Accuracy of weight and height estimation in an intensive care unit: Implications for clinical practice and research

University of Aberdeen, Aberdeen, Scotland, United Kingdom
Critical Care Medicine (Impact Factor: 6.15). 09/2006; 34(8):2153-7. DOI: 10.1097/01.CCM.0000229145.04482.93
Source: PubMed

ABSTRACT Numerous calculations routinely used in the intensive care require the knowledge of patients' weight and height, although these measurements are not always made. Estimates by doctors or nurses are often substituted. This study sought to ascertain the accuracy of estimates of weight and height of patients made by intensive care unit (ICU) staff.
: Prospective clinical study.
Sixteen-bed mixed medical and surgical ICU in a university teaching hospital.
Fourteen patients had their height and weight estimated by 20 members of the medical and nursing staff.
After all estimates had been recorded, measurements of weight and height were obtained. Weight was measured by means of a patient hoist with a calibrated weighing facility and height using a steel tape measure.
Estimation of weight was poor, with 47% of estimates at least 10% different and 19% of estimates at least 20% different from the measured values. The majority of height estimates were within 10% of the measured values.
Individual estimates of weight and height are frequently inaccurate. These errors of estimation could compromise application of effective therapies, as well as contribute to a reduction in design sensitivity of clinical trials.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A dose of 0.9 mg/kg of intravenous tissue plasminogen activator (t-PA) has proven to be beneficial in the treatment of acute ischemic stroke (AIS). Dosing of t-PA based on estimated patient weight (PW) increases the likelihood of errors. Our objectives were to evaluate the accuracy of estimated PW and assess the effectiveness and safety of the actual applied dose (AAD) of t-PA. We performed a prospective single-center study of AIS patients treated with t-PA from May 2010 to December 2011. Dose was calculated according to estimated PW. Patients were weighed during the 24 h following treatment with t-PA. Estimation errors and AAD were calculated. Actual PW was measured in 97 of the 108 included patients. PW estimation errors were recorded in 22.7 % and were more frequent when weight was estimated by stroke unit staff (44 %). Only 11 % of patients misreported their own weight. Mean AAD was significantly higher in patients who had intracerebral hemorrhage (ICH) after t-PA than in patients who did not (0.96 vs. 0.92 mg/kg; p = 0.02). Multivariate analysis showed an increased risk of ICH for each 10 % increase in t-PA dose above the optimal dose of 0.90 mg/kg (OR 3.10; 95 % CI 1.14-8.39; p = 0.026). No effects of t-PA misdosing were observed on symptomatic ICH, functional outcome or mortality. Estimated PW is frequently inaccurate and leads to t-PA dosing errors. Increasing doses of t-PA above 0.90 mg/kg may increase the risk of ICH. Standardized weighing methods before t-PA is administered should be considered.
    Journal of Thrombosis and Thrombolysis 05/2015; DOI:10.1007/s11239-015-1232-4 · 2.04 Impact Factor
  • Source
    Journal of the Intensive Care Society 01/2014; 15(1 Supplement):91.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Objectives Patient weight is a key measure for safe medication management and monitoring of patients. Here we report the recording of patient's body weight on admission in three hospitals in West London and its relationship with the prescription of antibiotic drugs where it is essential to have the body weight of the patient. Methods A prospective cross-sectional study was conducted in three teaching hospitals in West London. Data were collected during March 2011–September 2011 and July 2012–August 2012, from adult admissions units, medical and surgical wards. Data from each ward were collected on a single day to provide a point prevalence data on weight recording. Patient medication charts, nursing and medical notes were reviewed for evidence of weight and height recording together with all the medication prescribed for the patients. An observational study collecting data on the weight recording process was conducted on two randomly selected wards to add context to the data. Results Data were collected on 1012 patients. Weight was not recorded for 46% (474) of patients. Eighty-nine patients were prescribed a narrow therapeutic antibiotic, in 39% (35/89) of these weight was not recorded for the patient. Intravenous vancomycin was the most commonly prescribed antibiotic requiring therapeutic monitoring. In total 61 patients were receiving intravenous vancomycin and of these 44% (27/61) did not have their weight recorded. In the observational study, the most frequently identified barrier to weight not being recorded was interruptions to the admission process. Conclusions Despite the clinical importance of body weight measurement it is poorly recorded in hospitalised patients, due to interruptions to the workflow and heavy staff workloads. In antibiotics a correct, recent patient weight is required for accurate dosing and to keep drugs within the narrow therapeutic index, to ensure efficacy of prescribing and reduce toxicity.
    BMJ Open 04/2015; 5(4). · 2.06 Impact Factor