|EVIDENCE BASED DATA
|Year : 2009 | Volume
| Issue : 3 | Page : 367-368
Tetanus: Anaesthetic Management
Senior Prof. & Head, Department of Anaesthesiology, R.N.T.Medical College, Udaipur (Raj.), India
|Date of Web Publication||3-Mar-2010|
25, Polo Ground, Udaipur (Raj.)
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Bajaj P. Tetanus: Anaesthetic Management. Indian J Anaesth 2009;53:367-8
Tetanus is a rare condition in the western world, primarily due to widespread vaccination programs, from infancy to adulthood.
Clostridium tetani spores usually enter the tissue through a penetrating contaminated wound, and after a period of anaeroi incubation, they become bacilli that release tetanus toxin. The toxin enters peripheral neurons and travels retrograde up axons to the central nervous system. It can enter motor, sensory, and autonomic neurons, although radiolabelled assays have shown a predilection for inhibitory neurons. Most of the clinical disease results from motor and autonomic inhibition. Tetanospasmin is a metalloprotease substance which acts at the presynaptic membrane to cleave synaptobrevin, a protein that allows fusion of neurotransmitter vesicles to nerve membranes. When this fusion process is prevented , neurotransmitters are not released into the synapse and neurotransmission is blocked. Centrally, transmission along the inhibitory gamma-amino butyric acid (GABA) and glycinergic neurons is interrupted, and at the level of the spinal cord, inhibitory interneurons are blocked  .
Initial management of muscle spasms involves sedation and a dark, quiet room. Numerous approaches are reported in the literature to relieving spasms, including benzodiazepines, barbiturates, anticonvulsants, narcotics, baclofen, dantrolene  , and propofol  . Pretreatment with sedatives and analgesics may be necessary prior to nursing care and procedures to avoid triggering paroxysms. Benzodiazepines are often used as first-line treatment. Baclofen has been shown in a few case series to completely relieve spasms when given via the intrathecal route but carries a significant risk of respiratory depression  .
The anaesthesiologists may be consulted for management of emergent acute respiratory failure from laryngospasm or subacute respiratory failure. The diaphragm and the laryngeal and pharyngeal muscles are all affected, and in combination with the profuse bronchial and oral secretions seen in tetanus, management of an unsecured airway is difficult. Accompanied by increased abdominal pressures and gastrointestinal stasis, even the awake patient is at increased risk of aspiration, which is a common complication  . It should be noted that the literature does not report trismus to be a problem during tracheal intubation after neuromuscular relaxation. The response to depolarizing and non-depolarizing neuromuscular blockade is normal in tetanus  , although use of depolarizing agents, such as succinlycholine, should be carefully considered. Repeated administration of intramuscular succinylcholine with complication has been documented for the treatment of tetanic contractures  . However, there are at least two reports of hyperkalemic cardiac arrest after succinylcholine administration late in the course of tetanus  . Pancuronium carries the theoretical risk of increased adrenergic activity but has been shown not to increase complications when compared to other agents  . Hypoxemia is a common problem, even in the intubated patient, because of a restrictive defect from chest wall rigidity leading to atelectasis and increased bronchial secretions obstructing the airways  . Hypoxemia from ventilation-perfusion mismatch may occur without chest radiograph abnormalities  . Prolonged ventilation puts the patient at increased risk of pneumonia, which often complicates the course of severe tetanus, as does sepsis and acute respiratory distress syndrome ,.
Surgical procedures in tetanus patients are occasionally necessary, such as debridement of the injury and tracheostomy. Little evidence exists to recommend specific anaesthetic protocols. Similar to the recommendation to pretreat patients prior to nursing care  .
Patients should be deeply anaesthetized and possibly paralyzed to prevent triggering hypertensive crises and spasms during the procedure. Most intravenous anaesthetic agents and sedatives have been used in tetanus patients. Epidural mepivicaine and high continuous spinal bupivacaine  have been used successfully to treat autonomic instability without complications related to the neuraxial technique, but norepinephrine infusions were required to maintain mean arterial pressure. Spinal anaesthesia has been used for lower extremity debridement in a patient with mild tetanus who was not tracheally intubated  . There is no literature examining the safety of volatile anaesthetics.
Electrolyte derangements from tetanus-induced renal dysfunction should be corrected preoperatively  . Appropriate invasive monitoring should be secured, and titrable drug infusions for intra-operative management of autonomic storms should be prepared before proceeding with a surgical procedure. Ideally, patients being considered for debridement and tracheostomy should undergo anaesthesia and surgery before severe autonomic dysfunction develops.
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