Etiquette of the antibiotic decision-making process for surgical prophylaxis in Ethiopia: a triangulated ethnographic study

Background

Prophylactic antibiotics reduce surgery-associated infections and healthcare costs. While quantitative methods have been widely used to evaluate antibiotic use practices in surgical wards, they fall short of fully capturing the intricacies of antibiotic decision-making in these settings. Qualitative methods can bridge this gap by delving into the often-overlooked healthcare customs that shape antibiotic prescribing practices.

Aim

This study aimed to explore the etiquette of the antibiotic decision-making process of surgical prophylaxis antibiotic use at Tikur Anbessa Specialized Hospital (TASH).

Methods

The observational study was carried out at TASH, a teaching and referral hospital in Addis Ababa, Ethiopia, from 26 August 2021 to 1 January 2022. Overall, 21 business ward rounds, 30 medical record reviews, and 11 face-to-face interviews were performed sequentially to triangulate and cross-validate the qualitative observation. The data were collected until saturation. The data were cleaned, coded, summarized, and analyzed using the thematic analysis approach.

Result

Surgical antibiotic prophylaxis (SAP) discussions were infrequent during surgical ward rounds in TASH, leading to practices that deviated from established recommendations. Clear documentation differentiating SAP from other antibiotic uses was also lacking, which contributed to unjustified extended SAP use in the postoperative period. Missed SAP documentation was common for emergency surgeries, as well as initial dose timing and pre-operative metronidazole administration. Importantly, there was no standardized facility guideline or clinical protocol for SAP use. Furthermore, SAP prescriptions were often signed by junior residents and medical interns, and administration was typically handled by anesthesiologists/anesthetists at the operating theater and by nurses in the wards. This suggests a delegation of SAP decision-making from surgeons to senior residents, then to junior residents, and finally to medical interns. Moreover, there was no adequate representation from pharmacy, nursing, and other staff during ward rounds.

Conclusion

Deeply ingrained customs hinder evidence-based SAP decisions, leading to suboptimal practices and increased surgical site infection risks. Engaging SAP care services and implementing antimicrobial stewardship practices could optimize SAP usage and mitigate SSI risks.

Experience with modified radical mastectomy in a low-income country: a multi-center prospective observational study

BACKGROUND

Modified radical mastectomy is the procedure of choice in centers with little to no radiotherapy services. Studying the in-hospital outcome and complications associated with the procedure is important in low-income countries.

METHODS

This is a multi-center prospective observational study involving all patients operated with modified radical mastectomy with curative intent.

RESULTS

A total of 87 patients were studied with 10.3% of which were male and 54% were between the age of 30-49 years. Clinical stage IIB and IIIA were reported in 33 (37.9%) and 25 (28.7%) respectively and 62.1% had clinically positive lymph nodes at presentation. All of the studied patients underwent curative surgery, with an average lymph node dissection of 10.2 ± 0.83. Seroma rate was 17.2% and was significantly associated with diabetes (AOR: 6.2 (CI 1.5-8.7)) and neoadjuvant chemotherapy (AOR: 8.9 (CI 1.2-14.2)). Surgical site infection occurred in 14.9% and was significantly associated with Retroviral infections (AOR: 4.2 (CI 2.1-5.8)) and neoadjuvant chemotherapy (AOR: 1.8 (CI 1.3-3.9)). No in-hospital mortality occurred during the course of the study.

CONCLUSION

Seroma rate was lower than published studies while surgical site infections rate was higher. Neoadjuvant chemotherapy was associated with increase in seroma and surgical site infection rates. Additionally, diabetes increased the rate of seroma. Surgical site infections were higher in patients with retroviral infections.

Pattern and outcome of perforated peptic ulcer disease patient in four teaching hospitals in Addis Ababa, Ethiopia: a prospective cohort multicenter study

BACKGROUND

Perforated peptic ulcer disease is a surgical emergency with a high morbidity and mortality. The socio-demographic characteristic and the factors associated with morbidity and mortality seems to differ between the developed and developing world. This is the first a prospective cohort study in Ethiopia designed to analyze pattern and outcome of patients with perforated peptic ulcer disease in four teaching hospitals affiliated with SOM, CHS of Addis Ababa University.

METHOD

This is a prospective cohort study of patients operated for perforated peptic ulcer disease from June 1, 2018 to May 31, 2019 in four teaching hospital affiliated to department of surgery of SOM, CHS of Addis Ababa university.

RESULT

A total of 97 patients were operated in a year. 86.6% were males with a male to female ratio of 6.5:1. The age group 21-30 were most affected constituting 42.3% of all patients. Mean age is 31.9, Median of 27, age ranges from 16 to 76. Alcohol use (45.4%) and previous history of ulcer disease (75.3%) were the most prevalent risk factors.33% were smokers. Abdominal was present in all and most presented within 48 h (79.4%). 85.6% had pneumo = peritoneum in an x-ray at presentation. Size of the perforation is 10 mm or less in 81.3%. 91(93.8%) had anterior first part duodenum perforation. Repair with pedicled omental patch was done in 65 (67.1%) patients. Age, duration of presentation, hypotension at presentation, size of perforation, degree of peritoneal contamination were found to be the significant factors for morbidity and mortality. Major morbidities were observed in 16 (16.5%) and mortality occurred in 3 (3.1%) patients.

CONCLUSION

Perforation of peptic ulcer disease here occurs in the young. Age, duration of presentation, hypotension at presentation, size of perforation, degree of peritoneal contamination were found to be the significant factors for morbidity and mortality. Morbidity and mortality rate of 16.5 and 3.1% observed here are quite acceptable.

The role of clinical criteria, genetic and epigenetic alterations in Lynch-syndrome diagnosis

Lynch syndrome (hereditary nonpolyposis colorectal cancer, HNPCC) represents 1-3% of all diagnosed colorectal cancers (CRCs). This study aimed to evaluate the benefit of clinical criteria and several molecular assays for diagnosis of this syndrome. We examined tumors of 104 unrelated clinically characterized colorectal cancer patients for causal mismatch repair (MMR) deficiency by several methods: microsatellite instability (MSI) and loss of heterozygosity (LOH) presence, MMR protein absence, hypermethylation of MLH1 promoter and germline mutation presence. Twenty-five (24%) patients developed CRCs with a high level of MSI (MSI-H). Almost all (96%) had at least one affected relative, while this simple criterion was satisfied in only 22% (17/79) of individuals with low level MSI or stable cancers (MSI-L, MSS). Using strict Amsterdam criteria, the relative proportion of complying individuals in both sets of patients (MSI-H vs. MSI-L and MSS) decreased to 68% and 9%, respectively. The right-sided tumors were located in 54% of MSI-H persons when compared to 14% of cancers found in MSI-L or MSS patients. In 16 MSI positive patients with identified germline mutation by DNA sequencing, the gene localization of mutation could be indicated beforehand by LOH and/or immunohistochemistry (IHC) in four (25%) and 14 cases (88%), respectively. The IHC findings in MSI-H cancers with methylation in distal or both regions of MLH1 promoter have not confirmed the epigenetic silencing of the MLH1 gene. None of the patients with MSIL or MSS tumors was a carrier of the MLH1 del616 mutation, despite seven of them meeting Amsterdam criteria. The effective screening algorithm of Lynch-syndrome-suspected patients consists of evaluation of Bethesda or Revised Bethesda Guidelines fulfilling simultaneous MSI, LOH and IHC analyses before DNA sequencing. Variable methylation background in MLH1 promoter does not affect gene silencing and its role in Lynch-syndrome tumorigenesis is insignificant.

Novel and recurrent germline alterations in the MLH1 and MSH2 genes identified in hereditary nonpolyposis colorectal cancer patients in Slovakia

Hereditary non-polyposis colorectal cancer (HNPCC) is associated with germline mutations in DNA mismatch repair genes, predominantly MSH2 and MLH1. Mutation carriers develop cancers in the colorectum, endometrium, ovary, stomach, small intestine and the upper urinary tract. We describe here the results of a mutational analysis of 11 unrelated HNPCC patients by direct genomic sequencing of MLH1 and MSH2. The alterations found include 7 novel changes and 4 different pathogenic mutations described previously in Poland, Moldavia, Finland, Germany, France and USA. Four novel pathogenic mutations in the MLH1 gene include two frameshift mutations (c.1150delG and c.1210_1211delCT), one missense mutation (c.793C>A) and one intron-exon border mutation (c.546- 2A>C). The last change resulted in the skipping of exon 7, as shown by sequencing of RT-PCR products. The only novel MSH2 pathogenic change was a nonsense mutation c.1129C>T. The novel intronic change c.381-41A>G in MLH1 was found in a patient carrying a previously-described mutation in the MSH2 gene. Interestingly, two unrelated patients carried also a novel change in the promoter region of MLH1 in one of the CpG islands (c.-269C>G). However, this alteration does not abrogate transcription, as shown by RT-PCR analysis. In summary, most (approximately 80%) pathogenic germline mutations detected in the studied group of patients by direct genomic sequencing of MLH1 and MSH2 were located in the MLH1 gene. These and previous data indicate that the majority of germline point mutations and small deletions/insertions in HNPCC families in Slovakia affect the MLH1 locus.

Disruption of theRAD51 gene sensitizesS. cerevisiae cells to the toxic and mutagenic effects of hydrogen peroxide

The RAD51 gene was disrupted in three different parental wild-type strains to yield three rad51 null strains with different genetic background. The rad51 mutation sensitizes yeast cells to the toxic and mutagenic effects of H2O2, suggesting that Rad51-mediated repair, similarly to that of RecA-mediated, is relevant to the repair of oxidative damage in S. cerevisiae. Moreover, pulsed-field gel electrophoresis analysis demonstrated that increased sensitivity of the rad51 mutant to H2O2 is accompanied by its decreased ability to repair double-strand breaks induced by this agent. Our results show that ScRad51 protects yeast cells from H2O2-induced DNA double-strand breakage.

Hypertonic saline/dextran treatment for severe pressure-driven hemorrhage in dehydrated conscious swine

Although dehydration impairs the response to a fixed volume hemorrhage, both 7.5% hypertonic saline/6% dextran 70 (HSD: 4 mL/kg) and standard Ringer's lactate (33 mL/kg) are effective resuscitation fluids. However, the efficacy of resuscitation during continuing hemorrhage remains in question. Using a conscious swine model of continuous pressure-driven hemorrhage, we evaluated the effects of dehydration and HSD resuscitation on survival time, hemorrhage volume, regional blood flows, and central hemodynamics. Three groups of pigs were compared: euhydrated control (EC), dehydrated control (48 h water deprived) (DC); and dehydrated and resuscitated with HSD (D + HSD). All pigs were subjected to an initial 37% blood volume hemorrhage for 60 min followed by a continuous hemorrhage proportional to the instantaneous mean arterial pressure. The D + HSD pigs were resuscitated at the end of the 37% blood volume hemorrhage. Dehydration reduced body weight (-6.5 +/- .3%) and increased hematocrit (8.9 +/- 1.8%), serum osmolality (11.6 +/- .9%), serum sodium (11.9 +/- .9%), and serum total protein (9.4 +/- 1.8%). Compared with the EC group, DC had a greater increase in heart rate and arterial base deficit in response to the pressure-driven hemorrhage and a reduced pH and survival time (159 vs. 107 min). In contrast to the DC group, D + HSD had increased mean arterial pressure, cardiac output, oxygen delivery, and regional blood flows to the gut (superior mesenteric artery), kidneys, liver (hepatic artery), and adrenals at 5 min after HSD resuscitation. The HSD did not increase blood loss but tended to prolong survival (+26 min; p = .1079). thus, dehydration compromises survival time (-33%) and the hemodynamic and metabolic responses to pressure-driven hemorrhage, while treatment with HSD improves the hemodynamic responses.

L-NAME, nitric oxide and jejunal motility, blood flow and oxygen uptake in dogs

1. The effects of the inhibitor of nitric oxide (NO) synthesis, NG-nitro-L-arginine methyl ester (L-NAME), on systemic arterial blood pressure and jejunal motility, blood flow, and oxygen uptake have been investigated in anaesthetized dogs. 2. L-NAME (cumulative doses of 0.1-20 mg kg-1, i.v.) dose-dependently increased blood pressure and jejunal motility and decreased heart rate. The maximal response of these three variables occurred at doses, 3, 10 and 10 mg kg-1, respectively. L-NAME (cumulative doses of 0.5-5 mg kg-1) also dose-dependently induced jejunal vasoconstriction. The jejunal vascular resistance returned to control values as the cumulative doses reached 10 and 20 mg kg-1, which corresponded to the maximal increase in jejunal motility. 3. A single intravenous injection of L-NAME (10 mg kg-1) produced a prompt increase in blood pressure, which lasted for at least 50 min. 4. L-NAME (10 mg kg-1) produced a progressive rise in jejunal motility reaching its maximum (47 +/- 6 mmHg) 15 min after the administration, and lasting for 40-50 min. Both the basal lumen pressure and the amplitude of rhythmic contractions increased during this period. 5. L-NAME (10 mg kg-1) produced a triphasic change in jejunal vascular resistance and blood flow measured by timed collection of venous outflow. The blood flow decreased initially (-43% at 5 min), increased (+35%) and returned to control value between 15 and 35 min, then decreased (-35%) 40-50 min post-infusion. Jejunal vascular resistance reflected the blood flow response (+88% at both 5 and 50 min). The time during which the reversal of the vasoconstriction occurred (15-35 min) corresponded to the time of marked increase in motility, and was accompanied by a significant increase in jejunal oxygen uptake (+ 18%).6. The L-NAME-induced increase in motility was prevented by L-arginine (1 g kg-1, i.v.) but not by D-arginine pretreatment. The interim (15-35 min) changes in jejunal blood flow, vascular resistance and oxygen uptake were also prevented by L-arginine pretreatment.7. L-Arginine pretreatment attenuated L-NAME-induced hypertension for 5 min.8. The L-NAME-induced increases in jejunal vascular resistance and motility were inhibited by either local intra-arterial infusion of L-arginine (32 mM local arterial blood concentration) or topical application of 2 MicroM nitroglycerin. Infusion of D-arginine (32 mM local arterial blood concentration) had no such effect.9. The L-NAME-induced increase in blood pressure was not the mechanism by which jejunal motility was increased, because similar increases in blood pressure by mefenamate (10 mg kg-1, i.v.) had no such effect.10. Thus, inhibition of nitric oxide synthesis by L-NAME increased jejunal motility and vascular resistance and the marked increase in motility can abolish or reverse the vasoconstriction. Endogenous nitric oxide may play a role in regulating motility and blood flow in the resting canine jejunum.

Differences in vascular response to thromboxane between intestinal mucosa and muscularis

The effects of a thromboxane A2 (TxA2)-endoperoxide analogue, U-44069 (0.16 micrograms/min. i.a.) on blood flows to the total wall, the mucosal (= mucosa+submucosa), and muscularis (= muscularis+serosa) layers of the canine jejunum, were determined utilizing radiolabelled microspheres (diam = 13.75 microns). U-44069 significantly decreased total (-64 +/- 5%), mucosal (-67 +/- 5%), and muscularis (-53 +/- 6%) blood flows in the natural flow preparation. In the constant flow preparation, U-44069 increased jejunal vascular resistance from 2.02 +/- 0.27 to 4.6 +/- 0.65 mmHg/ml/min/100g and increased mucosal and muscularis vascular resistance by 3.5-fold and 1.5-fold, respectively. As a result, it decreased mucosal blood flow (-19 +/- 5%), but increased muscularis blood flow (+52 +/- 10%). The magnitude of U-44069-induced percent change in mucosal blood flow was significantly different from that of the muscularis. Furthermore, U-44069 significantly redistributed the total jejunal blood flow in favor of the muscularis in both natural and constant flow preparations. Intra-arterial administration of a TxA2 receptor antagonist, SQ-29548 (2.0 micrograms i.a.) reversed all of the above U-44069-induced blood flow changes to control values. Our study indicates that TxA2 produces a significantly greater vasoconstriction in the mucosa than in the muscularis of the canine jejunum. This differential action of TxA2 may have some physiological and pathophysiological significance.

Thromboxane plays a role in postprandial jejunal oxygen uptake and capillary exchange

The effects of a thromboxane A2 (TxA2)-endoperoxide receptor antagonist, SQ 29548, on jejunal blood flow, oxygen uptake, and capillary filtration coefficient (Kfc) were determined in anesthetized dogs under resting conditions and during the presence of predigested food in the jejunal lumen in three series of experiments. In series 1, 2.0 micrograms intra-arterial administration of SQ 29548 was found to abolish completely the vasoconstrictor action of graded doses (0.05-2.0 micrograms) of intra-arterial injection of a TxA2-endoperoxide analogue, U44069. SQ 29548 (2.0 micrograms ia) per se did not significantly alter resting jejunal blood flow, oxygen uptake, capillary pressure, or Kfc. Before SQ 29548, placement of food plus bile into the jejunal lumen increased blood flow +42 +/- 9%, oxygen uptake +28 +/- 7%, and Kfc +24 +/- 6%. After SQ 29548, the food placement increased blood flow +37 +/- 8%, oxygen uptake +52 +/- 11%, and Kfc +63 +/- 20%. The food-induced increases in oxygen uptake and Kfc after SQ 29548 were significantly greater than those induced before the blocking of TxA2-endoperoxide receptors by SQ 29548. Our study indicates that endogenous thromboxane does not play a role in regulating jejunal blood flow, capillary filtration, and oxygen uptake under resting conditions. However, it plays a role in limiting the food-induced increases in jejunal oxygen uptake and capillary exchange capacity without influencing the food-induced hyperemia.

Prostanoids in regulation of postprandial jejunal hyperemia and oxygen uptake

The role of prostanoids in regulation of jejunal blood flow (JBF) was studied in anesthetized dogs. Intra-arterial infusions of arachidonate produced biphasic changes and dose-dependent decreases in jejunal vascular resistance (JVR) in untreated and aspirin-pretreated dogs, respectively; mefenamate abolished these responses. The jejunum released prostaglandin I2 (PGI2) greater than PGE2 greater than thromboxane A2 (TXA2) (radioimmunoassay) under resting conditions, and food enhanced the release of PGE2 greater than PGI2 greater than TXA2 greater than PGF2 alpha. Addition of arachidonate to food enhanced TXA2 and PGF2 alpha releases and decreased PGI2 and PGE2 releases, while inhibiting the food-induced increases in JBF and O2 uptake; mefenamate inhibited these arachidonate actions. A TXA2 receptor antagonist (SQ-29548) reversed the arachidonate vascular and metabolic actions. Intra-arterial infusions of PGI2 or PGE2 decreased, whereas TXA2 analogue U-44069 or PGF2 alpha increased JVR. A mixture of these prostanoids infused at blood concentrations similar to the increase observed during food placement did not alter JVR. At concentrations similar to the increases observed when arachidonate was added to luminal food, the infusions increased JVR and abolished the food-induced decrease in JVR. In conclusion, jejunal productions of PGI2, PGE2, TXA2, and PGF2 alpha increase during nutrient absorption. Addition of arachidonate to food attenuates the former two and enhances the latter two releases, which act to attenuate food-induced jejunal hyperemia.