Man in a Hot Climate - Early Studies of the Institute of Military Physiology 

Ezra Sohar, Yair Shapiro, Yoram Epstein

Institute of Military Medicine, Medical Corps, Israel Defense Forces and Heller Institute of Medical Research, Sheba Medical Center, Tel Hashomer

In the 1950's many IDF soldiers were hospitalized for heat stroke - about 25% of whom died. Analyzing these cases revealed that commanders misinterpreted human ability to perform in the heat and ignored basic concepts of fluid and electrolyte balance and heat load.

In the early 1960's a series of studies was conducted with regard to soldiers' performance in the heat. The first study (1959), which later became a classic, was conducted during a 21-day march from Eilat to Metula, crossing all climatic zones of Israel. The study was followed by other investigations which approached the issues of voluntary dehydration, fluid consumption vs sweat loss, salt additives, and the effect of heat load on performance.

Based on these early studies, proper regulations were issued to field officers. Over the years, the lessons learned from these studies saved many lives. The number of cases of heat stroke and of other climate-related injuries was dramatically reduced, and performance was enhanced.

Pre-Induction Sport Activity in Prevention of Stress Fractures 

Aharon S. Finestone, Arieh Eldad, Charles Milgrom

Medical Corps, Israel Defense Forces, and Dept. of Orthopedics, Rabin Medical Center, Beilinson Campus, Petah Tikva and Hadassah University Hospital, Ein Kerem, Jerusalem

Pre-induction sports participation of 392 elite infantry recruits was evaluated for correlation with incidence of stress fractures (SF) during 14 weeks of basic training. 23.7% developed lower extremity stress fractures. 72% of the recruits had participated in sports on a regular basis during the 2 years prior to induction. Their fitness as examined by the Bar-Or induction fitness test, was significantly better than that of those who had not trained. 14.9% of the soldiers who had previously participated in ball games (primarily basketball) as an only sport suffered stress fractures, compared to 31.0% of those whose only sport was running (p<0.005).

Training for only 6 months prior to induction had no effect on the incidence of SF. The reason for the difference between ball games and running is probably related to the higher strains and strain rates developed during ball games and to their multidirectional nature, as compared to running.

These findings suggest that participation in a pre-induction program that includes activities that create strains, such as basketball, can reduce incidence of SF in infantry recruits. The training period has to last at least 2 years.

Prediction of Physiological Response from Mathematical Models 

Yoram Epstein, Yuval Heled, Daniel Moran, Yair Shapiro

Institute of Military Medicine, Medical Corps, Israel Defense Forces and Heller Institute of Medical Research, Sheba Medical Center, Tel Hashomer

The ability to predict the physiological responses of workers exposed to extreme environmental conditions, has been a challenge to environmental physiologists for more than 3 decades. Therefore, mathematical models have been developed to predict metabolic rate under various levels of work intensity and dynamic changes in body temperature and heart rate.

Based on the effect of exercise on the cardiovascular system, a model was developed to predict mean arterial blood pressure as a function of heart rate. Physiological strain could also be estimated on the basis of thermoregulatory and cardiovascular strains.

This paper summarizes knowledge accumulated during 25 years of studies in the field of mathematical modeling of physiological parameters. Besides analyzing the logic underlying each model, it explains the scientific approach in developing a model from its early concept to the model's application in the field.

Laparoscopic Approach in Treating Hepatic Cysts 

P. Schachter, V. Sorin, M. Shimonov, A. Rosen, A. Czerniak

Dept. of Surgery A, Wolfson Medical Center, Holon

Solitary and multiple hepatic cysts are now more commonly found because of advances in imaging techniques. Most hepatic cysts are asymptomatic, but when they do cause symptoms they require surgical intervention. The advent of laparoscopy and of laparoscopic ultrasonography allow comprehensive evaluation and treatment of the cysts.

12 patients with hepatic cysts were treated laparoscopically. 8 with single cysts underwent successful subtotal cyst resection without signs of recurrence (up to 20 years of follow-up). 4 with polycystic liver disease underwent sub-total resection of superficial cysts. Deep cysts were unroofed and drained under laparoscopic ultrasound guidance. In this group, 1 experienced recurrence of symptoms and required partial hepatectomy of the involved segment. In another, a connection between a deep cyst and bile ducts was demonstrated and cystojejunostomy was performed.

The laparoscopic approach in the management of patients with liver cysts is effective and safe, and we recommend it as the procedure of choice for single hepatic cysts. In polycystic liver disease the procedure is much less successful.

Preflight Assessment by Hypoxic Inhalation Test in Cardio-Pulmonary Patients 

J. Lebzelter, G. Fink, E. Kleinman, I. Rosenberg, M.R. Kramer

Pulmonology Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva

Flying may expose passengers to hypoxic conditions, which may induce hypoxemia, particularly in those with chronic heart and/or lung disease. Onset of dyspnea, wheezing, chest pain, cyanosis and right heart failure can lead to urgent need for oxygen during flight. The hypoxia inhalation test (HIT) provides a safe and simple means of identifying those who may develop hypoxemia during flight.

We report our experience with 48 self-reporting patients who underwent HIT prior to pre-planned air travel. They inhaled for 15-minute periods a reduced oxygen concentration (F₁O₂ 15%) under normobaric conditions, during which O₂ saturation was monitored by pulse oximeter; electrocardiogram, blood pressure and symptoms were also monitored. O₂ saturation of 85% (PaO₂ 50 mm Hg) was considered a positive test. In the 8 cases (17%) with a positive test, 5 had chronic obstructive pulmonary disease and 3 had cardiovascular and/or combined heart-lung disease.

We calculated predicted O₂ partial pressure in altitude (PaO₂ ALT) and compared it to actual results in the 8 patients with a positive HIT. In 5, use of the predicted formula would have under-diagnosed the hypoxemia that developed during the HIT. Thus, the results of the HIT changed treatment strategy in these patients. We recommend that patients with positive tests use O₂ (2LPM or 4LPM) during flight.

HIT is practical and of potential benefit in the objective assessment of patients with various degrees of heart, lung or combined heart-lung disease. Clinicians should be aware of the relative risk of hypoxia during flight in such patients, and of the value of HIT in identifying them, leading to increase in its use.

Placenta Accreta with Placenta Previa after Previouscesarean Sections 

Eylon Lachman, Alexander Mali, Gabriel Gino, Michael Burstein, Michael Stark

Depts. of Obstetrics and Gynecology and of Pathology, Misgav Ladach Hospital, Jerusalem

The increased rate of cesarean sections in recent decades has brought with it an increase in the frequency of placenta accreta. There are direct correlations between previous cesarean deliveries and also maternal age, with the risk of placenta accreta. There is also a direct correlation between placenta accreta and placenta previa.

The risk of placenta accreta in women who have had placenta previa is 2% for those younger than 35 years and with no history of uterine surgery. The risk increases to 39% for those over 35 who have had 2 or more cesarean sections.

We present 3 cases of placenta accreta admitted in 15 months, all of whom had a history of cesarean sections. The frequency of placenta accreta in our hospital is 1:1,579 deliveries, in line with the 1:1,420 in the literature. We consider hysterectomy the treatment of choice for this serious complication. When performing a cesarean in cases of placenta previa with a history of cesarean sections, the possibility of placenta accreta should be considered.

Laparoscopic Adrenalectomy 

G. Zamir, D. Hazzan, D.J. Gross, S. Lyass, O. Jurim, E. Shiloni, P. Reissman

Depts. of Surgery, Endocrinology and Metabolism, Hadassah University Hospital, Ein-Kerem, Jerusalem

Constant advances and increasing experience in laparoscopic surgery renders it applicable for adrenal surgery. The wide exposure required for open adrenal surgery makes this minimally invasive procedure an attractive and advantageous alternative.

Between 1996-1999, we performed 35 laparoscopic adrenal-ectomies in 30 patients 20-72-years old. Indications included: Conn's syndrome - 14, pheochromocytoma - 11, Cushing's syndrome - 6, nonfunctioning adenoma - 3, and metastatic sarcoma - 1.

5 underwent bilateral laparoscopic adrenalectomy. In 3 (8.5%) the procedures were converted to open operations. Overall morbidity was 13% and there was no mortality. Mean operative time was 188 minutes, but only 130 in our last 10 cases. Mean hospital stay was 4 days and they returned to normal activity an average of 2 weeks later.

According to our study and previous reports, laparoscopic adrenalectomy is feasible and safe and it may soon become the procedure of choice for adrenal tumors.

Non-Penetrating Deep Sclerectomy without Collagen Implantfor Glaucoma

Ben Zion Silverstone, Isaac Aizenman, Carmit Landau, Yaacov Rozenman

Ophthalmology Dept., Shaare Zedek Medical Center, Jerusalem

Deep sclerectomy (DS) can be used in glaucoma with increased intraocular pressure when medical treatment fails. It involves removing part of the ocular drainage apparatus. Resistance to intraocular fluid drainage is decreased, improving drainage and decreasing intraocular pressure. By avoiding anterior chamber penetration, DS diminishes frequency of the complications of filtering surgery.

24 eyes of 23 patients underwent DS for primary or secondary open angle glaucoma with elevated intraocular pressure not controlled medically. It included preparation of a 4.0 x 4.0 mm limbal-based external scleral flap, dissecting and removing most of an internal scleral flap (leaving it 1 mm smaller than the external flap), unroofing Schlemm's canal and removing fine endothelial tissue lining its inner walls. The external scleral flap was then repositioned and sutured. Collagen implants were not used. In some cases DS was combined with extracapsular cataract extraction and intra-ocular lens implantation.

Mean intraocular pressure decreased from 24.8‏3.9 mmHg initially to 12.8‏4.4 mmHg 6 months after operation (p<0.0001). There was no difference in postoperative intra-ocular pressure between DS as a single procedure or as part of a combined operation. Comations were mild and of short duration.

If long-term follow-up shows that lowered intraocular pressures are maintained, DS should be a surgical option in earlier stages of glaucoma.

Presurgical Neuropsychological assessment in Epilepsy: The Wada Test

Fani Andelman, Miri Neufeld, Irith Reider-Groswasser, Uri Kremer, Yoram Segev, Itzhak Fried

Functional Neurosurgery and EEG and Epilepsy Units, Section of Neuroradiology; and Pediatric Neurology Unit; Tel Aviv-Sourasky Medical Center, Tel Aviv

37 candidates for epilepsy surgery underwent the intra-carotid amytal procedure (IAP; also known as the Wada test) to determine hemispheric speech dominance and memory capacity. 31 demonstrated left hemisphere speech dominance, 2 showed evidence for bilateral language and 4 demonstrated right hemispheric language dominance.

Our study supports a correlational relationship between handedness, lesion laterality and age of onset of seizures, as reported in earlier studies. Left-handed patients with a left hemisphere lesion whose seizures began to an early age had a strong tendency for reversed language dominance.

Asymmetry of at least 20% in performing the memory test was taken as the cutoff score for demonstrating laterality of lesions. The asymmetry score correctly predicted laterality of lesions in all 28 patients; 6 did not have asymmetry scores and 3 were examined for language only. None of the patients who successfully passed the Wada memory test had any significant postsurgical memory deficits; 1 had transient reduction in verbal memory and 4 who did not pass the test were not operated on for this reason.

Our results demonstrate the importance of the Wada test in determining cerebral speech dominance, in predicting post-surgical amnesia, and support its usefulness in predicting laterality of seizure focus in candidates for temporal lobectomy.

Carbon Dioxide Gas Embolism during Laparascopic Cholecystectomy

Anat Laver-Segal, Miguel Iuchtman, Paltiel Weiner

Depts. of Anesthesiology, Surgery A and Medicine A, Hillel Yaffe Medical Center, Hadera and Rappaport Medical School, The Technion, Haifa

A case of carbon dioxide gas embolism during laparascopic cholecystetomy is presented. Prompt diagnosis and immediate treatment resulted in positive outcome. Laparascopic cholecystectomy is nowadays one of the most common operations for cholecystectomy and certainly the most frequent endoscopic surgical procedure. It is usually safe and effective. However, a number of serious complications have been reported during the procedure.

Gas embolism is one of the complications that may occur during the initial gas insufflation or during dissection of the gall bladder. Symptoms are mainly related to the speed and the amount of gas that reaches the venous system. Early recognition and prompt treatment are required to prevent severe morbidity or even fatal outcome.

Transesophageal echocardiography has detected many unsuspected cases of gas embolism. However, capnograph monitoring of end-tidal CO₂, routinely used in everyday anesthesia, is highly reliable in alerting to the possibility of gas embolism and also in confirming its occurrence.

In cases of suspected gas embolism close collaboration between anesthetist and surgeon is required.

Autologous Chondrocyte Transplantation - from Science Fiction to Routine Clinical Practice

Dror Robinson, Hana Ash, David Aviezer, Gabriel Agar, Nahum Halperin, Zvi Nevo

Dept. of Clinical Biochemistry, Sackler Medical School, Tel Aviv University, Ramat Aviv; Dept. of Orthopedic Surgery, Assaf Harofeh Medical Center, Zerifin; and CTI Ltd., Science Park, Kiriat Weizmann, Nes Ziona

Adult articular cartilage lacks the capacity for self-repair. The limiting factor appears to be the inability of chondrocytes to proliferate while embedded in the extracellular matrix typical of hyaline cartilage. Cartilage defects larger than 1 cm² change articular biomechanics and lead to eventual osteoarth-ritis and joint destruction.

During the past decade, several competing techniques have evolved to stimulate articular cartilage repair. Small lesions can be successfully treated by either micro-fracture or osteochondral cylinder grafting. The latter technique allows immediate weight bearing but leads to damage of previously uninvolved areas of articular cartilage, which limits its application to lesions of less than 2 cm².

When the damaged area is more extensive, grafting of autologous chondrocytes should be considered. First a diagnostic arthroscopy is performed to assess the damaged area and a small cartilage biopsy is taken. 6 weeks later, arthrotomy and chondrocyte transplantation are performed. In the interval, the antologous chondrocytes have expanded by 2 to 3 orders of magnitude. Our experience to date includes 10 cases with follow-up of 6 months to 5 years. Preoperative complaints of crepitation and locking disappear. There is functional improvement and pain reduction of approximately 50%. This procedure, currently limited to patients under 55 years of age with limited damage to an articular surface, for the first time allows reconstruction of damaged articular areas without resorting to allografts.

Family Physicians' Attitudes to Clinical Guidelines for Treatment of Diabetes 

Sasson Nakar, Shlomo Vinker, Tal Baro-Aloni, Eliezer Kitai

Dept. of Family Medicine, Rabin Medical Center and Sackler Faculty of Medicine, Tel Aviv University

Clinical guidelines are systematically developed statements designed to help practitioners and patients make decisions about appropriate health care for specific clinical states. Attitudes of family physicians to clinical guidelines for treating diabetes and guidelines in general were evaluated from anonymous questionnaires answered by physicians participating in continuous medical education throughout the country (May-June 1998). The questionnaire dealt with attitudes to the recently published specific guidelines for treating the diabetic patient and overall perception of the efficacy of clinical guidelines.

293 family physicians, aged 40.2‏7.0 responded (83%). 93.5% appreciated the guidelines and thought them applicable. Most (83.7%) reported the guidelines to be of help in their daily work; 31.4% said they were oversimplified; a quarter said they aimed main at containing costs. Most respondents preferred written guidelines of up to 5 pages.

In view of our results, attention can now be turned to developing ways to implement the guidelines. To improve adherence, they need to be short and the rate of publication of new clinical guidelines should be slowed.

Management of Compound High Energy Injuries of the Limbs 

A. Lerner, I. Weisz, G. Nierenberg, D. Horer, H. Stein

Dept. of Orthopedic Surgery A, Rambam Medical Center, and Technion Medical Faculty, Haifa

We treated 49 patients with high energy injuries of the limbs between 1.1.94-31.12.97. They had sustained 61 fractures, 50 of which were open; 14 had bilateral injuries, and 3 had lost a limb. All fractures were stabilized on arrival with an A-O tubular external fixator. Soft tissue loss was covered by a combination of split skin graft and tissue flaps following repeated surgical debridement.

After 10 days, or when all soft tissue defects were covered, the cantilever external fixation frame was exchanged for a hybrid ring which provided three-dimensional stability and allowed early full weight bearing and joint mobilization. The hybrid ring frame did not interfere with the care of soft tissue injuries. Furthermore, it kept the risk of developing deep infections to a bare minimum. At follow-up after a median of 20 months, 1 patient had developed osteomyelitis but all had returned to independent function.

Early Detection of Glaucoma by a Mobile Unit

S. Kurtz, M. Goldenfeld, S. Melamed

Sam Rothberg Glaucoma Center, Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer

Glaucoma, the third leading cause of blindness in the western world, is characterized by painless, gradual loss of visual fields which may lead to severe visual impairment or even blindness. In 4 years of operation of a mobile glaucoma unit for screening and early diagnosis of glaucoma, 10,037 subjects aged 18-95 years were screened (4504 women, 45%); 55% were under 50 years (Graph 1).

Ocular hypertension was diagnosed in 8.0%; primary open angle glaucoma (POAG) in 0.8%, with 2/3 already under treatment, the rest newly diagnosed. Pseudo-exfoliative glaucoma was diagnosed in 0.2%; only 2 cases had closed angle glaucoma; 91% of those screened were normal (Fig. 4; age stratification, Graph 3).

POAG increased with age, from 0.2% in those under 40 years to 10% in those over 80; POAG was more common in men, but OHT was similar in both sexes (6.0% vs. 5.3%). There was no correlation between incidence of POAG and place of work except in the Sorek Nuclear Center (1.9% vs. 0.8%, p=0.11). Other conditions significantly more frequent in POAG than normals were diabetes mellitus (x 2.5), systemic hypertension (x 4), myopia (x 2) and history of intraocular surgery (x 6).

Emergency Cesarean Section in a Comatose Parturient after Head Trauma 

R. Aviram, A. Shtraizent, Yoram Beyth, M. Fejgin

Ultrasound Division and High Risk Unit, Dept. of Obstetrics and Gynecology, Meir Hospital, Sapir Medical Center, Kfar Saba (Affiliated with the Sackler School of Medicine) and Neurosurgery Dept.,Rabin Medical Center, Petah Tikva)

Coma in pregnancy and labor is a rare and complicated situation. One of the causes is severe head trauma, which requires neurosurgical consultation and possibly urgent transfer to a neurosurgical unit. This should follow stabilization, confirmation of fetal viability, and cesarian section when indicated.

A 38-year-old primigravida at term and in labor, with severe head injury from a vehicular accident is reported. Emergency cesarean section was performed for severe fetal distress during resuscitation. Fetal distress in a comatose parturient with severe head injury may require a short delay in referral to a tertiary trauma center to allow for an emergency cesarean section.