cells were obtained from ear pinna upon punch hole injury in the donor rabbit. Under general anesthesia, a complete transverse tenotomy was performed on the midsubstance of deep digital flexor tendon followed by suture-repair. In the treatment group, 1 × 106 blastema cells suspended in buffer saline were injected intratendinously at the repair site, while the control group received only the buffer saline. Cast coaptation was maintained for two weeks. Eight weeks after the operation, tendons were harvested, and histopathological, biomechanical, and biochemical assays were performed on samples. RESULTS: Mechanical testing showed a significant increase in ultimate load, energy absorption, stiffness, yield load, stress, and strain in blastema-treated tendons compared to controls. Also, higher hydroxyproline content and improved collagen alignment along with lower inflammatory cell infiltration and decreased angiogenesis were observed in blastema-treated tendons. CONCLUSION: Increased levels of hydroxyproline and improved histopathological and biomechanical parameters in the treatment group suggest that blastema cells could be considered an adjunct to tendon repair in rabbits.

The effect of volatile anaesthetics on the relative sensitivity of facial and distal thoracic limb muscles to vecuronium in dogs.

OBJECTIVE: To compare n. facialis-m. nasolabialis (nF-mNL) and n. ulnar-mm. carpi flexorii (nU-mCF) sensitivity to vecuronium during halothane or isoflurane anaesthesia. STUDY DESIGN: Randomized, prospective, experimental study. ANIMALS: Forty-four client-owned dogs (19 male, 25 female) undergoing surgery; mean age: 5.0 years; mean body mass: 24.7 kg. METHODS: Thirty minutes after acepromazine (0.05 mg kg(-1)) and morphine (0.5 mg kg(-1)), anaesthesia was induced with intravenous (IV) thiopental and maintained with either halothane (n = 22) or isoflurane (randomly allocated) in oxygen. The lungs were mechanically ventilated and end-tidal inhaled anaesthetic (FE'(IAA)) maintained at 1.2 x MAC values. Neuromuscular transmission at nF-uNL and nU-mCF was monitored using the train of four count. Vecuronium (50 microg kg(-1) IV) was injected (t = 0) after 15 trains, 50-60 minutes after inhalational anaesthesia began, when FE'(IAA) had been constant for >15 minutes. Times of the disappearance (-) and reappearance (+) of the fourth (T4) and first twitch (T1) were recorded allowing the calculation of: latent (t = 0 to T4-) and manifest onset times (t = 0 to T1-) duration of blockade (T1- to T1+) and drug effect (T4- to T4+) and recovery time (T1+-T4+). Student's paired t-test was used to compare simultaneous responses at nF-uNL and nU-mCF. An unpaired t-test was used to compare anaesthetic effects. RESULTS: Latent and manifest onset times were significantly (p < 0.05) briefer, blockade and drug effects were significantly longer and recovery from blockade were significantly slower in the nF-mNL unit in both halothane and isoflurane recipients. Profound block duration and drug action were significantly longer and recovery from blockade were significantly slower in halothane recipients at both nerve-muscle units. CONCLUSION AND CLINICAL RELEVANCE: The nF-mNL was more sensitive than nU-mCF to vecuronium, particularly in halothane-anaesthetized dogs.

The post-tetanic count during vecuronium-induced neuromuscular blockade in halothane-anaesthetized dogs.

OBJECTIVE: To evaluate the post-tetanic count (PTC) for predicting the return of reversible neuromuscular blockade at the n. facialis-m. nasolabialis (nF-mNL) and n. ulnaris-mm. carpi flexorii (nU-mCF) nerve-muscle units (NMUs) during profound vecuronium neuromuscular blockade in halothane-anaesthetized dogs. STUDY DESIGN: Randomized, prospective, experimental study. ANIMALS: Twenty-five dogs (seven male 18 female) undergoing surgery; mean age: 4.8 years; mean body weight 22 kg. METHODS: Thirty minutes after acepromazine (0.05 mg kg(-1)) and morphine (0.5 mg kg(-1)) pre-medication, anaesthesia was induced with intravenous (IV) thiopental and maintained with halothane, N(2)O and O(2). The lungs were mechanically ventilated and end-tidal halothane concentration (Fe'(HAL)) maintained at 1.04%. Neuromuscular transmission was monitored using the train-of-four count (TOFC) at one nF-mNL and both nU-mCF units. Vecuronium (50 microg kg(-1) IV) was injected after 15 minutes constant Fe'(HAL). When the first twitch (T1) at both nU-mCF units had disappeared (t = 0) one (randomly allocated) ulnar nerve was stimulated every 5 minutes using PTC; TOF stimulation continued at the other sites. The PTC was plotted against the interval between recording time and T1's reappearance at the other NMUs. RESULTS: At t = 0, the mean PTC in the contralateral nU-mCF unit was 18 (range 0-20). Mean PTC was a minimum at t = 5, rising to the maximum (20) at 25 minutes. Six dogs were vecuronium-resistant as monitored by PTC. Excluding data from these revealed a strong negative relationship between ulnar PTC and the time taken for T1's return at the facial (r = -0.7018; p < 0.00001) and contralateral ulnar (r = -0.8409; p < 0.00001) NMUs. CONCLUSION AND CLINICAL RELEVANCE: Post-tetanic count monitoring beginning >5 minutes after the TOFC at nU-mCF = 0 provided a reliable estimate of T1's return at ulnar and facial NMUs.