Physiological and radiological parameters predicting outcome from penetrating traumatic brain injury treated in the deployed military setting.

INTRODUCTION: Penetrating traumatic brain injury (TBI) is the most common cause of death in current military conflicts, and results in significant morbidity in survivors. Identifying those physiological and radiological parameters associated with worse clinical outcomes following penetrating TBI in the austere setting may assist military clinicians to provide optimal care. METHOD: All emergency neurosurgical procedures performed at a Role 3 Medical Treatment Facility in Afghanistan for penetrating TBI between 01 January 2016 and 18 December 2020 were analysed. The odds of certain clinical outcomes (death and functional dependence post-discharge) occurring following surgery were matched to existing agreed preoperative variables described in current US and UK military guidelines. Additional physiological and radiological variables including those comprising the Rotterdam criteria of TBI used in civilian settings were additionally analysed to determine their potential utility in a military austere setting. RESULTS: 55 casualties with penetrating TBI underwent surgery, all either by decompressive craniectomy (n=42) or craniotomy±elevation of skull fragments (n=13). The odds of dying in hospital attributable to TBI were greater with casualties with increased glucose on arrival (OR=70.014, CI=3.0399 to 1612.528, OR=70.014, p=0.008) or a mean arterial pressure <90 mm Hg (OR=4.721, CI=0.969 to 22.979, p=0.049). Preoperative hyperglycaemia was also associated with increased odds of being functionally dependent on others on discharge (OR=11.165, CI=1.905 to 65.427, p=0.007). Bihemispheric injury had greater odds of being functionally dependent on others at discharge (OR=5.275, CI=1.094 to 25.433, p=0.038). CONCLUSIONS: We would recommend that consideration of these three additional preoperative clinical parameters (hyperglycaemia, hypotension and bihemispheric injury on CT) when managing penetrating TBI be considered in future updates of guidelines for deployed neurosurgical care.

Intra-ocular pressure changes following laryngeal mask airway insertion: a comparative study.

We compared the effects of the Brain laryngeal mask airway with a tracheal tube on intra-ocular pressure. Propofol was used as induction agent and atracurium as relaxant. Twenty-six patients with normal intra-ocular pressure undergoing cataract surgery were randomly allocated to two groups. Group A (n = 13) had a laryngeal mask airway inserted and Group B (n = 13) had a tracheal tube inserted. Intra-ocular pressure was measured just before insertion of the airway, 20 s after insertion and at 2 min. In the laryngeal mask airway group there were no significant changes in mean intra-ocular pressure. In the tracheal tube group there was a significant rise in mean intra-ocular pressure at 20 s (p = 0.0056) which returned to pre-insertion levels at 2 min. We conclude that the laryngeal mask airway continues to have advantages over the tracheal tube for ophthalmic surgery despite the use of propofol and atracurium as anaesthetic agents.

The effect of tourniquet release time on the analgesic efficacy of intraarticular morphine after arthroscopic knee surgery.

A randomized, controlled study was conducted in patients undergoing elective arthroscopic knee surgery to assess the effects of tourniquet release time on analgesia after intraarticular (I.A.) injection of morphine. Standardized general anesthetic and surgical techniques were used for all patients, including a thigh tourniquet inflated at pressures between 300 and 350 mm Hg. At the conclusion of the arthroscopic procedure, 5 mg morphine in 25 mL saline was administered I.A. Patients were then randomized to one of two treatment groups. In Group 1 (n = 20), the tourniquet was kept inflated for 10 min after I.A. injection, whereas in Group 2 (n = 20), the tourniquet was deflated immediately after I.A. injection. Postoperative pain was assessed using a visual analog scale in the recovery room when the patients were awake and at 2, 4, 6, 8, and 24 h after I.A. injection. Patients who complained of pain in the recovery room received increments of intravenous meperidine 25-50 mg. On discharge from the recovery room, patients received oral mefenamic acid 250-500 mg for pain relief. The time and quantity of analgesics required were recorded. Patients in Group 1 had significantly (P < 0.05) lower pain scores than those in Group 2 at 2, 4, 6, and 8 h postoperatively. These low pain scores were associated with lower requirements of supplementary analgesics. We conclude that, as compared with releasing the tourniquet immediately after I.A. injection of morphine, maintaining the tourniquet inflated for 10 min provides superior analgesia and decreases the need for supplemental analgesics.