Mineralocorticoid deficiency in hemorrhagic shock

BACKGROUND

In the critically ill, mineralocorticoid deficiency (MD) is associated with greater disease severity, the development of acute renal insufficiency, and increased mortality. We hypothesized that severely injured trauma patients presenting with hemorrhagic shock would demonstrate a high degree of MD. We also hypothesized that MD in these patients would be associated with increased length of stay, hypotension, fluid requirements, and acute kidney injury (AKI).

MATERIALS AND METHODS

Thirty-two trauma patients in hemorrhagic shock on admission to the trauma bay (SBP <90 mm Hg × 2) were enrolled. Blood samples were obtained on ICU admission and 8, 16, 24, and 48 hours later. Plasma aldosterone (PA) and renin (PR) were assayed by radioimmunoassay. MD was defined as a ratio of PA/PR ≤2. Demographic data, injury severity score, ICU and hospital length of stay, fluid requirements, mean arterial pressure, serum sodium, hypotension, and risk for AKI were compared for patients with and without MD.

RESULTS

At ICU admission, 48% of patients met criteria for MD. Patients with MD were significantly more likely to experience hypotension (MAP ≤60 mm Hg) during the study period. MD patients required significantly more units of blood in 48 h than non-MD patients (13 [7-22] versus 5 [2-7], P = 0.015) and had increased crystalloid requirements (18L [14-23] versus 9L [6-10], P < 0.001). MD patients were at higher risk for AKI according to RIFLE and AKIN criteria.

CONCLUSIONS

MD is a common entity in trauma patients presenting in hemorrhagic shock. Patients with MD required a more aggressive resuscitative effort, were more likely to experience hypotension, and had a higher risk of AKI than non-MD patients. Future studies are needed to fully understand the impact of MD following trauma and the potential role for hormonal replacement therapy.

Hyperbaric oxygen therapy in necrotizing soft tissue infections

BACKGROUND

Surgical debridement and antibiotics are the mainstays of therapy for patients with necrotizing soft tissue infections (NSTIs), but hyperbaric oxygen therapy (HBO) is often used as an adjunctive measure. Despite this, the efficacy of HBO remains unclear. We hypothesized that HBO would have no effect on mortality or amputation rates.

METHODS

We performed a retrospective analysis of our institutional experience from 2005 to 2009. Inclusion criteria were age > 18 y and discharge diagnosis of NSTI. We abstracted baseline demographics, physiology, laboratory values, and operative course from the medical record. The primary endpoint was in-hospital mortality; the secondary endpoint was extremity amputation rate. We compared baseline variables using Mann-Whitney, chi-square, and Fisher's exact test, as appropriate. Significance was set at P < 0.05.

RESULTS

We identified 80 cases over the study period. The cohort was 54% male (n = 43) and 53% white (n = 43), and had a mean age of 55 ± 16 y. There were no significant differences in demographics, physiology, or comorbidities between groups. In-hospital mortality was not different between groups (16% in the HBO group versus 19% in the non-HBO group; P = 0.77). In patients with extremity NSTI, the amputation rate did not differ significantly between patients who did not receive HBO and those who did (17% versus 25%; P = 0.46).

CONCLUSIONS

Hyperbaric oxygen therapy does not appear to decrease in-hospital mortality or amputation rate after in patients with NSTI. There may be a role for HBO in treatment of NSTI; nevertheless, consideration of HBO should never delay operative therapy. Further evidence of efficacy is necessary before HBO can be considered the standard of care in NSTI.

Therapeutic hypothermia for treatment of intractable intracranial hypertension after liver transplantation

A comatose 23-year-old woman with acute liver failure due to an overdose of acetaminophen had indications of intracranial hypertension and underwent liver transplantation. Her level of arousal did not improve, and on postoperative day 1, clinical signs of cerebral herniation became apparent. An intracranial pressure monitor was placed, and intracranial hypertension was documented. Elevations in intracranial pressure persisted despite maximal osmotherapy, and therapeutic hypothermia was started. Normalization of intracranial pressure was rapid. Findings on neurological examination improved and the patient was discharged from the hospital with no neurological impairment.

Analgesia for older adults with abdominal or back pain in emergency department

OBJECTIVE

To determine the association between age and analgesia for emergency department (ED) patients with abdominal or back pain.

METHODS

Using a fully electronic medical record, we performed a retrospective cohort study of adults presenting with abdominal or back pain to two urban EDs. To assess differences in analgesia administration and time to analgesia between age groups, we used chi-square and Kruskal-Wallis test respectively. To adjust for potential confounders, we used a generalized linear model with log link and Gaussian error.

RESULTS

Of 24,752 subjects (mean age 42 years, 65% female, 69% black, mean triage pain score 7.5), the majority (76%) had abdominal pain and 61% received analgesia. The ≥80 years group (n=722; 3%), compared to the 65-79 years group (n=2,080; 8%) and to the <65 years group (n=21,950; 89%), was more often female (71 vs. 61 vs. 65%), black (72 vs. 65 vs. 69%), and had a lower mean pain score (6.6 vs. 7.1 vs. 7.6). Both older groups were less likely to receive any analgesia (48 vs. 59 vs. 62%, p<0.0001) and the oldest group less likely to receive opiates (35 vs. 47 vs. 44%, p<0.0001). Of those who received analgesia, both older groups waited longer for their medication (123 vs. 113 vs. 94 minutes; p<0.0001). After controlling for potential confounders, patients ≥80 years were 17% less likely than the <65 years group to receive analgesia (95% CI 14-20%).

CONCLUSION

Older adults who present to the ED for abdominal or back pain are less likely to receive analgesia and wait significantly longer for pain medication compared to younger adults.

Randomized, double-blind, placebo-controlled trial of effects of enteral iron supplementation on anemia and risk of infection during surgical critical illness

BACKGROUND

Critical illness is characterized by hypoferremia, iron-deficient erythropoiesis (IDE), and anemia. The relative risks and benefits of iron supplementation in this setting are unknown.

METHODS

Anemic, critically ill surgical patients with an expected intensive care unit length of stay (ULOS) >or= 5 days were randomized to either enteral iron supplementation (ferrous sulfate 325 mg three times daily) or placebo until hospital discharge. Outcomes included hematocrit, iron markers (i.e., serum concentrations of iron, ferritin, and erythrocyte zinc protoporphyrin [eZPP]), red blood cell (RBC) transfusion, transfusion rate (mL RBC/study day), nosocomial infection, antibiotic days, study length of stay (LOS), ULOS, and death. Iron-deficient erythropoiesis was defined as an elevated eZPP concentration.

RESULTS

Two hundred patients were randomized; 97 received iron, and 103 received placebo. Socio-demographics, baseline acuity, hematocrit, and iron markers were similar in the two groups. No differences were observed between the iron and placebo groups with respect to either hematocrit or iron markers following up to 28 days. However, patients treated with iron were significantly less likely to receive an RBC transfusion (29.9% vs. 44.7%, respectively; p = 0.03) and had a significantly lower transfusion rate (22.0 mL/day vs. 29.9 mL/day; p = 0.03). Subgroup analysis revealed that these differences were observed in patients with baseline IDE only. Iron and placebo groups did not differ with respect to incidence of infection (46.8% vs. 48.9%; p = 0.98), antibiotic days (14 vs. 16; p = 0.45), LOS (14 vs. 16 days; p = 0.24), ULOS (12 vs. 14 days; p = 0.69), or mortality rate (9.4% vs. 9.9%; p = 0.62).

CONCLUSIONS

Enteral iron supplementation of anemic, critically ill surgical patients does not increase the risk of infection and may benefit those with baseline IDE by decreasing the risk of RBC transfusion. A trial comparing enteral and parenteral iron supplementation in this setting is warranted (ClinicalTrials.gov number, NCT00450177).