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S N Mardel

Publications and source records attributed to S N Mardel.

10 recordsLinked to original sources
PubMed1998

Reduced quality of clot formation with gelatin-based plasma substitutes.

We have studied, over a wide range of dilutions using techniques of clot weight, thrombelastography and scanning electron microscopy, the physical properties of a blood clot formed in vitro when fresh blood was diluted with gelatin-based colloid solutions compared with crystalloid controls. The colloid solutions tested (3.5% polygeline (Haemaccel) and 4% succinylated gelatin (Gelofusine)) produced clots that had reduced median weight (P < 0.001 and P = 0.018, respectively) and reduced mean shear modulus (P < 0.001) compared with crystalloid controls. Scanning electron microscopy showed that the fibrin formed a less extensive mesh in the presence of the gelatin-based colloids compared with crystalloid. Reduction in clot quality with gelatin-based colloids has not been noted previously and further work is needed to ascertain if this occurs in vivo as these solutions are used frequently in patients who require full haemostatic competence.

Blood Cells↗
PubMed1996

A computer model of major haemorrhage and resuscitation.

An interactive computer model is described which uses 'blood volume deficit' and 'bleeding duration' together with rates of infusion to simulate the first two hours of haemorrhage. It allows multiple infusions of various fluids to be specified and includes an estimation of the volumes added by the transcapillary refill mechanism. The output is expressed graphically in terms of blood pressure and haematocrit at intervals of one minute. This computer model has proved useful for assessing the effects of a range of variables in hypovolaemic shock. It has considerable potential for investigating the relative efficacy of various clinical protocols and could provide an alternative to animal experimentation which has so far been the primary method of obtaining data on acute haemorrhage. It is also a useful teaching aid.

Animals↗
PubMed1995

Validation of a computer model of haemorrhage and transcapillary refill.

A computer model is described which uses blood volume deficit and its duration to simulate the first two hours of haemorrhage, including an estimation of the blood volume added by Starlings transcapillary refill mechanism. Computer prediction of the haematocrit was compared with published data on haemorrhage in animals. There was close correlation with data on the haemodilution caused by Starling's transcapillary refill mechanism in conscious swine (r = 0.84).

Animals↗
PubMed1993

Cervical collars: a potential risk to the head-injured patient.

Interface pressures beneath six types of collar in volunteers were measured. Under certain types of collar mean interface pressures of more than 10 mmHg were obtained, with several individual readings around 30 mmHg. By causing jugular venous obstruction a similar rise in intracranial pressure may be produced inadvertently. The mechanisms of action for this are discussed. Those collars with the least tendency to produce jugular venous obstruction were of the moulded variety which extend support to the occiput, mandible and shoulder girdle. The authors therefore recommend this type of cervical splintage device where injury of the cervical spine is suspected. This paper emphasizes the potential danger to head-injured patients when the other devices are applied too tightly, producing a 'venous tourniquet' effect.

Craniocerebral Trauma↗
PubMed1992

Management of the moribund carbon monoxide victim.

Carbon monoxide (CO) poisoning is the commonest single cause of fatal poisoning in the U.K. (Broome & Pearson, 1988). The clinical features are numerous and include headache, fatigue, dizziness, confusion, memory loss, paraesthesia, chest pain, abdominal pain, nausea, and diarrhoea as well as coma, convulsions and death. Without adequate treatment many patients develop neuropsychiatric sequelae including headaches, irritability, memory loss, confusion and personality changes. The diagnosis of CO poisoning is often suggested only by circumstances surrounding the victim, and remains a challenge to the A&E department. Hyperbaric oxygen therapy (HBO) is internationally accepted as the most powerful form of treatment in severe cases (Drug & Therapeutics Bulletin, 1988; Lowe-Ponsford & Henry, 1989). However, in the U.K. treatment with HBO is often not considered due to lack of hyperbaric facilities (Meredith & Vale, 1988; Anand et al., 1988), and due to inadequate awareness on the part of hospital staff. We report a case of a patient deeply unconscious as a result of CO poisoning, in which serial treatments with HBO over a period of 14 days, produced dramatic results.

Adult↗