'How Do I Test the Waters? How Do I Go Forward?': Co-designing a Supportive Pathway after Critical Illness.

Rationale: Long-term recovery following critical illness can be affected by Post-intensive Care Syndrome (PICS), a significant burden which can impact return to activities and work. There is need for streamlined support for Intensive Care Unit (ICU) patients in their recovery whilst enduring PICS symptoms. Objectives: To explore critical illness recovery from the experiences, perspectives, and beliefs of former ICU patients, their caregivers, and multidisciplinary clinicians to design a future rehabilitation pathway to support ICU patients. Methods: An experience-based co-design (EBCD) study underpinned by the Behaviour Change Wheel (BCW) framework involving ICU patients (

Beta-hydroxy-beta-methylbutyrate supplementation and functional outcomes in multitrauma patients: A pilot randomized controlled trial.

BACKGROUND: Beta-hydroxy-beta-methylbutyrate (HMB) is a nutrition supplement that may attenuate muscle wasting from critical illness. This trial aimed to determine feasibility of administering a blinded nutrition supplement in the intensive care unit (ICU) and continuing it after ICU discharge. METHODS: Single-center, parallel-group, blinded, placebo-controlled, randomized feasibility trial. After traumatic injury necessitating admission to ICU, participants were randomized to receive an enteral study supplement of 3 g of HMB (intervention) or placebo daily for 28 days or until hospital discharge. Primary outcome was feasibility of administering the study supplement, quantified as protocol adherence. Secondary outcomes included change in quadriceps muscle thickness, measured weekly until day 28 or hospital discharge by using ultrasound and analyzed by using a linear mixed model. RESULTS: Fifty randomized participants (intervention, n = 26; placebo, n = 24) showed comparable baseline characteristics. Participants received 862 (84.3%) of the 1022 prescribed supplements during hospitalization with 543 (62.8%) delivered via an enteral feeding tube. The median (IQR) number of study supplements successfully administered per participant was 19.5 (13.0-24.0) in the intervention group and 16.5 (8.5-23.5) in the placebo group. Marked loss of quadriceps muscle thickness occurred in both groups, with the point estimate favoring attenuated muscle loss with the intervention, albeit with wide CIs (mean intervention difference after 28 days, 0.26 cm [95% CI, -0.13 to 0.64]). CONCLUSION: A blinded, placebo-controlled, randomized clinical trial of daily enteral HMB supplementation for up to 28 days in hospital is feasible. Any effect of HMB supplementation to attenuate muscle wasting after traumatic injury remains uncertain.

Methodological and Clinimetric Evaluation of Inspiratory Respiratory Muscle Ultrasound in the Critical Care Setting: A Systematic Review and Meta-Analysis.

OBJECTIVE: Significant variations exist in the use of respiratory muscle ultrasound in intensive care with no society-level consensus on the optimal methodology. This systematic review aims to evaluate, synthesize, and compare the clinimetric properties of different image acquisition and analysis methodologies. DATA SOURCES: Systematic search of five databases up to November 24, 2021. STUDY SELECTION: Studies were included if they enrolled at least 50 adult ICU patients, reported respiratory muscle (diaphragm or intercostal) ultrasound measuring either echotexture, muscle thickness, thickening fraction, or excursion, and evaluated at least one clinimetric property. Two independent reviewers assessed titles, abstracts, and full text against eligibility. DATA EXTRACTION: Study demographics, ultrasound methodologies, and clinimetric data. DATA SYNTHESIS: Sixty studies, including 5,025 patients, were included with 39 studies contributing to meta-analyses. Most commonly measured was diaphragm thickness (DT) or diaphragm thickening fraction (DTF) using a linear transducer in B-mode, or diaphragm excursion (DE) using a curvilinear transducer in M-mode. There are significant variations in imaging methodology and acquisition across all studies. Inter- and intrarater measurement reliabilities were generally excellent, with the highest reliability reported for DT (ICC, 0.98; 95% CI, 0.94-0.99). Pooled data demonstrated acceptable to excellent accuracy for DT, DTF, and DE to predicting weaning outcome after 48 to 72 hours postextubation (DTF AUC, 0.79; 95% CI, 0.73-0.85). DT imaging was responsive to change over time. Only three eligible studies were available for intercostal muscles. Intercostal thickening fraction was shown to have excellent accuracy of predicting weaning outcome after 48-hour postextubation (AUC, 0.84; 95% CI, 0.78-0.91). CONCLUSIONS: Diaphragm muscle ultrasound is reliable, valid, and responsive in ICU patients, but significant variation exists in the imaging acquisition and analysis methodologies. Future work should focus on developing standardized protocols for ultrasound imaging and consider further research into the role of intercostal muscle imaging.

Comparison of 6-Month Outcomes of Survivors of COVID-19 versus Non-COVID-19 Critical Illness.

Rationale: The outcomes of survivors of critical illness due to coronavirus disease (COVID-19) compared with non-COVID-19 are yet to be established. Objectives: We aimed to investigate new disability at 6 months in mechanically ventilated patients admitted to Australian ICUs with COVID-19 compared with non-COVID-19. Methods: We included critically ill patients with COVID-19 and non-COVID-19 from two prospective observational studies. Patients were eligible if they were adult (age ⩾ 8 yr) and received ⩾24 hours of mechanical ventilation. In addition, patients with COVID-19 were eligible with a positive laboratory PCR test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Measurements and Main Results: Demographic, intervention, and hospital outcome data were obtained from electronic medical records. Survivors were contacted by telephone for functional outcomes with trained outcome assessors using the World Health Organization Disability Assessment Schedule 2.0. Between March 6, 2020, and April 21, 2021, 120 critically ill patients with COVID-19, and between August 2017 and January 2019, 199 critically ill patients without COVID-19, fulfilled the inclusion criteria. Patients with COVID-19 were older (median [interquartile range], 62 [55-71] vs. 58 [44-69] yr; P = 0.019) with a lower Acute Physiology and Chronic Health Evaluation II score (17 [13-20] vs. 19 [15-23]; P = 0.011). Although duration of ventilation was longer in patients with COVID-19 than in those without COVID-19 (12 [5-19] vs. 4.8 [2.3-8.8] d; P < 0.001), 180-day mortality was similar between the groups (39/120 [32.5%] vs. 70/199 [35.2%]; P = 0.715). The incidence of death or new disability at 180 days was similar (58/93 [62.4%] vs. 99/150 [66/0%]; P = 0.583). Conclusions: At 6 months, there was no difference in new disability for patients requiring mechanical ventilation for acute respiratory failure due to COVID-19 compared with non-COVID-19. Clinical trial registered with www.clinicaltrials.gov (NCT04401254).

ß-Hydroxy-ß-methylbutyrate (HMB) supplementation and functional outcomes in multi-trauma patients: a study protocol for a pilot randomised clinical trial (BOOST trial).

BACKGROUND: There are no therapies proven to diminish the muscle wasting that occurs in patients after major trauma who are admitted to the intensive care unit (ICU). ß-Hydroxy-ß-methylbutyrate (HMB) is a nutrition intervention that may attenuate muscle loss and, thereby, improve recovery. The primary aim of this study is to determine the feasibility of a blinded randomised clinical trial of HMB supplementation to patients after major trauma who are admitted to the ICU. Secondary aims are to establish estimates for the impact of HMB when compared to placebo on muscle mass and nutrition-related patient outcomes. METHODS: This prospective, single-centre, blinded, randomised, placebo-controlled, parallel-group, feasibility trial with allocation concealment will recruit 50 participants over 18 months. After informed consent, participants will be randomised [1:1] to receive either the intervention (three grams of HMB dissolved in either 150 ml of orange juice for those allowed oral intake or 150 ml of water for those being enterally fed) or placebo (150 ml of orange juice for those allowed oral intake or 150 ml of water for those being enterally fed). The intervention will be commenced in ICU, continued after ICU discharge and ceased at hospital discharge or day 28 post randomisation, whichever occurs first. The primary outcome is the feasibility of administering the intervention. Secondary outcomes include change in muscle thickness using ultrasound and other nutritional and patient-centred outcomes. DISCUSSION: This study aims to determine the feasibility of administering HMB to critically ill multi-trauma patients throughout ICU admission until hospital discharge. Results will inform design of a larger randomised clinical trial. TRIAL REGISTRATION: The protocol is registered with Australian New Zealand Clinical Trials Registry (ANZCTR) ANZCTR: 12620001305910 . UTN: U1111-1259-5534.

Physiotherapy management for COVID-19 in the acute hospital setting and beyond: an update to clinical practice recommendations.

This document provides an update to the recommendations for physiotherapy management for adults with coronavirus disease 2019 (COVID-19) in the acute hospital setting. It includes: physiotherapy workforce planning and preparation; a screening tool for determining requirement for physiotherapy; and recommendations for the use of physiotherapy treatments and personal protective equipment. New advice and recommendations are provided on: workload management; staff health, including vaccination; providing clinical education; personal protective equipment; interventions, including awake proning, mobilisation and rehabilitation in patients with hypoxaemia. Additionally, recommendations for recovery after COVID-19 have been added, including roles that physiotherapy can offer in the management of post-COVID syndrome. The updated guidelines are intended for use by physiotherapists and other relevant stakeholders caring for adult patients with confirmed or suspected COVID-19 in the acute care setting and beyond.

The impact of COVID-19 critical illness on new disability, functional outcomes and return to work at 6 months: a prospective cohort study.

BACKGROUND: There are few reports of new functional impairment following critical illness from COVID-19. We aimed to describe the incidence of death or new disability, functional impairment and changes in health-related quality of life of patients after COVID-19 critical illness at 6 months. METHODS: In a nationally representative, multicenter, prospective cohort study of COVID-19 critical illness, we determined the prevalence of death or new disability at 6 months, the primary outcome. We measured mortality, new disability and return to work with changes in the World Health Organization Disability Assessment Schedule 2.0 12L (WHODAS) and health status with the EQ5D-5LTM. RESULTS: Of 274 eligible patients, 212 were enrolled from 30 hospitals. The median age was 61 (51-70) years, and 124 (58.5%) patients were male. At 6 months, 43/160 (26.9%) patients died and 42/108 (38.9%) responding survivors reported new disability. Compared to pre-illness, the WHODAS percentage score worsened (mean difference (MD), 10.40% [95% CI 7.06-13.77]; p < 0.001). Thirteen (11.4%) survivors had not returned to work due to poor health. There was a decrease in the EQ-5D-5LTM utility score (MD, - 0.19 [- 0.28 to - 0.10]; p < 0.001). At 6 months, 82 of 115 (71.3%) patients reported persistent symptoms. The independent predictors of death or new disability were higher severity of illness and increased frailty. CONCLUSIONS: At six months after COVID-19 critical illness, death and new disability was substantial. Over a third of survivors had new disability, which was widespread across all areas of functioning. Clinical trial registration NCT04401254 May 26, 2020.

Quantifying Response to Nutrition Therapy During Critical Illness: Implications for Clinical Practice and Research? A Narrative Review.

Critical illness causes substantial muscle loss that adversely impacts recovery and health-related quality of life. Treatments are therefore needed that reduce mortality and/or improve the quality of survivorship. The purpose of this Review is to describe both patient-centered and surrogate outcomes that quantify responses to nutrition therapy in critically ill patients. The use of these outcomes in randomized clinical trials will be described and the strengths and limitations of these outcomes detailed. Outcomes used to quantify the response of nutrition therapy must have a plausible mechanistic relationship to nutrition therapy and either be an accepted measure for the quality of survivorship or highly likely to lead to improvements in survivorship. This Review identified that previous trials have utilized diverse outcomes. The variety of outcomes observed is probably due to a lack of consensus as to the most appropriate surrogate outcomes to quantify response to nutrition therapy during research or clinical practice. Recent studies have used, with some success, measures of muscle mass to evaluate and monitor nutrition interventions administered to critically ill patients.

Early Detection of Muscle Weakness and Functional Limitations in the Critically Ill: A Retrospective Evaluation of Bioimpedance Spectroscopy.

BACKGROUND: The potential for bioimpedance spectroscopy (BIS) to identify muscle weakness and functional limitations in critical illness is unknown; this study aimed to determine association of BIS with strength/function and differences between 3 intensive care units (ICUs). METHODS: A retrospective post hoc analysis of BIS, strength, and functional data from adults who required ≥48 hours of mechanical ventilation was conducted. Measures of body composition included the proportion (%) of total body water (TBW), fat mass (FM), and fat-free mass (FFM). The Medical Research Council sum score (MRC-ss) and Physical Function in ICU Test-Scored (PFIT-s) were used for strength and functional assessments. Nonparametric cross-sectional analyses were done at enrollment (≤48 hours of admission: site-A, site-C) and awakening from sedation (site-A, site-B). Raw impedance variables including 50-kHz phase angle (PA) and impedance ratio (IR) were available from site-A and site-B. RESULTS: Participants were 135 adults (site-A n=59, site-B n=33, site-C n=44), with a median (interquartile range) age of 59 (50-69) years. At enrollment, TBW%, FM%, and FFM% were similar between site-A and site-C (P>.05); pooled data were not associated with MRC-ss at awakening or MRC-ss/PFIT-s at ICU discharge. At awakening, there was less TBW%, less FFM%, and greater FM% at site-B vs site-A (P≤.001) but no associations with MRC-ss/PFIT-s when using pooled data. Trends with pooled data of a lower PA and higher IR being associated with awakening MRC-ss were confirmed within site-B (PA ρ=0.70, P≤.001; IR ρ=-0.79, P≤.001). CONCLUSION: Site-by-site data suggest that raw impedance variables might be useful for screening weakness and poor function.

Targeted Full Energy and Protein Delivery in Critically Ill Patients: A Pilot Randomized Controlled Trial (FEED Trial).

BACKGROUND: International guidelines recommend greater protein delivery to critically ill patients than they currently receive. This pilot randomized clinical trial aimed to determine whether a volume-target enteral protocol with supplemental protein delivered greater amounts of protein and energy to critically ill patients compared with standard care. METHODS: Sixty participants received either the intervention (volume-based protocol, with protein supplementation) or standard nutrition care (hourly-rate-based protocol, without protein supplementation) in the intensive care unit (ICU). Coprimary outcomes were average daily protein and energy delivery. Secondary outcomes included change in quadriceps muscle layer thickness (QMLT, ultrasound) and malnutrition (subjective global assessment) at ICU discharge. RESULTS: Mean (SD) protein and energy delivery per day from nutrition therapy for the intervention were 1.2 (0.30) g/kg and 21 (5.2) kcal/kg compared with 0.75 (0.11) g/kg and 18 (2.7) kcal/kg for standard care. The mean difference between groups in protein and energy delivery per day was 0.45 g/kg (95% CI, 0.33-0.56; P < .001) and 2.8 kcal/kg (95% CI, 0.67-4.9, P = .01). Muscle loss (QMLT) at discharge was attenuated by 0.22 cm (95% CI, 0.06-0.38, P = .01) in patients receiving the intervention compared with standard care. The number of malnourished patients was fewer in the intervention [2 (7%) vs 8 (28%); P = .04]. Mortality and duration of admission were similar between groups. CONCLUSIONS: A high-protein volume-based protocol with protein supplementation delivered greater amounts of protein and energy. This intervention was associated with attenuation of QMLT loss and reduced prevalence of malnutrition at ICU discharge.

Targeted full energy and protein delivery in critically ill patients: a study protocol for a pilot randomised control trial (FEED Trial).

BACKGROUND: Current guidelines for the provision of protein for critically ill patients are based on incomplete evidence, due to limited data from randomised controlled trials. The present pilot randomised controlled trial is part of a program of work to expand knowledge about the clinical effects of protein delivery to critically ill patients. The primary aim of this pilot study is to determine whether an enteral feeding protocol using a volume target, with additional protein supplementation, delivers a greater amount of protein and energy to mechanically ventilated critically ill patients than a standard nutrition protocol. The secondary aims are to evaluate the potential effects of this feeding strategy on muscle mass and other patient-centred outcomes. METHODS: This prospective, single-centred, pilot, randomised control trial will include 60 participants who are mechanically ventilated and can be enterally fed. Following informed consent, the participants receiving enteral nutrition in the intensive care unit (ICU) will be allocated using a randomisation algorithm in a 1:1 ratio to the intervention (high-protein daily volume-based feeding protocol, providing 25 kcal/kg and 1.5 g/kg protein) or standard care (hourly rate-based feeding protocol providing 25 kcal/kg and 1 g/kg protein). The co-primary outcomes are the average daily protein and energy delivered to the end of day 15 following randomisation. The secondary outcomes include change in quadriceps muscle layer thickness (QMLT) from baseline (prior to randomisation) to ICU discharge and other nutritional and patient-centred outcomes. DISCUSSION: This trial aims to examine whether a volume-based feeding protocol with supplemental protein increases protein and energy delivery. The potential effect of such increases on muscle mass loss will be explored. These outcomes will assist in formulating larger randomised control trials to assess mortality and morbidity. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN: 12615000876594 UTN: U1111-1172-8563.

Measurement of physical activity levels in the Intensive Care Unit and functional outcomes: An observational study.

PURPOSE: Primary aims were: (1) objectively quantify levels of physical activity with the sensewear armband mini-fly motion sensor (SWA-MF), (2) evaluate the correlation of SWA-MF measurement of active and resting energy expenditure against the ICU Mobility scale (IMS) and indirect calorimetry respectively. MATERIALS AND METHODS: Adults mechanically ventilated ≥48h and anticipated to remain in ICU≥5days were included. Physical activity (PA) was measured using a SWA-MF (over the first five days); energy expenditure was measured with both the SWA-MF and the Deltatrac II metabolic cart on day three; highest level of mobility was assessed on the IMS. RESULTS: Fifty-five participants performed median [IQR] 16.8 [0.6-152.4] minutes of PA per day (defined as >1.0 metabolic equivalent). A strong correlation between active energy expenditure and highest level of mobility (IMS), r=0.76, p=0.00 was observed on day 5. The SWA-MF demonstrated moderate to good agreement with the Deltatrac II metabolic cart (n=20), intra-class correlation co-efficient=0.71 (p=0.00) for the measurement of energy expenditure on day 3. CONCLUSIONS: Participants demonstrated low levels of PA. Motion sensors may be a promising non-invasive measure of energy expenditure and further investigation is warranted.

What factors affect implementation of early rehabilitation into intensive care unit practice? A qualitative study with clinicians.

PURPOSE: To identify the barriers and enablers that influence clinicians' implementation of early rehabilitation in critical care. MATERIALS AND METHODS: Qualitative study involving 26 multidisciplinary participants who were recruited using purposive sampling. Four focus groups were conducted using semistructured questions to explore attitudes, beliefs, and experiences. Data were transcribed verbatim and thematic analysis was performed. RESULTS: Six themes emerged, as follows: (1) the clinicians' expectations and knowledge (including rationale for rehabilitation, perceived benefits, and experience), (2) the evidence for and application of rehabilitation (including beliefs regarding when to intervene), (3) patient factors (including prognosis, sedation, delirium, cooperation, motivation, goals, and family), (4) safety considerations (including physiological stability and presence of devices or lines), (5) environmental influences (staffing, resources, equipment, time, and competing priorities), and (6) culture and teamwork. Key strategies identified to facilitate rehabilitation included addressing educational needs for all multidisciplinary team members, supporting junior nursing staff, and potential expansion of physiotherapy staffing hours to closer align with the 24-hour patient care model. CONCLUSIONS: Key barriers to implementation of early rehabilitation in critical care are diverse and include both clinician- and health care system-related factors. Research targeted at bridging this evidence-practice gap is required to improve provision of rehabilitation.

Functional outcomes in ICU ­ what should we be using? ­ an observational study.

INTRODUCTION: With growing awareness of the importance of rehabilitation, new measures are being developed specifically for use in the intensive care unit (ICU). There are currently 26 measures reported to assess function in ICU survivors. The Physical Function in Intensive care Test scored (PFIT-s) has established clinimetric properties. It is unknown how other functional measures perform in comparison to the PFIT-s or which functional measure may be the most clinically applicable for use within the ICU. The aims of this study were to determine (1) the criterion validity of the Functional Status Score for the ICU (FSS-ICU), ICU Mobility Scale (IMS) and Short Physical Performance Battery (SPPB) against the PFIT-s; (2) the construct validity of these tests against muscle strength; (3) predictive utility of these tests to predict discharge to home; and (4) the clinical applicability. This was a nested study within an ongoing controlled study and an observational study. METHODS: Sixty-six individuals were assessed at awakening and ICU discharge. Measures included: PFIT-s, FSS-ICU, IMS and SPPB. Bivariate relationships (Spearman's rank correlation coefficient) and predictive validity (logistic regression) were determined. Responsiveness (effect sizes); floor and ceiling effects; and minimal important differences were calculated. RESULTS: Mean ± SD PFIT-s at awakening was 4.7 ± 2.3 out of 10. On awakening a large positive relationship existed between PFIT-s and the other functional measures: FSS-ICU (rho = 0.87, p < 0.005), IMS (rho = 0.81, p < 0.005) and SPPB (rho = 0.70, p < 0.005). The PFIT-s had excellent construct validity (rho = 0.8, p < 0.005) and FSS-ICU (rho = 0.69, p < 0.005) and IMS (rho = 0.57, p < 0.005) had moderate construct validity with muscle strength. The PFIT-s and FSS-ICU had small floor/ceiling effects <11% at awakening and ICU discharge. The SPPB had a large floor effect at awakening (78%) and ICU discharge (56%). All tests demonstrated responsiveness; however highest effect size was seen in the PFIT-s (Cohen's d = 0.71). CONCLUSIONS: There is high criterion validity for other functional measures against the PFIT-s. The PFIT-s and FSS-ICU are promising functional measures and are recommended to measure function within the ICU. TRIAL REGISTRATION: Clinicaltrials.gov NCT02214823. Registered 7 August 2014).

Assessment of impairment and activity limitations in the critically ill: a systematic review of measurement instruments and their clinimetric properties.

PURPOSE: To identify measures used to evaluate the broad constructs of functional impairment and limitations in the critically ill across the continuum of recovery, and to evaluate, synthesise and compare the clinimetric properties of the measures identified. METHODS: A systematic review of articles was carried out using the databases Medline (1950-2014), CINAHL (1982-2014), EMBASE (1980-2014), Cochrane Library (2014) and Scopus (1960-2014). Additional studies were identified by searching personal files. Eligibility criteria for selection: Search 1: studies which assessed muscle mass, strength or function using objective non-laboratory measures; Search 2: studies which evaluated a clinimetric property (reliability, measurement error, validity or responsiveness) for one of the measures identified in search one. Two independent reviewers assessed articles for inclusion and assessed risk of bias using the consensus-based standards for selection of health status measurement instruments checklist. RESULTS: Thirty-three measures were identified; however, only 20 had established clinimetric properties. Ultrasonography, dynamometry, physical function in intensive care test scored and the Chelsea critical care physical assessment tool performed the strongest for the measurement of impairment of body systems (muscle mass and strength) and activity limitations (physical function), respectively. CONCLUSIONS: There is considerable variability in the type of measures utilized to measure physical impairments and limitations in survivors of critical illness. Future work should identify a core set of standardized measures, which can be utilized across the continuum of critical illness recovery embedded within the International Classification of Functioning framework. This will enable improved comparisons between future studies, which in turn will assist in identifying the most effective treatment strategies to ameliorate the devastating longer-term outcomes of a critical illness.

The efficacy of minitracheostomy for the management of sputum retention: a systematic review.

BACKGROUND: Suction via a minitracheostomy is a safe procedure, but its efficacy in facilitating sputum clearance in individuals with an acute condition has not been systematically reviewed. OBJECTIVES: The aim of this study was to identify and synthesise the efficacy of the insertion of a minitracheostomy and tracheal suction via minitracheostomy for sputum clearance in adults who have undergone surgery or have an acute condition characterised by sputum retention. DATA SOURCES: A systematic literature search using the electronic databases MEDLINE, CINAHL, EMBASE, Cochrane Library and PEDro, with searches limited to English language journal articles published between 1984 and September 2011. DATA EXTRACTION AND DATA SYNTHESIS: All study designs were included. Two independent reviewers used pre-defined inclusion and exclusion criteria to identify all eligible articles. RESULTS: Six studies in six patient groups met the inclusion criteria, with two randomised controlled trials and four case series included. These studies presented the results of 278 patients following surgery and 13 with acute medical conditions. There were a range of criteria that defined the efficacy of minitracheostomy for sputum retention. Studies reporting the adjunctive role found a reduced incidence of complications associated with sputum retention following thoracic surgery. Other studies reported limited benefit in overall respiratory status with minitracheostomy. Heterogeneity among the studies was evident, with major limitations identified. CONCLUSIONS: Limited evidence suggests that minitracheostomy may be a useful adjunct in optimising sputum clearance in adults following thoracic surgery, but the effects in adults with an acute condition and other types of surgery are inconclusive.

Regulation of the follicle-stimulating hormone beta gene by the LHX3 LIM-homeodomain transcription factor.

FSH is a critical hormone regulator of gonadal function that is secreted from the pituitary gonadotrope cell. Human patients and animal models with mutations in the LHX3 LIM-homeodomain transcription factor gene exhibit complex endocrine diseases, including reproductive disorders with loss of FSH. We demonstrate that in both heterologous and pituitary gonadotrope cells, specific LHX3 isoforms activate the FSH beta-subunit promoter, but not the proximal LHbeta promoter. The related LHX4 mammalian transcription factor can also induce FSHbeta promoter transcription, but the homologous Drosophila protein LIM3 cannot. The actions of LHX3 are specifically blocked by a dominant negative LHX3 protein containing a Kruppel-associated box domain. Six LHX3-binding sites were characterized within the FSHbeta promoter, including three within a proximal region that also mediates gene regulation by other transcription factors and activin. Mutations of the proximal binding sites demonstrate their importance for LHX3 induction of the FSHbeta promoter and basal promoter activity in gonadotrope cells. Using quantitative methods, we show that the responses of the FSHbeta promoter to activin do not require induction of the LHX3 gene. By comparative genomics using the human FSHbeta promoter, we demonstrate structural and functional conservation of promoter induction by LHX3. We conclude that the LHX3 LIM homeodomain transcription factor is involved in activation of the FSH beta-subunit gene in the pituitary gonadotrope cell.