Ketamine for prehospital trauma analgesia in a low-resource rural trauma system: a retrospective comparative study of ketamine and opioid analgesia in a ten-year cohort in Iraq.

BACKGROUND: Opioid analgesics are used in most trauma systems, and only a few studies report on the use of ketamine for prehospital analgesia. In a low-cost rural trauma system in Iraq paramedics have been using prehospital ketamine analgesia for ten years. This study aims to evaluate the effects of prehospital analgesia on physiologic trauma severity indicators and compare the effect of ketamine and pentazocine on those indicators. METHODS: The investigation was conducted as a retrospective cohort study with parallel group design. Three subsamples of trauma patients were compared: no analgesia (n = 275), pentazocine analgesia (n = 888), and ketamine analgesia (n = 713). Physiologic severity scores were calculated based on rated values for respiratory rate, blood pressure, and consciousness. The associations between outcomes and explanatory variables were assessed using a generalized linear model. RESULTS: Paramedic administration of analgesia was associated with a better physiologic severity score (PSS) outcome (p = 0.01). In the two subsamples receiving analgesia significantly better outcomes were observed for respiration (p < 0.0001) and systolic blood pressure (p < 0.0001). In patients with Injury Severity Score >8 ketamine was associated with a significantly better effect on the systolic blood pressure compared to opioid analgesia (p = 0.03). CONCLUSION: Prehospital analgesia for trauma victims improves physiologic severity indicators in a low-resource trauma system. Compared to pentazocine, ketamine was associated with improved blood pressure for patients with serious injuries. In a low-resource setting, ketamine seems to be a good choice for prehospital analgesia in trauma patients.

A comparison of ketamine and morphine analgesia in prehospital trauma care: a cluster randomized clinical trial in rural Quang Tri province, Vietnam.

BACKGROUND: The use of opioid analgesics in prehospital trauma care has been reported to have negative side effects on the airway and circulation. Several studies of urban trauma management have recommend ketamine as a safe and efficient analgesic. To date, however, no controlled trials of prehospital opioid analgesics versus ketamine in rural trauma management have been published. OBJECTIVE: This study aimed to compare the analgesic effects and side effects of ketamine and morphine in a prehospital, low-resource setting. METHODS: The study was conducted with a prospective, cluster-randomized design. The Quang Tri province of Vietnam was divided into two sectors that alternated monthly between ketamine and morphine treatments. A total of 169 trauma patients were treated outside hospital settings with ketamine, while 139 patients were treated with morphine. RESULTS: The treatment effects were measured by comparing the Visual Analogue Scale (VAS) ratings in the field to those upon on admission. The analgesic effects were positive and similar for the two drugs. The rate of vomiting was significantly lower in the ketamine group (5%) than in the morphine group (19%, 95% CI for difference 8-22%). The rate of hallucinations and agitation was higher in ketamine-treated patients (11%) than in the morphine-treated patients (1.5%, 95% CI for difference 4-16%). In this study, patients with head trauma (n = 57) showed no adverse effects on consciousness level after being treated with ketamine. CONCLUSION: Ketamine had an analgesic effect similar to morphine and carried a lower risk of airway problems. The risk of hallucinations and agitation was increased in the ketamine group. These findings are of medical significance, particularly in rough and low-resource scenarios.

Confusion with cerebral perfusion pressure in a literature review of current guidelines and survey of clinical practice.

BACKGROUND: Cerebral perfusion pressure (CPP) is defined as the difference between the mean arterial pressure (MAP) and the intracranial pressure (ICP). However, since patients with traumatic brain injury (TBI) are usually treated with head elevation, the recorded CPP values depends on the zero level used for calibration of the arterial blood pressure. Although international guidelines suggest that target values of optimal CPP are within the range of 50 - 70 mmHg in patients with TBI, the calibration of blood pressure, which directly influences CPP, is not described in the guidelines.The aim of this study was to review the literature used to support the CPP recommendations from the Brain Trauma Foundation, and to survey common clinical practice with respect to MAP, CPP targets and head elevation in European centres treating TBI patients. METHODS: A review of the literature behind CPP threshold recommendations was performed. Authors were contacted if the publications did not report how MAP or CPP was measured. A short questionnaire related to measurement and treatment targets of MAP and CPP was sent to European neurosurgical centres treating patients with TBI. RESULTS: Assessment methods for CPP measurement were only retrieved from 6 of the 11 studies cited in the TBI guidelines. Routines for assessment of CPP varied between these 6 publications. The 58 neurosurgical centres that answered our survey reported diverging routines on how to measure MAP and target CPP values. Higher CPP threshold were not observed if blood pressure was calibrated at the heart level (p = 0.51). CONCLUSIONS: The evidence behind the recommended CPP thresholds shows no consistency on how blood pressure is calibrated and clinical practice for MAP measurements and CPP target values seems to be highly variable. Until a consensus is reached on how to measure CPP, confusion will prevail.

Surgical strategy in grade II astrocytoma: a population-based analysis of survival and morbidity with a strategy of early resection as compared to watchful waiting.

BACKGROUND: We recently demonstrated a survival benefit of early resection in unselected diffuse low-grade gliomas (LGG). However, heterogeneity within the LGG entity warrants investigation in a homogenous subgroup. Astrocytoma represents the largest subgroup of LGG, and is characterized by diffuse growth and inferior prognosis. We aimed to study the effects of early resection compared to biopsy and watchful waiting in this subgroup. METHODS: Patient data was retrospectively reviewed in two neurosurgical departments with regional referral practice. In one hospital, initial diagnostic biopsies and watchful waiting was favored, while early resections guided with three-dimensional (3D) ultrasound were advocated in the other hospital. This created a natural experiment with patient management heavy influenced by residential address. In the hospitals' histopathology databases, all adult patients diagnosed with supratentorial LGG from 1998 through 2009 were screened (n = 169) and underwent blinded histopathological review. Histopathological review concluded with 117 patients with grade II astrocytomas that were included in the present study. The primary end-point was overall survival assessed by a regional comparison. RESULTS: Early resections were performed in 51 (82 %) versus 12 (22 %) patients in the respective hospitals (p < 0.001). The two patient populations were otherwise similar. Median survival was 9.7 years (95 % CI 7.5-11.9) if treated in the hospital favoring early resections compared to 5.6 years (95 % CI 3.5-7.6) if treated at the hospital favoring biopsy and watchful waiting (p = 0.047). No difference in surgical-related neurological morbidity was seen (p = 0.843). CONCLUSIONS: Early 3D ultrasound guided resections improve survival, apparently without increased morbidity, compared to biopsy and watchful waiting in patients with diffuse World Health Organization (WHO) grade II astrocytomas.

Adenosine instead of supranormal potassium in cardioplegic solution preserves endothelium-derived hyperpolarization factor-dependent vasodilation.

OBJECTIVE: We have recently shown that adenosine instead of supranormal potassium in cold crystalloid cardioplegia improves cardioprotection. Studies indicate that hyperkalemia has unfavorable effects on vascular endothelial function. Three pathways have been identified as major vasodilatory pathways: the nitric oxide (NO) pathway, the cyclooxygenase (COX) pathway, and the endothelium-derived hyperpolarization (EDHF) pathway, where the EDHF pathway, in particular, seems susceptible to hyperkalemia. We hypothesized that adenosine cardioplegia improves postcardioplegic endothelial function. METHODS: Sixteen pigs were randomized to receive either cold (6 degrees C) hyperkalemic cardioplegia (n=8) or cardioplegia where hyperkalemia was substituted with 1.2 mM adenosine (n=8). After 1h of cold ischemic arrest, coronary blood flow was monitored for the following 2h. The LAD artery was then explanted, and cylindrical rings were mounted for isometric tension recordings in organ chambers. Vessels were preconstricted with U46610 (Thromboxane A(2) analog) and then bradykinin-mediated relaxation was investigated. To differentiate between the vasodilatory pathways the relaxation was assessed in the absence and presence of inhibitors of the COX (indomethacin), NO (L-NAME+carboxy-PTIO), and EDHF (apamin+charybdotoxin) pathways. RESULTS: Invivo: The adenosine group had, as distinct from the hyperkalemic group, a significantly increased coronary blood flow index 1h after cross-clamp release (from (ml/min/100 g, mean+/-SD) 50.9+/-13.9 to 72.8+/-21.9, p=0.010). The difference was, however, not statistically significant between groups. Invitro: Maximal relaxation without blockers was 27.4+/-10.1% of maximal tension in the adenosine group and 22.2+/-7.5% in the hyperkalemic group. To investigate EDHF-dependent vasodilation the vessel rings were simultaneously treated with indomethacin, L-NAME, and carboxy-PTIO. Maximal relaxation in the hyperkalemic group was then reduced to 47.4+/-17.4% of maximal tension, which was a significant reduction compared to the adenosine group with a maximal relaxation of 20.6+/-8.7% (p=0.028). CONCLUSION: Adenosine instead of supranormal potassium in cold crystalloid cardioplegia increases postcardioplegic myocardial blood flow and preserves EDHF-dependent vasodilation.