Mortality From Burns Sustained on Home Oxygen Therapy Exceeds Predicted Mortality. Singer KE, Harvey JA, Heh V, Dale EL. J Burn Care Res. 2020 Sep 23;41(5):976-980.
Take Home: Patients with burn injuries sustained while smoking on home oxygen had significantly higher mortality at one year than would be anticipated by standard predictive models. Clinical management in the inpatient setting and decision making with regards to long term prognosis and goals of care should be thoughtfully considered.
Summary: This study retrospectively examined 48 inpatients at a large academic burn center who sustained burns while smoking on home oxygen therapy. Accepted predictive models for burn mortality (Boston Criteria and Abbreviated Burn Severity Index) were compared to actual mortality at one year following injury. Expected to observed mortality using predictive models versus cohort study patients was examined as were secondary endpoints. Univariate analysis and chi-squared analysis was performed. Observed one year mortality in the cohort was 54.2% compared to predicted 23.5% (Boston Criteria) (P<0.05) and 19.7% (ABSI Criteria) (P=0.59). Other interesting secondary outcomes observed included ten patients (20.8%) who either died while inpatient or were discharged to hospice, death of all three patients requiring tracheostomy within one year, and discharge of 21 patients (43.8%) to home. All patients discharged to LTACH died within a year and 60% of those discharged to SNF died within a year. The authors cite a 6.3% rate of end-of-life care discussion documentation in this cohort, citing potential room for improvement in communication. Though limited by the relatively small size of the subgroup this study highlights that outcomes in this specific injury mechanism lend a more dire prognosis than predicted. Clinical optimization while inpatient and thoughtful goals of care and expectations management is essential.
The Predictive Applicability of Liberal vs Restrictive Intubation Criteria in Adult Patients With Suspected Inhalation Injury-A Retrospective Cohort Study. Chotalia M, Pirrone C, Mangham T, Torlinska B, Mullhi R, England K, Torlinski T. J Burn Care Res. 2020 Nov 30;41(6):1290-1296.
Take Home: A liberal intubation criteria for inhalation injury was more specific in predicting the presence of inhalation injury therefore liberal intubation criteria utilization is recommended by the authors. Restrictive intubation criteria use was highly sensitive and specific for detecting presence/absence of inhalation injury.
Summary: Predicting the need for intubation in inhalation injury is more clinically relevant than the diagnosis of inhalation injury alone. The diagnosis of inhalation injury by standard means is often subjective and is provider experience-dependent. Delaying intubation in a patient who ultimately requires it may cause harm. 85 patients with suspected inhalation injury admitted to an ICU in the UK were retrospectively studied. Restrictive criteria for intubation, as per ABA (Full-thickness facial burn, stridor, respiratory distress, airway swelling on laryngoscopy, airway trauma, altered mentation, hypoxia/hypercarbia, hemodynamic instability) were compared to UHB institutional liberal criteria for intubation (Facial burn, stridor/cough/hoarse voice, bronchospasm/dyspnea/chest pain, hypoxia/hypercarbia/raised carbon monoxide, soot around mouth/nose, loss of consciousness at any point, enclosed space, carbonaceous sputum). Since liberal intubation criteria had higher sensitivity in detecting need for prolonged intubation (> 48 hours) in this cohort the authors recommend its use over a restrictive approach. With consideration to the limitations of this study (single-center, retrospective nature, subjectivity of data collection and assignment of cohort) this paper points out the yet imperfect approach to suspected inhalation injury and its management. Opportunity exists for characterization and standardized management of this injury pattern.
A Multicenter Evaluation of Outcomes Following the Use of Nebulized Heparin for Inhalation Injury (HIHI2 Study). Cox CL, McIntire AM, Bolton KJ, Foster DR, Fritschle AC, Harris SA, Pape KO, Whitten JA, Harman BC, Sood R, Walroth TA. J Burn Care Res. 2020 Sep 23; 41(5): 1004-1008.
Inhalation injuries continue to be a challenging aspect of treating burn patients. Not only do inhalation injuries increase the volume of resuscitation, but they also prolong ventilation and raise ventilator associated complication rates. While the use of nebulized heparin has been discussed in the literature for nearly 30 years, these studies are nearly universally single-center retrospective studies, that are largely the result of changes in treatment paradigm and compare them to historical controls. In addition, these studies have varied in terms of their actual protocol—varying the dose of heparin, and use of concomitant medications with some combination of albuterol, N-acetylcysteine, and/or sodium bicarbonate. This has led to results that have tended towards improvement (usually demonstrated by decreases in number of ventilator days and length of stay) but no definitive data.
The HIHI2 study attempts to remedy some of those problems by comparing two separate doses of heparin (5000 units and 10,000 units) with a control that did not use nebulized heparin. This work builds on the results of the HIHI study that found patients who received 10,000 units had fewer ventilator days relative to those who were not treated with nebulized heparin therapy. This trial is multicenter, as they added a second center that supplied a cohort of patients treated with 5000 unit dosages. Using three separate patient cohorts that were matched on age and percent total body surface area (TBSA) burned, they compared patients not treated with heparin to those treated with 5000 units and those treated with 10,000 units. These dosages were administered q4h for up to 7 days or until extubation (whichever came first). The cases are seemingly well-matched and showed a decrease in duration of mechanical ventilation (17.9d control vs. 6.1d in 5000 vs. 10.5d in 10,000). Among the secondary outcomes, length of hospitalization also was significantly different, with the greatest decrease being present in the group receiving 5000 unit doses. These conclusions (decreases in ventilator days and length of stay) are in agreement with recently published meta-analyses. While this paper draws the conclusion that either dose is beneficial, the rate of ventilator days, length of stay, and incidence of ventilator-associated pneumonia are much lower in the 5000 unit group over the 10,000 unit group. This raises concern that some of these differences may be due to institutional practice, as only one institution provided the data on those patients. Overall, this paper adds to the growing literature that suggests that treatment with nebulized heparin is likely beneficial in patients with inhalation injury. A prospective multi-center randomized trial would further clarify the degree of impact of nebulized heparin and optimal dosing.
The impact of serum zinc normalization on clinical outcomes in severe burn patients. Olson LM, Cofey R, Porter K, Thomas S, Bailey JK, Jones LM, Murphy CV. J Burn Care Res. 2020 May; 46(3):589-595.
Wound healing is a multifaceted challenge that involves adequate nutrition, appropriate trace elements, and infection control. While much attention has been paid to nutrition and infection control, elemental supplementation remains an afterthought. Zinc is one such element that is integral to wound healing and immunity. At present, it is recommended that 50 mg of elemental zinc be administered daily for supplementation, though this level is rarely monitored or dose adjusted. The authors of this study attempted to increase supplementation of zinc based on serum levels and compared the outcomes of those patients that attained normal serum levels (>=60 mcg/mL) vs. those that were not normal (<60 mcg/mL).
This is a retrospective single-center cohort analysis of all patients admitted over a 78-month period. Patients with burns that exceeded 10% total body surface area (TBSA) and had at least three serum zinc measurements during their hospital stay were included. The patients were divided into a group that attained normal serum zinc levels at third zinc assessment (generally, 12-14 days after admission) and those that did not. On admission, the median zinc level at presentation was below normal in both groups, while the normal group tended to have less severe burns (lower TBSA, less full thickness injuries). Doses were adjusted based on serum levels. At the third zinc assessment, a majority of patients in the normal group required 50 mg doses, while a majority of the below normal group required 100 mg or more. Overall, 59% of all individuals were eventually able to reach normal serum levels prior to discharge, though it took an average of 28 days to do so. Using a multivariable regression that adjusted for TBSA and number of procedures, attaining normal zinc serum levels was not associated with improved clinical outcomes in terms of length of stay, duration of mechanical ventilation, infectious complications, poor blood glucose control, time to 90% re-epithelization, or mortality. This trial indicates that dosing regimens to attain normalization of serum zinc level is not necessary, and fixed dose zinc supplementation is adequate. The authors further advocate for use 100 mg of elemental zinc based on their experience that patients that reached normal serum levels required 100 mg or less.