Outcome measures used in studies and summary of results
| Outcome | Outcome measure | Study author | Summary of results |
| Breathlessness and peripheral oedema | Freedom from congestion | Frea et al, Zheng et al 27 29 | Pooled data from 161 patients showed improvement in favour of CFI for freedom from congestion (OR 2.80, 95% CI 1.45 to 5.40; I2=0%,). Improvement in both groups with statistically significant difference in favour of CFI in both studies was also reported for the other outcomes. |
| Borg’s scale | Zheng et al 29 | ||
| Treatment failure using wet score | Frea et al 27 | ||
| Reduction in body weight | Weight loss from the time of enrolment to treatment termination | Frea et al, Ragab et al, Thomson et al, Zheng et al, Palazzuoli et al 24–27 29 | Pooled data from three studies with 194 patients showed no significant difference between groups (MD 0.89, 95% CI −0.22 to 2.00, I2=0%). |
| Urine output | Total urinary output | Frea et al 27 | Pooled data from four studies with 234 patients found that participants receiving CFI compared with BFI had a significantly greater urine output at 24 hours (MD 344.76, 95% CI 132.87 to 556.64; I2=44%) |
| Mean total daily urinary output | Thomson et al, Palazzuoli et al, Jaya Shree et al 24 26 28 | ||
| Hourly urine output for every kg of body weight | Ragab et al 25 | ||
| Total net urinary output | Zheng et al 29 | ||
| Net daily urinary output | Thomson et al 26 | ||
| Net daily urinary output normalised for amount of furosemide received | Thomson et al 26 | ||
| Total daily urinary output normalised for amount of furosemide received | Thomson et al 26 | ||
| Renal Function | Increase in prevalence of acute kidney injury | Frea et al, Ragab et al, Thomson et al, Zheng et al, Palazzuoli et al 24–27 29 | Pooled data from five studies with 314 participants demonstrated no significant difference between groups in the odds of AKI measured by number of patients with elevated serum creatinine during treatment period (OR 1.27, 95% CI 0.74 to 2.17; I2=0%). Pooled data from 274 participants showed no significant difference in serum creatinine levels between both groups (MD 0.22, 95% CI −0.04 to 0.48; I2=78%). Three reported on the estimated glomerular filtration rate,24 27 28 but only Palazzuoli et al 24 reported significantly greater prevalence in the CFI group. |
| Increase in serum creatinine | Frea et al, Ragab et al, Zheng et al, Palazzuoli et al, Jaya Shree et al 24 25 27–29 | ||
| Decrease in glomerular filtration rate | Frea et al. Palazzuoli et al, Jaya Shree et al 24 27 28 | ||
| Decrease in serum creatinine clearance | Ragab et al 25 | ||
| Serious adverse events | Electrolyte disturbances | Ragab et al, Thomson et al, Zheng et al, Palazzuoli et al, Jaya Shree et al 24–26 28 29 | Pooled data from three studies with 194 patients showed no difference between CFI and BFI on serum sodium levels (Mean Difference 0.15, 95% CI −1.97 to 2.27; I2=0%). Three studies with 194 patients found a significantly lower serum potassium in the BFI group compared with the CFI group (Mean Difference −0.20, 95% CI −0.38 to −0.01; I2=0%). |
| Prevalence of hypokalaemia | Ragab et al, Zheng et al 25 29 | ||
| Need for additional treatments during the intervention period | Palazzuoli et al, Thomson et al 24 26 | ||
| Increased Rehospitalisation and mortality | Palazzuoli et al 24 | ||
| Prevalence of Significant hypotension | Thomson et al, Zheng et al 26 29 | ||
| Tinnitus | Zheng et al 29 | ||
| Length of hospital stay | Increase in length of hospital stay | Thomson et al, Zheng et al, Palazzuoli et al 24 26 29 | Five of the six included studies reported outcomes related to length of hospital stay. Pooled data from three studies with 194 patients showed no significant difference in the length of hospital stay between both groups (MD −1.09, 95% CI −7.05 to 4.86; I2=82%). |
| Increase in length of ICU stay | Ragab et al, Jaya Shree et al 25 28 | ||
| New York Heart Association (NYHA) Classification | Improvement in NYHA Class | Ragab et al, Jaya Shree et al 25 28 | Improvement in both groups. A meta-analysis was not possible due to insufficient data. |
| Thoracic Fluid Content (TFC) | Decrease in TFC | Ragab et al 25 | Improvement in both groups. |
AKI, acute kidney injury; BFI, bolus furosemide infusion; CFI, continuous furosemide infusion; ICU, intensive care unit; MD, mean difference.