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Instantaneous rigor or something else?

Instantaneous rigor or something else?”>Correspondence

Instantaneous rigor or something else?B,BB

To the Editor,

Lee and Jung [1] had interpreted Jaw muscle stiffness (Masseter spasm) as instantaneous rigor. “Cadaveric spasm” or “instantaneous rigor” is a rare form of virtually rapid rigor that develops at the time of death with no period of post-mortem primary ftaccidity of muscles [2]. It often crystallizes the last activity of the victim prior to death, and hence, it becomes an important one in forensic investiga- tions. It rarely involves the whole body but typically involves only a group of muscles, such as the hands or arms. This phenomenon occurs when ATP supply of the body is exhausted at the time of death, for example, in a man who was shot dead after struggle.

Chakravarthy [3] reported antemortem muscle stiffness in the form of Rigor mortis in a live patient and it was criticized. Masseter spasm is a common feature of hypoxia and is not an unheard phenomenon in patients with cardiac arrest, which is often known as hypoxic clenching or jaw clenching. Unfortunately, it is less or never discussed in the life support training programs. In the present context, we would like to highlight the mechanism and implications of this entity.

Muscle stiffness may happen owing to interplay of several brain stem structures and neurochemicals released during hypoxia affecting modulation of muscle tone. Kranjc et al.

[4] reported the occurrence of maximal neurotransmitter changes after hypoxic insult. Probably, oxygen and/or glucose deprivation disturb electrical transmission in the brain, alter cerebral energy mechanisms and contribute to accumulation of free radicals, all of which enhance resting muscle tension with a more pronounced effect on the masseter, thus resulting in Hypoxic jaw clenching [5].

The rigidity/spasm is usually transient and resolves spontaneously but may be prolonged as reported [1]. This stresses the importance of pre-oxygenation in rapid sequence intubation and a contingency plan in failed airway. Proper bag mask ventilation and blind Nasotracheal intubation with or without lighted stylet are viable options if masseter spasm is prolonged.

Before embarking non-responsiveness to succinylcholine, one has to exclude improper technique of drug administra- tion, ineffective chest compression or malfunction of the intravenous line rather than patient’s physiology. The succinylcholine per se can produce transient masseter spasm [6] but resolves while fasciculation stops. However, other differential diagnoses for masseter spasm are pseudo- cholinesterase deficiency, myotonia and trismus of masseter as seen in malignant hyperthermia. The entity of masseter spasm or hypoxic jaw clenching has to be included in the educational programs on resuscitation.

? Financial support-Nil.

?? Conftict of interest-Nil.

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Subramanian Senthilkumaran

Sri Gokulam Hospitals & Research Institute

Salem, TamilNadu, India E-mail address: [email protected]

Ritesh G. Menezes

Srinivas Institute of Medical sciences & Research Centre

Mangalore, India

Savita Lasrado

Father Muller Medical College

Mangalore, India

Ponniah Thirumalaikolundusubramanian

Chennai Medical College Hospital & Research Center

Irungalur, Trichy, India

http://dx.doi.org/10.1016/j.ajem.2012.08.017

References

  1. Lee JH, Jung KY. Emergency cricothyrotomy for trismus caused by instantaneous rigor in cardiac arrest patients. Am J Emerg Med 2012;30: 1014.e1-2.
  2. Knight B. Forensic pathology. 2nd ed. London: Arnold; 1996.
  3. Chakravarthy M. “Rigor mortis” in a live patient. Am J Forensic Med Pathol 2010;31:87-8.
  4. Krajnc D, Wemlinger TA, Neff NH, Hadjiconstantinou M. Neonatal hypoxia: early neurotransmitter responses and the consequences of treatment with GM1 ganglioside. J Pharmacol Exp Ther 1994;271: 1299-305.
  5. Pedersen JZ, Bernardi G, Centonze D, Pisani A, Rossi L, Rotilio G, et al. Hypoglycemia, hypoxia, and ischemia in a corticostriatal slice preparation: electrophysiologic changes and ascorbyl radical formation. J Cereb Blood Flow Metab 1998;18:868-75.
  6. Roman CS, Rosin A. Succinylcholine-induced masseter muscle rigidity associated with rapid sequence intubation. Am J Emerg Med 2007;25: 102-4.

    Optimal initial anticoagulant therapy in pulmonary thromboembolism: randomized trial suggested

    To the Editor,

    Numerous lines of evidence suggest a need for an improvement in pulmonary thromboembolism (PTE) therapy:

    According to relevant US data (Heart Disease and Stroke Statistics-2012 Update), 30-day mortality of PTE is no less than 40.9%, which is clearly not acceptable [1].

  7. Moreover, residual thrombosis in pulmonary arteries can be found in 50% of PTE patients despite adequate antic- oagulation at 1 year [2]. Sometimes, residual thrombosis is diagnosed in as many as 70.9% of PTE patients, months after the index episode, which is much higher than we usually think [3]. American Heart Association Guidelines have recognized that the amount of residual thrombus after

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