HBOT For Tetanus

This 1964 case report observed nine clinical tetanus patients who showed positive symptom regression after HBOT. Disease progression was halted and reversed, convulsions decreased. Patients remained conscious and cooperative, allowing better management of respiratory issues and nutritional needs. The use of tetanus antitoxin and tracheostomy was avoided.

*Ref: PASCALE LR, et al. TREATMENT OF TETANUS BY HYPERBARIC OXYGENATION. JAMA. 1964 Aug 10;189:408-410.*

HBOT Protocol: 2 ATA. Compression: 8-15 min. Oxygen was inhaled during both compression and decompression, with a stable treatment phase of two hours. For patient comfort and safety, air breaks of 1-3 minutes were given every 15-30 minutes. Inhaled oxygen concentration ranged from 85% to 95%, typically exceeding 90%. For the first three patients, humidified oxygen was delivered via uncuffed tracheostomy tubes; dry oxygen was used for the remaining six. One or two physicians were present during each treatment.

Case Summaries:

Case 1: A 73-year-old unimmunized white male with rapidly progressing severe tetanus received standard care (including tracheostomy) plus two HBOT sessions. Each session provided temporary calm before convulsions recurred. He recovered slowly with continued conventional treatment.

Case 2: A 5-year-old unimmunized white female with moderate tetanus received conventional treatment (including tracheostomy) plus two HBOT sessions. She appeared calmer after each and showed gradual improvement after the second, recovering with a seemingly shortened course.

Case 3: An 11-year-old unimmunized female with severe tetanus (already tracheostomized) was taken directly to the chamber. Convulsions stopped during the first session. After a mild relapse, a second session allowed her to speak and cry. Trismus partially eased. Following a setback after 36 hours, she gradually improved after third and fourth sessions.

Case 4: A 70-year-old unimmunized white male with advanced tetanus (already tracheostomized) received three HBOT sessions plus conventional care. Symptoms eased after the first two sessions. He developed a high fever after the third and died 33 hours later. Autopsy revealed acute bacterial endocarditis.

Case 5: A 22-year-old unimmunized female with mild tetanus was treated without antitoxin. Despite other medications, symptoms progressed. After one HBOT session, symptoms disappeared rapidly without recurrence.

Case 6: A 19-year-old unimmunized white female with early tetanus symptoms (trismus, stiffness, severe headache) received HBOT only. Symptoms resolved completely during the first session but recurred within 12 hours. They resolved again after the second session, recurred after 42 hours, and resolved completely after a third session. She was discharged after seven days with HBOT as the sole treatment.

Case 7: A 31-year-old unimmunized male with severe tetanus (convulsions every minute) received an immediate six-hour HBOT session (cycling between 2 ATA and 1 ATA). Upon exit, he only had occasional spasms with definite improvement. He received daily sessions for the next five days, avoiding tracheostomy and achieving adequate oral intake by day three. His course appeared significantly shortened.

Case 8: A 62-year-old unimmunized white male with moderately severe tetanus (already tracheostomized) showed definite improvement in convulsions after the first HBOT session. Oral intake improved after a second session. He developed delirium tremens but improved rapidly nonetheless.

Case 9: A 55-year-old unimmunized white male with severe, rapid tetanus (already tracheostomized, stuporous) began HBOT immediately. He began to relax and respond during the first session. With daily sessions over the next two days, spasms decreased, convulsions were controlled, and he maintained oral nutrition.

Extended Literature & Discussion:

Pascale's initial series reported significant improvement in most of nine patients with 1-3 HBOT sessions and no complications.

Other reports were less optimistic. Milledge (1968) reported treating eight severe cases with 19 sessions at 2.2 ATA. Convulsions during treatment complicated six sessions, and often no clear effect was observed.

Current tetanus mortality remains high (30-50%). Conventional reliance on antitoxin, penicillin, and muscle relaxants has limitations. Antitoxin has not proven beneficial and may be harmful.

HBOT's theoretical basis: Creating high oxygen partial pressure in local anaerobic infected areas may inhibit C. tetani and prevent toxin production. High oxygen levels may also directly oxidize and detoxify the toxin or beneficially affect affected nerve cells.

Observations from these nine cases suggested HBOT could: 1) halt or reverse disease progression; 2) suppress convulsions; 3) reduce the need for tracheostomy and antitoxin; 4) lead to a more alert, cooperative patient.

No significant adverse effects from HBOT were observed in this series. Potential difficulties (ear pain during compression, oxygen toxicity, decompression sickness) were managed with techniques like intermittent air breaks and, in one case, myringotomy.

Current Clinical Management of Tetanus

Current treatment for clinical tetanus is disappointing, with a mortality rate of 30-50% showing little improvement. Conventional therapy relies on tetanus antitoxin, high-dose penicillin, muscle relaxants, sedatives, and various forms of anesthesia. The efficacy of any single element is difficult to assess. Tetanus antitoxin has not been proven beneficial, and recent observations suggest it may have harmful effects.

**Rationale for Hyperbaric Oxygen Therapy (HBOT)**

Boerema et al. demonstrated excellent results using HBOT for gas gangrene sepsis, later confirmed by Smith's team. The local anaerobic areas of *C. tetani* infection should also be susceptible to the 20-fold increase in oxygen partial pressure produced by this technique. Furthermore, tetanus toxin may be detoxified by these high oxygen pressures, as various bacterial toxins are oxygen-labile—including tetanolysin from *C. tetani*. Given HBOT's potential for a positive and specific therapeutic effect in tetanus, conducting clinical trials appears reasonable.

**Case Series Experience**

Nine clinical tetanus patients received HBOT. As consecutive patients were observed, confidence in HBOT's efficacy grew bolder. Gaining sufficient confidence from their responses, we came to use HBOT almost exclusively, essentially eliminating all standard treatments.

Patients 1-4 received HBOT plus full standard medical therapy. However, we did not believe antitoxin halted or reversed disease progression.

Patient 5, presenting with mild disease, was intentionally not given antitoxin. Her symptoms progressed over two days despite other medications. After one HBOT session, her symptoms nearly completely disappeared.

Patient 6 was hospitalized with early, progressive tetanus signs. She received **HBOT only**. Symptoms resolved rapidly and significantly during each of three sessions, with recurrences at 12 hours (after first) and 48 hours (after second). Complete recovery followed the third session.

Patients 7, 8 & 9 were admitted with severe tetanus and near-continuous convulsions. Despite prior antitoxin, penicillin, and sedatives, their disease had progressed. They received intensive HBOT, with only sodium amobarbital added for rest and antibiotics for superimposed infections. After the first HBOT session, they could take adequate oral nutrition, cooperate with care, and maintain good visceral function. Tonic spasms became intermittent after the first session and disappeared completely after the 3rd to 5th sessions. Each spontaneously reported relief of muscle pain and spasm. The clinical course in these severe cases appeared shortened, with each ready for discharge in less than two weeks.

Observed Effects & Mechanisms of HBOT

HBOT appeared to directly influence the clinical course of tetanus by:

1.  Permanently or temporarily halting or reversing disease progression. With each treatment, recurrence became less likely and benefits lasted longer.

2.  Suppressing or abolishing spasms and convulsions more rapidly, though repeated sessions might be needed for complete abolition.

3.  Relaxing muscle rigidity more easily in mild than in severe cases. In more severe cases, the response might be slight, but each subsequent treatment tended to further relax the spasms. The extent and frequency of HBOT must be individualized for each case.

The indirect impacts of these responses on the clinical course were significant: The need for tracheostomy was reduced, if not nearly eliminated. Patients could accept oral feeding. Having a more alert, manageable, and cooperative patient changed the requirement for a dark, quiet room with deep sedation to a normal hospital environment. Eliminating antitoxin avoided using a potentially harmful and dangerous agent.

The mechanism of HBOT's action may be specific or non-specific. High oxygen pressure should penetrate hypoxic areas, inhibiting *C. tetani* and preventing toxin production. Direct oxidation of the toxin, either free or at its site of action on nerve cells, is a distinct possibility. Additionally, high oxygen pressure may have a non-specific beneficial effect on affected nerve cells.

Safety and Potential Difficulties

No significant adverse effects from HBOT were observed. Potential difficulties, which must be considered, fall into three periods:

1.  **During Compression:** Primarily ear discomfort, possibly severe pain, hemorrhage, and eardrum rupture. In the final patient, needle myringotomy was attempted to manage this.

2.  **During HBOT at Pressure:** The main concern is oxygen toxicity. Symptoms progress from twitching to convulsions, hemiplegia, and death. The mechanism is unclear. In acutely ill, anesthetized, or comatose patients, these signs may be hard to recognize. We interrupted oxygen inhalation every 15-30 minutes to try to prevent this complication.

3.  **During Decompression:** Various symptoms of decompression sickness may be encountered.

Commentary:

Most foreign literature on HBOT for tetanus dates from the 1960s-70s.

Clinical results vary. The poor outcomes in Milledge's eight severe cases, compared to the positive results here, may relate to the use of a higher pressure (2.2 ATA/34 Psi) pure oxygen chamber for two hours, potentially exacerbating spasms. HBOT pressure and frequency must be individualized.

HBOT has a clear therapeutic target: creating a high-oxygen environment to inhibit the anaerobic C. tetani.

Drug Timing Note: Metronidazole is the antibiotic of choice for tetanus. As HBOT may inactivate its metabolites, it is recommended to administer metronidazole after each HBOT session. For antibiotics requiring normoxia (e.g., aminoglycosides), IV administration 30-60 minutes before HBOT or oral administration 2-3 hours before is ideal.

Promoting the understanding and proper application of HBOT requires our collective effort.

Key Takeaway: This historical case series suggests HBOT may be a valuable adjunctive therapy for tetanus, potentially improving symptoms, shortening course, and reducing the need for invasive procedures. Treatment parameters must be carefully individualized.

Article reposted from Renyi Hyperbaric Oxygen