[Methods for the phase IV evaluation of malaria vector control interventions: a case-control study of the effectiveness of long lasting impregnated bed nets after their deployment in Benin]. / Méthodes d'évaluation en phase IV de l'efficacité de la lutte antivectorielle: l'exemple d'une étude cas-témoin de l'impact des moustiquaires imprégnées d'insecticide à longue durée d'action après leur déploiement au Bénin.

Vector-control measures are a component of integrated malaria control strategies. After evaluation in phase III pilot studies, these measures are currently being deployed in many endemic malaria zones. Their effectiveness must be evaluated under actual conditions of use but it is not ethically acceptable to use unexposed individuals for control groups. In a attempt to overcome this problem, a case-control study was undertaken to evaluate the effectiveness of long-lasting insecticide treated mosquito nets (LLITN) against clinical malaria attacks due to Plasmodium falciparum in an endemic area of southern Benin. During a 4-month period (July to October 2008), 35 clinically documented cases of uncomplicated malaria (fever + parasite density > 3000/microL) were diagnosed in children less than 5 years old from 6 villages in the Tori Bossito medical district. The parents of these children were interviewed at the same time as the parents of 181 children randomly selected from the same 6 villages. A total of 115 of the randomly selected children who had not been feverish during study period were used as controls. The proportion of children having consistently slept under LLITN throughout the study period was 46% in the case group and 78% in the control group (OR=0.32, 95%CI: 0.15-0.71). These data show that the LLITN provided a significant level of protection, i.e., 68% (IC95%: 29%-85%). This case-control study shows that vector control measures can be effectively evaluated after deployment in population. The limitations of this methodology are discussed.

[Epidemiologic evaluation of malaria in endemic areas]. / Evaluation épidémiologique du paludisme en zone d'endémie.

For decades malarial control has been implemented to control the impact of the disease on the health of populations living in endemic zones. The use of artemisinine combination therapy, intermittent preventive treatment for children and pregnant women, vector-control methods such as long-lasting insecticide-impregnated mosquito nets and indoor remanent insecticide spraying has proven to be effective. These practices have lead to such an extensive reduction of the malaria burden in some endemic areas that the objective of eradication that was unimaginable a few years ago is now back to the forefront. Regardless of the method chosen, careful evaluation and surveillance of its effectiveness in man is necessary. Achieving epidemiologic impact is the main goal of malaria control methods. The main measures for evaluation involve parasitological and clinical aspects of human malaria. The purpose of this article is to review methods used for epidemiologic evaluation of malaria burden.

[Will climate and demography have a major impact on malaria in sub-Saharan Africa in the next 20 years?]. / Le climat et la démographie peuvent-ils avoir un impact important sur le paludisme en afrique subsaharienne dans les 20 prochaines années?

The purpose of this review of the literature is to present factors possibly affecting the spread of malaria in sub-Saharan Africa over the next 20 years. Malaria is a vector-borne disease that depends on environmental and human constraints. The main environmental limitations involve susceptibility of the vector (mosquitoes of the Anopheles genus) and parasite (Plasmodium falciparum) to climate. Malaria is a stable, endemic disease over most of the African continent. Climatic change can only affect a few regions on the fringes of stable zones (e.g. altitude areas or Sahel) where malaria is an unstable, epidemic disease. Higher temperatures could induce a decrease of malaria transmission in regions of the Sahel or an increase in the highlands. The extent of these overall trends will depend on the unpredictable occurrence of major meteorological phenomenon as well as on human activities affecting the environment that could lead to dramatic but limited outbreaks in some locations. The most influential human factors could be runaway demographic growth and urban development. Estimations based on modeling studies indicate that urbanization will lead to a 53.5% drop in exposure to malaria by 2030. However this reduction could be less than expected because of adaptation of Anopheles gambiae and An. arabiensis, the main vectors of malaria in sub-Saharan Africa, to the urban environment as well as increasing vector resistance to insecticides. Another unforeseeable factor that could induce unexpected malaria epidemics is mass migration due to war or famine. Finally immunosuppressive illnesses (e.g. HIV and malnutrition) could alter individual susceptibility to malaria. Social constraints also include human activities that modify land use. In this regard land use (e.g. forest clearance and irrigation) is known to influence the burden of malaria that is itself dependent on local determinants of transmission. Overall the most important social constraint for the population will be access to malarial prevention and implementation action to control this scourge.

[Guidelines for phase III evaluation of vector control methods against malaria]. / Guide pour l'évaluation en Phase III de la lutte antivectorielle contre le paludisme.

Most new vector control methods against malaria involve the use of pesticides. Prior to release of these products for general use, their efficacy, persistence, and cross-resistance must be tested on mosquito colonies raised in the laboratory (phase I) then on wild mosquitoes in the field (small-scale), individual dwellings, or experimental huts (phase II). The goal of phase III studies is to evaluate the efficacy and effectiveness of the vector-control product or method against malaria in a population at regular risk for transmission. The main objective of phase III tests is to measure the epidemiologic impact, e.g. on the incidence or prevalence of malaria in humans. This article presents guidelines for carrying out phase III tests of vector-control methods against malaria (e.g. home insecticide spraying or insecticide-impregnated bednet use). It was written by participants in a workgroup formed to define recommendations for the WHOPES (WHO Pesticide Evaluation Scheme).

Effect of anesthetic agent on lung tumor induction in hamsters given benzo[a]pyrene-ferric oxide.

The effects of an anesthetic agent on lung tumor induction in noninbred Syrian golden hamsters were investigated after intratracheal instillation of a benzo[a]pyrene-ferric oxide mixture. Inhalation anesthesia with ether or methoxyflurane was accomplished with a closed recirculatory system that allowed a short induction time for anesthesia and a good control over the concentration of anesthetic. This type of anesthetic induction was compared with systemic induction by Brevital. Survival rates during the 10 weekly instillations were least for the Brevital-treated group and greatest for the methoxyflurane-treated group. Body weight gain was lower in both the ether- and Brevital-treated groups as compared to the group anesthetized with methoxyflurane. The animals anesthetized with Brevital had the shortest tumor latency, but the tumor incidence during the weeks of the experiment was similar in the group treated with this agent and the group treated with ether. Exposure to methoxyflurane and the carcinogen produced a slow onset of deaths from tumors and lower tumor incidence. These results are discussed in relation to retention of the dose of carcinogen in the respiratory tract and effect of inhalation anesthia on consequent lung tissue pathology.

Nephrotoxic potential of cis-diamminedichloroplatinum and four analogs in male Fischer 344 rats.

Cis-diamminedichloroplatinum [cis-DDP; NSC-119875] and four analogs (NSC-241240, NSC-271674, NSC-263158, and NSC-268252) were evaluated for their acute nephrotoxic potential in male F344 rats following iv administration. Indices of nephrotoxicity included blood urea nitrogen, serum creatinine, kidney weights, and microscopic examination. Results indicated that renal function, organ weights, and histology are important criteria for assessing the nephrotoxic potential of cis-DDP analogs, although alterations in these parameters may have been influenced by severe body weight loss. cis-DDP appeared to be the most nephrotoxic compound studied, and NSC-241240 demonstrated minimal renal damage. Ranking of compounds in order of their nephrotoxic potential (most to least) was cis-DDP, NSC-263158, NSC-268252, NSC-271674, and NSC-241240.

[Popular nosology of infantile diseases in West Côte-d'Ivoire and consequences for malaria care management]. / Nosologie populaire des maladies infantiles dans l'Ouest de la Côte-d'Ivoire. Implications pour le paludisme.

In a rural area of intense and permanent malaria transmission in Southwest Côte-d'lvoire, traditional midwifes of the Yacouba ethnic group, with also an important function for the children health and care, were interviewed in 2002 about their knowledge of the infantile pathologies. Their nosology is greatly based on symptoms and etiologic explanations of the disorder of secretions. The accumulation of a viscous liquid in different parts of the body, especially in the chest, the throat or the head, explains numerous febrile or afebrile diseases, including malnutrition. Some pathologies, particularly convulsions, are described by analogy with animals behaviour Relations between these entities and the biomedical ones are difficult to establish. The traditional care and treatments result from these concepts. A vomiting child or a child suffering from diarrhoea is subject to devices to evacuate his excess of liquid. Yellow brews are used against jaundice. Furthermore, an important mistrust remains towards medical treatments particularly for all parenteral therapies. Health facilities are only used as a the last resort. Their bad reputation is confirmed by the high rate of mortality of patients coming often too late. To improve malaria care management, health-care workers have to take into consideration these concepts and also prove their abilities to ensure good medical practices.

Importance of physical properties of benzo(a)pyrene-ferric oxide mixtures in lung tumor induction.

Three mixtures of benzo(alpha)(a)pyrene (BP) and ferric oxide with different physical properties were given intratracheally to Syrian golden hamsters for an examination of their neoplastic potential. Hamsters treated with a preparation containing large aggregates of BP and ferric oxide resulting from nucleation of BP on the particles showed an earlier onset and higher incidence of respiratory tract tumors than animals given a mixture containing smaller aggregates prepared by hand-grinding. The greatest number of tumors were present in the trachea and the predominant type was the squamous carcinoma. A third preparation in which the carcinogen was not attached to the ferric oxide showed a low tumor incidence similar to that present after intratracheal intubation of BP in gelatin without a carrier particle. For this model system of respiratory carcinogenesis, the physical attachment of BP and the carrier dust is necessary for a high tumor yield.

Parasitological observations of chronic diarrhoea in suspected AIDS adult patients in Kinshasa (Zaire).

The parasitological profile of chronic diarrhoea in 46 Zairian adults suspected of Aids demonstrated that the frequency of protozoa was five times higher than that of helminths; 86% of the protozoa were sporozoa: Isospora belli was the most frequent (19%), followed by Cryptosporidium isolated for the first time in Zaire (8%) and Blastocystis hominis (2%). 37 of the 46 patients were immunodeficient.

PIP: Chronic diarrhea occurs in close to 90% of acquired immunodeficiency syndrome (AIDS) cases Zaire, but there has been no systematic analysis of the parasite species. In the present study, 46 adults with a history of episodic diarrhea (mean duration, 18 months) and clinical symptoms suggestive of AIDS underwent fecal diagnosis. In the 19 stool samples that were positive for parasites, protozoa were 5 times more common than helminths. 13 (86%) of the 15 protozoa-positive samples contained sporozoa. Of these, Isospora belli was the most common (19%), followed by Cryptosporidium (8%). Laboratory analysis and clinical symptoms revealed that 37 of these 46 chronic diarrhea patients were, in fact, immunosuppressed. Of the 9 immunocompetent patients, 5 had parasite- free stools. Significant was the finding that all 4 patients with cryptosporidiosis and 8 of the 9 patients with isosporosis were immunodeficient. Overall, these findings suggest that the parasitological profile of chronic diarrhea differs between immunosuppressed and immunocompetent African patients.

Alternative polymerase chain reaction method to identify Plasmodium species in human blood samples: the semi-nested multiplex malaria PCR (SnM-PCR).

A simplified protocol for the identification of Plasmodium species by semi-nested multiplex polymerase chain reaction (SnM-PCR) in human blood samples is compared with microscopical examination of thin and thick blood films in 2 field trials in Côte d'Ivoire and Cameroon. Also, dried blood spots or liquid blood collected from Dutch soldiers returning from Goma, Zaire (n = 141), Angola (n = 40), and from Marechaussee (Dutch border police) returning from various parts of the world (n = 161) were examined, together with miscellaneous other material obtained from laboratories and hospitals. The method is based on features of the small subunit nuclear ribosomal ribonucleic acid (RNA) gene (ssrDNA), a multicopy gene which possesses both highly conserved domains and domains characteristic for each of the 4 human malaria parasites. The first reaction of the SnM-PCR includes a universal reverse primer with 2 forward primers specific for Plasmodium and mammals, respectively. The mammalian-specific primer was included as a positive control to distinguish uninfected cases from simple PCR failures. The second PCR reaction includes a Plasmodium-specific forward primer plus species-specific reverse primers for P. vivax, P. ovale, P. falciparum and P. malariae. The technique worked better with samples collected in the field as dried blood spots on filter paper and heparinized blood rather than with frozen pelleted blood; it was more sensitive and more specific than the standard microscopical examination.

Preliminary data on the genetic differentiation of Onchocerca volvulus in Africa (Nematoda: Filarioidea).

Data are reported on the genetic structure of three Onchocerca volvulus populations, respectively from Mali (savanna), Ivory Coast (forest), and Zaire (forest gallery in savanna). Electrophoretic analysis, carried out on 25 gene-enzyme systems, has shown a remarkable genetic heterogeneity existing within O.volvulus. Zaire and West Africa populations appear chiefly differentiated at Mdh-1 and 6Pgdh loci, their average Nei's genetic distance being 0.11. In West Africa Nei's D found between the savanna and forest samples is 0.04. The savanna population from Zaire is more similar to the savanna one from Mali (D = 0.09) than to the forest one from Ivory Coast (D = 0.13). This appears mainly due to the loci Ldh and Hbdh (possibly linked), some alleles of which seem to be selected for in forest populations (Ldh110, Hbdh108), while others in the savanna ones (Ldh100, Hbdh100). The hypothesis that the discrepant epidemiological patterns of human onchocerciasis are related to intrinsic differences in the parasite seems supported by the obtained data. The differences in allele frequencies found at the reported loci appear strong enough to allow biochemical identification of O. volvulus populations from different geographic regions and different habitats.

In vivo sensitivity of Plasmodium falciparum to chloroquine in rural areas of Côte d'Ivoire.

In vivo testing of Plasmodium falciparum sensitivity to chloroquine was carried out in four rural sites of differing socio-geographical environment in Côte d'Ivoire. Of a total of 1282 patients of all ages with fever or previous history of fever, 649 were slide positive, with 435 patients with a pure P. falciparum infection; 191 fulfilled all the criteria for inclusion in this study, and 113 completed it. Treatment failure rates ranged from 9.7% (Djébonoua) to 38.1% (Tiéviéssou), and were most often associated with higher degrees of resistance (RII = 54.2%; RIII = 37.5%). Blood chloroquine levels measured by ELISA test suggest that many people take chloroquine routinely; furthermore 37.5% of resistance cases occurred in subjects who had high blood chloroquine concentrations on day 0. Twenty-three out of 24 cases of resistance were found in children under 7 years of age. Nearly all children with persisting parasitaemia were afebrile on day 7, even those (7/8) with RIII resistance. Children aged < 7 years represent the the best sentinel group for monitoring P. falciparum sensitivity to chloroquine in Côte d'Ivoire.

Association of out-of-hospital criteria with need for hospital admission.

OBJECTIVE: To validate high-risk historical and physiologic out-of-hospital criteria as predictors of the need for hospitalization following ED evaluation. METHODS: Consecutive patients entered into the Suffolk County advanced life support system were enrolled. Previously proposed historical and physiologic "high-risk" criteria for hospitalization were prospectively collected. Criteria were associated with the need for hospital admission following ED evaluation. RESULTS: 1,238 patients were enrolled; 391 were released from an ED after transport. Most patients (843/1,238; 68%) were admitted to a hospital; and four died in the ED. Factors associated with an increased likelihood of admission or death among the transported patients were: bradycardia (90% admitted, p < 0.02); hypotension (80%, p < 0.03); hypertension (89%, p < 0.03); and age > 55 years (81%, p < 0.0001). Unresponsiveness and other abnormal vital signs were not associated with admission on univariate analysis. Logistic regression analysis identified two other factors associated with admission or death: tachycardia (72% admitted, p < 0.01) and head injury (78% admitted, p < 0.001). CONCLUSIONS: Abnormal pulse or blood pressure, head injury, and age > 55 years are associated with patients' requiring hospital admission after accessing the emergency medical services system. These criteria may aid the design of out-of-hospital refusal-of-care policies.

Poor correlation of short- and long-term cosmetic appearance of repaired lacerations.

OBJECTIVE: To describe the consistency of a cosmetic scale for repaired lacerations and to determine whether the appearance of lacerations at the time of suture removal correlates with the appearance six to nine months later. METHODS: A convenience sample of patients who had lacerations repaired in a university teaching hospital were evaluated at the time of suture removal and six to nine months following repair. All lacerations were assigned 0 or 1 point each for the presence or absence of a step-off borders, contour irregularities, margin separation, edge inversion, excessive distortion, and overall appearance. A total cosmetic score (0-6) was calculated by adding the scores for the categories above. The consistency of the cosmetic scale was assessed by comparison of scores given by two different practitioners evaluating each patient at suture removal and long-term follow-up. The 38 evaluating practitioners were assigned based on availability and did not necessarily perform serial evaluations of the same patient. RESULTS: The 41 participating patients had a median age of 19 years (range, 2-82 years). Wounds were located predominantly on the head (73%) and upper extremity (22%). Long-term follow-up was performed at a median of 219 days (range, 155-280 days) after suture removal. Interpractitioner concordance regarding optimal appearance (score of 6 vs < or = 5) was moderate (kappa = 0.52) at the time of suture removal and substantial at the time of long-term follow-up (kappa = 0.68). However, the correlation of actual scores at the time of suture removal vs at long-term follow-up was poor (r = 0.17, p = 0.29). CONCLUSION: For our clinicians, the six-item categorical scale appears consistent as a tool for the assessment of the cosmetic appearance of wounds. However, correlation between laceration appearance at the time of suture removal and six to nine months later is poor.

On-line telemetry: prospective assessment of accuracy in an all-volunteer emergency medical service system.

OBJECTIVE: To evaluate the need for on-line telemetry control in an all-volunteer, predominantly advanced emergency medical technician (A-EMT) ambulance system. METHODS: Emergency medical service (EMS) advanced life support (ALS) providers were asked to transmit the ECG rhythms of monitored patients over a six-month period in 1993. The ECG rhythm interpretations of volunteer EMS personnel were compared with those of the on-line medical control physician. All discordant readings were reviewed by a panel of physicians to decide whether the misdiagnosis would have resulted in treatment aberrations had transmission been unavailable. RESULTS: Patients were monitored and rhythms were transmitted in 1,825 cases. 1,642 of 1,825 rhythms were correctly interpreted by the EMS providers (90%; 95% CI 89-91%). The accuracy of the EMS providers was dependent on the patient's rhythm (chi-square, p < 0.00001), the chief complaint (chi-square, p = 0.0001), and the provider's level of training (chi-square, p = 0.02). Correct ECG rhythm interpretations were more common when the out-of-hospital interpretation was sinus rhythm (95%), ventricular fibrillation (87%), paced rhythm (94%), or agonal rhythm (96%). The EMS providers were frequently incorrect when the out-of-hospital rhythm interpretation was atrial fibrillation/flutter (71%), supraventricular tachycardia (46%), ventricular tachycardia (59%), or atrioventricular block (50%). Of the 183 discordant cases, 124 (68%) involved missing a diagnosis of, or incorrectly diagnosing, atrial fibrillation/flutter. Review of the discordant readings identified 11 cases that could have resulted in treatment errors had the rhythms not been transmitted, one of which might have resulted in an adverse outcome. CONCLUSIONS: In this all-volunteer, predominantly A-EMT ALS system, patients with a field interpretation of a sinus rhythm do not require ECG rhythm transmission. Field interpretations of atrial fibrillation/flutter, supraventricular tachycardia, ventricular tachycardia, and atrioventricular blocks are frequently incorrect and should continue to be transmitted.

Impact of interventions for patients refusing emergency medical services transport.

OBJECTIVE: To evaluate the effect of a documentation checklist and on-line medical control contact on ambulance transport of out-of-hospital patients refusing medical assistance. METHODS: Consecutive patients served by four suburban ambulance services who initially refused emergency medical services (EMS) transport to the hospital were prospectively enrolled. In phase 1 (control phase), all patients who initially refused medical attention or transport had an identifying data card completed. In phase 2 (documentation phase), out-of-hospital providers completed a similar data card that contained a checklist of high-risk criteria for a poor outcome if not transported. In phase 3 (intervention phase), a data card similar to that used in phase 2 was completed, and on-line medical control was contacted for all patients with high-risk criteria who refused transport. The primary endpoint was the percentage of patients transported to the hospital. RESULTS: A total of 361 patients were enrolled. Transport rate varied by phase: control, 17 of 144 (12%); documentation, 11 of 150 (7%); and intervention, 12 of 67 (18%) (chi-square, p = 0.023). Transport of high-risk patients improved with each intervention: control, two of 60 (3%); documentation, seven of 70 (10%); and intervention, 12 of 34 (35%) (chi-square, p = 0.00003). Transport of patients without high-risk criteria decreased with each intervention: control, 15 of 84 (18%); documentation, four of 80 (5%); and intervention, 0 of 33 (0%) (p = 0.0025). Of the 28 patients for whom medical control was contacted, 12 (43%) were transported to the hospital, and only three of these 12 patients (25%) were released from the ED. CONCLUSION: Contact with on-line medical control increased the likelihood of transport of high-risk patients who initially refused medical assistance. The appropriateness of the decreased transport rate of patients not meeting high-risk criteria needs further evaluation.

Association of training level and short-term cosmetic appearance of repaired lacerations.

OBJECTIVE: To determine the association between emergency practitioner level of training and cosmetic appearance of primarily closed wounds as evaluated at the time of suture removal. METHODS: A retrospective analysis of wound registry data was performed. At the time of wound closure, standard data were collected including details of patient demographics, wound characteristics, preparation, closure, and postoperative care, for consecutive patients sutured in the ED. Follow-up data were obtained at the time of the return visit using a previously described cosmetic scale. With the scale, all lacerations were assigned 0 or 1 point each for the presence or absence of six items: a step-off of borders; contour irregularities; margin separation; edge inversion; excessive distortion; and overall appearance. For analysis, the proportion of wounds with a score of 6 (optimal cosmetic appearance in all categories) was associated with practitioner level of training. RESULTS: Five hundred fifty-two patients' wounds were evaluated. The percentages of various practitioners' achieving an optimal cosmetic score were: medical students (MSs), 50%; first-year residents (EM1s), 54%; second-year residents (EM2s), 66%; third-year residents (EM3s), 68%; physician assistants (PAs), 70%; and attending physicians (APs), 66%. The senior practitioners (EM2s, EM3s, PAs, APs) were significantly more likely to obtain a maximal cosmetic score than were the junior practitioners (MSs, EM1s) (68% vs 52%, p = 0.016). CONCLUSION: Significant improvement in short-term cosmetic results following wound repair is associated with a training level beyond PGY1. These data reinforce the need for careful patient selection and close supervision of wound repair by trainees, especially of wound repair by medical students and interns.

Refusal of out-of-hospital medical care: effect of medical-control physician assertiveness on transport rate.

OBJECTIVE: Previous studies have shown that contacting an on-line medical-control physician increases the transport rate of patients who attempt to refuse medical assistance. The authors studied the physician-patient interaction to determine the type of interaction that was more likely to result in patient transport. METHODS: A prospective, observational study of patient-initiated refusals of medical assistance (RMAs) was performed in a suburban volunteer emergency medical services (EMS) system, with 12 receiving hospitals county-wide. Medical-control contact was required for all patient-initiated RMAs. Consecutive patients who attempted out-of-hospital RMA over a 3-month period were monitored. Structured data instruments were completed by the medical-control operator and medical-control physician for all patients who attempted RMA. Data collected included patient demographics and contact information, scene characteristics, history and physical examination data, length of time of interaction, and the physician's assessment of the need for transport and the patient's capacity to refuse transport. The operator and physician independently graded the physician's assertiveness in talking to the patient on a continuous 10-point scale. RESULTS: There were 130 patients who attempted RMA; 69 (53%) refused transport even after discussion with the medical-control physician, while 61 (47%) were transported to a hospital. The patients who were transported did not differ from those not transported with respect to age, chief complaint, vital signs, or presence of police on scene. Using the operators' independent assessments, the physicians were more assertive when they graded the patient as being more ill (needs transport, 8.8; may need transport, 7.7; doesn't need transport, 4.1; p < 0.01). When the physicians were more assertive, the patients were more likely to agree to transport (assertiveness > 8, 81% transport; assertiveness < 8, 19% transport; p < 0.01). CONCLUSIONS: Contact with a medical-control physician appears to markedly improve the transport rate for patients who initially attempt to refuse out-of-hospital medical care. This is especially so when physicians are more assertive in recommending transport.

Thermal characteristics of neutralization therapy and water dilution for strong acid ingestion: an in-vivo canine model.

OBJECTIVE: To determine whether in-vivo neutralization therapy for acid ingestions will superimpose a thermal injury upon tissue already damaged by acid. METHODS: An in-vivo canine model was used with repeated measures of tissue and luminal temperatures. All dogs were placed under halothane general anesthesia. The stomach was exteriorized and temperature probes were placed in the lumen and mucosa. 25 mL of 0.5 N HCl (25 degrees C) was placed in the gastric lumen followed 5 minutes later by 75 mL of either 8% NaHCO3 neutralization (25 degrees C, n = 10) or water dilution (25 degrees C, n = 10). Temperature measurements were recorded at specified intervals for 5 minutes post HCl acid exposure and for 30 minutes post treatment. Temperature profiles were analyzed by repeated-measures ANOVA. Post-treatment changes were evaluated using signed-rank tests. RESULTS: In both treatment groups, treatment resulted in significant decreases in initial mucosa and intraluminal temperatures. Both the mucosa and intraluminal temperatures decreased immediately after treatment with HCO3 by an average of 1.6 degrees C (p = 0.05). In the water dilution treatment group, both temperatures decreased by 1.1 degrees C (p = 0.05). Ensuing post-treatment temperatures increased but did not reach baseline temperatures at any time up to 30 minutes post treatment. CONCLUSIONS: In the in-vivo setting, there is no evidence of hazardous temperature elevation when a weak alkali or dilution therapy is used to neutralize strong acid-induced injury. Contraindication of this form of emergency treatment should not be based on the preconceived idea that a resultant exothermic reaction will cause a superimposed thermal injury. Further clinical study is needed to determine the clinical utility of this emergency therapeutic modality.

Thermal effects of neutralization therapy and water dilution for acute alkali exposure in canines.

OBJECTIVE: To evaluate the change in temperature of the gastric mucosa and lumen contents when a weak acid or water is used to manage acute alkali exposure. METHODS: A prospective in-vivo canine model was used in a university-based animal laboratory setting. Eighteen adult canines weighing 20-25 kg were placed under a surgical plane of anesthesia and a laparotomy was performed. A gastrotomy was then made later ligation of the distal esophagus and proximal duodenum. Separate mucosa and lumen temperature probes were placed. Then 25 mL of room-temperature (24-26 degrees C) 50% sodium hydroxide (NaOH) was instilled in the gastric lumen. After 5 minutes, each canine was given treatment. Group 1 (n = 10) was treated with 75 mL of room-temperature orange juice. Group 2 (n = 8) was treated with 75 mL of room-temperature water. Continuous mucosa and lumen temperatures were observed and recorded at baseline and at specified intervals for 35 minutes after the alkali insult. Repeated-measures analysis of variance was used to evaluate the overall temperature profile. Signed-rank tests were used to compare the changes in temperature immediately following neutralization treatment. RESULTS: Significant temperature decreases of 1.1 degrees C and 2.1 degrees C were observed for both mucosa (p = 0.002) and lumen (p < 0.001) temperature, respectively, following neutralization therapy with room-temperature orange juice. In the group treated with room-temperature water, significant temperature decreases of 2.1 degrees C for mucosa (p = 0.01) and 2.4 degrees C for lumen (p = 0.01) were observed. Posttreatment temperatures did not exceed baseline for the entire observation period. CONCLUSION: Neutralization therapy with room-temperature orange juice or water dilution for acute gastric injuries by liquid alkali does not cause a rise in mucosal or intraluminal temperatures in an in-vivo canine model.