RESUMEN
BACKGROUND: The recent consensus definition for the diagnosis of fracture-related infection (FRI) includes the identification of indistinguishable microorganisms in at least 2 surgical deep-tissue specimens as a confirmatory criterion. However, this cut-off, and the total number of specimens from a patient with suspected FRI that should be sent for microbiological testing, have not been validated. We endeavored to estimate the accuracy of different numbers of specimens and diagnostic cut-offs for microbiological testing of deep-tissue specimens in patients undergoing surgical treatment for possible FRI. METHODS: A total of 513 surgical procedures in 385 patients with suspected FRI were included. A minimum of 2 surgical deep-tissue specimens were submitted for microbiological testing; 5 or more specimens were analyzed in 345 procedures (67%). FRI was defined by the presence of any confirmatory criteria other than microbiology. Resampling was utilized to model the sensitivity and specificity of diagnostic cut-offs for the number of surgical specimens yielding indistinguishable microorganisms and for the total number of specimens. The likelihood of detecting all clinically relevant microorganisms was also assessed. RESULTS: A diagnostic cut-off of at least 2 of 5 specimens with indistinguishable microorganisms identified by culture was 68% sensitive (95% confidence interval [CI], 62% to 74%) and 87% specific (95% CI, 81% to 94%) for the diagnosis of FRI. Two out of 3 specimens were 60% sensitive (95% CI, 55% to 66%) and 92% specific (95% CI, 88% to 96%). Submitting only 3 deep-tissue specimens risked missing clinically relevant microorganisms in at least 1 in 10 cases. CONCLUSIONS: The present study was the first to validate microbiological criteria for the diagnosis of FRI, supporting the current confirmatory diagnostic criteria for FRI. Analysis of at least 5 deep-tissue specimens in patients with possible FRI is recommended. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Asunto(s)
Fijación de Fractura/efectos adversos , Fracturas Óseas/cirugía , Infección de la Herida Quirúrgica/microbiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Consenso , Medicina Basada en la Evidencia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Infección de la Herida Quirúrgica/diagnóstico , Adulto JovenRESUMEN
Aims: This study aimed to investigate the role of quantitative histological analysis in the diagnosis of fracture-related infection (FRI). Patients and Methods: The clinical features, microbiology culture results, and histological analysis in 156 surgically treated nonunions were used to stratify the likelihood of associated infection. There were 64 confirmed infected nonunions (one or more confirmatory criteria: pus, sinus, and bacterial growth in two or more samples), 66 aseptic nonunions (no confirmatory criteria), and 26 possibly infected nonunions (pathogen identified from a single specimen and no confirmatory criteria). The histological inflammatory response was assessed by average neutrophil polymorph (NPs) counts per high-power field (HPF) and compared with the established diagnosis. Results: Assuming a cut-off of over five neutrophils per high-power field to diagnose septic nonunion, there was 80% sensitivity and 100% specificity (accuracy 90%). Using a cut-off of no neutrophils seen in any high-power field to diagnose aseptic nonunion, there was a sensitivity of 85% and a specificity of 98% (accuracy 92%). Conclusion: Histology can be used in a bimodal fashion as a diagnostic test for FRI. The presence of more than five NPs/HPF had a positive predictive value for infected nonunion of 100%, while the complete absence of any NPs is almost always indicative of an aseptic nonunion (positive predictive value of 98%). Cite this article: Bone Joint J 2018;100-B:966-72.
Asunto(s)
Fracturas Óseas/complicaciones , Fracturas no Consolidadas/complicaciones , Infección de Heridas/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Consenso , Femenino , Fracturas Óseas/microbiología , Fracturas Óseas/patología , Fracturas no Consolidadas/microbiología , Fracturas no Consolidadas/cirugía , Humanos , Recuento de Leucocitos/métodos , Masculino , Técnicas Microbiológicas/métodos , Persona de Mediana Edad , Neutrófilos/patología , Sensibilidad y Especificidad , Infección de Heridas/etiología , Infección de Heridas/microbiología , Adulto JovenRESUMEN
Minimum intervention dentistry (MID) is the evidence-based delivery of oral healthcare which aims to maximise preservation of tooth structure and longevity of tooth life, improving long-term oral health and wellbeing. In general dental practice implementing such an ethos and approach can require change in the practice structure and processes. Such change in processes requires careful management and planning. Planning should include financial as well as business planning. A detailed understanding of the planning that may be required is described here as a guide to help oral healthcare practice staff and other stakeholders to facilitate the delivery of MID.
Asunto(s)
Atención Odontológica/organización & administración , Atención Odontológica/economía , Atención Odontológica/métodos , Humanos , Guías de Práctica Clínica como AsuntoRESUMEN
AIMS: Advocates of debridement, antibiotics and implant retention (DAIR) in hip periprosthetic joint infection (PJI) argue that a procedure not disturbing a sound prosthesis-bone interface is likely to lead to better survival and functional outcome compared with revision. This case-control study aims were to compare outcome of DAIRs for infected primary total hip arthroplasty (THA) with outcomes following primary THA and two-stage revision of infected primary THAs. PATIENTS AND METHODS: We retrospectively reviewed all DAIRs, performed for confirmed infected primary hip arthropasty (n = 82) at out institution, between 1997 and 2013. Data recorded included full patient information and type of surgery. Outcome measures included complications, mortality, implant survivorship and functional outcome. Outcome was compared with two control groups matched for gender and age; a cohort of primary THAs (n = 120) and a cohort of two-stage revisions for infection (n = 66). RESULTS: Mean age at DAIR was 69 years (33 to 87) and mean follow-up was eight years (2 to 17; standard deviation (sd) 5). A total of 52 (63%) of DAIRs were for early PJI (less than six weeks). Greater success in the eradication of infection with DAIR was identified with early PJI, comprising an interval less than a week between onset of symptoms and exchange of modular components with the DAIR procedure. Eradication of infection, complications and re-operation rates were similar in the DAIR and two-stage revision groups. For hips with successful eradication of infection with DAIR, the five-year survival (98%; 95% confidence interval (CI) 94 to 100) was similar to the primary THA group (98%; 95% CI 95 to 100) (n = 43; p = 0.3). The DAIR group had inferior mean Oxford Hip Scores (OHS) (38; 12 to 48) compared with the primary THA group (42; 15 to 48) (p = 0.02) but a significantly better mean OHS compared with the two-stage revision group (31; 0 to 48) (p = 0.008). Patients who required only one DAIR for eradication of infection had a similar mean OHS (41; 20 to 48) to the primary THA group (p = 0.2). CONCLUSION: The DAIR procedure is associated with a similar complication rate and ability to eradicate infection as two-stage revision. This study emphasises the need for exchange of modular components for improved chances of eradication of infection. This is the first study showing that DAIR is better than a two-stage revision regarding functional outcome. Cite this article: Bone Joint J 2017;99-B:614-22.
Asunto(s)
Antibacterianos/uso terapéutico , Artroplastia de Reemplazo de Cadera/métodos , Desbridamiento/métodos , Prótesis de Cadera/efectos adversos , Infecciones Relacionadas con Prótesis/terapia , Adulto , Anciano , Anciano de 80 o más Años , Artroplastia de Reemplazo de Cadera/instrumentación , Estudios de Casos y Controles , Terapia Combinada , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Reoperación/métodos , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
AIMS: Chronic osteomyelitis may recur if dead space management, after excision of infected bone, is inadequate. This study describes the results of a strategy for the management of deep bone infection and evaluates a new antibiotic-loaded biocomposite in the eradication of infection from bone defects. PATIENTS AND METHODS: We report a prospective study of 100 patients with chronic osteomyelitis, in 105 bones. Osteomyelitis followed injury or surgery in 81 patients. Nine had concomitant septic arthritis. 80 patients had comorbidities (Cierny-Mader (C-M) Class B hosts). Ten had infected nonunions. All patients were treated by a multidisciplinary team with a single-stage protocol including debridement, multiple sampling, culture-specific systemic antibiotics, stabilisation, dead space filling with the biocomposite and primary skin closure. RESULTS: Patients were followed up for a mean of 19.5 months (12 to 34). Infection was eradicated in 96 patients with a single procedure and all four recurrences were successfully managed with repeat surgery. Adverse events were uncommon, with three fractures, six wound leaks and three unrelated deaths. Outcome was not dependant on C-M host class, microbial culture, wound leakage or presence of nonunion. CONCLUSION: This single-stage protocol, facilitated by the absorbable local antibiotic, is effective in the treatment of chronic osteomyelitis. It offers a more patient-friendly treatment compared with other published treatment options. Cite this article: Bone Joint J 2016;98-B:1289-96.
Asunto(s)
Sulfato de Calcio/uso terapéutico , Implantes de Medicamentos , Durapatita/uso terapéutico , Gentamicinas/uso terapéutico , Osteomielitis/tratamiento farmacológico , Cicatrización de Heridas/fisiología , Materiales Biocompatibles , Regeneración Ósea/efectos de los fármacos , Sustitutos de Huesos , Enfermedad Crónica , Estudios de Cohortes , Desbridamiento/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Osteomielitis/diagnóstico , Estudios Prospectivos , Radiografía/métodos , Medición de Riesgo , Resultado del Tratamiento , Cicatrización de Heridas/efectos de los fármacosRESUMEN
BACKGROUND: Patient handovers (handoffs) following surgery have often been characterized by poor teamwork, unclear procedures, unstructured processes, and distractions. A study was conducted to apply a human-centered approach to the redesign of operating room (OR)-to-ICU patient handovers in a broad surgical ICU (SICU) population. This approach entailed (1) the study of existing practices, (2) the redesign of the handover on the basis of the input of hand over participants and evidence in the medical literature, and (3) the study of the effects of this change on processes and communication. METHODS: The Durham [North Carolina] Veterans Affairs Medical Center SICU is an 11-bed mixed surgical specialty unit. To understand the existing process for receiving postoperative patients in the SICU, ethnographic methods-a series of observations, surveys, interviews, and focus groups-were used. The handover process was redesigned to better address providers' work flow, information needs, and expectations, as well as concerns identified in the literature. RESULTS: Technical and communication flaws were uncovered, and the handover was redesigned to address them. For the 49 preintervention and 49 postintervention handovers, the information transfer score and number of interruptions were not significantly different. However, staff workload and team behaviors scores improved significantly, while the hand over duration was not prolonged by the new process. Handover participants were also significantly more satisfied with the new handover method. CONCLUSIONS: An HCD approach led to improvements in the patient handover process from the OR to the ICU in a mixed adult surgical population. Although the specific handover process would unlikely be optimal in another clinical setting if replicated exactly, the HCD foundation behind the redesign process is widely applicable.
Asunto(s)
Hospitales de Veteranos , Unidades de Cuidados Intensivos , Quirófanos , Pase de Guardia/normas , Antropología Cultural , Humanos , Modelos Organizacionales , North CarolinaAsunto(s)
Administración Financiera/organización & administración , Medicina Militar , Especialidades Quirúrgicas , United States Department of Defense , United States Department of Veterans Affairs , Procedimientos Quirúrgicos Vasculares , Conducta Cooperativa , Hospitales de Veteranos , Humanos , Estados UnidosRESUMEN
We report our experience using a biodegradable calcium sulphate antibiotic carrier containing tobramycin in the surgical management of patients with chronic osteomyelitis. The patients were reviewed to determine the rate of recurrent infection, the filling of bony defects, and any problems with wound healing. A total of 193 patients (195 cases) with a mean age of 46.1 years (16.1 to 82.0) underwent surgery. According to the Cierny-Mader classification of osteomyelitis there were 12 type I, 1 type II, 144 type III and 38 type IV cases. The mean follow-up was 3.7 years (1.3 to 7.1) with recurrent infection occurring in 18 cases (9.2%) at a mean of 10.3 months post-operatively (1 to 25.0). After further treatment the infection resolved in 191 cases (97.9%). Prolonged wound ooze (longer than two weeks post-operatively) occurred in 30 cases (15.4%) in which there were no recurrent infection. Radiographic assessment at final follow-up showed no filling of the defect with bone in 67 (36.6%), partial filling in 108 (59.0%) and complete filling in eight (4.4%). A fracture occurred in nine (4.6%) of the treated osteomyelitic segments at a mean of 1.9 years (0.4 to 4.9) after operation. We conclude that Osteoset T is helpful in the management of patients with chronic osteomyelitis, but the filling of the defect in bone is variable. Prolonged wound ooze is usually self-limiting and not associated with recurrent infection.
Asunto(s)
Profilaxis Antibiótica/métodos , Sulfato de Calcio/farmacología , Portadores de Fármacos , Osteomielitis/tratamiento farmacológico , Tobramicina/administración & dosificación , Implantes Absorbibles , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Estudios de Cohortes , Desbridamiento/métodos , Femenino , Estudios de Seguimiento , Humanos , Cuidados Intraoperatorios/métodos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Osteomielitis/diagnóstico , Osteomielitis/cirugía , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Estadísticas no Paramétricas , Resultado del Tratamiento , Cicatrización de Heridas/efectos de los fármacos , Cicatrización de Heridas/fisiologíaRESUMEN
An aberrant right subclavian artery is a known arch variant with surgical intervention reserved for those patients presenting symptomatically, those with aneurysmal degeneration particularly of a Kommerell diverticulum, or those with adjacent aortic pathology. Varied surgical approaches have been described, often involving a supraclavicular approach in conjunction with a thoracotomy, or more recently, hybrid endovascular techniques. In the absence of aneurysmal degeneration or associated aortic pathology, surgical repair can be performed safely through a single supraclavicular incision. We present a case of a patient repaired in this fashion.
Asunto(s)
Aneurisma/cirugía , Anomalías Cardiovasculares/cirugía , Trastornos de Deglución/cirugía , Arteria Subclavia/anomalías , Procedimientos Quirúrgicos Vasculares/métodos , Anciano , Aneurisma/complicaciones , Aneurisma/diagnóstico , Sulfato de Bario , Anomalías Cardiovasculares/complicaciones , Anomalías Cardiovasculares/diagnóstico , Arterias Carótidas/cirugía , Medios de Contraste , Trastornos de Deglución/complicaciones , Trastornos de Deglución/diagnóstico , Humanos , Masculino , Arteria Subclavia/cirugía , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
OBJECTIVES: New-onset aortic insufficiency (AI) can be encountered after instituting mechanical circulatory support and seems more common and severe with continuous flow (CF) left ventricular assist devices (LVADs) compared with pulsatile devices. Treatment algorithms for de novo, post-LVAD AI have not been well defined. In the present report, we have described 6 patients who underwent aortic valve surgery for new-onset post-LVAD AI. METHODS: From 2005 to 2011, 271 patients underwent LVAD implantation. Of these LVADs, 225 were CF devices (203 HeartMate II devices, Thoratec Corp, Pleasanton, Calif; and 22 HVAD devices, HeartWare Intl, Inc, Framingham, Mass). The patients were examined for new-onset severe AI requiring surgical intervention. RESULTS: During follow-up, 6 CF LVAD patients developed new, severe AI that was accompanied by heart failure. After medical therapy had failed, 4 patients underwent redo sternotomy for aortic valve procedures (1 bioprosthetic valve replacement, 1 Dacron patch closure, and 2 aortic valve repairs), and 2 patients underwent transcatheter aortic valve procedure, with 1 requiring revision by open surgery for aortic valve replacement. Of the 6 patients, 5 experienced significant improvement in functional capacity and symptoms. One patient died postoperatively secondary to multiorgan failure and sepsis. CONCLUSIONS: Surgical treatment of post-LVAD AI with aortic valve oversewing or leaflet repair or by bioprosthetic aortic valve replacement is effective at restoring functional capacity for CF LVAD patients who develop symptomatic, severe AI and can be performed safely with good results. Various transcatheter approaches to these difficult problems are also available and offer less invasive alternatives to conventional surgery.
Asunto(s)
Insuficiencia de la Válvula Aórtica/terapia , Cateterismo Cardíaco , Insuficiencia Cardíaca/terapia , Implantación de Prótesis de Válvulas Cardíacas/métodos , Corazón Auxiliar/efectos adversos , Técnicas de Sutura , Función Ventricular Izquierda , Adulto , Anciano , Insuficiencia de la Válvula Aórtica/diagnóstico , Insuficiencia de la Válvula Aórtica/etiología , Insuficiencia de la Válvula Aórtica/mortalidad , Insuficiencia de la Válvula Aórtica/cirugía , Cateterismo Cardíaco/efectos adversos , Cateterismo Cardíaco/mortalidad , Fármacos Cardiovasculares/uso terapéutico , Femenino , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/mortalidad , Humanos , Masculino , Diseño de Prótesis , Recuperación de la Función , Reoperación , Índice de Severidad de la Enfermedad , Esternotomía , Técnicas de Sutura/efectos adversos , Técnicas de Sutura/mortalidad , Resultado del TratamientoRESUMEN
BACKGROUND: Post-sternotomy mediastinitis reduces survival after cardiac surgery, potentially further affected by details of mediastinal vascularized flap reconstruction. The aim of this study was to evaluate survival after different methods for sternal reconstruction in mediastinitis. METHODS: Two hundred twenty-two adult cardiac surgery patients with post-sternotomy mediastinitis were reviewed. After controlling infection, often augmented by negative pressure therapy, muscle flap, omental flap, or secondary closure was performed. Outcomes were reviewed and survival analysis was performed. RESULTS: Baseline characteristics were similar. In-hospital mortality (15.7%) did not differ between groups. Secondary closure was correlated with negative pressure therapy and reduced length hospital of stay. Recurrent wound complications were more common with muscle flap repair. Survival was unaffected by sternal repair technique. By multivariate analysis, heart failure, sepsis, age, and vascular disease independently predicted mortality, while negative pressure therapy was associated with survival. CONCLUSIONS: Choice of sternal repair was unrelated to survival, but mediastinal treatment with negative pressure therapy promotes favorable early and late outcomes.
Asunto(s)
Mediastinitis/etiología , Mediastinitis/terapia , Esternotomía/efectos adversos , Adulto , Factores de Edad , Antibacterianos/uso terapéutico , Procedimientos Quirúrgicos Cardiovasculares/efectos adversos , Desbridamiento , Insuficiencia Cardíaca/epidemiología , Mortalidad Hospitalaria , Humanos , Tiempo de Internación , Mediastinitis/mortalidad , Mediastino/microbiología , Mediastino/cirugía , Análisis Multivariante , Terapia de Presión Negativa para Heridas , Estudios Retrospectivos , Sepsis/epidemiología , Esternón/cirugía , Colgajos Quirúrgicos , Enfermedades Vasculares/epidemiologíaAsunto(s)
Fracturas Abiertas/cirugía , Fracturas de la Tibia/cirugía , Femenino , Humanos , MasculinoRESUMEN
The diagnosis of prosthetic joint infection (PJI) in the routine microbiology laboratory is labour-intensive, but semi-automated methods may be appropriate. We prospectively compared four microbiological culture methods on samples taken at prosthetic joint revision surgery. Automated BACTEC blood culture bottles and cooked meat enrichment broth were the most sensitive methods (87% and 83%, respectively, as compared with fastidious anaerobic broth (57%) and direct plates (39%)); all were highly specific (97-100%). To our knowledge, this is the first prospective study aimed at comparing culture methods in routine use in UK clinical laboratories for the diagnosis of PJI.
Asunto(s)
Bacterias/crecimiento & desarrollo , Medios de Cultivo/química , Infecciones Relacionadas con Prótesis/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Bacterias/efectos de los fármacos , Bacterias/aislamiento & purificación , Técnicas Bacteriológicas , Medios de Cultivo/análisis , Femenino , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Infecciones Relacionadas con Prótesis/microbiología , Sensibilidad y Especificidad , Adulto JovenRESUMEN
BACKGROUND: Lung transplantation, definitive therapy for end-stage lung disease, is limited long-term by allograft dysfunction including bronchiolitis obliterans syndrome (BOS). Few modifiable risk factors for pulmonary transplant-related mortality are recognized. However, oropharyngeal dysphagia frequently occurs after thoracic surgical procedures, including lung transplantation, and increases morbidity. We evaluated the impact of oropharyngeal dysphagia on survival and BOS after lung transplantation. METHODS: A total of 263 consecutive lung transplant patients were reviewed. Each underwent clinical swallowing evaluation early after surgery; 149 patients underwent additional fiberoptic or videofluoroscopic swallowing evaluation (SE). Results of SE were correlated with BOS, defined by accepted criteria, and mortality using Kaplan-Meier survival curves. Cox proportional hazard modeling assessed preoperative and postoperative variables associated with development of BOS and mortality. RESULTS: Mean follow-up was 920 ± 560 days. The SE identified tracheal aspiration and (or) laryngeal penetration in 70.5%. Preoperative tobacco abuse, gastroesophageal reflux, and cardiopulmonary bypass independently predicted oropharyngeal dysphagia. Peak FEV(1) (forced expiratory volume in the first second of expiration) alone independently predicted BOS (hazard ratio 0.98; confidence interval 0.975 to 0.992, p < 0.0001); oropharyngeal dysphagia was not associated with BOS. Independent predictors of mortality by multivariable analysis were ventilator dependence (p = 0.038) and peak FEV(1) (p < 0.0001); normal SE was associated with improved survival (hazard ratio 0.13; confidence interval 0.03 to 0.54, p = 0.03). CONCLUSIONS: Oropharyngeal dysphagia, often overlooked on clinical examination, is common after lung transplantation. Normal deglutition may improve survival after lung transplantation, but oropharyngeal dysphagia does not independently affect BOS. Institution of protocols aimed at identifying previously unrecognized dysphagia may improve results of pulmonary transplantation.
Asunto(s)
Bronquiolitis Obliterante/etiología , Trastornos de Deglución/complicaciones , Trasplante de Pulmón/mortalidad , Adulto , Deglución , Trastornos de Deglución/fisiopatología , Femenino , Volumen Espiratorio Forzado , Humanos , Trasplante de Pulmón/efectos adversos , Masculino , Persona de Mediana Edad , Modelos de Riesgos ProporcionalesRESUMEN
OBJECTIVE: This study assesses the effect of using a comprehensive swallowing evaluation before starting oral feedings on aspiration detection and pneumonia occurrence after esophagectomy. METHODS: The records of all patients undergoing esophagectomy between January 1996 and June 2009 were reviewed. Multivariable logistic regression analysis assessed the effect of preoperative and operative variables on the incidence of aspiration and pneumonia. Separate analyses were performed on patients before (early era, 1996-2002) and after (later era, 2003-2009) a rigorous swallowing evaluation was used routinely before starting oral feedings. RESULTS: During the study period, 799 patients (379 from the early era and 420 from the later era) underwent esophagectomy; 30-day mortality was 3.5% (28 patients). Cervical anastomoses were performed in 76% of patients in the later era compared with 40% of patients in the early era. Overall, 96 (12%) patients had evidence of aspiration postoperatively, and the pneumonia incidence was 14% (113 patients). Age (odds ratio, 1.05 per year; P < .0001) and later era (odds ratio, 1.90; P = .0001) predicted aspiration in all patients in a multivariable model. In the early era, cervical anastomosis and aspiration independently predicted pneumonia. With a comprehensive swallowing evaluation in the later era, the detected incidence of aspiration increased (16% vs 7%, P < .0001), whereas the incidence of pneumonia decreased (11% vs 18%, P = .004) compared with the early era, such that neither anastomotic location nor aspiration predicted pneumonia in the later era. CONCLUSIONS: Esophagectomy is often associated with occult aspiration. A comprehensive swallowing evaluation for aspiration before initiating oral feedings significantly decreases the occurrence of pneumonia.