Alessandro Marroni

DAN Europe · Research

Background: The present study was designed to observe if different decompression profiles, calculated as a function of tissue supersaturation during ascent, would result in significantly different outcomes, measured through different physiological stress indicators, even in the absence of symptoms of decompression sickness. Aim: The aim of this stu...

Background The aim of this work was to investigate the serum amino acid (AA) changes after a breath-hold diving (BH-diving) training session under several aspects including energy need, fatigue tolerance, nitric oxide (NO) production, antioxidant synthesis and hypoxia adaptation. Twelve trained BH-divers were investigated during an open sea trainin...

Inert gas bubbles in tissues and in blood have been historically considered as the only triggering factors for DCS, but now many other factors are considered to affect the final outcome of a decompression profile for a certain individual. In this sense, inflammation seems to play a relevant role, not only due to the physical damage of tissues by th...

(1) Background: SCUBA diving can influence changes of several hematological parameters (HP) but the changes of HP in the decompression phases are still unclear. The aim of this study was to investigate any possible relationship between HP and predisposition to inert gas bubble formation after a single recreational dive. (2) Methods: Blood, obtained...

Background Breath-hold diving (BH-diving) is associated to extreme environmental conditions, prolonged physical activity, and complex adaptation mechanisms to supply enough O2 to vital organs. Consequently, one of the biggest effects could be an increased exercise-induced muscle fatigue, in both skeletal and cardiac muscles that can induce an incre...

Introduction: Divers with a patent Foramen Ovale (PFO) have an increased risk for decompression sickness (DCS) when diving with compressed breathing gas. The relative risk increase, however, is difficult to establish as the PFO status of divers is usually only determined after a DCS occurrence. Methods: This prospective, single-blinded, observation...

The metabolism of nitric oxide plays an increasingly interesting role in the physiological response of the human body to extreme environmental conditions, such as underwater, in an extremely cold climate, and at low oxygen concentrations. Field studies need the development of analytical methods to measure nitrite and nitrate in plasma and red blood...

Introduction: Heart rate variability (HRV) during underwater diving has been infrequently investigated because of environment limitations and technical challenges. This study aims to analyze HRV changes while diving at variable hyperoxia when using open circuit (OC) air diving apparatus or at constant hyperoxia using a closed-circuit rebreather (CC...

Introduction Nitric oxide (NO) is an essential signaling molecule modulating the endothelial adaptation during breath-hold diving (BH-diving). This study aimed to investigate changes in NO derivatives (NOx) and total antioxidant capacity (TAC), searching for correlations with different environmental and hyperbaric exposure. Materials and methods B...

Background Several mechanisms allow humans to resist the extreme conditions encountered during breath-hold diving. Available nitric oxide (NO) is one of the major contributors to such complex adaptations at depth and oxidative stress is one of the major collateral effects of diving. Due to technical difficulties, these biomarkers have not so far be...

Introduction: The effects of scuba diving on the vessel wall have been studied mainly at the level of large conduit arteries. Data regarding the microcirculation are scarce and indicate that these two vascular beds are affected differently by diving. Methods: We assessed the changes in cutaneous microcirculation before an air scuba dive, then 30...

The purpose of this study was to analyze the correlation between decompression-related physiological stress markers, given by inflammatory processes and immune system activation and changes in Heart Rate Variability, evaluating whether Heart Rate Variability can be used to estimate the physiological stress caused by the exposure to hyperbaric envir...

As a result of strict preventive measures taken by almost all countries worldwide to combat the spread of SARS-CoV2 and COVID-19 disease, there is a significant impact on the availability of healthcare resources, not only hospital-based but also for emergency first aid and patient transport. Generally, all sports activities are advised against, exc...

In Europe, most of Hyperbaric Oxygen (HBO) sessions are conducted in multiplace chambers under the direct supervision of medical personnel. Regardless of strict cleaning and disinfection procedures of breathing masks or oxygen hoods implemented in all hyperbaric medical facilities, a cumulation of several patients in the confined space creates the...

The article describes a dataset of doppler ultrasound audio tracks taken on a sample of 30 divers according to the acquisition protocol defined by the Divers Alert Network. The audio tracks are accompanied by a medical evaluation for the decompression sickness risk according to the Spencer's scale levels. During the acquisition campaign, each diver...

Divers’ health state after underwater activity can be assessed after the immersion using precordial echo Doppler examination. An audio analysis of the acquired signals is performed by specialist doctors to detect circulating gas bubbles in the vascular system and to evaluate the decompression sickness risk. Since on-site medical assistance cannot a...

Divers Alert Network Europe has created a database with a large amount of dive-related data that has been collected since 1993 within the scope of the Diving Safety Laboratory citizen science project. The main objectives of this study are the grouping divers by their health information and revealing significant differences in diving parameters usin...

Introduction: Nitric oxide (NO) plays an important role in the physiology and pathophysiology of diving, and the related endothelial dysfunction and oxidative stress roles have been extensively investigated. However, most available data have been obtained before and after the dive, whilst, as far as we know, no data is available about what happens...

Dive computers have an important potential for citizen science projects where recreational SCUBA divers can upload the depth temperature profile and the geolocation of the dive to a central database which may provide useful information about the subsurface temperature of the oceans. However, their accuracy may not be adequate and needs to be evalua...

Introduction: Because a significant association between training to perform emergency free ascent (EFA) and the occurrence of pulmonary barotrauma (PBT) was demonstrated in 2006, the Belgian Underwater Federation (BUF) decided to discontinue this procedure. An evaluation was needed 10 yr after the implementation of this change. Methods: All medi...

Background: The physiological and pathophysiological mechanisms that govern diving, both self-contained underwater breathing apparatus (SCUBA) and breath-hold diving (BH-diving), are in large part well known, even if there are still many unknown aspects, in particular about cell metabolism during BH-diving. The scope of this study was to investiga...

Introduction: Scuba diving is an important marine tourism sector, but requires proper safety standards to reduce the risks and increase accessibility to its market. To achieve safety goals, safety awareness and positive safety attitudes in recreational scuba diving operations are essential. However, there is no published research exclusively focusi...

The use of precordial Doppler monitoring to prevent decompression sickness (DS) is well known by the scientific community as an important instrument for early diagnosis of DS. However, the timely and correct diagnosis of DS without assistance from diving medical specialists is unreliable. Thus, a common protocol for the manual annotation of echo Do...

Introduction: The popularity of SCUBA diving is steadily increasing together with the number of dives and correlated diseases per year. The rules that govern correct decompression procedures are considered well known even if the majority of Decompression Sickness (DCS) cases are considered unexpected confirming a bias in the “mathematical ability”...

Drowning is the major cause of death in self-contained underwater breathing apparatus (SCUBA) diving. This study proposes an embedded system with a live and light-weight algorithm which detects the breathing of divers through the analysis of the intermediate pressure (IP) signal of the SCUBA regulator. A system composed mainly of two pressure senso...

Dr Sherlock asks for clarification on the approach adopted by the European Committee on Hyperbaric Medicine (ECHM) to assessing evidence for establishing indications for hyperbaric oxygen treatment (HBOT). Firstly, regardless of the strict process of editing and proof-reading of tables included in the above-mentioned publication, we received commen...

Consistent with the Committee on Publication Ethics guidelines, we the above authors are initiating a partial retraction and correction of our paper: Mathieu D, Marroni A, Kot J: Tenth European Consensus Conference on Hyperbaric Medicine: recommendations for accepted and non-accepted clinical indications and practice of hyperbaric oxygen treatment....

This study is about a system for monitoring the glucose of scuba divers while underwater. The system measures the glucose of the diver at intervals of five minutes and transmits the recorded data to the surface surpervision team. This is specifically beneficial to the diabetic scuba divers, allowing their supervisers to monitor their glucose level...

The tenth European Consensus Conference on Hyperbaric Medicine took place in April 2016, attended by a large delegation of experts from Europe and elsewhere. The focus of the meeting was the revision of the European Committee on Hyperbaric Medicine (ECHM) list of accepted indications for hyperbaric oxygen treatment (HBOT), based on a thorough revie...

"CADDY - Cognitive Autonomous Diving Buddy" is an FP7 project that that is devoted to developing a cognitive underwater robotic system that will help divers during their activities in this hazardous environment. The envisioned resulting system will play a threefold role similar to those that a human buddy diver should have: buddy "observer", buddy...

Solutions and services for e-Health and telemedicine are constantly spreading and becoming increasingly important in the health area thanks to last innovations in electronics, informatics and telecommunications. This work proposes an innovative service for the e-Health oriented to the maximum ease of use and to the sharing of vital signs. The propo...

Divers Alert Network (DAN) created a database (DB) with a big amount of dive related data which has been collected since 1994 within the scope of Dive Safety Laboratory (DSL) project. The aim of this study is to analyze the DB using data mining techniques. The clustering of divers by their health and demographic information and reveal significant d...

Divers operate in harsh and poorlymonitored environments, inwhich the slightest unexpected disturbance, technical malfunction, or lack of attention can have catastrophic consequences. Motivated by these considerations, the “CADDY—Cognitive Autonomous Diving Buddy” FP7 project sets forth the main goal of developing a cooperative autonomous underwate...

Abstract INTRODUCTION: Neurological symptoms after breathhold (BH) diving are often referred to as "Taravana" and considered a form of decompression sickness. However, the presence of "high" gas embolism after BH diving has never been clearly shown. This study showed high bubble formation after BH diving. MATERIALS AND METHODS: We performed transth...

The tenth European Consensus Conference on Hyperbaric Medicine took place in Lille, France, 14-16 April, 2016, attended by a large delegation of experts from Europe and elsewhere. The focus of the meeting was the revision of the European Committee on Hyperbaric Medicine (ECHM) list of accepted indications for hyperbaric oxygen treatment (HBOT), bas...

INTRODUCTION: Insulin-dependent diabetes has been considered a scuba diving contraindication. This is currently being reconsidered for well-controlled diabetes. We developed a real-time continuous glucose monitor (CGM) to check glycemia, or blood glucose (BG), during diving, both for prospective studies and to increase diabetic diver safety, allowi...

"CADDY - Cognitive Autonomous Diving Buddy" is an FP7 project that started in January 2014. Seven partner institutions have joined their efforts towards developing a cognitive underwater robotic system that will help divers during their activities in this hazardous environment. The resulting system will play a threefold role similar to those that a...

Decompression sickness (DCS) is a systemic disorder assumed due to gas bubbles, but additional factors are likely to play a role. Circulating microparticles, vesicular structures with diameters of 0.1 to 1.0 µm, have been implicated but data in human divers has been lacking. We hypothesized that the number of blood-borne annexin V-positive micropar...

Breath-hold diving-induced hemoptysis (BH-DIH) has been reported in about 25% breath-hold divers (BHD) and is characterized by dyspnea, coughing, hemoptysis and chest pain. We investigated whether eNOS G894T, eNOS T786C and ACE insertion/deletion I/D genetic variants, are possible BH-DIH risk factors. 108 experienced healthy instructor BHDs with th...

This paper summarizes the main accomplishments of the first year of the FP7 project “CADDY — Cognitive Autonomous Diving Buddy”. The main objective of the project is to replace a human buddy diver with an autonomous underwater vehicle and add an autonomous surface vehicle to improve monitoring, assistance, and safety of the diver's mission. While a...

The main objective of the CADDY project is to replace a human buddy diver with an autonomous underwater vehicle and add a new autonomous surface vehicle to improve monitoring, assistance, and safety of the diver's mission. However, the use of robots underwater may also bring additional safety requirements. Within the scope of this research, the exi...

Inert gas accumulated after multiple recreational dives can generate tissue supersaturation and bubble formation when ambient pressure decreases. We hypothesized that this could happen even if divers respected the currently recommended 24-hour pre-flight surface interval (PFSI). We performed transthoracic echocardiography (TTE) on a group of 56 hea...

The physiology and pathology of decompression have been studied for over 100 years. The procedures that have been developed for preventing decompression sickness and for its treatment have proven to be relatively effective, even though a large number of individual factors – of which many are not sufficiently understood – seem to play a role. Even i...

Compared with other sports, SCUBA diving remains a relatively safe activity but precisely defining risk is important. Diving databases such as the Diving Safety Laboratory (DSL) collection by Divers Alert Network (DAN) Europe can provide new insights into the causes of diving accidents, including decompression sickness (DCS) incidence with respect...

Diving above sea level has different motivations for recreational, military, commercial and scientific activities. Despite the apparently wide practice of inland diving, there are three major discrepancies about diving at altitude: threshold elevation that requires changes in sea level procedures; upper altitude limit of the applicability of these...

Introduction: Flying after diving may increase decompression sickness risk (DCS), but strong evidence indicating minimum preflight surface intervals (PFSI) is missing. Methods: On return flights after a diving week on a live-aboard, 32 divers were examined by in-flight echocardiography with the following protocol: 1) outgoing flight, no previous...

Diving is defined as an underwater activity during which a person breathes from a source of compressed gas. In this chapter it also includes breath-hold diving in which the person stays underwater for the duration of the breath-hold time and then returns to the surface for a further breath. The definition does not include diving by head-first entry...

The majority of diving-related fatalities are encountered during recreational diving. Advances have to be made to prevent these fatalities to happen. Unfortunately, there is generally little awareness within the diving community on the importance of injury prevention and drowning prevention. As a result, there is lack of data on why and when these...

A detailed knowledge of the physics and physiology of diving is not needed by those concerned with the prevention and management of drowning. What is necessary to know is that increased environmental pressure is a unique physiological variable that affects all those who descend below the surface of the sea. By definition man is exposed to 1 atm of...

First aid and resuscitation to an injured or drowned diver follow most of all the common resuscitation guidelines. There are however some modifications. This chapter describes the first aid protocol as is developed by the Divers Alert Network (DAN). The guidelines can be considered to be the world’s standard in the field of diving first aid. One mo...

The first divers, historically, were the breath-hold divers who, through the centuries, have dived for sponges, shellfish and salvage. This type of diving is still a practical activity in many parts of the world. The duration underwater for a diver with no breathing apparatus is limited by the breath-hold endurance. This is called apnoeic diving. N...

Water is a hazardous and unforgiving environment, but if the hazards are controlled, the risks of diving are low. The objective of this chapter is to outline ways in which the risk of drowning among divers may be reduced and also to focus on those additional features of management that do not feature routinely in the treatment of a nondiver. Althou...

The existence of a right-to-left shunt may increase the likelihood of micro-embolism by allowing a flux of bubbles under hyperbaric conditions. The aim of the study was to measure the relationship between these shunts and bubbles in 10 consecutive subjects using trans-thoracic and trans-esophageal echocardiography. In video frames, all cardiac cham...

La diffusione dello sport subacqueo tra le donne è aumentata dagli anni ottanta (23%) ai giorni nostri (26,4%), coinvolgendo tutte le fasce di età (media 35 anni) e con un numero di immersioni/anno quasi pari a quello dei maschi (48 vs 52). Se infatti all’origine dell’attività subacquea moderna, nella seconda metà del 20° secolo, questa era derivat...

Scuba and breath-hold divers are compared to investigate whether endothelial response changes are similar despite different exposure(s) to hyperoxia. 14 divers (nine scuba and five breath-holding) performed either one scuba dive (25m/25 minutes) or successive breath-hold dives at a depth of 20 meters, adding up to 25 minutes of immersion time in a...

After repetitive deep dives, breath-hold divers are often affected by a syndrome characterized by typical symptoms such as cough, sensation of chest constriction, blood-striated expectorate (hemoptysis) and, rarely, an overt acute pulmonary edema syndrome, often together with various degrees of dyspnea. The aim of this work is an epidemiological in...

The aim of this study was to evaluate the effect of a single, shallow, swimming pool scuba dive on pulmonary function in divers with asthma as compared to controls. Opinions concerning the risks of diving with asthma are still contradictory and inconclusive in the diving community. Baseline pulmonary function tests (PFTs) were performed on a group...

Type 1 diabetes is commonly considered a contraindication for scuba diving, mainly on account of the risk of hypoglycemia. The Diabete Sommerso (Diabetes Underwater) project was launched in 2004 in Milan. The rationale was that, provided all the necessary safety conditions are satisfied, there are many good reasons for proposing this sport to young...

Bubble recognition is a challenging problem in a broad range from mechanics to medicine. These gas–filled structures whose pattern and morphology alter in their surrounding environment would be counted either manually or with computational recognition procedures. In cardiology, user dependent bubble detection and temporal counting in videos require...

2D echocardiography which is the golden standard in clinics becomes the new trend of analysis in diving via its high advantages in portability for diagnosis. By the way, the major weakness of this system is non-integrated analysis platform for bubble recognition. In this study, we developed a full automatic method to recognize bubbles in videos. Ga...

In cardiology, automatic recognition and image analysis still conserve computational challenges in terms of medical guidance and diagnosis. Bubbles or microemboli that circulate into cardiopulmonary system are considered suspicious for several medical problems such as decompression sickness, stroke and migraine. The aim of our work is to develop an...

Unlabelled: Recreational divers are introducing "deep stops" at half the depth (HD-DS) to reduce the risk of spinal DCS with only Doppler evidence to support it. Therefore this research was designed to show the effect of an HD-DS on spinal DCS manifestations by evaluating whether: (1) air diving-induced spinal DCS could be produced in awake, freel...

The purpose of the study was to analyze the ultrasound lung comets (ULCs) variation, which are a sign of extra-vascular lung water. Forty-two healthy individuals performed breath-hold diving in different conditions: dynamic surface apnea; deep variable-weight apnea and shallow, face immersed without effort (static maximal and non-maximal). The numb...

(Lafere P, Balestra C, Hemelryck W, Donda N, Sakr A, Taher A, Marroni S. Germonpre P. Evaluation of critical flicker fusion frequency and perceived fatigue in divers after air and enriched air nitrox diving. Diving and Hyperbaric Medicine. 2010;40(3):114-8.) Introduction: Many divers report less fatigue following dives breathing enriched air nitrox...

Many divers report less fatigue following dives breathing enriched air nitrox (EANx) compared with breathing air. A reduction of post-dive fatigue with EANx would suggest a pathological origin, possibly the presence of asymptomatic nitrogen bubbles in the body after a dive. We studied fatigue in 219 healthy divers performing either an air (n = 121)...