Executive summary: Guidelines for the diagnosis and treatment of septic arthritis in adults and children, developed by the GEIO (SEIMC), SEIP and SECOT / Resumen ejecutivo: Guía de diagnóstico y tratamiento de la artritis séptica en adultos y niños de GEIO (SEIMC), SEIP y SECOT

Infection of a native joint, commonly referred to as septic arthritis, is a medical emergency because of the risk of joint destruction and subsequent sequelae. Its diagnosis requires a high level of suspicion. These guidelines for the diagnosis and treatment of septic arthritis in children and adults are intended for use by any physician caring for patients with suspected or confirmed septic arthritis. They have been developed by a multidisciplinary panel with representatives from the Bone and Joint Infections Study Group (GEIO) belonging to the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), the Spanish Society of Paediatric Infections (SEIP) and the Spanish Society of Orthopaedic Surgery and Traumatology (SECOT), and two rheumatologists. The recommendations are based on evidence derived from a systematic literature review and, failing that, on the opinion of the experts who prepared these guidelines. A detailed description of the background, methods, summary of evidence, the rationale supporting each recommendation, and gaps in knowledge can be found online in the complete document.(AU)

La infección de una articulación nativa, generalmente denominada artritis séptica, constituye una urgencia médica por el riesgo de destrucción articular y las consecuentes secuelas. Su diagnóstico requiere un alto nivel de sospecha. Esta guía de diagnóstico y tratamiento de la artritis séptica en niños y adultos está destinada a cualquier médico que atienda pacientes con sospecha de artritis séptica o artritis séptica confirmada. La guía ha sido elaborada por un panel multidisciplinar en el que están representados el Grupo de Estudio de Infecciones Osteoarticulares (GEIO) de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEIMC), la Sociedad Española de Infectología Pediátrica (SEIP) y la Sociedad Española de Cirugía Ortopédica y Traumatología (SECOT); además han participado dos reumatólogos. Las recomendaciones se basan en la evidencia proporcionada por una revisión sistemática de la literatura y, en su defecto, en la opinión de los expertos que han elaborado la presente guía. En el texto completo online se hace una descripción detallada de los antecedentes, métodos, resumen de la evidencia, fundamentos que apoyan cada recomendación y las lagunas de conocimiento existentes.(AU)

Diagnostic cutoff values of synovial fluid biomarkers for acute postoperative prosthetic joint infection: a systematic review and meta-analysis.

Introduction: The assessment of white blood cell (WBC) count and polymorphonuclear cell (PMN) percentage in synovial fluid can help in the diagnosis of acute postoperative peri-prosthetic joint infection (PJI). Their cutoff values, which would differ from those for chronic PJI, have not yet been determined in acute postoperative PJI. The aim of this study was (1) to analyse studies reporting the optimal cutoff values for WBC count and the PMN percentage in synovial fluid and (2) to determine which is the best diagnostic tool for acute postoperative PJI. Methods: We performed a systematic review (SR) of primary studies analysing WBC count and the PMN percentage for diagnosis of acute postoperative PJI. A search was performed in MEDLINE and EMBASE. We studied the risk of bias and quality assessment. We extracted data on cutoff values, sensitivity, specificity, positive and negative predictive value, area under the curve, and accuracy. We calculated the diagnosis odds ratio (DOR), performed the meta-analysis and summarized receiver operating curves (sROCs) for WBC count and the PMN percentage. Results: We included six studies. WBC count showed a DOR of 123.61 (95 % CI: 55.38-275.88), an sROC with an area under the curve (AUC) of 0.96 (SE: 0.009) and a Q index of 0.917. The PMN percentage showed a summary DOR of 18.71 (95 % CI: 11.64-30.07), an sROC with an AUC 0.88 (SE: 0.018) and a Q index of 0.812. Conclusion: We concluded that WBC count and the PMN percentage are useful tests for the diagnosis of acute PJI; WBC is the more powerful of the two. Studies centred on other synovial fluid biomarkers not yet studied could help in this diagnosis.

Executive summary: Guidelines for the diagnosis and treatment of septic arthritis in adults and children, developed by the GEIO (SEIMC), SEIP and SECOT.

Infection of a native joint, commonly referred to as septic arthritis, is a medical emergency because of the risk of joint destruction and subsequent sequelae. Its diagnosis requires a high level of suspicion. These guidelines for the diagnosis and treatment of septic arthritis in children and adults are intended for use by any physician caring for patients with suspected or confirmed septic arthritis. They have been developed by a multidisciplinary panel with representatives from the Bone and Joint Infections Study Group (GEIO) belonging to the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), the Spanish Society of Paediatric Infections (SEIP) and the Spanish Society of Orthopaedic Surgery and Traumatology (SECOT), and two rheumatologists. The recommendations are based on evidence derived from a systematic literature review and, failing that, on the opinion of the experts who prepared these guidelines. A detailed description of the background, methods, summary of evidence, the rationale supporting each recommendation, and gaps in knowledge can be found online in the complete document.

Cognitive, social, and behavioral manifestations of the co-occurrence of autism spectrum disorder and attention-deficit/hyperactivity disorder: A systematic review.

LAY ABSTRACT: This work aimed to review recent research on the characteristics of individuals who have both autism spectrum disorder and attention-deficit/hyperactivity disorder due to their high co-occurrence. Thirty-four studies were analyzed and main findings summarized in two content domains focusing on areas that could enhance our understanding of the cognitive and behavioral characteristics of individuals with autism spectrum disorder + attention-deficit/hyperactivity disorder (ASD+). Most of the results suggested that ASD+ is a co-occurring condition associated with more severe impairments in cognitive functioning, adaptive behavior, and increased likelihood to present more emotional/behavioral problems. These results will be helpful to provide improved care plans for individuals with both attention-deficit/hyperactivity disorder and autism spectrum disorder.

Laparoscopically assisted ilio-inguinal lymph node dissection versus inguinal lymph node dissection in melanoma.

AIM: Morbidity of open inguinal lymphadenectomy (OIL) is high. We use laparoscopy for pelvic time, preservation of the greater saphenous vein and transverse inguinal incisions (laparoscopically assisted ilio-inguinal lymphadenectomy, LIIL) to improve postoperative outcomes. PATIENTS & METHODS: Retrospective comparison of 14 patients who underwent LIIL and seven patients who underwent OIL. RESULTS: Fourteen LIIL compared with seven OIL showed a statistically significant reduction in morbidity (15.3 vs 75%) and hospital stay (7 vs 15.7 days). Pelvic lymph node involvement (27%) was not detected preoperatively. With a mean follow-up of 36.2 (range: 3-137) months, local recurrence rate was 58.3% in LIIL and 40% in OIL. Overall survival was significantly higher in OIL than in LIIL. CONCLUSION: Compared with OIL, LIIL reduced postoperative complications and hospital stay.

Rare Site Hepatocellular Carcinoma Metastasis.

INTRODUCTION: Besides more common sites such as lung or peritoneum, hepatocellular carcinoma (HCC) can metastatize to rare sites. We report herein a new metastatic site of HCC: the nail-bed. We also review other recently reported rare site HCC metastases (RSHM). CASE REPORT: A 66-year-old woman with a 12-year history of resected-stage IA HCC who later presented lung, spleen and brain metastases treated with surgery, systemic therapies (sorafenib, sunitinib, capecitabine) and radiotherapy. The patient was referred to us because of a painful and rapidly evolving mass in the nail-bed of the left thumb. Biopsy confirmed nail-bed HCC metastasis, and the finger was amputated. The patient died few weeks later. CONCLUSION: This case was an opportunity for us to review RSHM. This type of metastasis seems to be an early event, in the context of advanced stage HCC with elevated protein induced by vitamin K absence-II (PIVKA II). The Lee nomogram is useful in detecting patients at high risk of developing RSHM. We would suggest insisting on systemic treatment in these metastatic patients although overall survival after RSHM diagnosis is poor.

Prosthetic joint infection by Bordetella holmesii: Case report and a review of the literature.

INTRODUCTION: Bordetella holmesii is a Gram-negative coccobacillus involved in different infections mostly described in case reports. Prosthetic joint infections in relation to this pathogen are rare. Here, we present the third case of B. holmesii in a patient without anatomical or functional spleen dysfunction. CASE REPORT: The patient was a 62-year-old female with a total knee prosthesis implanted in 1997 that required multiple replacements of the femoral component due to aseptic loosening in the past years. The patient was admitted to our hospital for an elective replacement surgery due to new radiological signs of loosening. B. holmesii was isolated from synovial fluid obtained during surgery. The identification was performed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and confirmed by 16S rRNA gene amplification and sequencing. Antibiotic treatment was started but 14 days after surgery the patient presented pain and joint effusion. An arthrocentesis was performed and synovial fluid culture was positive again for B. holmesii. Surgical debridement including polyethylene replacement was performed and antibiotic treatment was continued for 3 months. After a 2-year follow-up period, the patient remained asymptomatic and physical examination showed normal function of the prosthesis. CONCLUSION: B. holmesii is an uncommon cause of bone and joint infections. This case indicates that this microorganism is a potential pathogen of prosthetic or native arthritis, and it should be considered when cultures are negative and in cases presenting torpid evolution.

Debridement, Antibiotics, and Implant Retention Is a Viable Treatment Option for Early Periprosthetic Joint Infection Presenting More Than 4 Weeks After Index Arthroplasty.

BACKGROUND: The success of debridement, antibiotics, and implant retention (DAIR) in early periprosthetic joint infection (PJI) largely depends on the presence of a mature biofilm. At what time point DAIR should be disrecommended is unknown. This multicenter study evaluated the outcome of DAIR in relation to the time after index arthroplasty. METHODS: We retrospectively evaluated PJIs occurring within 90 days after surgery and treated with DAIR. Patients with bacteremia, arthroscopic debridements, and a follow-up <1 year were excluded. Treatment failure was defined as (1) any further surgical procedure related to infection; (2) PJI-related death; or (3) use of long-term suppressive antibiotics. RESULTS: We included 769 patients. Treatment failure occurred in 294 patients (38%) and was similar between time intervals from index arthroplasty to DAIR: the failure rate for Week 1-2 was 42% (95/226), the rate for Week 3-4 was 38% (143/378), the rate for Week 5-6 was 29% (29/100), and the rate for Week 7-12 was 42% (27/65). An exchange of modular components was performed to a lesser extent in the early post-surgical course compared with the late course (41% vs 63%, respectively; P < .001). The causative microorganisms, comorbidities, and durations of symptoms were comparable between time intervals. CONCLUSIONS: DAIR is a viable option in patients with early PJI presenting more than 4 weeks after index surgery, as long as DAIR is performed within at least 1 week after the onset of symptoms and modular components can be exchanged.

Withholding Preoperative Antibiotic Prophylaxis in Knee Prosthesis Revision: A Retrospective Analysis on Culture Results and Risk of Infection.

BACKGROUND: A significant amount of patients undergoing revision surgery of a prosthetic joint turn out to have an infection. Withholding preoperative antibiotic prophylaxis in these patients to optimize culture yield during revision surgery remains a matter of debate. The aim of our study was to determine (1) the rate of positive intraoperative cultures with or without preoperative antibiotic prophylaxis and (2) the incidence of a prosthetic joint infection (PJI) during the follow-up in the 2 groups. METHODS: Medical files of patients in whom preoperative antibiotic prophylaxis was withheld until culture samples were taken (2007-2010, n = 284) and in whom antibiotic prophylaxis was given during the induction of anesthesia (2010-2013, n = 141) were retrospectively reviewed. RESULTS: The percentage of ≥1 positive cultures was the same in the group without (26%) and with preoperative prophylaxis (27%; P value, .7). PJI was diagnosed during revision surgery according to the Musculoskeletal Infection Society criteria in 6.7% patients not receiving preoperative prophylaxis and in 7.0% receiving it (P value, .79). We found no important differences in the type of microorganisms that were isolated in both groups. During a 3-month follow-up, an early PJI developed in patients undergoing total revision surgery in 6.4% of the nonpreoperative prophylaxis group vs 1.6% in the preoperative prophylaxis group (P value, .1). CONCLUSION: Preoperative antibiotic prophylaxis does not reduce culture yield in patients undergoing knee revision surgery. Our data show a trend toward a higher PJI rate in the postoperative period of total revision surgery when preoperative prophylaxis is withheld.

Estudio comparativo de eficacia y seguridad de la nefrolitotomía percutánea (NLPC) y la cirugía retrógrada intrarrenal (CRIR) para litiasis renales de 2-3, 5 cm / Comparative study for the efficacy and safety of percutaneous nefhrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for the treatment of 2-3,5 cm kidney stones

OBJETIVO: Comparar la eficacia y seguridad de Nefrolitotomía Percutánea (NLPC) y de Cirugía Retrógrada Intrarrenal (CRIR) para el tratamiento de litiasis renales entre 2 y 3,5 cm. MÉTODOS: Revisión de 142 casos con litiasis renal entre 2 y 3,5 cm tratados en nuestro centro entre diciembre 2009 y diciembre 2011; 106 casos de CRIR y 36 casos de NLPC. Se evalúan y comparan edad, sexo, composición, localización, unidades Hunsfield (UHC) y tamaño litiásico, tiempo quirúrgico, complicaciones, días de ingreso y éxito de la técnica en el primer procedimiento y tras un segundo procedimiento. Análisis estadístico con T Student, U Mann-Whitney y Chi2 - V Cramer (p = 0,05). RESULTADOS: No hay diferencias en la edad, distribución de sexos, UHC, tamaño litiasico entre ambos brazos. El tiempo quirúrgico fue menor en el grupo NLPC (mediana 85 minutos vs 112 minutos; p:0,04) La estancia hospitalaria fue significativamente más corta en la CRIR (mediana=16 horas vs 93 horas; p = 0,001). En cuanto a la tasa de complicaciones globales, 94,8% de procedimientos libres de complicaciones para CRIR frente a un 80% de la NLPC (p 0,08). La NLPC obtuvo mejor porcentaje de éxito (80,6% frente al 73,6% de CRIR) aunque estas diferencias no son estadísticamente significativas (p = 0,40). Si comparamos el éxito con segundas maniobras, la NLPC presenta un porcentaje del 94,3% de los casos frente al 93,5% (p = 0,88). CONCLUSIONES: La CRIR se presenta como una opción segura, eficaz y con corta estancia hospitalaria. Puede ser considerada como alternativa a la NLPC en el tratamiento de litiasis renales de hasta 3,5 cm. Sin embargo hacen falta más publicaciones con estudios aleatorizados que confirmen esta hipótesis

OBJECTIVES: Retrograde intrarenal surgery (RIRS) has become an important alternative for the treatment of kidney stones due to its increased safety and efficiency. The purpose of this study is to compare efficacy and safety features of RIRS against percutaneous nephrolithotomy (PCNL) for the treatment of 2 - 3.5 cm kidney stones. METHODS: 142 cases (106 RIRS and 36 PCNL) encompassing 2 - 3.5 cm kidney stones that have been treated in our center between December 2009 and December 2011 have been considered. Demographic variables, stone characteristics, surgical stay and surgical time have been evaluated. Additionally, the complication rate and success rate after one and two procedures (retreatment) have also been assessed. Student`s T, Mann-Whitney U y Chi2 - V Cramer (p = 0.05) tests were used for statistical analysis. RESULTS: There are not statistically significant differences in demographic or stone variables. The calculated mean surgical time was lower for PCNL (85 min) than for RIRS (112 min). Mean hospital stay was statistically significantly shorter in RIRS (16 h vs. 98 h in RIRS, p = 0.001). PCNL exhibited a higher global complication rate of 19.4% vs. 6.6% for RIRS (p = 0.001). PCNL also showed a higher successful rate (80.6% vs. 73.6% for RIRS), although this difference was not statistically significant (p = 0.40). When comparing the success rate after a second procedure, PCNL results in 94.3% vs. 93.5% for RIRS (p = 0.88). CONCLUSION: RIRS was found to be a safe and efficient procedure with a short hospital stay. Overall, RIRS can be considered as an alternative to PCNL for the treatment of renal stones smaller than 3.5 cm

A Prolonged Post-Operative Antibiotic Regimen Reduced the Rate of Prosthetic Joint Infection after Aseptic Revision Knee Arthroplasty.

BACKGROUND: The aim of this study was to compare the prosthetic joint infection (PJI) rate after knee revision arthroplasty in two consecutive periods with different antibiotic prophylaxis: short (one day) versus long (five days). METHODS: From January 2007 to September 2010 antibiotic prophylaxis consisted of 800 mg of teicoplanin and 2 g of ceftazidime intravenously and 1 g of ceftazidime two hours after the first dose. From October 2010, it was prolonged post-operatively using vancomycin and ceftazidime intravenously until the fifth day. RESULTS: During the study period, 341 revision surgeries met the inclusion criteria. The PJI rate was lower in the long-prophylaxis group (2.2% versus 6.9%, p=0.049). Prolonged post-operative antibiotic treatment was the only variable associated independently with a lower rate of PJI (odds ratio [OR]: 0.27, 95% confidence interval [CI]: 0.07-0.99).

Measuring Outcomes: Pain and Quality of Life 48 Months After Acute Postoperative Total Knee Prosthetic Joint Infection.

BACKGROUND: Measuring HRQOL is simple, inexpensive, permits the health status to be measured over time, and is useful to compare or initiate treatments and evaluate results, facilitating homogenization in patient inclusion. OBJECTIVES: To evaluate disease-specific and generic HRQOL and influence of associated factors in patients undergoing open debridement for acute postsurgical knee prosthetic joint infection after TKR at 12 and 48 months after completing antibiotic treatment and considered cured of infection. METHODS: Health-related quality-of-life measures were administered at baseline (WOMAC) and 12 and 48 months (WOMAC and SF-36) in patients with prosthesis retention, no symptoms of infection, and CRP (≤ 1 mg/dL). RESULTS: Thirty patients were included, and 24 were evaluated at 48 months. WOMAC scores improved significantly (P < 0.01) at 12 and 48 months. The effect size was 0.72 for stiffness, 2.01 for pain, and 2.15 for function. At 48 months, improvements were greater (P < 0.02) except for stiffness. The most frequently isolated microorganisms were Staphylococcus aureus (14 patients) and coagulase-negative staphylococci (9 patients). SF-36 physical role, bodily pain, emotional role, and mental health dimension scores at 12 and 48 months were significantly worse in patients with isolates of Staphylococcus aureus (P < 0.05). CONCLUSIONS: Health-related quality-of-life measures detected significant differences in outcomes in patients infected by S. aureus compared with patients infected by other microorganisms. HRQOL measures may provide useful complementary information on outcomes after acute postoperative infection.

Tibial tubercle osteotomy in septic revision total knee arthroplasty.

PURPOSE: The incidence of revision knee arthroplasty for infection is increasing and the required surgical approach for the revision is a challenge for surgeons. Extensile approaches are frequently used when it is impossible to evert the extensor mechanism. The aim of this paper is to report our experience with tibial tubercle osteotomy (TTO) and the functional results in patients who underwent a two-stage revision due to prosthesis infection. METHODS: Twenty-six patients underwent a TTO as a surgical approach in the second stage of revision for infection. The patients were clinically assessed by means of functional scales (the Knee Society Score and WOMAC) and X-rays. RESULTS: The TTO healed without complications in 22 patients (84.6%) and the average length of follow-up was 3.4 years. Non-union was observed in two patients. One patient presented an extension lag of 5°. A total of 23 patients (88.4%) were free from infection. Twenty-five patients (96.1%) had better scores on the Knee Society Score and WOMAC after the procedure. CONCLUSIONS: In patients undergoing the second stage of revision total knee arthroplasty for infection, the TTO approach provides a large operating field. This enables surgeons to withdraw spacers and position new implants without damaging the extensor mechanism of the knee or altering the postoperative rehabilitation process. The complications that have been reported as a result of this procedure could be reduced by performing a meticulous surgical technique. LEVEL OF EVIDENCE: Retrospective case series, Level IV.

New modified Achilles tendon allograft for treatment of chronic patellar tendon ruptures following total knee arthroplasty.

INTRODUCTION: Patellar tendon rupture is an infrequent but debilitating lesion. Several surgical repairs have been suggested for patellar tendon rupture. Our aim is to propose a modified technique from the classic Achilles allograft procedure. MATERIALS AND METHODS: Five consecutive patients diagnosed with chronic patellar tendon rupture following total knee arthroplasty (TKA) were included in the presented study. All patients were operated with a modified Achilles allograft technique, dividing the Achilles tendon into two bundles and overcrossing these through the distal part of the quadricipital tendon. RESULTS: All patients regained their extension mechanism and have discontinued using crutches. No complications were observed. CONCLUSIONS: The modified Achilles allograft has shown to be a safe, time-reducing repair for chronic patellar tendon ruptures following TKA, and should be considered as an alternative surgical repair.

Acute infection in total knee arthroplasty: diagnosis and treatment.

Infection is one of the most serious complications after total knee arthroplasty (TKA). The current incidence of prosthetic knee infection is 1-3%, depending on the series(.) For treatment and control to be more cost effective, multidisciplinary groups made up of professionals from different specialities who can work together to eradicate these kinds of infections need to be assembled. About the microbiology, Staphylococcus aureus and coagulase-negative staphylococcus were among the most frequent microorganisms involved (74%). Anamnesis and clinical examination are of primary importance in order to determine whether the problem may point to a possible acute septic complication. The first diagnosis may then be supported by increased CRP and ESR levels. The surgical treatment for a chronic prosthetic knee infection has been perfectly defined and standardized, and consists in a two-stage implant revision process. In contrast, the treatment for acute prosthetic knee infection is currently under debate. Considering the different surgical techniques that already exist, surgical debridement with conservation of the prosthesis and polythene revision appears to be an attractive option for both surgeon and patient, as it is less aggressive than the two-stage revision process and has lower initial costs. The different results obtained from this technique, along with prognosis factors and conclusions to keep in mind when it is indicated for an acute prosthetic infection, whether post-operative or haematogenous, will be analysed by the authors.

Long-term results of acute prosthetic joint infection treated with debridement and prosthesis retention: a case-control study.

PURPOSES: To evaluate the long-term outcome (at least 4 years) of patients who underwent a surgical debridement due to an acute prosthetic joint infection (PJI) and to compare them with a control group that did not have an acute septic complication. METHODS: From January 1999 to December 2007, 61 patients with an acute PJI in remission after 2 years of follow-up (cases) were retrospectively reviewed and compared with a control group (2:1) without an acute PJI matched by age, year of arthroplasty, and type of prosthesis. Septic and aseptic complications of each group were gathered and compared using a chi-square test. A two-tailed p value <0.05 was considered statistically significant. RESULTS: Out of 183 patients, 4 cases and 2 controls were excluded due to death or lost to follow up; 113 (63.8%) were females and 109 (61.5%) had a knee replacement. The mean age and time of followup were 68.3 and 6.4 years, respectively. There were no statistically significant differences between cases and controls in the percentage of late septic or aseptic loosening. However, the late relapse rate in patients with acute PJI caused by S. aureus, was 12.5% (2 out of 16) and there was a trend towards significance when compared with the rest of the cohort (3.3%, p = 0.09). Aseptic late complications were more frequent in GN-cases (10.7%) than in the other groups (3.4% in GP-cases and 5% in controls) but this difference was not statistically significant (p = 0.19). CONCLUSIONS: In conclusion, although analyzing all late complications together, patients with an acute PJI have a similar long-term outcome in comparison with controls; patients with an acute PJI due to S. aureus had a higher late relapse rate; and GN-cases developed an aseptic loosening more ?frequently. In the future, it is necessary to evaluate larger series to confirm our results.

[Listeria monocytogenes infection in a total knee arthroplasty]. / Infección por Listeria monocytogenes de una prótesis total de rodilla.

BACKGROUND: Acute blood borne prosthetic infections occur in patients with an asymptomatic prosthesis that, after an infection involving bacteremia, produces bacterial implantation in the prosthesis and causes an acute infection. This type of infection is usually caused by gram positive cocci, Streptococci and Staphylococci. We present the clinical case of a patient without a history of immunodeficiency, who had an acute blood borne knee prosthetic infection caused by Listeria monocytogenes. METHODS: The diagnosis of infection was made based on the clinical data, blood tests and the positive culture of an arthrocentesis. A prosthetic exchange was performed in two stages. RESULTS: After the revision arthroplasty, the patient was still infection free at the 24-month followup. CONCLUSIONS: This type of infection is rare, with very few cases published in the literature, and without a defined treatment modality. The two-stage prosthetic exchange is a valid alternative in prosthetic infections caused by this microorganism and avoids suppressive antibiotic therapy.

Adding fuel to fire: the impact of followers' arousal on ratings of charisma.

The authors conducted an experimental laboratory study and a longitudinal field study to investigate the impact of followers' arousal on ratings of charisma. Both studies examined 2 contrasting hypotheses: (a) the misattribution hypothesis, which posits a direct effect of arousal, and (b) the response-facilitation hypothesis, which posits an interactive effect of arousal and leaders' charismatic appeal on ratings of charisma. The overall results from both studies provide support for the response-facilitation hypothesis. In addition, the authors tested the hypothesis that arousal effects are limited to ratings of charisma. As expected, ratings of transactional leadership, in contrast with ratings of charisma, were not influenced by followers' arousal states. The authors discuss the implications of these results and offer suggestions for future research.