Karen Waak
Harvard University
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Featured researches published by Karen Waak.
Pm&r | 2011
Jaime Garzon-Serrano; Cheryl Ryan; Karen Waak; Ronald E. Hirschberg; Susan Tully; Edward A. Bittner; Daniel Chipman; Ulrich Schmidt; Georgios Kasotakis; John Benjamin; Ross Zafonte; Matthias Eikermann
To evaluate whether the level of mobilization achieved and the barriers for progressing to the next mobilization level differ between nurses and physical therapists.
Critical Care Medicine | 2012
George Kasotakis; Ulrich Schmidt; Dana Perry; Martina Grosse-Sundrup; John Benjamin; Cheryl Ryan; Susan Tully; Ronald E. Hirschberg; Karen Waak; George C. Velmahos; Edward A. Bittner; Ross Zafonte; J. Perren Cobb; Matthias Eikermann
Objectives:To test if the surgical intensive care unit optimal mobility score predicts mortality and intensive care unit and hospital length of stay. Design:Prospective single-center cohort study. Setting:Surgical intensive care unit of the Massachusetts General Hospital. Patients:One hundred thirteen consecutive patients admitted to the surgical intensive care unit. Investigations:We tested the hypotheses that the surgical intensive care unit optimal mobility score independent of comorbidity index, Acute Physiology and Chronic Health Evaluation II, creatinine, hypotension, hypernatremia, acidosis, hypoxia, and hypercarbia predicts hospital mortality, surgical intensive care unit and total hospital length of stay. Measurements and Main Results:Two nurses independently predicted the patients’ mobilization capacity by using the surgical intensive care unit optimal mobility score the morning after admission, whereas a third nurse recorded the achieved mobilization levels of patients at the end of the day. A multidisciplinary expert team measured patients’ grip strength and assessed their predicted mobilization capacity independently. Multivariate analysis revealed that the surgical intensive care unit optimal mobility score was the only independent predictor of mortality. Surgical intensive care unit optimal mobility score, hypotension, and hypernatremia (>144 mmol/L) independently predicted intensive care unit length of stay, whereas the surgical intensive care unit optimal mobility score and hypernatremia predicted total hospital length of stay. The Acute Physiology and Chronic Health Evaluation II score was not identified in the multivariate analysis. The surgical intensive care unit optimal mobility score was also a reliable and valid instrument in predicting achieved mobilization levels of patients. Conclusions:In surgical critically ill patients presenting without preexisting impairment of functional mobility, the surgical intensive care unit optimal mobility score is a reliable and valid tool to predict mortality and intensive care unit and hospital length of stay. (Crit Care Med 2012; 40:–1128)
Physical Therapy | 2012
Jeanette J. Lee; Karen Waak; Martina Grosse-Sundrup; Feifei Xue; Jarone Lee; Daniel Chipman; Cheryl Ryan; Edward A. Bittner; Ulrich Schmidt; Matthias Eikermann
Background Paresis acquired in the intensive care unit (ICU) is common in patients who are critically ill and independently predicts mortality and morbidity. Manual muscle testing (MMT) and handgrip dynamometry assessments have been used to evaluate muscle weakness in patients in a medical ICU, but similar data for patients in a surgical ICU (SICU) are limited. Objective The purpose of this study was to evaluate the predictive value of strength measured by MMT and handgrip dynamometry at ICU admission for in-hospital mortality, SICU length of stay (LOS), hospital LOS, and duration of mechanical ventilation. Design This investigation was a prospective, observational study. Methods One hundred ten patients were screened for eligibility for testing in the SICU of a large, academic medical center. The Acute Physiology and Chronic Health Evaluation (APACHE) II score, diagnoses, and laboratory data were collected. Measurements were obtained by MMT quantified with the sum (total) score on the Medical Research Council Scale and by handgrip dynamometry. Outcome data, including in-hospital mortality, SICU LOS, hospital LOS, and duration of mechanical ventilation, were collected for all participants. Results One hundred seven participants were eligible for testing; 89% were tested successfully at a median of 3 days (25th–75th percentiles=3–6 days) after admission. Sedation was the most frequent barrier to testing (70.6%). Manual muscle testing was identified as an independent predictor of mortality, SICU LOS, hospital LOS, and duration of mechanical ventilation. Grip strength was not independently associated with these outcomes. Limitations This study did not address whether muscle weakness translates to functional outcome impairment. Conclusions In contrast to handgrip strength, MMT reliably predicted in-hospital mortality, duration of mechanical ventilation, SICU LOS, and hospital LOS.
Anesthesiology | 2013
Hooman Mirzakhani; June-Noelle Williams; Jennifer Mello; Sharma Joseph; Matthew Meyer; Karen Waak; Ulrich Schmidt; Emer Kelly; Matthias Eikermann
Background:Prolonged mechanical ventilation is associated with muscle weakness, pharyngeal dysfunction, and symptomatic aspiration. The authors hypothesized that muscle strength measurements can be used to predict pharyngeal dysfunction (endoscopic evaluation–primary hypothesis), as well as symptomatic aspiration occurring during a 3-month follow-up period. Methods:Thirty long-term ventilated patients admitted in two intensive care units at Massachusetts General Hospital were included. The authors conducted a fiberoptic endoscopic evaluation of swallowing and measured muscle strength using medical research council score within 24 h of each fiberoptic endoscopic evaluation of swallowing. A medical research council score less than 48 was considered clinically meaningful muscle weakness. A retrospective chart review was conducted to identify symptomatic aspiration events. Results:Muscle weakness predicted pharyngeal dysfunction, defined as either valleculae and pyriform sinus residue scale of more than 1, or penetration aspiration scale of more than 1. Area under the curve of the receiver-operating curves for muscle strength (medical research council score) to predict pharyngeal, valleculae, and pyriform sinus residue scale of more than 1, penetration aspiration scale of more than 1, and symptomatic aspiration were 0.77 (95% CI, 0.63–0.97; P = 0.012), 0.79 (95% CI, 0.56–1; P = 0.02), and 0.74 (95% CI, 0.56–0.93; P = 0.02), respectively. Seventy percent of patients with muscle weakness showed symptomatic aspiration events. Muscle weakness was associated with an almost 10-fold increase in the symptomatic aspiration risk (odds ratio = 9.8; 95% CI, 1.6–60; P = 0.009). Conclusion:In critically ill patients, muscle weakness is an independent predictor of pharyngeal dysfunction and symptomatic aspiration. Manual muscle strength testing may help identify patients at risk of symptomatic aspiration.
BMJ Open | 2013
Matthew Meyer; Anne B. Stanislaus; Jarone Lee; Karen Waak; Cheryl Ryan; Richa Saxena; Stephanie A. Ball; Ulrich Schmidt; Trudy Poon; Simone Piva; Matthias Walz; Daniel Talmor; Manfred Blobner; Nicola Latronico; Matthias Eikermann
Introduction Immobilisation in the intensive care unit (ICU) leads to muscle weakness and is associated with increased costs and long-term functional disability. Previous studies showed early mobilisation of medical ICU patients improves clinical outcomes. The Surgical ICU Optimal Mobilisation Score (SOMS) trial aims to test whether a budget-neutral intervention to facilitate goal-directed early mobilisation in the surgical ICU improves participant mobilisation and associated clinical outcomes. Methods and analysis The SOMS trial is an international, multicentre, randomised clinical study being conducted in the USA and Europe. We are targeting 200 patients. The primary outcome is average daily SOMS level and key secondary outcomes are ICU length of stay until discharge readiness and ‘mini’ modified Functional Independence Measure (mmFIM) at hospital discharge. Additional secondary outcomes include quality of life assessed at 3 months after hospital discharge and global muscle strength at ICU discharge. Exploratory outcomes will include: ventilator-free days, ICU and hospital length of stay and 3-month mortality. We will explore genetic influences on the effectiveness of early mobilisation and centre-specific effects of early mobilisation on outcomes. Ethics and dissemination Following Institutional Review Board (IRB) approval in three institutions, we started study recruitment and plan to expand to additional centres in Germany and Italy. Safety monitoring will be the domain of the Data and Safety Monitoring Board (DSMB). The SOMS trial will also explore the feasibility of a transcontinental study on early mobilisation in the surgical ICU. Results The results of this study, along with those of ancillary studies, will be made available in the form of manuscripts and presentations at national and international meetings. Registration This study has been registered at clinicaltrials.gov (NCT01363102).
Respiratory Care | 2016
Annop Piriyapatsom; Elizabeth C Williams; Karen Waak; Karim S. Ladha; Matthias Eikermann; Ulrich Schmidt
BACKGROUND: Re-intubation is associated with high morbidity and mortality. There is limited information regarding the risk factors that predispose patients admitted to the surgical ICU to re-intubation. We hypothesized that preoperative comorbidities, acquired muscular weakness, and renal dysfunction would be predictors of re-intubation in the surgical ICU population. METHODS: This was a prospective observational study in 2 surgical ICUs of a large tertiary hospital. All patients who were extubated during their surgical ICU stay were included. Demographic and clinical data were collected before and after extubation. The primary outcome was re-intubation within 72 h. Using multivariate logistic regression analysis, independent risk factors of re-intubation were determined, and a prediction score was developed. RESULTS: Between December 1, 2012, and January 31, 2014, we included 764 consecutive subjects. Of these, 65 subjects (8.5%) required re-intubation. Independent risk factors of re-intubation were blood urea nitrogen level of >8.2 mmol/L (odds ratio [OR] 3.66, 95% CI 1.97–6.80), hemoglobin level of <75 g/L (OR 2.10, 95% CI 1.23–3.61), and muscle strength of ≤3 (OR 2.03, 95% CI 1.16–3.55). The presence of all 3 risk factors was associated with an estimated probability for re-intubation of 26.8%. CONCLUSIONS: In noncardiac surgery, surgical ICU subjects, elevated blood urea nitrogen level, low hemoglobin level, and muscle weakness were identified as independent risk factors for re-intubation. The presence of these risk factors can potentially aid clinicians in making informed decisions regarding optimal airway management in patients considered for an extubation attempt. (ClinicalTrials.gov registration NCT01967056.)
The Lancet | 2016
Stefan J. Schaller; Matthew Anstey; Manfred Blobner; Thomas Edrich; Stephanie D. Grabitz; Ilse Gradwohl-Matis; Markus Heim; Timothy T. Houle; Tobias Kurth; Nicola Latronico; Jarone Lee; Matthew Meyer; Thomas Peponis; Daniel Talmor; George C. Velmahos; Karen Waak; J. Matthias Walz; Ross Zafonte; Matthias Eikermann
Journal of Critical Care | 2013
Karen Waak; Sebastian Zaremba; Matthias Eikermann
Critical Care Medicine | 2016
Sandra Muse; Colleen Arsenault; Tharusan Thevathasan; Annop Piriyapatsom; Karen Waak; Ulrich Schmidt; Matthias Eikermann
Survey of Anesthesiology | 2014
Hooman Mirzakhani; June-Noelle Williams; Jennifer Mello; Sharma Joseph; Matthew Meyer; Karen Waak; Ulrich Schmidt; Elmer Kelly; Matthias Eikermann