Cave canem: HBO₂ therapy efficacy on Capnocytophaga canimorsus infections: a case series

BACKGROUND

Dog bites are a frequent injury, but the incidence and type of lesions vary across countries. Although only few patients develop complications, the treatment of advanced injuries has a considerable medical, social and economic impact. A frequently isolated pathogen in dog bite wounds is Capnocytophaga canimorsus, a bacterium that can cause sepsis or meningitis. Hyperbaric oxygen (HBO₂) therapy has been shown to be useful in treating anaerobic infections, most likely because it creates an inhospitable environment for the bacterium and enhances the patient's immune response.

AIM

We present a case series of C. canimorsus infections treated with HBO₂ in adjunction to antibiotic therapy. Furthermore, we tested the in vitro activity of ceftaroline against C. canimorsus, alone and in association with hyperbaric oxygen therapy.

METHODS

We included nine (9) patients admitted to the surgery department of "A. Cardarelli" Hospital (Naples) after dog bite, from 2010 to 2016. All were initially treated with antibiotics and required transfer to the intensive care unit due to worsening conditions. C. canimorsus was isolated from wounds, and HBO₂ therapy was administered in adjunction to antibiotics, until clinical improvement and microbiological test negativity. We tested the activity of hyperbaric oxygen therapy in adjunction to ceftaroline on cultured plates with C. canimorsus versus ceftaroline alone. Minimal inhibitory concentration was evaluated.

CONCLUSIONS

Our findings confirm the utility of HBO₂ therapy after biting injuries. Indeed, increased oxygen supply to the wound (as well as in vitro) may be toxic for bacteria, can improve healing and may improve the effectiveness of antibiotics.

Anaphylactic shock during hyperbaric oxygen therapy

A case of a 38-year-old woman is reported who was treated with hyperbaric oxygen therapy to cure a dehiscent wound. She suffered from "oral-allergy syndrome" (OAS) while eating certain fruits, and from itching when wearing latex gloves to handle hair dyes. Fifteen minutes after the start of compression, malaise, anxiety, dyspnoea, tachycardia, cold sweating and laryngeal stridor occurred. Despite intensive care treatment, face angioedema persisted for several days. On the basis of history, radioallergosorbent test (RAST) and prick tests, latex was assumed to be responsible for the anaphylactic reaction. To our knowledge, this is the first extensive report of an anaphylactic reaction to latex in a hyperbaric chamber. The lesson drawn from this case record can be summarized as follows: 1) never fail to collect a thorough history; 2) set up a latex-safe hyperbaric chamber when needed; 3) have an emergency kit always near at hand.

Effects of enzyme-replacement therapy in patients with Anderson-Fabry disease: a prospective long-term cardiac magnetic resonance imaging study

BACKGROUND

Anderson-Fabry disease is a multisystem X linked disorder of lipid metabolism frequently associated with cardiac symptoms, including left ventricular (LV) hypertrophy gradually impairing cardiac function. Evidence showing that enzyme-replacement therapy (ERT) can be effective in reducing LV hypertrophy and improving myocardial function in the long term is limited.

OBJECTIVE

This study aimed to assess the long-term effects of ERT with recombinant alpha-galactosidase A (agalsidase beta, Fabrazyme) on LV function and myocardial signal intensity in 11 patients with Anderson-Fabry disease.

PATIENTS

Eleven patients (eight males, three females) with varying stages of genetically confirmed Anderson-Fabry disease were examined by means of physical examination and magnetic resonance imaging before ERT with agalsidase beta at 1 mg/kg every other week (study 1) and after a mean treatment duration of 45 months (study 2).

RESULTS

At 45 months of treatment, LV mass and LV wall thickness had significantly reduced: 188 (SD 60) g versus 153 (47) g, and 16 (4) mm versus 14 (4) mm, respectively. Furthermore, a significant reduction in myocardial T2 relaxation times was noted in all myocardial regions, that is, interventricular septum 80 (5) ms versus 66 (8) ms, apex 79 (10) ms versus 64 (10) ms, and lateral wall 80 (8) ms versus 65 (16) ms. Changes in LV ejection fraction were not significant. Amelioration of clinical symptoms was observed in all patients.

CONCLUSIONS

Long-term therapy with agalsidase beta at 1 mg/kg every 2 weeks was effective in significantly reducing LV hypertrophy, improving overall cardiac performance and ameliorating clinical symptoms in patients with Anderson-Fabry disease.

Effect of hyperbaric oxygen therapy in experimental subcutaneous and pulmonary infections due to Pseudomonas aeruginosa

About 80% of nosocomial infections are caused by aerobic bacteria. Pseudomonas aeruginosa is a Gram-negative bacterium belonging to the Pseudomonadaceae family; P. aeruginosa is responsible for 6-22% of all hospital infections. The aim of this study was to evaluate the efficacy of hyperbaric oxygen (HBO2) therapy (2 atm abs x 55 min.day-1) alone for 8 days and combined with antibiotic chemotherapy (amikacin 15 mg.kg-1.day-1 for 8 days by intraperitoneal route) in rats infected subcutaneously and via the pulmonary route. In the rats infected by P. aeruginosa, HBO2 induced a reduction in mortality and morbidity with bacteria eradication in blood culture, bronchial aspirate, and skin biopsies when compared to control. These effects were increased by the use of amikacin, an antibiotic used for the treatment of sensitive Gram-negative bacteria.

[Effects of hyperbaric oxygenation in skin and pulmonary infections caused by Pseudomonas aeruginosa]

About 80% of nosocomial infections are caused by aerobic bacteria. The Pseudomonas aeruginosa is a Gram-negative bacterium pertaining to the Pseudomonadaceae family. P. aeruginosa is responsible for 6-22% of all hospital infections. The aim of this paper is to evaluate the efficacy of both hyperbaric oxygen-therapy (HBO 2 Atm x 35 min/day) alone for 8 days and when associated to the chemoantibiotic therapy (amikacine 15 mg/kg/day for 8 days intraperitoneal), in rats infected through pulmonary and subcutaneous intake. In rats affected by P. aeruginosa, HBO induces a significant reduction in mortality and morbility with bacteria eradication in blood culture findings, bronchial aspirate and skin biopsies. These effects were increased by the use of amikacine which is an antibiotic used for the treatment of Gram-negative bacteria.

Vasomotor responses in rats "intoxicated" with doxorubicin

In rats intoxicated with doxorubicin, vasomotor responses were evaluated 12 hr after the last dosage. In rats pretreated with doxorubicin, hypertensive responses to L-norepinephrine and L-epinephrine, and hypertension by occlusion of both common carotid arteries were significantly (p < 0.05) reduced when compared with controls. Doxorubicin pretreatment also significantly reduced the arterial hypotension due to L-isoprenaline. In rats intoxicated with doxorubicin, pretreatment with L-sulpiride (12.5 to 50 mg/Kg/day for 30 days in drinking water ad libitum) did not modify the effects of doxorubicin on vasomotor reactivity. In contrast, pretreatment with amitriptyline (12.5 to 50 mg/Kg/day in drinking water ad libitum for 30 days) potentiated the inhibitory effects of doxorubicin on vasomotor responses. In conclusion, our research shows that doxorubicin intoxication induces a significant reduction of alpha- and beta-adrenergic reactivity and of baroreceptor activity.