About Us

North of England Medical and Hyperbaric Services (NEMHS) has a 20-year history of providing state of the art Hyperbaric Oxygen Treatment to the National Health Service. The unit has received over 600 case of diving illness, from the worried well to complex cases of diving induced paraplegia.

Key features include:

  • A hospital based multi-place hyperbaric facility.
  • An Intensive Care Unit ideally located next to the chamber.
  • A strong and knowledgeable medical, nursing and technical team, led by Mr Bruce Mathew Consultant Neurosurgeon supported by Dr Ananthakrishnan Ananthasayanam and Dr Vincent Hong, both Consultant Anaesthetists with a special interest in Cardiothoracic Anaesthesia and Intensive Care Medicine.
  • Technical & Research Director Gerard Laden has 39 years of experience in all aspect of civilian sport, oilfield and military diving operation including medical research. The unit maintains a strong link with the Post Graduate Medical School with over 35 peer reviewed publications.

Meet the Directive Team

Mr Bruce Mathew

Mr Bruce Mathew

Medical Director North England Medical and Hyperbaric Services, NEMHS
Bruce is a Consultant Neurosurgeon who has also been involved in Diving and Submarine medicine for 36 years. His specific interest is in improving the management and functional outcomes in severe DCI involving the spinal cord.

+ Full Bio

Dr Ananthakrishnan Ananthasayanam

Dr Ananthakrishnan Ananthasayanam

MD FRCA FICM MSc.,(Healthcare Leadership) Consultant Anaesthetist and Intensivist
Dr Ananthasayanam is currently is one of the three clinicians managing the North of England Medical Hyperbaric unit, Spire and East Riding of Yorkshire.

He has qualified as a Consultant Anaesthetist and Intensivist with a special interest in Cardio-thoracic anaesthesia in 2005. He has extensive experience in this field, having worked in Australia, India and a number of centres in Yorkshire.

Dr Ananthasayanam, currently is the Clinical Director for Surgery in Hull and East Yorkshire Hospitals NHS Trust.

He also is the Clinical Lead Cardiothoracic Intensive care in the same Trust and has been involved in risk assessment and stratification in cardiac intensive care. He is also member of the steering group of the ICU national audit project, ArCTIC.

Dr Ananthasayanam is also the Lead Clinician for the Intensive Care Unit, Spire Hospitals, Hull and East Riding of Yorkshire.

Dr. Vincent Hong MB. BCh. BAO., FRCA, FFICM, MBA

Dr. Vincent Hong MB. BCh. BAO., FRCA, FFICM, MBA

Consultant Anaesthetist and Intensivist
Vincent is a very keen diver who prefers to spend as much time underwater as possible. He is also a passionate underwater photographer and marine conservationist. In his spare time, he loves to organise frequent dive trips to various UK and overseas dive locations.

Consultant in Cardiothoracic Anaesthesia and Intensive Care Medicine

Hull & East Yorkshire Hospitals NHS Trust
Spire Hull & East Riding Hospital

Hyperbaric Physician
North England Hyperbaric and Medical Services

Member of United Kingdom Diving Medical Committee

Recreational and Technical (CCR) Diving Instructor
PADI, BSAC, ITDA & PSAI

Gerard Laden

Gerard Laden

Technical and Research Director
Technical and Research Director of NEMHS Ltd Originally trained to dive in the Royal Navy. Last position held member of the instructional training staff of the Royal Naval diving school. Extensive experience in air, mix gas and saturation diving.

Qualifications: BSc Physiology
HSE Diving Certificate part 11, (saturation diver)

Over 33 publications including:

Pre-hospital Medicine: the principles and practice of immediate care.
Chapter 37 Acute diving emergencies.
London: Edited Greaves I, Porter KM 1999: Arnold. ISBN 0 3406 7656 6.

Hyperbaric Evacuation Contingency Planning (all adrift in a moral sea)
The international journal of the society for underwater technology SUT. Vol 31,no 3, pp109-112; 2013.

Editorial invitation - Commentary: Hyperbaric oxygen treatment for wounds - evidence and the Sword of Damocles. Laden G. Diving Hyperb Med. 2015 Dec;45(4):218.

Management of severe spinal cord injury following hyperbaric exposure.
Mathew B, Laden G. Diving Hyperb Med. 2015 Sep;45(3):210

Madden LA, Laden G. Gas bubbles may not be the underlying cause of decompression illness - The at-depth endothelial dysfunction hypothesis. Med Hypotheses 2009 April;72(4):389-92.

Vince RV, McNaughton LR, Taylor L, Midgley AW, Laden G, Madden LA. Release of VCAM-1 associated endothelial micro-particles following simulated SCUBA dives. Eur J Appl Physiol 2009 March;105(4):507-13.

Madden LA, Vince RV, Sandstrom ME, Taylor L, McNaughton L, Laden G. Microparticle-associated vascular adhesion molecule-1 and tissue factor follow a circadian rhythm in healthy human subjects. Thromb Haemost 2008 May;99(5):909-15.

Yogaratnam JZ, Laden G, Guvendik L, Cowen M, Cale A, Griffin S. Pharmacological preconditioning with hyperbaric oxygen: can this therapy attenuate myocardial ischemic reperfusion injury and induce myocardial protection via nitric oxide? J Surg Res 2008 September;149(1):155-64.

Laden GD, Purdy G, O'Rielly G. Cold injury to a diver's hand after a 90-min dive in 6 degrees C water. Aviat Space Environ Med 2007 May;78(5):523-5.

Yogaratnam JZ, Laden G, Guvendik L, Cowen M, Cale A, Griffin S. Can hyperbaric oxygen be used as adjunctive heart failure therapy through the induction of endogenous heat shock proteins? Adv Ther 2007 January;24(1):106-18.

Yogaratnam JZ, Laden G, Guvendik L, Cowen M, Cale A, Griffin S. Hyperbaric oxygen: a novel technology for modulating myocardial schemia-reperfusion via a single drug. Adv Ther 2006 July;23(4):528-33.

Yogaratnam JZ, Laden G, Madden LA, Seymour AM, Guvendik L, Cowen M et al. Hyperbaric oxygen: a new drug in myocardial revascularization and protection? Cardiovasc Revasc Med 2006 July;7(3):146-54.

Alex J, Laden G, Cale AR, Bennett S, Flowers K, Madden L et al. Pretreatment with hyperbaric oxygen and its effect on neuropsychometric dysfunction and systemic inflammatory response after cardiopulmonary bypass: a prospective randomized double-blind trial. J Thorac Cardiovasc Surg 2005 December;130(6):1623-30.

Laden G. Hyperbaric oxygen therapy for radionecrosis: clear advice from confusing data. J Clin Oncol 2005 July 1;23(19):4465-8.

Laden GD, Grout P. Aseptic bone necrosis in an amateur scuba diver. Br J Sports Med 2004 October;38(5):E19.

Abidia A, Laden G, Kuhan G, Johnson BF, Wilkinson AR, Renwick PM et al. The role of hyperbaric oxygen therapy in ischaemic diabetic lower extremity ulcers: a double-blind randomised-controlled trial. Eur J Vasc Endovasc Surg 2003 June;25(6):513-8.

Titu LV, Laden G, Purdy GM, Wedgwood KR. Gastric barotrauma in a scuba diver: report of a case. Surg Today 2003;33(4):299-301.

Laden G. Helium/oxygen and severe COPD. Lancet 2001 February 17;357(9255):559-60.

Laden G, Colvin A. Incidence of decompression sickness arising from air diving operations. Undersea Hyperb Med 1998;25(4):237-9.

Laden G. HOT MI pilot study. Hyperbaric Oxygen and Thrombolysis in Myocardial Infarction. Am Heart J 1998 October;136(4 Pt 1):749.

Laden GD. Patent foramen ovale and decompression illness in divers. Lancet 1997 January 25;349(9047):288.