Impact of the 2017 revised Japanese obstetric hemorrhage management guidelines on tranexamic acid use in patients undergoing cesarean delivery: an interrupted time series analysis.

BACKGROUND: Tranexamic acid is one component of a complex management algorithm for postpartum hemorrhage. In Japan, the 2010 obstetric hemorrhage management guidelines was revised in 2017, adding the recommendation for the administration of tranexamic acid for postpartum hemorrhage. This research aims to delineate the temporal trends in tranexamic acid administration in patients undergoing cesarean deliveries and to examine the impact of the obstetric hemorrhage management guidelines implementation. METHODS: An interrupted time series analysis was conducted on data from patients who underwent cesarean deliveries from April 2012 to August 2021, sourced from Japan's nationwide health insurance claims database. We examined the trends of tranexamic acid usage and blood transfusion use before and after the implementation of the revised guidelines in 2017. RESULTS: The study cohort comprised 91 166 cesarean deliveries. Prior to the guideline implementation, the rate of tranexamic acid usage decreased. Post-guidelines implementation, there was a statistically significant increase in the rate of tranexamic acid use, with a quarterly percentage change of 0.48% (95% confidence interval: 0.36 to 0.60; P < 0.001). The guidelines implementation in 2017 was not significantly associated with a change in the rate of transfusions. CONCLUSIONS: This interrupted time series analysis demonstrated a significant increase in the rate of tranexamic acid administration following the implementation of the revised guidelines, reversing the previously observed downward trend. Our findings could reflect the impact of the revised guideline on the use of tranexamic acid for postpartum hemorrhage, but this did not translate to fewer blood transfusions.

Acute kidney injury requiring hemodialysis in patients with anicteric leptospirosis.

BACKGROUND: Leptospirosis is an infrequent disease in the US, with most cases reported in the state of Hawaii. Renal involvement is common (44 - 67%), ranging from a mild prerenal azotemia in anicteric disease to renal failure requiring dialysis in Weil's syndrome (severe leptospirosis with jaundice, renal failure, and hemorrhage). METHODS: To describe the pattern of leptospiral renal disease at our institution, we performed a retrospective analysis (1992 - 2004) of all hospitalized cases of laboratory confirmed leptospirosis presenting with acute kidney injury (AKI), defined as a presenting serum creatinine > 1.5 mg/dl. RESULTS: During this time period, 18 patients were hospitalized with laboratory confirmed leptospirosis. Among these patients, 12 had AKI on presentation, and hemodialysis was required in 3 patients. Renal biopsies were performed in 2 of these patients, revealing acute tubulointerstitial nephritis. Interestingly, the patients who required dialysis did not have Weil's syndrome. They did not exhibit jaundice or hemorrhage, and serum AST (mean 51.7 U/l (range 36 - 60)), ALT (mean 51.0 U/l (range 38 - 64)), and total bilirubin (mean 1.2 mg/dl (range 0.8 - 1.8)) were either within normal limits or only slightly elevated, despite having the worst renal disease. CONCLUSIONS: This series adds to other evidence that severe AKI (requiring dialysis) can complicate anicteric leptospirosis in contrast to the notion that the AKI in anicteric disease is typically mild and prerenal. Leptospirosis should be considered in all patients who present with fever and AKI, especially if associated with thrombocytopenia or travel to an endemic area.

Air travel in patients with chronic obstructive pulmonary disease.

Air travel exposes patients with chronic obstructive pulmonary disease to the risk of severe hypoxemia. We sought to determine the frequency and outcome of airline travel in patients with chronic obstructive pulmonary disease. A cohort of 100 patients (76 men and 24 women; age 67 +/- 7 years [mean +/- SD]) with severe chronic pulmonary obstructive disease examined by means of spirometry (forced expiratory volume in the first second, 0.04 +/- 0.35 L), all military retirees, or their dependents, comprised the study population. Forty-four patients traveled by commercial air carrier over a 28-month interval, giving an annual frequency of 18.9% of these patients per year. The group that did not travel by air (n = 56) had a lower mean value for forced expiratory volume in the first second and greater prevalence of home oxygen use than did the group that did travel by air. Twelve of the travelers (27.3%) consulted a physician beforehand. Flights reached foreign destinations for 22.7% of patients. The median duration of the longest flight segment was 3 hours. A minority of patients (34.3%) occupied seats in the smoking sections of aircraft. A majority (56.8%) ambulated aboard the aircraft during flights. Eight patients (18.2%) reported transient symptoms during air travel. We conclude that patients with chronic obstructive pulmonary disease travel with appreciable frequency, often without medical consultation, and develop symptoms in some cases.

Hemodynamic effects of altitude exposure and oxygen administration in chronic obstructive pulmonary disease.

PURPOSE: Cardiovascular events are the leading cause of death during air travel. Because patients with chronic obstructive pulmonary disease (COPD) develop severe hypoxemia at altitude, we sought to determine whether changes in systemic hemodynamics may contribute to health risks during hypobaric hypoxia. PATIENTS AND METHODS: We recorded radial artery catheter blood pressure, cardiac frequency, and cardiac ectopy in 18 men (aged 68 +/- 6 years, mean +/- SD) with severe COPD (forced expiratory volume in 1 second 0.97 L +/- 0.32 L) at sea level, after 45 minutes of steady-state hypobaric hypoxia at 2,438 m in a hypobaric chamber, and after oxygen supplementation at 2,438 m. RESULTS: Mean arterial pressure (mm Hg), systolic blood pressure (SBP), diastolic blood pressure, and pulsus paradoxus during acute hypobaric exposure did not differ from baseline. During oxygen supplementation, SBP declined (p = 0.028). Decreases in pulsus paradoxus and pulse pressure were noted on oxygen (p < 0.05). We found no changes in cardiac frequency. Cardiac ectopy was uncommon; for one subject, ectopy increased with hypobaric hypoxia and decreased with oxygen administration. CONCLUSION: Vasopressor responses to hypoxia do not add to the risk of air travel in patients with severe COPD. Supplemental oxygen may cause beneficial hemodynamic changes in patients with COPD during acute hypobaric exposure.

Hypoxemia during altitude exposure. A meta-analysis of chronic obstructive pulmonary disease.

A previous study identified spirometric testing as a useful adjunct for estimating PaO2 during altitude exposure in patients with chronic obstructive pulmonary disease (COPD). We sought to examine the validity of this finding by quantitative analysis of recent published reports. We analyzed acute hypoxic exposures from five prior studies involving 71 patients. Across all studies, the change in arterial oxygen tension per unit change in inspired oxygen partial pressure (linear slope, dPaO2/dP1O2) correlated with the preexposure forced expiratory volume in 1 s (FEV1, p < 0.01). The correlation with FEV1 held for values weighted or unweighted by sample size, with rotating deletion of each study from analysis one at a time, and with semilog slope as the dependent variable. A formula derived from the semilog slope relationship with FEV1 gave accurate description of the mean hypoxic response in each prior study and individual responses from one study (n = 18): ln (PaO2alt/PaO2g) = Kn.(PIO2alt-PIO2g). We found that FEV1 modulated the values of kn in this study. We conclude, based on analysis of prior studies, that preexposure arterial oxygen tension and FEV1 both influence the prediction of PaO2 during hypoxic exposures in patients with COPD.

Oxygen supplementation during air travel in patients with chronic obstructive lung disease.

The objective of this study was to quantitate the effects of O2 supplementation by nasal cannula (NC) and Venturi mask (VM) on PaO2 in patients with chronic obstructive pulmonary disease (COPD) during acute hypobaric exposure, simulating a commercial jet aircraft cabin. We conducted a crossover intervention trial in which subjects served as their own controls in an ambulatory outpatient pulmonary disease service of a tertiary care military medical center and a hypobaric research facility. The subjects were a volunteer sample of 18 men with stable severe COPD, not requiring long-term O2 therapy, and uncomplicated by hypercapnea or cardiac disease. Mean age was 68 years, and mean FEV1 was 0.97 L (31.3 percent predicted). We exposed patients to conditions equivalent to 8,000 feet in a hypobaric chamber. Radial artery catheters provided blood samples at ground level and 8,000 feet. O2 was sequentially administered at 8,000 feet by NC at 4 L/min and 24 percent or 28 percent VM. We describe changes in blood gas data from baseline values and between interventions. O2 at 4 L/min NC flow at 8,000 feet caused PaO2 to increase from 47.4 +/- 6.3 mm Hg to 82.3 +/- 14 mm Hg (n = 18), an increase of 34.9 +/- 14.8 mm Hg. Supplementation of O2 by 24 percent VM caused PaO2 at 8,000 feet to increase by 12.7 +/- 3.8 mm Hg. Twenty-eight percent VM caused PaO2 at 8,000 feet to increase by 19.7 +/- 8.2 mm Hg. Changes in PaO2 with 4 L/min NC were greater than those with either VM. The increase with 28 percent VM was greater than that caused by 24 percent VM (p less than 0.05). Compared with ground level, 4 L/min NC increased mean PaO2 by 9.9 +/- 12.6 mm Hg; 24 percent and 28 percent VM did not cause mean PaO2 to increase above ground level values. We describe a range of capability of familiar O2 therapy devices to increase PaO2 to levels that will maintain tissue oxygenation of patients during acute altitude exposure.

Pasteurella multocida pneumonia in a man with AIDS and nontraumatic feline exposure.

A case of acute pneumonia due to Pasteurella multocida ssp multocida occurred in a young man with AIDS and chronic sinusitis. The pneumonia was diagnosed by bronchoscopy and responded to treatment with aztreonam. Epidemiologic investigation revealed the case was temporally related to nontraumatic exposure to cat secretions that the patient presumably had acquired via an aerosol. The cat's oral cavity was cultured and an isolate of P multocida ssp multocida with identical biochemical reactions, DNA restriction patterns, and nearly identical fatty acid profile to that of the patient's isolate was obtained suggesting they were identical strains and therefore epidemiologically linked. A control strain with identical biochemical reactions and antibiotic sensitivities exhibited different patterns. To our knowledge, this is the first such reported infection in a patient infected with human immunodeficiency virus.

Computer keyboards and faucet handles as reservoirs of nosocomial pathogens in the intensive care unit.

PURPOSE: We postulate that computer keyboards and faucet handles are significant reservoirs of nosocomial pathogens in the intensive care unit (ICU) setting. METHODS: Sterile swab samples were obtained from 10 keyboards and 8 pairs of faucet handles in the medical ICU at Tripler Army Medical Center during a period of 2 months. Methicillin-resistant Staphylococcus aureus (MRSA) obtained from the environmental and patient specimens were sent for DNA identification by using pulsed-field gel electrophoresis. RESULTS: A total of 144 samples were obtained (80 keyboards and 64 faucet handles), yielding 33 isolates. The colonization rate for keyboards was 24% for all rooms and 26% in occupied rooms. Rates for faucet handles in all rooms and occupied rooms were 11% and 15%, respectively. The environmental isolates annd their prevalence were: MRS, 49%; Enterococcus, 18%; Enterobacter, 12%; and all other gram-negative rods, 21%. Fourteen individual patient isolates were recorded: MRSA, 43%; Enterobacter, 21%; other gram-negative rods, 36%; and Enterococcus, 0%. By using pulsed-field gel electrophoresis, an indistinguishable strain of MRSA was identified in two patients, the keyboards and faucet handles in their respective rooms, and on other keyboards throughout the ICU, including the doctors' station. CONCLUSIONS: The colonization rate for keyboards and faucet handles, novel and unrecognized fomites, is greater than that of other well-studied ICU surfaces in rooms with patients positive for MRSA. Our findings suggest an associated pattern of environmental contamination and patient infection, not limited to the patient's room. Pulsed-field gel electrophoresis results have documented an indistinguishable strain of MRSA present as an environmental contaminant on these two fomites and in two patients with clinical infections patients during the same period. We believe these findings add evidence to support the hypothesis that these particular surfaces may serve as reservoirs of nosocomial pathogens and vectors for cross-transmission in the ICU setting. New infection control policies and engineering plans were initiated on the basis of our results.

Humidity resistant live-dead stain for spermatozoa.

Live-dead slides of bovine spermatozoa, prepared using conventional procedures, were found to be unstable at high relative humidities (RH) because of migration of water soluble dyes, such as eosin, into previously unstained cells At 85 percent RH, complete loss of contrast between "live" and "dead" cells occurred within 60 minutes. Comparable slides, prepared using erythrosin B and brilliant green, were found to maintain satisfactory contrast between the "live" and "dead" cells, even at 98 percent RH, throughout the seven-day humidity exposure trials.

Accuracy of oxyhemoglobin saturation monitors during simulated altitude exposure of men with chronic obstructive pulmonary disease.

Patients with chronic obstructive pulmonary disease (COPD) are at risk for hypoxemia during air travel. We assessed the comparative performance of oxyhemoglobin saturation (%O2Hb) monitors on these patients during hypobaric exposure. We measured %O2Hb by arterial catheter blood co-oximetry (COOX) and compared these values to those from a transmittance ear oximeter and a reusable digital pulse oximeter. Additionally, we examined the effect of oxygen supplementation (4 L/min) on %O2Hb. A total of 18 ambulatory males with severe COPD were exposed to 8,000 ft (565 mm Hg) in a hypobaric chamber. Multiple measures of %O2Hb were made with each monitor at sea level and at 8,000 ft, with and without supplemental oxygen. By COOX, %O2Hb fell at altitude to clinically significant levels, and was subsequently corrected with supplemental oxygen. Saturations measured by the transmittance ear oximeter were very close to the COOX, underestimating the true value by only 0.6% at altitude (p less than 0.05), while the reusable digital pulse oximeter over-estimated %O2Hb alinearly by a mean of 3.8% at altitude.

Lung function during moderate hypobaric hypoxia in normal subjects and patients with chronic obstructive pulmonary disease.

BACKGROUND: We sought to describe changes in spirometric variables and lung volume subdivisions in healthy subjects and patients with chronic obstructive pulmonary disease (COPD) during moderate acute hypobaric hypoxia as occurs during air travel. We further questioned whether changes in lung function may associate with reduced maximum ventilation or worsened arterial blood gases. METHODS: Ambulatory patients with COPD and healthy adults comprised the study populations (n = 27). We obtained baseline measurements of spirometry, lung volumes and arterial blood gases from each subject at sea level and repeated measurements during altitude exposure to 8000 ft (2438 m) above sea level in a man-rated hypobaric chamber. RESULTS: Six COPD patients and three healthy subjects had declines in FVC during altitude exposure greater than the 95% confidence interval (CI) for expected within day variability (p < 0.05). Average forced vital capacity (FVC) declined by 0.123 +/- 0.254 L (mean +/- SD; 95% CI = -0.255, -0.020; p < 0.05) for all subjects combined. The magnitude of decline in FVC did not differ between groups (p > 0.05) and correlated with increasing residual volume (r = -0.455; <0.05). Change in maximum voluntary ventilation (MVV) in the COPD patients equaled -1.244 +/- 4.797 L x min(-1) (95% CI = -3.71, 1.22; p = 0.301). Decline in maximum voluntary ventilation (MVV) in the COPD patients correlated with decreased FVC (r = 0.630) and increased RV (r = -0.546; p < 0.05). Changes in spirometric variables for patients and controls did not explain significant variability in the arterial blood gas variables PaO2, PaCO2 or pH at altitude. CONCLUSIONS: We observed a decline in forced vital capacity in some COPD patients and normal subjects greater than expected for within day variability. Spirometric changes correlated with changes in reduced maximum voluntary ventilation in the patients but not with changes in resting arterial blood gases.

Symptomatic vascular rings in adulthood: an uncommon mimic of asthma.

Symptomatic thoracic vascular rings presenting in adulthood are thought to be rare. During a 3-year time period, we diagnosed four cases of symptomatic vascular rings, which had been treated unsuccessfully for suspected asthma. Spirometry was characterized by normal forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and FEV1/FVC, decreased peak expiratory flow (PEF), and truncation of the expiratory flow volume loop. Chest radiographs revealed a right aortic arch in each case with computed tomography (CT) or magnetic resonance imaging (MRI) confirming the diagnosis of a vascular ring. The specific abnormalities consisted of right aortic arch with mirror branching of the main arteries and persistent ligamentum arteriosum; right aortic arch with diverticulum and a fibrous embryonic left arch; right aortic arch with aberrant left subclavian artery arising from a diverticulum of Kommerell; and a right aortic arch with persistent ligamentum arteriosum. Although they are uncommon, vascular rings first presenting in adulthood as a mimic of asthma are not rare. This diagnosis should be considered in adults when abnormal truncation of the flow-volume loop occurs or when radiographic aortic arch abnormalities are found.

Screening for micro-albuminuria with Micro-Bumintest tablets and albumin/creatinine ratio.

The value of Micro-Bumintest tablets and the albumin/creatinine ratio in first morning (FM) urine samples to screen for micro-albuminuria in diabetic patients was evaluated. The A/C ratio in FM urine was highly correlated with the urinary albumin excretion (UAE) rate in micrograms/min in timed overnight (0) urine (R = 0.95, p < 0.001). The sensitivity, specificity and positive and negative predictive values of an A/C ratio > 3.0 to predict micro-albuminuria defined as an UAE > 20 micrograms/min were 94, 92, 92 and 94% respectively. The day-to-day fluctuation of albumin excretion varied between 10 and 105%. The sensitivity, specificity and positive and negative predictive values of micro-bumintest tablet reactions on FM urine samples to predict an A/C ratio > 3.0 were 93, 59, 63 and 91% respectively. It is concluded that for screening of micro-albuminuria the A/C ratio in FM urine is as precise as timed 0 urine collection, but with more comfort for the patient. Micro-Bumintest tablets are useful as an initial screening test and will decrease the number of quantitative albumin measurements in the screening programme by about 30% if only urine samples with positive tablet test are selected for a further investigation. Because of considerable day-to-day fluctuation of urinary albumin excretion several urine samples should be investigated before presence of incipient diabetic nephropathy is assumed.

Ionized calcium plays a pivotal role in controlling blood pressure during haemodialysis.

The influence of dialysate bicarbonate concentration on ionized plasma calcium as well as on haemodynamics have been studied prospectively. In 3 consecutive weeks, 7 chronic patients were dialysed with a dialysate containing low bicarbonate (30 mEq/l), medium bicarbonate (35 mEq/l) and high bicarbonate (39.5 mEq/l), respectively. Notwithstanding the same considerable influx of calcium during high, medium and low bicarbonate dialysis (Bc-D), a significant increase in ionized calcium from 1.09 to 1.41 mmol/l was observed during low Bc-D only. During medium and high Bc-D no significant increase in ionized calcium occurred. In multivariate analysis the only significant predictive variable for the changes in ionized calcium was the change in total CO2 (r = 0.70; p less than 0.001). During low Bc-D the mean arterial pressure remained almost the same, while during medium and high Bc-D a significant decrease of mean arterial pressure was observed. Multivariate analysis revealed that only the change in ionized calcium had a significant predictive effect on the changes of blood pressure (r = 0.69; p less than 0.001). In conclusion, during dialysis an increasing ionized plasma calcium level was counteracting the negative effect of fluid removal on blood pressure. The results of this study underline the pivotal role of ionized plasma calcium for the regulation of blood pressure.

Superior vena caval syndrome due to substernal goitre.

Superior vena caval syndrome is usually due to malignant disease, however, benign cases do occur. Two patients with superior vena caval syndrome due to substernal goitre are reported, and the use of phleboscintigraphy and/or vena caval phlebography are advocated. A review of potentially helpful diagnostic procedures is given.

Hypoxemia during air travel in patients with chronic obstructive pulmonary disease.

STUDY OBJECTIVE: To quantitate and identify determinants of the severity of hypoxemia during air travel in patients with chronic obstructive pulmonary disease. DESIGN: Prospective study of physiologic variables before and during intervention. SETTING: Referral-based pulmonary disease clinic at a U.S. Army medical center. PATIENTS: Eighteen ambulatory retired servicemen (age 68 +/- 6 [SD] years) with severe chronic obstructive pulmonary disease (forced expiratory volume in the first second [FEV1] 31% +/- 10% of predicted). INTERVENTION: Altitude simulation equivalent to 2438 meters (8000 feet) above sea level in a hypobaric chamber. MEASUREMENTS AND MAIN RESULTS: Radial artery catheter blood oxygen tension in the patients declined from a ground value (PaO2G) at sea level of 72.4 +/- 9 mm Hg to an altitude value (PaO2Alt) of 47.4 +/- 6 mm Hg after 45 minutes of steady state hypobaric exposure. The PaO2G correlated with PaO2Alt (r = 0.587; P less than 0.01). Multiple regression analysis revealed that the preflight FEV1 reduced the variability in PaO2Alt not explained by PaO2G in the equation: PaO2Alt = 0.453 [PaO2G] + 0.386 [FEV1% predicted] + 2.440 (r = 0.847; P less than 0.001). Residuals from two previously published formulas using PaO2G also correlated with FEV1 (r greater than or equal to 0.765; P less than 0.001). CONCLUSIONS: Arterial blood oxygen tension declined to clinically significant levels in most patients during hypobaric exposure. When combined with the preflight arterial PO2 at ground level (PaO2G), the measurement of the preflight FEV1 improved prediction of PaO2 at altitude (PaO2Alt) in patients with severe chronic obstructive pulmonary disease.